Consultation represents the next step on the journey towards achieving a more effective system of CPD
Some dental professionals feel that CPD is little more than a tick-box exercise,” says Rebecca Cooper, the General Dental Council’s Head of Policy and Research. Last month, the GDC published a consultation document inviting ideas, comments, and views on the short and long-term future of professional learning and development in dentistry.
It follows the GDC’s launch last year of ‘Enhanced CPD’, its new model of continuing professional development. Some of the changes ECPD brought included the introduction of a personal development plan (PDP) to help record CPD activity and aid further development; a change in the number of CPD hours required (100 hours for dentists, 75 hours for hygienists, therapists, clinical technicians and orthodontic therapists and 50 hours for nurses and technicians); and doing away with the need to submit non-verifiable CPD.
“While the Enhanced CPD scheme made some good progress towards increasing professional ownership of CPD and placing greater emphasis on reflection and planning,” adds Rebecca, “we know a more supportive model of learning can be achieved to provide dental professionals with the information and tools they need to meet and maintain high professional standards and quality patient care.
“Our proposals look at how we might move to a system that is flexible and responsive for the full range of dental professionals and where professionals can increasingly take responsibility for their own development, without the need for heavy-handed enforcement. This discussion document represents a significant milestone in achieving this goal and we really want to hear from as many people as possible about where lifelong learning should go from here.”
The discussion document is presented in three parts: a future model for lifelong-learning which seeks views on a portfolio model and the merits of continuing with set CPD hour requirements; CPD practices, and how professionals can be encouraged to take up more high-value activities, such as peer learning and reflection; and informing CPD choices, which asks about the insights and intelligence dental professionals refer to when selecting learning activities and how these can be improved and promoted.
The publication represents the next step on the GDC’s journey towards achieving a more effective system of CPD. That journey began with commitments made in the regulator’s 2017 publication Shifting the Balance and the introduction of the Enhanced CPD scheme last year. Since then, this journey has continued with the gathering of further information and evidence through stakeholder feedback, a systematic literature review on CPD and, most recently, through workshops with professional associations, educators and other regulators which took place earlier this year.
After building a robust base of evidence, the GDC says it wants explore ideas for developing the CPD scheme with dental professionals and stakeholders and that it is “opening a conversation” about what meaningful CPD is, how it can be achieved, and what the obstacles might be that prevent dental professionals from accessing and undertaking it.
The literature review synthesised relevant articles and outlined the approach other professionals are taking. It provided the GDC with evidence, which can support its development of a more qualitative approach to the delivery and monitoring of CPD for the dental workforce. The aim was to inform and strengthen GDC policy development for dental CPD that would promote registrants’ sense of ownership and pride in their continuing educational achievements and in turn improve engagement between the regulator and the dental workforce.
It concluded that aspects of qualitative-based models which could form part of an outcomes-focused model for dental UK professionals include: emphasis on reflection and reflective practice, active learning, portfolios, peer (and mentor) interaction and feedback; development of online, user-friendly tools, enabling registration of required evidence; a well-designed change and implementation process; reinforcement of close engagement of registrants with regulators through easily accessible communication channels; quality-assurance mechanisms embedded in the model, valuable for both regulators and registrants.
“If the aspiration is to create motivation across all registrants to actively pursue meaningful, relevant CPD activities,” said the review, “then of course the approach to CPD should promote the concept of a responsible professional, who takes pride in keeping up to date and enhancing their clinical and professional skills and sharing their experience with others.”
Scott J F Wright, Dental Core Trainee, Glasgow Dental Hospital & School
ABSTRACT: The use of preformed metal crowns (PMCs) or stainless steel crowns (SSCs) within paediatric dentistry is widely accepted. Predominantly, this is for the treatment of carious primary molars. This article aims to increase readers’ awareness of the use of PMCs for permanent molars in a paediatric population.
The majority of treatment of paediatric patients in the UK is carried out by general dental practitioners. It is therefore crucial that GDPs are aware of treatment options for these patients.
Preformed metal crowns (PMCs) were first described by Engel in the 1950s1. Primarily, their use has been for the restoration of primary molars that have caries or structural defects. There is a large and growing body of evidence to suggest that primary teeth restored with PMCs are less likely to develop problems or cause pain in the long term than those primary teeth restored with conventional restorations.2 Teeth that were restored using the Hall Technique were also shown to give less discomfort at the time of placement than conventional restorations.2 There is wide acceptance of this technique to restore primary molars in both the United States and United Kingdom.3, 4
There is less evidence and information surrounding the use of PMCs for permanent molars , but they can be a useful addition to the armamentarium of any dentist treating paediatric patients. Permanent molars of poor prognosis can interfere with eating, sleeping, attending school, and taking part in daily activities. 8, 9, 10 Children can experience pain and infection, as well as a reduction in their overall quality of life.9, 10 Additionally, retention of permanent molars of poor long-term prognosis can be beneficial orthodontically. RCS England guidelines suggest that the ideal time for extraction of first permanent molars is between eight and 10 years old.13 PMCs can be helpful in assisting with this and prolong the retention of molars that would otherwise be lost.
Dean et. al6 found that about 48 per cent of Scottish GDPs assessed in their study were already using PMCs with the Hall Technique for the management of caries in primary molars. Anecdotally, however, there is limited knowledge of GDPs surrounding the use of PMCs in the permanent dentition.
As mentioned above, there is a comparative limited body of evidence to support use of SSCs in permanent molars to that of primary molars. In 2016, a study in the US suggested that use of permanent tooth SSCs as an interim restoration resulted in an 88 per cent success rate, with an average lifespan of 45.18 months in all age groups. This result was statistically significant in the under-nine age group (P=0.001). However, this was a small sample size.
PMCs are valuable in the interim management poor prognosis permanent molars. This article aims to give GDPs an introduction to the use of PMCs in the permanent dentition for paediatric patients. Many of the principles and skills used in restoration of primary molars with PMCs can be applied to permanent teeth.
There are many clinical circumstances in which PMCs for permanent molars can be a useful treatment choice. Paediatric patients can present with difficult clinical scenarios that require operative intervention due to caries or structural defects in these teeth. This can be further complicated by social factors including parental or guardian wishes, child anxiety and medical history.
Of benefit is the limitation to caries progression and reduction in symptoms that can be achieved through use of PMCs.
There are relatively few contraindications to the above.However, below are some aspects that require consideration.
The technique for placement of PMCs in permanent molars is very much dependent on compliance of the child patient. Many previous articles advocate the use of conventional preparations however, the use of a modified ‘Hall Technique’ approach can also be used.
Post-operative instructions can be given that are very similar to those given when placing PMCs on primary teeth. Advise parents and children that occlusion will be slightly high but will settle within three to five days. Analgesia may be required, and paracetamol and ibuprofen, if not contraindicated, would be appropriate. Asking parents to reinforce positive messages between appointments is of benefit to developing co-operation, particularly if multiple PMCs are being placed.
Complications can occur with all treatment and therefore it is key to ensure that after placement, PMCs are monitored clinically and radiographically to assess for signs of success and failure.
During placement, if the crown is deemed to be in the wrong position, it may be possible to remove it with an excavator before the cement sets. If this is not possible, removal can be performed by cutting a slot bucco-lingually across the occlusal surface of the crown, and extending this down the buccal aspect. The crown can then be peeled away using
Adapting the margins of PMCs on permanent molars is crucial. Failure to do so may result in secondary caries, periodontal disease or impaction of unerupted teeth.5, 11 The margins should sit tightly around the neck of the tooth to reduce the aggregation of plaque leading to the development of carious lesions or periodontal disease. Assessment clinically using a sharp probe, floss and bitewing radiographs should be conducted to determine success.
To conclude, the use of PMCs in paediatric patients should not simply be limited to primary teeth. PMC placement in permanent molars for a paediatric population should be part of the skillset of all GDPs in order to best manage clinical scenarios without the need for referral to specialist services. Development of this aspect of paediatric dentistry can only come with education and practice; the authors hope that this article can assist with this.
The author wishes to express grateful thanks to Mrs Christine Park, Honorary Consultant in Paediatric Dentistry, Glasgow Dental Hospital & School, University of Glasgow.
Implementing the best available evidence and enabling positive sustainable change in practice is an enviable goal for anyone providing healthcare services. In this final article of a three-part series, we will discuss applying the evidence and methods of evaluating the outcome, as the final two parts of taking an evidence-based approach. These final two parts are arguably the most important but are often perceived as the two most difficult to achieve.
In general dental practice there are any number of barriers to implementing effective change, including the healthcare system, the will of staff, patient expectations and time available. That said, this stage does not need to be overly complex but it does need to be planned and there are a number of tools we can use to deliver evidence-based dentistry to each and every patient. This article is focused on giving some practical advice and pointers.
Any challenge is easier when it is broken down into smaller chunks. So think of what you are trying to achieve, then the process that takes place to get to that goal and the system it is part of. Everything we interact with is a system, and there are processes within that system. As soon as we walk out the door in the morning we begin to interact with systems and we start processes.
The footpath network is part of a national infrastructure system that we interact with, queuing for a coffee at the train station is part of a small local system, the surgery at work is a complex local system with many interacting and moving parts. Within these systems there are various different processes; for example, the footpath network has a series of pedestrian crossings, the process to crossing the road will often start by pushing a button and waiting for the green man on the traffic lights, but, of course, it is often a lot more complex than this.
In order to understand the system and how best to implement evidence within a system you need to be able to map the processes you are thinking of changing and determine what might influence the application of evidence. This is called process mapping. Once you have the map, then you can think about the possible barriers to applying the best evidence and equally think about what would enable application of best evidence. The ultimate system makes it easy to do the right thing without relying on humans to do so. Equally, an effective system can make it difficult to do the wrong thing.
Figure 1 illustrates how a process map for crossing the road might look. This map is very simple and doesn’t take into account all potential choices or influences, but it should give you an idea of how to go about constructing a process map (see below).
Let’s return to our clinical example of our paediatric patient in practice whose parent has withheld consent for fluoride varnish application. After completing parts 1,2 and 3 of an evidence-based approach, (1: Asking the right question, 2: Searching for the best available evidence, 3: Critically appraising the evidence), and based on the evidence found, we are confident that for this child, fluoride varnish application would be the best approach to prevent decay. The current barrier to you doing so is the lack of consent from the parent. We need a pragmatic solution to the problem, and providing the information only at the time of application at chair side may not be the best solution. There are many different elements of the system and processes that lead up to that point that could influence the outcome. The appointment booking, check-in, walking to the chair, interaction between you the child and the parent. How many members of staff have been parts of the process? Any change will need to take the system, processes and staff into account. Likewise, there have been a number of tools used, including IT, telephones and dental instruments that also need to be taken into account. A good way to visualise the process and possibly facilitate brainstorming sessions with staff is to again create a process map, similar to Figure 2 (below). This figure is quite obviously simplified, as in reality there are many more influences and choices!
