Change the way you look at things

22 April, 2011 / Infocus

Since qualifying nearly 15 years ago I have taken a somewhat atypical professional pathway. After qualifying I took up an oral surgery house job, however, this was destined to be a short appointment as I had already been awarded an Action Research (now Action Medical Research) Training Fellowship to pursue my PhD. The following five years were spent at Harvard Medical School investigating craniofacial and skeletal development.

On completing my PhD I returned from the United States to take up a position at Manchester University as a lecturer in biosciences. During this time I ran a small research group and taught undergraduate and postgraduate students. While immersed in a non-clinical academic setting I began to yearn for a return to clinical practice. I took the plunge and so began the next chapter.

The return to clinical practice was extremely exciting and, with the support of the practice owner, this transition was readily made. I was surrounded by a great team; the principal was involved in implant dentistry and another associate was developing an interest in periodontics. Both had previously been on one of Paul Tipton’s courses and both had returned full of enthusiasm and new-found skills. I enrolled on the year-long restorative course.

I must say it changed the way I viewed what I do day-to-day. One of the course components was a day of endodontics. Gary Zolty was the endodontist and he was so passionate about his subject that he opened my eyes to this exciting and challenging discipline. I started to look for postgraduate courses in endodontics and in 2006 I started the simplyendo endodontic coaching programme led by Mike Horrocks.

During this time I developed a greater understanding of the biology of endodontic disease and explored contemporary endodontic techniques. In collaboration with Chester University, Mike has developed a Masters Programme in Endodontology. To date I have completed the Post-graduate Diploma in Endodontology. Mike has been an inspiration; his commitment to endodontic practice and teaching is unfaltering.

I had started offering in-house endodontic referral services while practising in England and this continued after moving to Scotland. I now offer endodontic referral services to all. This includes all aspects of endodontics from first-time treatments to retreatment – including management of cases with complex anatomy, sclerosed canals, open apices, resorptive defects and removal of fractured posts and separated instruments.

We are all aware of the ever-increasing provision of implant restorations and, in the appropriate clinical situation, these are the gold standard for replacing missing teeth. It is, however, very important to recognise that the retention of a restorable tooth is still the ideal. In fact, with a large number of patients receiving bisphosphonate therapy and the concomitant risk of bisphosphonate-related osteonecrosis of the jaw, retaining borderline restorable teeth can be considered favourable1. Treatment outcome studies clearly show that success rates of good quality endodontic therapy can equate to that of implant restorations2.

I recognise that retention of a tooth may not be the right choice for all patients for reasons of, for example, finance or health but what I always discuss with patients is that dental treatment is a journey, each step taking a finite time, this may be five or 15 years but each appropriate intervention delays progression to the next step with the ultimate aim of retaining natural teeth for as long as possible. However, it must be remembered that even the treatments following tooth loss have a finite lifespan and this includes implants.

Having spent much of my practising life in both NHS and private general practice, I am acutely aware of the demands that are placed upon us. We all want to provide the best level of care for our patients and ensure predictability of the treatments we offer. The diagnosis and management of endondontic pathologies are among the most challenging.

Despite a myriad of treatment systems proclaiming to be the answer to all of our endodontic needs, canal preparation and obturation in complex cases is technically demanding. When asked, Rupert Hoppenbrouwers, Head of the DDU reported that in 2008 (the most recent year for which figures have been published) endodontics represented around 19 per cent of dental claims. Endodontics also represents an increasing proportion of the claims settled by the DDU on behalf of members in recent years.

How do we make our endodontics as predictable as possible? Despite recent advances in endodontics, especially in preparation with the introduction of nickel-titanium rotary instruments, we still fall down if we cannot see what we are doing. The importance of magnification became apparent very early on in my endodontic training. The dental operating microscope (DOM) offers an unrivalled view.

