Transitional Dentistry-A collection of presentations to the New Zealand Hospital and Community Dentists Society, Briefing paper to the Minister of Health on Oral Grooming, and some reflections on Hospital Dentistry 1999-2003

Kevin Scally

For a number of years I have been involved in Hospital Dentistry as a clinician, teacher, researcher, and inventor. As those years went by in this hospital environment I became increasingly disenchanted with the failure of the traditional drill, fill, and bill approach for many patients being treated in this system. This was especially so for patients with chronic medical conditions. These ranged from patients with graft verses host disease, Sjogren’s Syndrome, idiopathic high caries, refractory periodontal disease, and patients with idiopathic erosion, to name just a few.

As a management strategy I changed my approach to their care about ten years ago and began using glass ionomer cement (GIC) in what ever form that was available at the time, while trying to get to the bottom of their disease: investigation of saliva quality, buffering capacity, searching for a range of investigative tools to see if there was any logical explanation for their high disease rate. For example, some multiple sclerosis patients developed rapid decay and periodontal disease in spite of what seemed to be adequate oral hygiene and copious applications of fluoride varnish. That is still a mystery (although there are a number of hypotheses I have put forward to explain why. As yet they remain untested).

I was supported in my approach by Professor Martin Ferguson who was a visiting Oral Physician to the hospital dental clinic. About the time a number of us were noticing that, even if the glass ionomer cement restorations fell out, the teeth remained sound. The explanation that has been suggested: the remineralising potential of GIC, and that it releases fluoride.

For the at-risk decay patient we could stabilize the situation with very little clinical time and feel confident that we could offer a better level of care using this approach and manage to salvage a significant number of teeth. Along with the precision plastic partial dentures I had developed, (based on the Every plastic partial denture design) patients could transition through to full dentures over a number of years.

At various meetings of the Hospital Dental Surgeons Association a small group of us would talk about the even more adventurous uses of GIC. I started using “GIC bandages” preemptively about root services for oncology patients, and other patients with xerostomic disorders. I developed simple matrices with celluloid crown forms to do quick build-ups of at risk teeth and severely eroded teeth.

During that time the materials improved and Graham Mount and Hien Ngo visited New Zealand presenting lectures on new approaches to dental care and the role of GICs. It was after one of the early lectures by Graham Mount that I started thinking about using colored markers to indicate the condition of the treated tooth. Carisolv appeared on the market and a new method of decay management was at our disposal (even if I could not convince the institution to buy it).

My experience in Vietnam in the early 70’s and subsequent years in Australia in private practice exposed me to a range of ethnic dental practices that were at odds with the teaching I had had. Some of these seemed to be successful: the precast crowns for example. The influx of refugees into New Zealand in the late 90’s, likewise introduced me to a wide range of prosthetic practices that most dentists denigrated. I wondered if some of these approaches could be adapted to patients on low incomes or for patients that needed stabilization before proceeding with a definitive treatment plan.

That brought me back to having a look a why we did what we did and the rationale behind it. The first paper in the series (1999): “The Whys of Dentistry: Zen and the Art of Oral Care – a medical management model of dental disease” laid out the grand plan. It got comment from the converted but was largely ignored. I pushed GIC as an alternative to amalgam and composite in the first phase of treatment. This has become my model of care in both private general and specialist dental practice.

The problem is there is a prejudice to GIC – they are generally considered temporary restorations. I wondered if there was some way of marking the restoration to indicate that it was an intermediate or transitional restoration (in the 1970’s colored reinforced zinc oxide and eugenol was used) then some of that prejudice would be reduced and the dentist would know what had happened to the tooth and what was underneath the GIC. The next challenge was how to colour the GIC.

My research work and thinking on human evolution, on how human teeth work, in paleoanthropology, and comparative dentistry has taught me a lot about the life cycles of dentitions in a wide variety of creatures; and, like Begg’s work in orthodontics where he used his research on the interproximal tooth wear and the reduction of the dental arch length in Australian aboriginal gather-hunters as a justification for premolar removal, I came to the conclusion that 32 teeth in a contemporary human was more like a 200% dentition when compared with an adult hunter gatherer dentition. As adults we have a significant excess of enamel and dentine. For many individuals the maintenance of this volume of tooth tissue is a liability. This view complements the WHO goal of 20 teeth for life, the Japanese goal of 20 teeth at the age of 80, and the Dutch arguments for a reduced dental arch as a model and public health goal for oral health. This position would give oral health care planners in Public Health a good basis on which to allocate oral health dollars: fund the maintenance of a 24 or 20 tooth dentition. My approach is now the planned extraction of second and third molars if they are severely compromised, and then allocate the resources that would have been used to maintain them to the remaining dentition. If the first molars are also severely compromised then extracting them is my recommended treatment for patients with high decay and periodontal oral debt.