So thinking of the system, the processes and the current barrier, how about if a leaflet had gone out with the appointment in advance that explained the benefits of the treatment to the parent, would it have helped? This could be a change idea to test out in the practice. There are a number of ways that you could implement and evaluate this change.
We will look at a few methods at our disposal. First: Quality improvement methodology.
QI is an approach we can use to build change into processes and systems that is sustained. It is a new kid on the block in dentistry, but it has been around in healthcare for more than 30 years and for much longer in industry.
The first formal introduction to QI in Scottish dentistry was through the Scottish Patient Safety Programme
Our healthcare colleagues working in the acute and other Scottish primary care services have been doing QI for just over 10 years now. We have some catching up to do, but the benefit is that we can learn from those that have gone before. There are plenty of QI success stories published in a bespoke journal for QI, BMJ quality and safety.
QI methodology and science take a pragmatic approach to implementation of change in a system, focused on tests of change and clear measures so we understand the implications of any change. This controlled approach to implementing change is ideal for use in dental practices. QI is also ideal for finding ways to implement best practice that is supported by evidence.
There is a level of skill and knowledge required to maximise all the QI tools available. NES has developed a number of useful resources that can be accessed online to help navigate QI.
Changes to the SDR in October 2017 mean that dentists can now include quality improvement work where
this would have been traditionally audit activity.
Another method to achieve the final two parts of an evidence-based approach might be to use peer review. This is a process of collaborative working with colleagues to establish a group that facilitates peer-to-peer discussion. It involves practitioners outside your practice and could bring a fresh point of view to the processes in your practice. NES has laid out some advice on the requirements of a peer review group on their website.
If done correctly this approach can be used to fulfil quality improvement hours.
One way to use peer review to improve care might be for discussion and implementation of the updated SDCEP guidance on paediatric dentistry that has recently been published1.
You could establish a local group of dentists to come together and discuss the guidance, using it as your standard of care and benchmarking against it, then working together to make changes that will benefit patients and improve the quality of care.
In our example of using a leaflet as a test of change, the practice down the road might have more success in winning parents over because they give the leaflet out with appointment letters rather than when they arrive at the reception desk. Or they might have more experience of paediatric dentistry and could share some tips on behavioural management and helping kids accept treatment.
Sometimes implementation can come up against a lot of barriers and it seems like there is no path through all the issues and reasons not to change. Susan Michie’s research group at University College London has produced a number of models and theories that could be helpful.
The TRIADS (translational research in a dental setting) team uses some of these methods alongside guidance development and implementation of SDCEP guidance 2. Thinking about barriers to change, it is sometimes down to the physical confines of the working environment or maybe it is the people within it. There are various methods for helping to work through the barriers and understand how to break them down and facilitate positive behaviour change.
The theoretical domains framework is made up of 14 domains that can help you understand what the barriers are by providing a framework to create questions from3.
For example, the first domain is knowledge, questions in this domain might look like: Do practitioners know that new SDCEP guidance for paediatrics has been published? The second domain is skills; a question in this domain might be: Do dentists in the practice know how to place a Hall crown?
Once you gain answers to these questions you can begin the frame ideas and develop facilitators that will enable application of evidence-based practice and guidance. That might be issuing each practitioner with the guidance and arranging a team meeting to discuss it, changing pro-formas on the surgery operating system to include risk assessments that hadn’t been previously included or arranging for the practice to have a training day on fitting Hall crowns. You can only come up with effective solutions if at first, you understand the real underlying barriers. You can read more about the TDF in a free open access journal.
All of the approaches above have evaluation built in. The usual go-to mechanism for measuring and evaluating change tends to be a traditional style audit of pre- and post-intervention data collection. This is an effective method of evaluating an outcome, but it only gives a snapshot, usually of quantitative data, of an ongoing and dynamic system. This type of audit activity still has a place to ensure standards are met and identify areas where there could be improvements but we shouldn’t be restricted to it.
There are many other ways of evaluating outcomes and presenting evidence of effective change. It is important though, to distinguish between process measures and outcome measures. In the fluoride varnish example, a process measure might be the number of successful applications of varnish applied, but the outcome measure would be the reduction in caries rate or continued prevention of caries for the patient. Having the ultimate health outcome in mind throughout the project is important, as after all everything the project is striving to achieve is improve the quality of care we provide to patients and improve their health.
Qualitative feedback from staff on a new process is an important measure when evaluating outcomes and could be gathered in staff meetings or in questionnaire form. Staff often come up with pragmatic and innovative ideas that might not have been thought of previously.
Gathering patient feedback is another very valuable measure. The Scottish Government’s Health and Social Care standards provide some useful questions and themes to base outcome markers on 4. An example of the headline outcomes in the document are ‘I have confidence in the people who support and care for me’ and ‘I am fully involved in all decisions about my care and support’. The document is worth a read; the standards are meant to compliment already existing standards set out by various legislative bodies.
Staff and patient feedback could be combined with quantitative data as part of the evaluation of a project in your practice. Returning to QI, the method of quantitative data collection in QI uses a sustained approach to data collection. QI has a programme of active data collection taking place throughout the change process. Instead of collecting large amounts of data at two time points, QI asks that you collect smaller amounts of data at more regular time points. This provides greater levels of regular feedback that can help you understand the implications of any changes you have made earlier.
The three articles we have published in this magazine should give you a good basis for moving forward and practicing evidence-based dentistry. Providing high-quality care and sustaining it is the end goal. Backing up your clinical decision-making and informing your treatment plans with evidence will inevitably help you achieve that. Hopefully the top tips in these articles help you to do that.
If you are further interested in the implementation of evidence in practice and want to be part of testing ideas more formally, then the Scottish Dental Practice-Based Research Network will be of interest to you, check out their website to find out about their current projects how to get involved.
Niall McGoldrick BDS, MFDS RCPS(Glasg); Derek Richards BDS, FDS, MSc, DDPH,FDS(DPH)
A paediatric dental avulsion is not a clinical scenario that you will be faced with on a daily basis in general practice. Being confident in the steps required to manage a paediatric dental avulsion may reduce the stress of the situation and will allow for the most effective treatment to be provided in a timely manner. When managing a paediatric trauma, a clear, structured history and initial assessment will allow for the most appropriate treatment to be administered quickly, ensuring that no potential child protection concerns are missed. The initial assessment should establish; any head injury concerns, whom the child is with, the nature and timing of the injury and the child’s medical and tetanus status. The extra oral dry time and the stage of the tooth’s development will affect your subsequent management and the tooth’s long-term prognosis. This article is going to highlight the key factors that should be taken into consideration when assessing and managing an acute paediatric dental avulsion.
The management of acute paediatric dental trauma within general practice doesn’t occur on a daily basis, so when it does occur it can be a daunting experience. The blood, tears & worried parents will inevitably create a more stressful encounter than a routine treatment appointment. Being confident in the initial history taking and clinical steps required to manage the patient’s care will reduce the stress and will improve the long-term prognosis of the damaged teeth. This article aims to highlight the key factors that should be considered when you are presented with a paediatric dental avulsion.
Twenty-five per cent of children experience dental trauma 1, ranging from concussion to complex dental trauma affecting multiple teeth. The maxillary incisors are most commonly affected, most commonly affecting the 7–14 age group. The main aetiology includes sport, falls and fights 2. Other factors that can increase an individual’s risk of dental trauma include; the presence of a skeletal overjet or incompetent lips 3,4.
Avulsions account for 0.5 – 3 per cent of dental trauma 5. Although they are not the most common form, they are associated with a poor long-term prognosis and the initial management can have a significant input towards the short and long-term outcomes 6,7.
From the moment the child walks through the surgery door, your initial assessment should commence. Key factors that have to be taken into consideration include; the risk of head injury, the child’s medical history and tetanus status, the nature of the injury, the time from the trauma to the replantation, the child’s social and dental history, whether the tooth has an open or closed apex, the storage medium and the risk of infection.
Having an extra oral dry time of less than an hour will significantly affect the tooth’s long-term prognosis and will influence the management of the avulsion. Furthermore, an open apex will significantly improve the tooth’s long-term survival. The loss of neurovascular blood supply to the pulp following an avulsion is detrimental to survival. The International Association of Dental Trauma (IADT) Guidelines recommends the elective root canal treatment of all permanent teeth with a closed apex to prevent infection
and resorption 8.
Non-accidental injury should also be kept in mind when assessing any child presenting with a dental trauma injury. A study looking at 390 clinical case records of children with suspected physical abuse showed that 59 per cent of children had orofacial signs of the abuse 9. It may be necessary to discuss the patient’s case with the child’s named person or with the local social work department. If you deem the child to be in imminent danger the case may require escalation to the local police service.
Has there been any associated head injury or loss of consciousness? Is the child conscious and breathing with no threat to their airway? Any concerns over potential head/ c-spine injury or any compromise to the patient’s airway will require attention from the local Emergency Department. Ask about any nausea, sickness or loss of memory that may have occurred since the time of injury and rule out these potential concerns at the start of the consultation.
As with any consultation, any relevant medical conditions that may affect the subsequent management of the patient should be considered. Does the child have a bleeding disorder? Do they have any allergies to the metal wire you may plan to place or to the antibiotics you would consider prescribing? Are they asthmatic and already in distress over their current injury? If they are asthmatic, ibuprofen may not be an appropriate analgesia for when they are discharged home. If the child is immunosuppressed or has a cardiac defect immediate replantation may not be the most appropriate treatment option. Acute specialist input will likely be required.
These factors should all be considered before planning clinical treatment.
Bleeding is often associated with dental trauma. This can be active bleeding or a clotted wound with a bloodstained face. Regardless of whether the bleeding is fresh or residual staining, this can be distressing for the patient and the accompanying adult. Active bleeding may be from a tooth socket or from an associated laceration. Once the source of the bleeding has been identified, haemostasis should be achieved through the use of local anaesthetic, pressure and sutures as required. This can be challenging if the child is already distressed. If the child has a bleeding disorder achieving haemostasis may be difficult. This may necessitate a prompt referral to secondary care.
When taking a history for a paediatric trauma case it is firstly important to establish who is with the child – parents, carers, teacher etc. Time should be taken to listen to the history provided from both the child and their accompanying adult.
It is very important to find out when the injury occurred. Time is of extreme importance when planning treatment and discussing prognosis. If the tooth has been avulsed, the transport medium should also be established: water, milk, saliva, dry?
Once aware of when the injury occurred it is important to carefully find out where and how the injury happened. Was the child accompanied at the time of the injury? Does the story match with the clinical presentation? Does the child’s account match the history provided by the accompanying adult? Was the environment clean or dirty? Clear documentation of this discussion is crucial.