The DOM, in its first incarnation, was introduced nearly 30 years ago. However, it was not widely accepted due to ease of use issues. It was nearly a decade later that Gary Carr developed a DOM for endodontic use that overcame the limitations of the early DOM3. I am sure as you read this you are thinking how one could justify the cost of a DOM. Surprisingly, it is possible to find used examples of great quality or entry level new models for only a few thousand pounds more than a set of good quality loupes. It is not a huge stretch and after just a few days of use you will soon wonder how you worked without it.

The use of the DOM in conjunction with ultrasonics and micro-endodontic instruments has revolutionised the provision of endodontic therapy. In general, magnification can be set between 4x and 24x. Due to the use of a coaxial radiating light source, shadow-free lighting is produced. The enhanced magnification and illumination allows the operator to: diagnose micro fractures and vertical fractures; gain access to the pulp chamber with greater predictability; identify and remove pulp stones and negotiate obstructions due to canal calcification.

It is possible to identify and explore anatomy that would otherwise be missed. Just a few things to consider – 93 per cent of upper first molars have a MB24, 60 per cent of upper second molars have a MB24, up to 15 per cent of lower first molars have a mid-mesial5. I used to joke about using the force to identify canals (too much Star Wars as a child); with magnification the force is strong. Obviously an understanding of anatomy is essential, but the operator can be guided by the simplest of things – a few bubbles in the irrigant solution or a colour change in tooth substance.

The transition to microscopic endo- dontics was definitely eased by years of sitting behind microscopes in my exploration of developmental systems. In general it does take time to get used to using a DOM; treatment tends to be slower initially but, after time, one does become more efficient. I use the DOM from examination/diagnosis to completion of treatment. I sometimes return home from a day on the DOM and when I sit down with the family for dinner feel that everything on the plate seems just a little small!

It is at this point I should also highlight another massive advantage of using the scope – through improved working posture the physical impact of a day in the surgery is much reduced.

The DOM allows treatment of previously unsalvageable situations – perforation repair, retrieval of separated instruments and fractured posts. So often you are amazed at what you can see and therefore achieve. I still remember the first time I looked down to the apex of a straight root canal. It is this ability that makes the manipulation of mineral trioxide aggregate in apexification so predictable.

Just today I saw a patient who had been referred to me for removal of a separated instrument. Radiographically it was evident that the in
strument had separated in the apical third of the DB canal of an upper first molar. The canal system had been obturated up to the fragment but latterly the tooth had become symptomatic. Retrieval of instruments in this portion of the canal can be challenging.

Upon access and removal of the gutta percha it became apparent that the DB canal was curved but I could visualise the top of the instrument at the point of curvature. With patience, hand files and the use of ultrasonics the fragment was retrieved. This would have been impossible without the use of the DOM. The use of this level of magnification allows the operator to perform the task with minimal collateral damage. The more tooth preserved the better the long-term prognosis.

It is a difficult to convey in writing how much the DOM has changed my practising life. It allows complete immersion in the process. A few cubic millimetres of space fills my field of view for the time I am working on a tooth. With another reference to science fiction it is my own ‘Innerspace’.

Dr William McLean works at Care Dental Focus in Crieff. He is happy to partner with other practitioners by providing a timely referral service for their patients. For referrals, please emailor call 01764 655745.

If you would like to comment on this article you can contact William at

To see the clinical photographs from this article click here.


1. Kyrgidis A, Arora A, Lyroudia K, Antoniades K. Root canal therapy for the prevention of osteonecrosis of the jaws: an evidence-based clinical update. Aust Endod J. 2010 Dec;36(3):130-3.

2. Hannahan JP, Eleazer PD. Comparison of success of implants versus endodontically treated teeth. J Endod. 2008 Nov;34(11):1302-5.

3. Castellucci A. Magnification in endodontics: the use of the operating microscope for micro-endodontics. Endodontic Practice. 2003 Sept: 29-36.

4. Stropko JJ. Canal morphology of maxillary molars: clinical observations of canal configurations. J Endod. 1999 Jun;25(6):446-50.

5. Baugh D, Wallace J. Middle mesial canal of the mandibular first molar: a case report and literature review. J Endod. 2004 Mar;30(3):185-6.

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