It is important to compare the story with the injury to assess whether the two coincide. If the presentation is delayed find out if there is a legitimate reason for this delay in presentation. Follow the local practice policy to raise concerns if you are suspicious of the injury and associated circumstance. Under the new GIRFEC Guidelines, each child should have a named person. They can be contacted and the incident shared in a confidential manner if you are at all concerned.
When sharing information, the ‘golden rules’ should be followed 10:
Is the child’s tetanus up to date? They may require a booster if they are not up to date with their vaccinations or if it is out of date.
Standard vaccination protocol: The primary course of tetanus vaccination consists of three doses of a tetanus vaccination given within one-month intervals. At three years four months old the child should receive a tetanus booster. A second booster should then be given at age 14.
If in doubt, advise a medical review by their GMP.
There is minimal evidence supporting the use of antibiotics following an avulsion. The prescription of antibiotics is at the discretion of the clinician. Factors that can influence this are highlighted in the British Society of Paediatric Dentistry Avulsion Guidelines 11.
Find out the child’s level of dental anxiety, previous treatment and how likely they will cope with the required treatment. In this acute instance, the main priority is to replant the tooth as time efficiently as possible, if patient compliance will allow for this. It is also important to consider the subsequent treatment. If the patient is unlikely to cope with the treatment in general practice or if the treatment required involves specialist input, e.g. an MTA plug for an open apex, prompt referral will ensure no treatment delay is encountered.
When recording the child’s social history make a note of who they live with and which nursery/ school they attend. This information may be required if external services are being involved. Ensure they are registered with a GP and that you have their details.
The International Association of Dental Traumatology (IADT) Guidelines 12, updated in 2012, give clear guidance on the management of paediatric trauma.
A summary is provided below:
If a deciduous tooth has been avulsed don’t replant the tooth. Discuss with the child and the parents the potential risk of damage to the permanent successor. Discuss:
Provide general trauma advice and arrange a review appointment.
a) Tooth has been replanted prior to the patient’s arrival
b) Extra oral dry time <60mins
c) Extra oral dry time >60mins
a) Tooth has been replanted prior to the patient’s arrival
b) Extra-oral dry time <60mins
c) Extra oral dry time >60mins
This article has covered the key considerations required for the acute management of a paediatric dental avulsion. Following these steps will allow for the effective, timely management of your patients care, improving the long-term prognosis of the tooth and ensuring no potential child protection concerns are missed.
Authors: F. Capaldi, Paediatric Dental Core Trainee, Glasgow Dental Hospital; C. Park, Consultant in Paediatric Dentistry, Glasgow Dental Hospital
With the introduction of the first intraoral scanner, CEREC (Chairside Economical Restoration of Esthetic Ceramics) by Dentsply Sirona in 1985, dentistry was offered an exciting alternative to conventional means of impression-taking. Since then, digital technology has developed, resulting in faster, more accurate and smaller scanners than ever before.
As of writing, approximately 15 separate intraoral scanners are available from a variety of companies – all competing within a fierce, growing market. In 2014, the global intraoral scanner market was valued at US$55.3 million, estimated to expand with an annual growth rate of 13.9 per cent from 2015 to 2022 1.
Intraoral scanners have gained traction within the orthodontic speciality, with restorative dentistry following suit. Intraoral scanning technology aims to address fundamentally multiple contemporary clinical issues, including the intuitively error-prone volumetric changes of impression materials and the expansion of dental stone.
This review will provide an overview of the advantages, limitations and clinical applicability of intraoral scanners and serve as an introduction for those unfamiliar with this technology.
Firstly, it is pertinent to discuss the technology of intraoral scanners. The objective of an intraoral scanner is to record precisely the 3D geometry of an object, to allow this to be subsequently used to produce customised dental devices. The fundamentals of intraoral scanning relate to structured light being cast upon an object to be scanned by a handheld device. Images of the object of interest are then captured by image sensors within the handheld scanner and processed by software. This results in the production of a point cloud which is further analysed by software to create a 3D surface model, also known as a mesh 2. The most widely used output file is the STL (stereolithography/standard tessellation language 3).
Numerous technologies exist to process scan data including: triangulation, confocal, active wavefront sampling (AWS) and stereophotogrammetry.
Triangulation works by the concept that the point of a triangle (object of interest) can be calculated knowing the positions and angles of images from two points of view.
Confocal technology relates to the acquisition of focused and defocused images from selected depths – the sharpness of the image infers distance between points and is related to the focal length of the lens 4.
AWS needs a camera and an off-axis aperture module. The module moves around a circular path centred on a point of interest – the distance and depth information are derived from a pattern produced by each point5.
Stereophotogrammetry estimates all co-ordinates through analysing images using an algorithm – relying on passive light projection and software as opposed to active light projection and expensive hardware.
|Enhanced patient comfort||Initial learning curve|
|Gag reflex management||Unable to displace soft tissue – marginal inaccuracies|
|No physical study models requiring storage||Expensive hardware/annual software agreement|
|Streamlined workflow||Unpredictable for extended edentulous sites|
|Predictable for single teeth/implants/short span bridgework (<5 units)||Unable to register dynamic soft tissue relationships|
|Immediate preperation feedback in high magnification (undercut/margin depths)||Requires laboratory familiar with digital technology|
|Improved patient communication|
No matter the imaging processing technology, this data is then constructed into a virtual 3D model. The major challenge of this is rendering a point of interest taken at multiple angles. Accelerometers within the handheld scanner allow distances and angles to be measured between images, with extreme points eliminated statistically, culminating in the production of an STL file suitable for further use to create the custom dental device6.
The accuracy of an intraoral scan is paramount for a well-fitting custom dental prosthetic. This is assessed through the values of “trueness” – being the measured deviation from the actual value and “precision” – the repeatability of multiple measurements.
These terms were defined by the International Organization for Standardization – standard 5725-1. Studies investigating the accuracy of intraoral scanners should ideally include both measurements, to adequately represent both how “correct” a scanner is, as well as how predictably similar its measurements are.
In 2016 8, Ender and co-workers, and other studies, demonstrated intraoral scanner trueness of between 20 m and 48µm and precision between 4µm and 16µm 9-11.
Later, in 2017, Imburgia et al 7 reported scanner trueness and precision in the region of 45µm and 20µm respectively for the most accurate scanners tested. To put these figures into perspective, conventional impression trueness and precision is generally reported in the region of 20µm and 13µm respectively12-14. In its totality, the literature currently reports intraoral scanning is at least as accurate as conventional methods of impression-taking, subject to the complexity of the clinical case 11,15,16.
A common finding is that of partial scans being the most reliable and accurate, when compared to full arch scans2,17,18. When scanning over five units (implants or teeth), the data would suggest scanning is not as predictable as conventional impressions7.
Full arch scans are shown to suffer distortion, specifically at the distal end of the scan 17, 19, 20. Therefore, the scanning of extended preparations or the edentulous mandible is at high risk of error. Shorter scan distances therefore yield the most accurate results9, 21. A clinically acceptable marginal gap for an indirect restoration may be defined at below 100µm22-25.
It is evident that intraoral scanners can achieve errors of consistently less than this value (in single tooth and limited span situations), giving clinical validity.
Intraoral scanning provides many advantages for the clinician within single unit, tooth or implant supported restoration or full arch appliance (such as orthodontic retainers or aligners 26-28) situations. Digital records of the patient obviate the need to store plaster models. This has positive implications for storage and consumable costs 27. This data also allows the clinician to easily and accurately monitor changes within the dentition over time – for example, tooth wear or orthodontic relapse 5. It has been evidenced by multiple authors7, 11, 27, 29. that intraoral scanning results in less patient discomfort compared to conventional impressions.
Patients also prefer scanning to conventional methods of impression-taking 28,30 and gag reflexes can be avoided. There is a modest improvement in chairside time 30,31 with a reported average scan time of between four and 15 minutes4, however, greater time saving is gained through the elimination of certain following laboratory steps. A small quadrant scan is ideal for a single restoration 9,32.
Scans of prepared teeth can be scrutinised by the clinician at extreme magnification and software overlays of undercuts/preparation depths are available, with potential for improved clinical outcomes as a result. Files can be directly emailed to the laboratory – thus avoiding the need to physically post an impression. The dental technician can also assess the impression in real time and request another scan to be taken – avoiding an extra visit for the patient 33,34.
Certain problematic sections can be retaken thus avoiding the need to retake a full impression. Patients are shown to feel more involved with treatment and are interested in scanning technology – serving as a good advertising tool35-37.
Limitations exist within the practice of intraoral scanning however. As previously mentioned, scanning is currently predictable only within limited parameters. Full arch implant retained prostheses, extended bridgework and complete dentures are currently not supported by compelling evidence. In relation to complete dentures, a predictable dynamic impression of soft tissue borders, muscle attachments and mucosal compressibility is currently severely limited by technology 2.
There is an accepted learning curve in relation to intraoral scanning. It has been reported that subjects with a greater affinity for the world of technology will find the technology easier to adopt than those without this affinity 36,38,39. Issues arise in the detection of deep margins of prepared teeth39 as light cannot record the ‘non visible’ areas of the preparation 2 as normally conventional impression material may be able to displace the gingival margin and record valuable data, following the retraction process. As with conventional impressions, blood or saliva may obscure important margins 40.
With good technique and speed, it has been reported one can overcome many of the reported limitations15,29. The issue of reflective restorations or teeth may also arise. This can result in disruption of the matching of points of interest within the software – resulting in an inaccurate 3D model. This can be counteracted by changing the orientation of the scanner to increase diffuse light, using a camera with a polarizing filter or coating the teeth in powder. Powder coatings (aluminium oxide) can add a variable thickness of up to 90µm41 and further issues arise if taking a full arch scan as powder inevitably gets mixed with saliva – resulting in time spent cleaning teeth and reapplying powder 29.
The scan path can also affect the quality of the scan42 and can result in lost tracking. This should ideally be at a constant distance from the point of interest and moved in a fluid manner, avoiding jerky or fast movements – this can be clinically challenging6. When scanning and tracking is lost, one should return to an area easily recognisable by the software – for example, the occlusal surface of a molar – to predictably re-establish tracking. If scanning a complete arch, multiple small interocclusal records appear to be the most predictable method of achieving accurate articulation or a small scan of the anterior sextants, as described by a 2018 study 32.
The initial expense and management costs of hardware may also be prohibitive – the average intraoral scanner costs between £13,000 and £31,000. An annual update agreement may also exist to “unlock” STL files for use of the laboratory – this again has an associated cost.
As more scanners reach the market, it is likely these costs will become more competitive and attractive to new adopters.
In conclusion, intraoral scanning presents a viable alternative to (and occasionally outperforms) conventional impression techniques within the confines of strict case criteria. Despite being in its late “innovator” and “early adopter phase”, intraoral scanning has shown great potential within restorative dentistry, orthodontics and more recently guided implant surgery (combined with CBCT) 43. Many of its limitations can be circumvented with good clinical technique. Technology, potentially prohibitive costs and market inertia currently prevent its routine use in a wide array of clinical situations.
M Paterson, Specialty Registrar in Restorative Dentistry/Honorary Clinical Lecturer,
Glasgow Dental Hospital & School
Arvind Sharma, BDS(Dund), MSc(Endo), MJDFRCS(Eng), MFDSRCPS(Glas)
Arvind Sharma presents the second and final part of a structured critical review to evaluate the question whether the use of cone beam computed tomography (CBCT) in endodontics has an influence on clinical decision-making.
The methodology of this review is based on the aforementioned steps, as suggested by Boland et al 2014. Below is a brief summary of the methods used.
The following structure was therefore employed:
The topic considered was discussed with my supervisor and also with my peers to solicit their views.
The author attended a British Endodontic Society conference held in London in March 2015 and met Dr Patel (one of the speakers that day) when the topic of this review was discussed.
The author and Dr Patel corresponded by email, and Dr Patel suggested that there is a lack of evidence in this field due to lack of clinical studies and suggested that a systematic review would be difficult in his opinion. This led the author and his supervisor to consider a structured critical review instead.
Due to the aforementioned reasons and since the author’s time and resources are limited, a traditional systematic review was not possible. It was decided, therefore, to design and conduct a structured critical review of the literature to answer the question posed.
|F&T Level||Studies Identified|
|3-Diagnostic Thinking Efficacy||4|
|5-Patient Outcome Efficacy||1|
Table 4: Summary of included studies with associated F&T hierarchy levels
The review question was then formalised as a statement of my intention of the structured critical review. This was developed from what was found through the available evidence to what I further planned to find out. A theoretical approach, exploring factors that lead to a process, was to be taken.
The search identified eight publications that qualitatively or quantitatively assessed the use of CBCT in endodontics combined with clinical decision-making with respect to three levels of a six-tiered hierarchical model. (Level 3 diagnostic thinking efficacy, Level 4 therapeutic efficacy and Level 5 patient outcome efficacy).
The following table (table 3), shows the final eight papers that were included in this study along with the F&T hierarchy levels.
As can be seen from the above table (table 4), four papers were identified investigating the diagnostic thinking efficacy, three papers investigating the therapeutic efficacy and one paper investigating patient outcome.
Of all the eight studies, six concluded that CBCT made an influence in clinical decision-making and two did not.
A meta-analysis was not performed. Only a narrative summary of the data is presented since the included studies did not meet the criteria for conducting a meta-analysis. The differences across the trials, including inconsistent patient characteristics presented in some of the papers, small sample sizes, diversity in protocols (interventions and comparators were not uniform across all studies), and the inconsistency in reporting outcomes (not all studies reported the same results), including statistical data (not present in one study), precluded a statistical synthesis of the included trial results.
The aim of this structured critical review was to answer the question, “does the use of CBCT in endodontics influence clinical decision making?” Of the eight studies chosen for this review, 75 per cent concluded that CBCT did influence decision-making whereas 25 per cent of studies concluded that CBCT did not influence clinical decision-making.
From the evidence analysed in this review, CBCT appears to have a positive influence in clinical decision-making in endodontics. However, when data was extracted, the six studies (75 per cent) did show limitations, which will be discussed below.
Although the literature search provided an abundance of evidence on CBCT, the evidence available relating to the review question was limited. When considering the hierarchy of evidence (randomised controlled trials being the most robust form of study) and application of the inclusion criteria to the results of the searches there was a lack of studies in this area with only nine studies meeting criteria. One of the reasons for this is due to ethical considerations in relation to the exposure of patients to radiation when taking a CBCT for an in-vivo trial/study. So, although CBCT is being more commonly used in clinical endodontic practice, the number of in-vivo studies is lacking. This was further confirmed by personal communications with the well-published author and committee member of the European Society of Endodontology, Dr Shanon Patel.
The limited literature search was further compounded by the fact that Fryback and Thornbury Levels 3, 4 and 5 were applied and this resulted in fewer relevant studies. A number of studies were found but were mainly on levels 1 (technical quality of image) and 2 (diagnostic accuracy, sensitivity and specificity). The inclusion criteria of human, English language and in-vivo studies again limited the number of studies since published animal and foreign language studies were excluded. Applying a search for ‘all studies’ gave a wider net for the search with non-relevant studies due to their hierarchical level of evidence being excluded. This was the case with Kurt et al 2003, which was a cross-sectional observational study.
Considering the available studies, the author believes that all or at least a representative sample of the available evidence relating to the study question was obtained.
|Study||Study Title||F&T Levels|
|1. Abuabara et al 2012||Efficacy of clinical and radiological methods to identify second mesiobuccal canals in maxillary first molars||3|
|2. Balasundaram et al 2012||Comparison of Cone-beam computed tomography and periapical radiography in predicting treatment decision for periapical lesions: |
a clinical study
|3. Davies et al 2015||The detection of periapical pathoses using digital periapical radiography and cone beam computed tomography in endodontically retreated teeth-part 2: |
a one- year post-treatment follow-up
|3 + 4|
|4. Ee et al 2014||Comparison of endodontic diagnosis and treatment planning decision using cone-beam volumetric tomography versus periapical radiography||4|
|5. Hashem et al 2015||Clinical and radiographic assessment of the efficacy of calcium silicate indirect pulp capping: a randomised controlled clinical trial||3|
|6. Kurt et al 2014||Outcomes of periradicular surgery of maxillary first molars using a vestibular approach: a prospective, clinical study with one year of follow-up||5|
|7. Mota de Almeida et al 2014||The impact of cone beam computed tomography on the choice |
of endodontic diagnosis
|8. Mota de Almeida et al 2014||The effect of CBCT on therapeutic decision-making in endodontics||4|
Table 3: The final eight papers included in this study
Overall, on a hierarchy of evidence, since only two randomised controlled trials were included, the evidence gathered was not of the highest calibre. The included studies all had limitations that were either discussed by the individual authors or were identified during this review’s quality assessment process. The limitations identified included, small sample sizes in most studies, history and clinical information (signs and symptoms) not always provided, the number and clinical experience of observers varied from novice to most skilled, the radiation dose used with the CBCT modality was not always validated, the resolution of CBCT images was not always discussed as image enhancement may or may not have affected the image quality and hence results and detailed statistical data were not disclosed in three studies.
In one study where periradicular surgery was being performed, a microsurgical approach was not used, which is now accepted as the gold standard in retrograde endodontics, both in Europe and North America. The ability, for example, to identify artefacts due to beam hardening that could be misdiagnosed as a carious lesion is an important point. Therefore, image interpretation is still an area that requires further training especially for less experienced clinicians.
There were limitations with this structured critical review study with respect to the time that was spent on the literature search, the final selection of the chosen studies, the quality assessment and data extraction. This was mainly due to the part-time nature of this study and there only being one individual, namely the author, executing the various stages of this structured critical review.
It is the author’s opinion that by having more than one individual working on various aspects of this study, bias may have been eliminated, leading to a more rigorous study process.
The limitations were related to the methodological part of this study. Specifically:
With all of the above limitations considered, it is the author’s opinion that a thorough and reproducible literature search was performed using appropriate and relevant search terms, quality assessment of the chosen studies enabled the most appropriate studies to be used for data extraction purposes and since the conclusions reached for this critical review process are similar to other reviews in this field of study, the author is confident that the review process was conducted with appropriate methodology, is clear, reproducible, thorough and transparent.
Although the overall findings of this review seem to suggest that CBCT is influential in clinical decision-making, it is the author’s opinion that the findings cannot be generalised and applied to the everyday clinical practice of endodontics. There was disparity in the studies in terms of their design, sample size, age range, male-female ratio, setting, sample definition, F&T level, examiners used (experience and number of) and use of statistical data, which means it is difficult to make an absolute comparison of outcomes and reach a definitive conclusion based on the chosen studies. CBCT does have an important place in endodontic clinical decision-making but its use should still be limited as ESE recommend.
In conclusion, this critical review has shown that although most of the available evidence appears to show that CBCT does influence clinical decision-making in endodontics, high-quality longitudinal studies are lacking, and more research is required. Based on the current available evidence, the ESE guidelines seem appropriate and should be applied accordingly. The studies by Balasundaram et al 2012, Davies et al 2015 and Mota de Almeida et al 2014 all looked at the detection of periapical radiolucencies and, as discussed earlier, did not concur with their results. CBCT has a useful place in clinical decision-making in endodontics but its use should be kept for complex cases where radiographs do not give sufficient information. This would resonate with the ESE guidelines.
As discussed earlier, there are implications in using CBCT, namely, cost of equipment, training required for the use and interpretation of CBCT and importantly the radiation dose the patient is exposed to. No doubt, CBCT can be relevant and useful in endodontics and can have an influence in clinical decision-making, which in turn may help a patient with complex symptoms that routine investigative methods have proved limited. However, the overall consensus of the studies do not recommend the routine use of CBCT in endodontics but recommend its consideration when other methods of diagnosis prove to be inconclusive in reaching a definitive diagnosis. Again, this would in line with guidelines produced by the ESE. Looking into the future, if CBCT equipment can expose the patient to less radiation, perhaps in line with the amount produced by intra-oral radiographs, its use may well increase particularly if coupled with a more affordable price tag. Increasing CBCT education at undergraduate and postgraduate level would improve knowledge and application in the clinical setting. This would ultimately give the clinician more tooth detail, which could in turn improve patient care and the reputation of endodontics as a dental discipline amongst patients.
This structured critical review has shown that there is limited evidence on the influence of CBCT in clinical decision-making in endodontics. The available evidence does however seem to suggest that there is a place, although limited, for CBCT use in endodontics with decision-making. Application of ESE guidelines should be followed until further research can be carried out in this interesting and clinically relevant imaging modality
Aims and objectives
To give the reader an understanding of CBCT as a modern imaging tool and its application in endodontics
To provide details of the evidence surrounding clinical decision making in endodontics
To highlight the clinical applications where use of CBCT in endodontics would be advantageous
To understand the basics of how CBCT works
and its clinical application in endodontics
To be able to recognise when the use of CBCT
may help clinical decision-making
What kind of process was used to carry
out the research?
a) Systemic review?
b) Randomised controlled trial?
c) Structured critical review?
How to verify your CPD
Go online to www.sdmag.co.uk and click on the CPD tab to access all our CPD Q&As and certificates.
ABUABARA, A., BARATTO-FILHO, F., AGUIAR ANELE, J., LEONARDI, D.P. and SOUSA-NETO, M.D., 2013. Efficacy of clinical and radiological methods to identify second mesiobuccal canals in maxillary first molars. ActaOdontologicaScandinavica, 71(1), pp. 205-209.
ARAI Y, TAMMISALO E, IWAI K, HASHIMOTO K, SHINODA K (1999) Development of a compact computed tomographic apparatus for dental use.Dentomaxillofacial Radiology 28, 245–8.
BALASUNDARAM, A., SHAH, P., HOEN, M.M., WHEATER, M.A., BRINGAS, J.S., GARTNER, A. and GEIST, J.R., 2012. Comparison of cone-beam computed tomography and periapical radiography in predicting treatment decision for periapical lesions: a clinical study. International journal of dentistry, 2012.
BERGENHOLTZ, G. and KVIST, T., 2014.Evidence-based endodontics. Endodontic Topics, 31(1), pp. 3-18.
BROWN, J., JACOBS, R., LEVRING JGHAGEN, E., LINDH, C., BAKSI, G., SCHULZE, D. and SCHULZE, R., 2014. European Academy of DentoMaxilloFacial Radiology Basic training requirements for the use of dental CBCT by dentists: a position paper prepared by the European Academy of DentoMaxilloFacial Radiology. Dentomaxillofac.Radiol, 43(1), pp. 20130291.
CHEUNG, G., WEI, W. and MCGRATH, C., 2013. Agreement between periapical radiographs and cone-beam computed tomography for assessment of periapical status of root filled molar teeth. International endodontic journal, 46(10), pp. 889-895.
CHRISTIANSEN, R., KIRKEVANG, L., GOTFREDSEN, E. and WENZEL, A., 2009. Periapical radiography and cone beam computed tomography for assessment of the periapical bone defect 1 week and 12 months after root-end resection. Dentomaxillofacial Radiology, 38,pp.531-536.
DAILEY, B., MINES, P., ANDERSON, A. and SWEET, M., 2010. The use of cone beam computer tomography in endodontics: Results of a questionnaire. 2010. AAE Annual Session abstract presentation PR10. Journal of Endodontics, 36, pp. 567.
DAVIES, A., PATEL, S., FOSCHI, F., ANDIAPPAN, M., MITCHELL, P.J. and MANNOCCI, F,2015. The detection of periapical pathoses using digital periapical radiography and cone beam computed tomography in endodontically retreated teeth – part 2: a 1 year post-treatment follow-up. International endodontic journal, 48(6), pp. 582-592.
DE ALMEIDA, MOTA F J, KNUTSSON, K. and FLYGARE, L., 2015. The impact of cone beam computed tomography on the choice of endodontic diagnosis. International endodontic journal, 48(6), pp. 564-572.
EE, JONATHAN BDS,D.D.S., F.R.C.D., FAYAD, MOHAMED I D D S and JOHNSON, B.R.D.D.S., M.H.P.E., 2014. Comparison of Endodontic Diagnosis and Treatment Planning Decisions Using Cone-beam Volumetric Tomography Versus Periapical Radiography. Journal of endodontics, 40(7), pp. 910-916.
ESTRELA, C., HOLLAND, R., DE ARAJO ESTRELA, C R, ALENCAR, A.H.G., SOUSA-NETO, M.D. and PCORA, J.D., 2014.Characterization of successful root canal treatment. Brazilian dental journal, 25(1), pp. 3-11.
EUROPEAN COMMISSION. Evidence-based guidelines on cone beam CT for dental and maxillofacial radiology. Office for Official Publications of the European Communities. Radiation Protection 172, 2012.Cited December 2013: [about 154 pp.]. Available from: http:// ec.europa.eu/energy/nuclear/radiation_protection/doc/publication/ 172.pdf 30.
FRYBACK, D.G. and THORNBURY, J.R., 1991.The efficacy of diagnostic imaging. Medical decision making, 11(2), pp. 88-94.
GRONDAHL, H. and HUUMONEN, S., 2004. Radiographic manifestations of periapical inflammatory lesions: How new radiological techniques may improve endodontic diagnosis and treatment planning. Endodontic Topics, 8(1), pp. 55-67.
HASHEM, D., MANNOCCI, F., PATEL, S., MANOHARAN, A., BROWN, J.E., WATSON, T.F. and BANERJEE, A., 2015. Clinical and Radiographic Assessment of the Efficacy of Calcium Silicate Indirect Pulp Capping A Randomized Controlled Clinical Trial. Journal of dental research, 94(4), pp. 562-568.
HILTON, T.J., 2009. Keys to clinical success with pulp capping: a review of the literature. Operative dentistry, 34(5), pp. 615.
JENSEN, A. R., 1985. The nature of the black-white difference on various psychometric tests: Spearman’s hypothesis. Behavioural and Brain Sciences, 8(02), pp. 193-219.
KRUSE, C., SPINNETO, R., WENZEL, A. and KIRKEVANG, L.L., 2015. Cone beam computed tomography and periapical lesions: a systematic review analysing studies on diagnostic efficacy by a hierarchical model. International endodontic journal, 48(9), pp. 815-828.
KURT, S.N., STN, Y., ERDOGAN, Z., EVLICE, B., YOLDAS, O. and ZTUNC, H., 2014. Outcomes of periradicular surgery of maxillary first molars using a vestibular approach: a prospective, clinical study with one year of follow-up. Journal of Oral and Maxillofacial Surgery, 72(6), pp. 1049-1061.
KVIST, T. and REIT, C., 2000. Postoperative discomfort associated with surgical and nonsurgical endodontic retreatment. Dental Traumatology, 16(2), pp. 71-74.
KVIST, T., REIT, C., ESPOSITO, M., MILEMAN, P., BIANCHI, S., PETTERSSON, K. and ANDERSSON, C., 1994. Prescribing endodontic retreatment: towards a theory of dentist behaviour. International endodontic journal, 27(6), pp. 285-290.
KVIST, T. and REIT, C., 1999. Results of endodontic retreatment: a randomized clinical study comparing surgical and nonsurgical procedures. Journal of endodontics, 25(12), pp. 814-817.
LEDLEY, R.S. and LUSTED, L.B., 1959. Reasoning Foundations of Medical Diagnosis Symbolic logic, probability, and value theory aid our understanding of how physicians reason. Science, 130(3366), pp. 9-21.
LIANG, Y., JIANG, L., GAO, X., SHEMESH, H., WESSELINK, P.R. and WU, M., 2014. Detection and measurement of artificial periapical lesions by cone-beam computed tomography. International endodontic journal, 47(4), pp. 332-338.
LOFTHAG-HANSEN, S., HUUMONEN, S., GRNDAHL, K. and GRNDAHL, H., 2007.Limited cone-beam CT and intraoral radiography for the diagnosis of periapical pathology. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 103(1), pp. 114-119.
MOTA DE ALMEIDA, F J, KNUTSSON, K. and FLYGARE, L., 2014. The effect of cone beam CT (CBCT) on therapeutic decision-making in endodontics. Dentomaxillofacial Radiology, 43(4), pp. 564-572, (20130137).
MOZZO, P., PROCACCI, C., TACCONI, A., MARTINI, P.T. and ANDREIS, I.B., 1998. A new volumetric CT machine for dental imaging based on the cone-beam technique: preliminary results. European radiology, 8(9), pp. 1558-1564.
NG, Y., MANN, V. and GULABIVALA, K., 2010. Tooth survival following non-surgical root canal treatment: a systematic review of the literature. International endodontic journal, 43(3), pp. 171-189.
PATEL, S., WILSON, R., DAWOOD, A. and MANNOCCI, F., 2012. The detection of periapical pathosis using periapical radiography and cone beam computed tomography–Part 1: pre-operative status. International endodontic journal, 45(8), pp. 702-710.
PATEL, S., DURACK, C., ABELLA, F., ROIG, M., SHEMESH, H., LAMBRECHTS, P. and LEMBERG, K., 2014. European Society of Endodontology position statement: The use of CBCT in Endodontics. International endodontic journal, 47(6), pp. 502-504.
PATEL, S., DURACK, C., ABELLA, F., SHEMESH, H., ROIG, M. and LEMBERG, K., 2015. Cone beam computed tomography in endodontics–a review. International endodontic journal, 48(1), pp. 3-15.
POPE, O., SATHORN, C. and PARASHOS, P., 2014. A comparative investigation of cone-beam computed tomography and periapical radiography in the diagnosis of a healthy periapex. Journal of endodontics, 40(3), pp. 360-365.
REIT, C. and KVIST, T., 1998. Endodontic retreatment behaviour: the influence of disease concepts and personal values. International endodontic journal, 31(5), pp. 358-363.
RIGOLONE, M., PASQUALINI, D., BIANCHI, L., BERUTTI, E. and BIANCHI, S.D., 2003. Vestibular surgical access to the palatine root of the superior first molar: “low-dose cone-beam” CT analysis of the pathway and its anatomic variations. Journal of endodontics, 29(11), pp. 773-775.
ROSEN, E.D., TASCHIERI, SILVIO D D S, DEL FABBRO, M., BEITLITUM, I.D. and TSESIS, I.D., 2015. The Diagnostic Efficacy of Cone-beam Computed Tomography in Endodontics: A Systematic Review and Analysis by a Hierarchical Model of Efficacy. Journal of endodontics, 41(7), pp. 1008-1014.
SACKETT, D.L., ROSENBERG, W.M., GRAY, J.A., HAYNES, R.B. and RICHARDSON, W.S., 1996. Evidence based medicine: what it is and what it isn’t. BMJ: British Medical Journal, 312(7023), pp. 71.
SCARFE, W.C., LEVIN, M.D., GANE, D. and FARMAN, A.G., 2010. Use of cone beam computed tomography in endodontics. International journal of dentistry, 634567.
STAVROPOULOS A, WENZEL A, 2007. Accuracy of cone beam dental CT, intra oral digital and conventional film radiography for the detection of periapical lesions. An ex vivo study in pig jaws. Clinical Oral Investigation, 11(1),pp.101–106.
STRINDBERG, L.Z., 1956. The dependence of the results of pulp therapy on certain factors: an analytic study based on radiographic and clinical follow-up examinations. Mauritzon. Acta Odontologica Scandinavica; 14(suppl 21): 1-175.
TSAI, P., TORABINEJAD, M., RICE, D. and AZEVEDO, B., 2012. Accuracy of cone-beam computed tomography and periapical radiography in detecting small periapical lesions. Journal of endodontics,38(7), pp. 965-970.
VOORDE, H.V. and BJORNDAHL, A.M., 1969. Estimating endodontic “working length” with paralleling radiographs. Oral Surgery, Oral Medicine, Oral Pathology, 27(1), pp. 106-110.
WU, M.K., SHEMESH, H. and WESSELINK, P.R., 2009. Limitations of previously published systematic reviews evaluating the outcome of endodontic treatment. International endodontic journal, 42(8), pp. 656-666.
Ms B attends as a new patient at a local dental surgery complaining of sensitivity in a number of teeth. A dental associate – Mr W – arranges bitewing radiographs and these show extensive distal caries at LR6 and caries in a number of other teeth. He advises that LR6 is of most concern and recommends treatment by an amalgam filling, given the size and depth of the caries. Ms B insists on a composite filling as it looks more “natural”. Mr W agrees but records his discussion with the patient regarding the pros and cons of composite versus amalgam filling in this particular case.
Mr W places an extensive composite filling at LR6 but moisture control is difficult as Ms is intolerant of dental dam, has excess saliva and there is gingival bleeding due to the size of the cavity. Ms B is also phobic and “fidgety” and keeps closing her mouth. Mr W informs the patient that given the extent of the cavity and difficulty of the procedure, root canal treatment (RCT) may be necessary in the future if the tooth does not “settle”. Ms B is also advised that a small amount of decay remains, again due to the size of the cavity.
Ms B attends a different dentist complaining of pain in LR6. The dentist also notes untreated caries in three other teeth. A radiograph reveals decay under the filling at LR6 and the dentist undertakes the first stage of RCT and the tooth is appropriately dressed.
The patient returns to the new dentist and undergoes root canal treatment on LR6 and another appointment is scheduled to carry out further restorations on the other untreated caries, including crowning of LR6.
A letter of claim for clinical negligence is received by Mr W from solicitors acting on behalf of Ms B. It alleges incomplete removal of caries at LR6 and also inadequate moisture control resulting in a reduced bond in the composite filling causing recurrent caries and chronic pain with later irreversible pulpitis necessitating root canal treatment.
Ms B claims damages amounting to the cost of the RCT and crowning of LR6 as well as loss of earnings due to time off work due to chronic pain.
MDDUS obtains copies of the patient notes and all relevant radiographs and sets out a letter of response based on a detailed case report. It is argued that Mr W carried out the initial restoration on LR6 in very challenging circumstances and to the best of his ability – as would any reasonable and competent general dental practitioner.
Moisture control was difficult given the problems of a phobic patient, restricted access and intolerance of dental dam. Mr W used high aspiration, cheek retraction and cotton wool to absorb moisture the best he could. To the extent there may have been a reduced bond this was more likely to do with the extent of the cavity and use of a composite filling rather than amalgam as was advised by the dentist. Amalgam may not be as aesthetically pleasing, but it will restore a tooth even in the presence of moisture whereas with composite materials moisture control is essential as bonding is actively to the tooth substance.
In regard to causation, MDDUS argues that the root canal treatment could not be the result of any act or omission by Mr W. The patient presented with extensive caries in LR6 and rejected the dentist’s advice on an amalgam filling and – on the balance of probabilities – would have thus required root canal treatment at LR6 in any event.
It is clear that not all the decay was removed in Mr W’s restoration of LR6, but it would not be unreasonable to leave some decay, restore the tooth appropriately, advise the patient accordingly and keep the tooth in question under review both clinically and radiographically.
MDDUS sends the letter of response and receives notification that the case is being dropped.
About the author
Aubrey Craig is head of dental division at MDDUS. For more information, go to www.mddus.com
Due to its powerful regenerative properties, platelet rich growth factor Endoret (PRGF) is being increasingly used in many fields of medicine, such as plastic surgery and dental implantology.
It has been shown to reduce scarring, rejuvenate damaged facial tissue, and accelerate wound healing. Endoret (PRGF) is proven to promote angiogenesis, cell migration, cell proliferation and the secretion of growth factors active in the wound healing cascade, while at the same time decreasing inflammation and pain.
Through this simple case report, I would like to show how Endoret (PRGF) can be applied in the field of dental implantology to make treatment outcomes more predicable by optimising healing conditions.
Step one is to collect a small quantity of the patient’s blood. Four collection tubes, each containing 9ml of blood, are filled. A total of 36ml is usually sufficient for most implant cases (Fig 1) However, in larger cases where more augmentation is required it is usual to collect eight tubes (72ml).
Once the blood has been collected, the patient is asked to return to the waiting area while the fractionation process is carried out which takes about 15 minutes. The collection tubes are transferred to the centrifuge machine (Fig 2). At the end of the eight-minute cycle, the collection tubes are immediately returned to their stand. It is important that this is done carefully with minimal disruption to the blood, which is now separated into four distinctive bands.
Each tube is now marked. The erythrocytes are heaviest and lie in the bottom half.
Next is a thin buffy layer approximately 0.5cm thick. This is the leukocyte fraction which must be avoided as these cells will evoke pain and inflammation.
In the top half of the tube is the liquid fraction of interest. Concentrated in platelets, plasma and growth factors, this straw-coloured layer is itself divided into two fractions: 1 and 2.
While fraction 1 (F1) is richer in the fibrin, which will create the collagen matrix for wound healing, fraction 2 (F2) contains the greatest concentration of platelets and protein markers. It is these protein markers which signal to the regenerative cells and trigger their activity.
Marking each tube, a safe distance of 0.5cm from the visible upper limit of the buffy layer, you then measure two centimetres up and mark the tube again. This threshold divides the most superior layer F1 from the second layer F2 (Fig 3).
Using the plasma transfer device, F1 and F2 are then separated into labelled collection tubes F1 and F2. Without activation, these fractions will remain viable for up to four hours.
At this point, I will normally ask for the patient to return and we follow the usual asepsis protocol for surgery and deliver the local anaesthetic and or intravenous sedation where required. When placing implants, I always require two dental surgery assistants, one sterile and the other non-sterile.
Depending on the planned length of the procedure, I will indicate to my assistants when F1 and F2 should be activated with calcium chloride (Fig 4). Once activated the fractions are transferred into sterile glass bowls and placed into a special oven that incubates them at body temperature for 15-25 minutes (Fig 5).
Endoret (PGRF) is used in three distinct forms. There is the clot (F2), into which autogenous bone collected during implant site preparation is added, and also xenograft in situations where more augmentation is required (Fig 6).
There is the fibrin membrane (F1), which is placed on top of F2 (Fig 7). This stimulates fibroblasts which accelerates wound closure and often creates thicker mucosal biotype.
The liquid form of Endoret (PRGF) is used to promote healing after ridge-splitting procedures, and to improve implant integration by up to 40 per cent when the implant surface is coated immediately before placement.
In this simple case, all three forms of Endoret (PRGF) were used to achieve a small lateral augmentation of the implant site, as well as promote osseointregration of the implant and wound closure by primary intention.
A number 15 scalpel was used to make a palatally inclined incision at the site of the missing upper right first premolar. This cut was extended mesially and distally around the adjacent teeth without relieving incisions.
A number 12 scalpel was then used to make a periosteal releasing incision in the pocket flap created being mindful of the proximity of the infra-orbital nerve.
After the creation of the pilot hole using a drill with irrigation at 1800rpm, the remainder of the osteotomy was created following a biological drilling protocol advocated by Professor Eduardo Anitua, Scientific Director of BTI Biotechnology Institute.
This involves preparation without irrigation at speeds of between 50 and 150 rpm. A high level of control can be maintained at these low speeds while biologically viable autogenous bone debris can be collected from the drill flutes, which is transferred to the F2 for later augmentation.
Immediately before implant placement, the selected implant’s entire surface was dipped in liquid Endoret (PRGF). The liquid was also injected into the osteotomy. Engine placement of the Implant then proceeded as per normal protocol.
Lateral augmentation was completed easily and safely without the need for a membrane and in this case, without xenograft either. The F2 clot containing the collected autogenous bone drill debris was first placed against the bone (Fig 8). In situations where more lost bone volume needs to be replaced, a second clot of F2 containing xenograft is layered on top of the autogenous layer. Finally, the F1 fibrin membrane was placed on top (Fig 9).
The wound was closed with three interrupted sutures, which were removed after four days (Fig 10).
The autologous nature of Endoret (PRGF) means it has many applications in dentistry beyond the simple implant case described here.
In the atrophic maxilla where residual bone height below the sinus is very low, Endoret (PRGF) in combination with short implants can be used in a transalveolar elevation approach to gain 2-3mm of additional bone height very safely. Such an approach is now being used widely to avoid more traditional and invasive methods such the lateral window technique.
In the field of oral surgery accelerated and improved healing has obvious benefits; for example, the avoidance of dry socket through socket preservation with Endoret (PRGF), and the treatment of bisphosphonate osteoradionecrosis where necrotic bone has been resected.
Combining Endoret (PRGF) with traditional guided bone regeneration procedures significantly reduces the incidence of wound dehiscence as well as eliminating the need for costly and technique sensitive collagen membranes. When mixed with xenografts such as Bio Oss, Endoret (PRGF) will attract the osteogenic cells necessary to promote true bone formation.
Backed up by more than 15 years of research, and with more than 700,000 patients treated from 20 countries without adverse effects being reported, the applications for Endoret (PRGF) in surgical dentistry are wide-ranging, predictable and safe.
Dr Jerome P Sullivan BDS, DipImpDent RCS (Eng), PG cert sed UCL qualified from Manchester University in 1993. He graduated with a diploma in dental implantology from the Royal College of Surgeons (UK) in 2011 and was awarded an inaugural gold medal for the high standard of his clinical cases. He has become increasingly involved in the field of platelet rich growth factor, and he now uses this technique to deliver implant solutions to patients with complex dental needs
For more information please contact Info@gracefielddental.ie
Periodontitis is a term that refers to a heterogeneous group of diseases characterised by loss of the tooth-supporting tissues. It is well established that periodontal diseases are of an infectious nature and the impact of dental plaque biofilms on the etiology of periodontal diseases has been studied in details. In fact, certain bacterial pathogens are considered to play a significant role in the pathogenesis of periodontitis, formation of the periodontal pocket, destruction of the connective tissue and resorption of the alveolar bone.
Therefore, the primary cause of periodontitis is bacteria, and when the quantitative and qualitative change in bacterial composition in the oral cavity is such that homeostasis cannot be maintained any longer, the host response appears to be impaired and the activity of the tissues become abnormal.
A publication from Hasturk et al. (2007) outstandingly defined the possible pathogenesis of the periodontal infections; in fact, Hasturk and co-workers suggested that while the etiology of periodontitis is bacteria, the pathogenesis is inflammatory.
In other words, the interaction between the pathogenic bacteria and the host’s defence system could lead to the development of an inflammatory process.
Once periodontitis is established, the inflammatory infiltration of periodontal tissues is composed of different immunological cell types. These cells produce a large repertoire of specific types of cytokines and chemokines, which could play a significant role in the pathogenesis of periodontitis. Some of these, together with the end products of periodontal tissue destruction, could act as possible biomarkers and eventually could have diagnostic value by identifying patients with enhanced disease susceptibility and sites with active disease. They could also serve as surrogate end points for the monitoring of the patient treatment effects and treatment status, to tailor the maintenance care based on the biological needs of the subjects.
These biological mediators could support the clinical measurements already used in the routine diagnosis of periodontal diseases such as probing pocket depth, bleeding on probing, clinical attachment levels, plaque index and radiographs quantifying alveolar bone level. Nevertheless, they are often of limited usefulness because they are indicators of previous periodontal disease rather than the present disease activity. In addition, current periodontal examination procedures performed at single visit cannot determine whether or not sites are currently undergoing additional attachment loss.
As various immunopathogenic mechanisms are involved in the disease process of periodontitis, a combination of indicators is needed to improve the specificity of periodontal disease diagnosis. On the basis of the current understanding of the complexity of periodontitis, the identification of one single diagnostic marker for all forms of periodontal disease seems illusionary.
Nevertheless, researchers have been searching actively for unequivocal markers of periodontitis in different biological sources such as blood or serum, subgingival plaque sample, gingival crevicular fluid (GCF) and saliva to develop a simple test, to be used as chairside test or home-use device, to determine whether a patient suffers from periodontitis and needs therapy, as opposed to another patient who needs no intervention even though he/she has gingivitis and/or to establish a “custom-made” frequency of recall appointments.
The aim of this literature review is to summarise data from the literature on periodontal disease markers with special focus on saliva.
Saliva is a mirror of the body that contains a large number of proteins and peptides that are responsible for maintaining the integrity of the oral cavity (see table opposite page).
Saliva also meets the demand for inexpensive and easy-to-use diagnostic aids due to the non-invasive and simple nature of its collection. It can be collected with or without stimulation. The collection of gland specific saliva (from parotid, submandibular and sublingual gland) can allow differences in the amount of fluid and constituents of each gland to be determined. Differently, whole saliva consists of a mixture of oral fluids, and includes secretions of the major and minor salivary glands and constituents of non-salivary origin, such as derivates from GCF, serum and blood cells in case of bleeding gingiva or oral wounds, and expectorated bronchial secretions. It might also contain bacteria, bacterial products, viruses, fungi, desquamated epithelial cells and food debris.
The use of saliva for diagnosis of periodontal disease activity has been the subject of considerable research activity; in fact, it contains locally and systemically derived markers of periodontitis, thus offering the basis for a specific test. Several potential markers have been investigated to produce an assay system suitable for use in dental practices.
The main candidates in the search for biomarkers of periodontal disease activity fall into different general categories:
Inflammatory and immune products
While the bacterial infection triggers the destructive process, the host immune response to the bacterial challenge is responsible for the molecular processes leading to periodontal tissue destruction. The interaction between the pathogenic bacteria and their (toxic) components and the host defence system could lead to the development of periodontal pockets, loss of connective tissue, and bone resorption. Once periodontitis is established, the inflammatory infiltration is composed of different cell types, such as neutrophils, T and B lymphocytes, and macrophages migrating into the perivascular connective tissue.
The substances released by the inflammatory immune cells as well as by resident fibroblasts endothelial cells and others during the disease process include a large repertoire of molecules, such as antibodies, complement proteins, acute phase proteins and a broad range of inflammatory mediators (i.e. cytokines, chemokines, arachidonic acid metabolites etc.).
A recent investigation found that salivary level of MIP-1α was significantly correlated with Aggregatibacter actinomycetemcomitans positive students who developed periodontal disease six to nine months before radiographic detection of bone loss. MIP-1α level was also significantly associated with increasing probing depth and the number of pockets > 6mm (Fine et al. 2009).
Non-enzymatic proteins have been examined in a number of studies to investigate whether or not there was a relation between periodontal disease and these proteins in saliva. For example, platelet-activating factor (PAF), a potent phospholipid inflammatory mediator, was identified in the mixed saliva of subjects with periodontal disease. Salivary PAF levels have been found to be significantly higher in untreated chronic periodontitis patients compared to controls (Garito et al. 1995). Its levels correlate with clinical indices of disease severity and extent of the disease. Furthermore, a longitudinal evaluation of the effect of periodontal therapy on salivary PAF levels in chronic adult periodontitis patients was studied and initial salivary PAF levels were found to be decreased following supragingival plaque control and further reduced following scaling and root planning (Rash et al. 1995).
Saliva contains also numerous enzymes that degrade proteins, proteoglycans, lipids and carbohydrates. Enzymes in saliva can originate from GCF, salivary glands, microorganisms, epithelial cells and polymorphonuclear leukocytes (PMNs). PMNs are an important cell type in host defense against periodontopathogenic bacteria. Their primary role of phagocytosis of microorganisms may promote local tissue destruction by the release of tissue-degrading enzymes. In fact, PMNs granules contain hydrolytic neutral enzymes, such as elestase, cathepsin B, cathepsin D, glucuronidase. Matrix metalloproteinases (MMPs), peroxidase, lysozyme, lactoferrin, and many other enzymes are also sheltered in PMNs granules. Some of these are now discussed below.
MMPs represent a neutrophil granule content, which are involved in many biological processes, including the tissue destruction in periodontitis. MMPs degrade mostly components of the extracellular matrix (ECM) and many non-ECM molecules. The major MMPs in neutrophils are MMP-8 and -9 and these are the main collagen-degrading enzymes in saliva. Since MMPs can potentially cause tissue damage, their activity is controlled by four members of the tissue inhibitor of metallo-proteinase family (TIMP). The presence of MMPs in saliva has been studied comprehensively with ELISA techniques. The levels of MMP-1, -3, -8 and -9 and their endogenous inhibitor, TIMP-1, in saliva of patients with adult periodontitis were compared to localised juvenile periodontitis and controls. Both MMP-1 and TIMP-1 were detected in all studied saliva samples, but interestingly no significant differences were detected between adult periodontitis and healthy control groups (Ingman et al. 1996).
PMNs and macrophages produce reactive oxygen species (ROS) within their phagolysosomes and these may spill over into the tissues during phagocytosis or when they degenerate. This may cause bystander tissue damage around these cells. ROS have a great capacity to damage cells and tissues and are scavenged for within the tissues by antioxidants.
The antioxidant capacity of saliva has been investigated in healthy and chronic periodontitis patients. The major aqueous antioxidant component of whole saliva was found to be uric acid with lesser contributions from ascorbic acid and albumin. Using biochemical methods, the antioxidant capacity of the saliva was not found to be compromised in chronic periodontitis patients, and this was attributed to increased salivary flow and antioxidant flow from GCF.
Another research group investigated pheripheral (serum) and local (saliva) total antioxidant (TAO) capacities of chronic periodontitis and healthy patients using an enhanced chemiluminescent assay (Chapple et al. 1997). There were no differences in the serum TAO capacities but the salivary TAO capacities were significantly lower in the chronic periodontitis group compared with the healthy group. Thus the saliva of chronic periodontitis patients may have reduced TAO capacity, which could result from increased ROS production by inflammatory cells. The enhanced chemiluminescent assay provides a rapid simple method of measuring the total antioxidant defense in small volumes of biological fluid and hence could have diagnostic use. More work on its relationship to the progression of periodontal disease, and its capacity as biomarker needs to be done before this could be properly assessed.
Another enzymatic category, which has received the attention of periodontal researchers, is represented by enzymes released by dead cells (cytosolic enzymes). Aspartate amino transferase (AST) and lactate dehydrogenase (LHD) are soluble cytoplasmic enzymes that are confined to the cell cytoplasmic enzymes, and they can be released by dead or dying cells. Since cell death is an integral and essential component of periodontal tissue destruction, these enzymes should be released during this process and should pass with the inflammatory exudates into GCF and saliva.
While we do not have relevant studies on AST in saliva, a recent report demonstrated an increased LDH salivary activity in association with periodontal disease, specifically with the presence of calculus and pockets greater than 5mm (de La Peña et al. 2007). Clearly these markers are yet to be further investigated for their potential as salivary biomarkers for periodontitis.
Of the potential markers, PMNs-derived enzymes appear to be worthy of further study. The concentrations of host-derived elastase, chitinase and -glucuronidase are increased in patients with periodontitis and decrease following therapy (Lamster et al. 2003).
However, at the present state of knowledge, their salivary levels are not predictive of disease activity, which is the basic requirement of a diagnostic test.
Dr Fabiano Galassi D.D.S. M.Sc. (ACTA) Periodontology and Implant Dentistry. Practice limited to periodontology and implant dentistry. He received his Dental Degree from “La Sapienza” University of Rome. After two years general practice, he moved to Dublin where he continued working as a general practitioner until 2008.
Dr Galassi graduated with Honours from the MSc programme in Periodontology and Implant Dentistry at the Academic Center for Dentistry in Amsterdam (ACTA), in 2011. Has great interest in dental research, and he has published in peer-reviewed journals and written some chapters for periodontology textbooks.
As a member of the European Federation of Periodontology (EFP) and the Italian Federation of Periodontology (SIdP) Dr Galassi is now working at the Seapoint Clinic and Gleville Dental and his focus is on the treatment of periodontal disease, bone regeneration, cosmetic periodontal plastic surgery and implant dentistry.
Chapple, I.L., Mason, G.I., Garner, I., Matthews, J.B., Thorpe, H.G., Maxwell, S.R., & Whitehead, T.P. (1997). Enhanced chemiluminescent assay for measuring the antioxidant capacity serum, saliva, and crevicular fluid. Annals of Clinical Biochemistry 34, 412-421.
Patients suitable to undergo conscious sedation (CS) include those with moderate-severe anxiety, a swallow/gag reflex or a mild learning/physical disability such as cerebral palsy. Well-controlled medical conditions such as asthma, epilepsy, gastro-oesophageal reflux and mild hypertension are exacerbated by stress, making CS hugely beneficial. 1
Hospital-based intravenous (IV) CS helps patients with severe systemic disease or disability to avoid unnecessary general anaesthesia (GA). However, a small percentage of patients will still simply not tolerate dental treatment without being ‘knocked out’, making GA essential to facilitate dental treatment.
An in-depth medical, dental and social history is mandatory at a visit before treatment. It is important to ascertain the patient’s degree of dental anxiety. This helps determine the most suitable sedation technique as some patients with severe needle phobia are unable to tolerate cannulation making inhalation sedation the best option for them.2
Age is not an absolute contraindication to sedation but older patients are more sensitive
to sedatives.4 The incidence of delirium following treatment with midazolam was 10 per cent higher in the elderly.5 Elderly patients also tend to have poorly tethered, friable veins, which may be more susceptible to cannulation damage. IV sedative agents in children <12 is not recommended unless provided by a paediatric specialist. Disinhibition in adolescents is common and even slight over-sedation can lead to rapidly deteriorating respiratory depression.6
There should be no elective surgery if the diastolic value is >110 mmHg. However, when measuring blood pressure always consider the risk of “white coat hypertension”.
Patients with controlled/uncontrolled hypertension have a more labile haemodynamic profile during CS making hypotensive swings more likely.7
It has been shown that there is little evidence that a BP < 180mmHg/110mmHg causes perioperative complications. However, a BP>180/110mmHg is linked to perioperative ischaemia, arrhythmias and cardiovascular lability. There is no clear evidence that deferring anesthesia lowers perioperative risk. The intraoperative BP should be within 20 per cent of best BP estimate.8
Dentists must evaluate pre-operatively for the presence of target organ damage such as coronary artery disease. Target organ damage lowers the treatment thresholds for raised BP.9
A study examining the cardiovascular effects of epinephrine with IV midazolam examined 75 patients with heart disease treated in two groups.The rate-pressure product (RPP) was used to indicate myocardial ischemia. This is the systolic BP x heart rate = RPP, which is a reliable indicator of myocardial oxygen consumption. Ischemic changes were demonstrated in patients with an RPP of >12,000, increasing their CS risk. The pressure rate quotient, which is mean BP divided by heart rate, also assesses a patient’s suitability for CS. The results of this study indicated that treatment with midazolam and epinephrine does not generate significant ischemic risk. It is important that the lowest effective dose of local anaesthetic containing epinephrine is used and that intravascular injections are avoided.10
ASA According to Blood Pressure (BP):
|<140 systolic and <90 diastolic||ASA I||Primary care suitable|
|140-160/90-94mmHg||ASA II||Primary care suitable|
|160-199/95-115mmHg||ASA III||Specialist unit|
|200 systolic and >115 diastolic||ASA IV||In-patient services|
1 No hindrance to normal physical exertion
2 Slight limitation, angina with fast walking, ascending stairs, excitement
3 Significant limitation of regular movement. Angina on climbing a normal staircase
4 Angina with minimal activity/rest.
Increased stress levels exacerbate angina, making sedation and good local anaesthesia important in reducing heart rate. Unstable angina contraindicates elective treatment. Patients with angina that affects normal daily activity such as NYHA 3 are unsuitable for sedation in primary care. If the GP/cardiologist confirms stability of angina then NYHA 2 patients can progress with elective sedation.11
At six months post-infarctiona patient is classed as ASA 3. The risk of re-infarction is 16 per cent. Elective sedation in well-controlled patients reduces stress, helping to lower risk.
Patients must wait three months after stenting before elective sedation. Angina must always be successfully controlled before treatment.1
Patients with benign palpitations benefit from the stress reduction produced by CS. A patient with malignant palpitations, however, must be treated in hospital. Any individual with an automated implantable cardioverter-defibrillator is unsuitable for treatment in primary care. A hospital setting is mandatory for patients with a pacemaker or those following AV node/conduction pathway ablation surgery. Wolff-Parkinson-White syndrome is an absolute contraindication to sedation.1
Midazolam has a greater effect on the respiratory system compared to the cardiovascular system. Healthy patients who present with respiratory infections on the day of treatment should be rescheduled. Careful assessment of the patient’s disease and functional reserve will indicate the most suitable setting for CS. It must be remembered that opioids act synergistically with sedation with regards to respiratory depression.12
1 Mild dyspnoea
2 Moderate – limited outdoor movement – hospital management safest
3 Marked dyspnoea on minimal exertion indoors – unsuitable for outpatient sedation
4 Dyspnoea while resting – unsuitable for outpatient sedation.
The dentist must ensure the asthmatic is well controlled. A mild asthmatic is considered ASA 2; however, an untreated Grade 2 is unsuitable for treatment in primary care. Hospital management is necessary for ASA 3 patients who have frequent episodes/attacks. It must be borne in mind that theophylline can interact unfavourably with IV midazolam. Inhalation sedation can be a safer option due to guaranteed oxygen levels.13
Extreme caution is needed with COPD patients who suffer with emphysema or bronchitis. A patient with chronic bronchitis is ASA 3. Midazolam results in dose-related respiratory depression, which is more exaggerated in COPD patients. Hospital treatment of the patient in an upright position with supplemental oxygen is required due to the increased risk of hypoxia.
If a patient needs supplemental oxygen at home or has severe orthopnoea or a productive cough then sedation is contraindicated.12
Hepatic microsomal oxidation is responsible for midazolam’s biotransformation. This is susceptible to factors such as old age, hepatic cirrhosis and drugs (cimetidine) as they reduce the oxidative capacity. A high regular intake of alcohol increases midazolam clearance.
Renal failure causes a build-up of metabolites which prolongs sedation. CS is contraindicated in cases of advanced liver disease.1
Patients undergoing haemodialysis or continuous ambulatory peritoneal dialysis are unsuitable for sedation.
Haemodialysis patients swing from being centrally underfilled where they are at risk of hypotension to centrally overfilled. Day 2 is considered the safest time to treat but outpatient CS is still best avoided. Post-renal transplant patients with good renal function may be suitable for hospital-based CS.11
Methadone and midazolam are both metabolised by the cytochrome P450 3A pathway. Chronic methadone use leads to the induction of this pathway with more rapid midazolam metabolism and higher dosage requirements.14
IV midazolam helps to reduce involuntary movement in patients with multiple sclerosis and Parkinson’s disease making dental treatment more comfortable. Many patients will have reduced swallowing capacity so sitting the patient upright with adequate suction is vital. Controlled epileptics are suitable for CS although more research is needed to develop clearer guidelines. Liaising with the GP/neurologist confirms if the patient has a driving licence and when the last three seizures occurred. Anti-epileptic drugs such as phenytoin can increase or decrease plasma concentration of sedatives.11
Recovered stroke victims may experience a re-emergence of symptoms when benzodiazepines are administered. Light sedation can trigger a re-occurrence of symptoms such as right-sided paralysis and dysphasia. Sedation is contraindicated for one year after a stroke.15
Sedation should be avoided in patients with sickle cell anaemia and thalassaemia. This cohort are high risk for reduced oxygen tension with respiratory depression or over-sedation. Inhalation sedation is preferred.16
The second trimester is the safest time to treat, but the mother’s metabolism is altered due to the increased demands of the baby. This makes sedation unpredictable. There are also foetal teratogenic risks.12
Patients with mild learning disabilities are suitable for sedation. Severe learning or physical difficulties require management by an anaesthetist-led team.17
HbA1c helps identify pre-diabetic patients. It also helps recognise diabetics at risk of complications. A BM check of >5mmol/l pre-treatment is advisable.18
Pre-operative starvation can upset blood sugar levels. The evidence for fasting is low so a degree of clinical judgement required.19 Well-controlled diabetics are best treated in the morning to avoid interference with their insulin routine. Poorly controlled diabetics requires hospital management. Inhalation sedation can be a safer option as it is easily reversible.16
Patients on long-term steroids must be treated in an anaesthetist-led facility to avoid an adrenal crisis.13
Hyperthyroidism can cause tachycardia and atrial fibrillation. Hypothyroidism can cause bradycardia, making CS unpredictable.12
Cardiac medication: Ace inhibitors, beta blockers, calcium channel blockers and nitrates enhance the hypotensive effect of midazolam20
Erythromycin effects metabolism of midazolam21
Midazolam interacts with herbal medicine potentiating CNS depression22
Opioids such as heroin can cause significant respiratory depression with midazolam. Veins are often unusable1
Cocaine adversely effects respiratory/cardiovascular control with sedation1
Cannabis makes oxygen saturation levels unpredictable during sedation1
Central nervous system depressants for mental health conditions can act synergistically with benzodiazepines. Tolerance may have developed in these patients similar to recreational drug users.20
Blood pressure, oxygen saturation, BMI, heart and respiratory rate must provide a satisfactory baseline indicating fitness for sedation. Sometimes a screening may reveal an unknown condition requiring further investigation by a GP before sedation can be performed.16 It is important to predict a patient’s risk for conscious sedation. Hospital-based sedation is advisable in the following instances:
Patients with a history of more than one attempt for previous intubation.23
A patient with a BMI of <35kg/m2 is suitable for primary care CS. Caution is advised with a BMI of 35-40kg/m2 especially if the patient has co-morbidities such as hypertension and diabetes.
The standard dental chair has an upper weight limit of 140kg making referral to hospital sometimes necessary for the use of a DIACO chair which can hold 500kg. Successful cannulation can be difficult due to the effects of increased adipose tissue on vein morphology.24
Sleep apnoea is more common in individuals with a BMI of >35. Sedation is an absolute contraindication in patients with obstructive sleep apnoea(OSA). The pharyngeal airway dilator muscles are highly sensitive to benzodiazepines.25 The STOP-BANG questionnaire is a useful screening tool for identifying potential cases of OSA.26
This is a visual assessment of the distance from the base of the tongue to the soft palate. A Class 3 or 4 patient is at increased risk of airway obstruction. The patient must be asked to protrude their tongue. It is important to document the level of visibility of the back of the mouth.27
A difficult airway can also be judged if the thyromental distance is <6.5cm. A short, fat neck and receding jaw is an airway risk. Males are more susceptible to airway obstruction.28
IS can be used from the age of three. 29 Patients who are allergic to benzodiazepines or those tolerant to them due to treatment for anxiety/insomnia are suitable for IS. In patients previously addicted to benzodiazepines IV, CS can reactivate dependence making inhalation sedation safer.30
IV sedation suits mouth-breathers, anyone taking methotrexate due to the anti-folate effects of IS and also someone who had vitreoretinal surgery within 12 weeks. Severe autism or ADHD patients are unsuitable for IS due to compliance difficulties. A hearing impediment reduces the hypnotic suggestion aspect of IS treatment making CS more effective.16
If titratable techniques are deemed inappropriate then oral or intranasal sedation may be considered. Special care dental patients with challenging behaviour benefit greatly from these advanced techniques.31
A treatment plan is devised by combining the information gathered during history-taking and the clinical exam. The patient must be of sound mind to give their valid written consent at a visit separate to treatment. If needed, the presence of a responsible adult escort must be possible.32 Careful consideration regarding the nature of the patient’s disease and functional capacity is essential. The dentist has a duty of care to predict patients at risk of complications with CS such as cardiac, respiratory or neurological deterioration. After risk stratification, the optimum timing and setting for treatment must be decided to ensure patient safety.
There will always be a place in dentistry for general anaesthesia, especially for treatment plans involving extensive work on multiple teeth that make multiple sedation visits impractical and overall more expensive. Also in certain sedation cases, patients can move unpredictably, compromising the quality of the dentistry performed, which may necessitate the use of general anaesthesia.
Dr Laura Fee graduated with an honours degree in dentistry from Trinity College, Dublin, where she was awarded the Costello medal for undergraduate research on cross-infection control procedures. She is a member of the Faculty of Dentistry at the Royal College of Surgeons. She has a Certificate in Implant Dentistry from Northumberland Institute of Oral Medicine and has been awarded the Diploma in Implant Dentistry with the Royal College of Surgeons Edinburgh.
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