This pragmatic approach is set against the prevailing mantra of “teeth for life”, and a focus of most graduates in the western world for the last thirty years. It is not likely to be embraced in a hurry.

At the Hospital and Community Dental Society’s meeting in 2000 in “Transitional Dentistry: trailblazing into the new millennium” I introduced the idea of using Silver Ketac cylinders as a method of putting a mark into the restoration and this started my investigation into symbology in a quest to find out what shapes to use. I was using the symbol set from “Corel Draw” (a computer drawing program), as this was the program the laser cutter used to cut the dies. While the symbols in this program showed promise, the resolution at the small point size was not good enough – but it was a start and I was able to get some clinical experience with the system. The symbols were easy to make and place, and they stayed in the GIC restoration.

After that conference I did some serious research into the history of symbols in general and the development of written languages in various cultures. After a number of dead ends I settled on, what now seems to be, a simple symbol set. These were presented at the Society’s meeting in 2001 as “There were runes all about us, signs, and symbols – we did not understand them: transitional dentistry continued”.

There was another idea embedded in my model and approach to oral health, the idea of oral grooming. This was presented in 2002 as “I’ve been thinking, For a very long time: A model for oral health care delivery based on recent developments in dental materials, breakthroughs in the etiology of dental decay and periodontal disease, and ideas from evolutionary biology, sociobiology, evolutionary psychology, behavioral psychology, and a few other ideas tossed in for good measure.A recipe for change.”

This presentation introduced a wider idea of a societal model of oral health care, an approach where professionals, other than dentists and dental therapists, would polish teeth – a bit like a hairdresser. A similar auxiliary could be used to debride the carious lesion with materials like “Carisolv”, under the supervision of a dentist or dental therapist. While promoting this idea, legislation currently being introduced in New Zealand will make this class of worker illegal, since what I propose they would do is considered “dentistry” and only allowed in the scope of practice of dentists, dental therapists, and dental hygienists.

With the evolutionary, social, and pragmatic arguments in place for an different base or understanding of oral care, the next development of Transitional Dentistry will be in transitional endodontics, implants, crowns, fixed prostheses, removable prosthodontics. During my Fellowship year in 2002, with Canterbury Health Board, I continued my research into what I started calling Trancultural Dentistry looking for clinical practices that could be grafted into Transitional dental practice model.

But apart from simple and cost effective treatments to manage the decay there has been a rapid development in oral physiology and oral medicine that suggests that an Oral Medicine approach to oral health care would yield better public health outcomes. In the area of oral medicine the development of salivary substitutes, and the pharmacological management of xerostomia, gastric reflux, and some national policy on the modification and control of the beverage industry marketing low pH beverages, there will be inroads into the management of decalcifying gradients in the oral cavity of susceptible individuals.

During my career in dentistry to date I have been at the forefront of a number of developments in dental understanding and clinical practice. The first of these is my work on thegosis. All of my career has been devoted to progressing understanding in tooth wear and the biological underpinning of tooth form, function, behaviour, and evolution within the framework developed by Dr Ronald G Every (thegotics). In spite of a significant body of literature and argument over four decades, both for the basic science and the clinical application of his insights, there has been almost no impact of this work in every day clinical practice. In the meantime, I have seen models of care that have no scientific merit gain popularity with significant iatrogenic consequences to the patients treated within those models. Understanding why dentists and other health professionals are so susceptible to non-testable hypotheses and resistant to evidence based treatment and diagnosis is a major impediment to the health professions advancing. This is a research project in itself, but I feel that in our training there is not enough time given to training in the scientific method, evolutionary biology, and a consideration that some of our contemporary way of life is at odds with our basic biology as social primates and gather hunters.

The second area in which I see myself as being part of the vanguard has been in the development of transitional dental treatments, and in bringing understanding from socio-biology into clinical practice (Oral Grooming and Oral Care of the Terminally Ill Patient ). I have been excited by the possibilities of new understandings of dental decay and periodontal disease, but at the same time dismayed at the dogma driven surgical approach to oral health care as currently practiced. What is really very simple seems almost impossible to absorb itself into every day dental practice. The challenge to dentistry and other professions is how institute changes based on evidence and understanding into everyday clinical practice.

The work of Dr John McIntyre, Graham Mount, Hein Ngo, and Professor Larry Walsh in Australia is making inroads into a medical management model of oral health care that will transform the profession. They are being successful in instituting change into everyday clinical practice.

Graduates will approach oral health care as physicians first and as surgeons secondly. Even with these changes in practice and approach, oral health care delivery will simply not meet the demand for treatment in the short term, even with vaccines, and remineralising system, and other preventive measures in place. To cope in a timely fashion with the oral health needs worldwide, there will need to be revolution in the diagnosis and treatment of oral disease, and more cost effective clinical delivery systems. National benchmarks of what treatments will be funded in the public system and the reasoning behind them will need to be clearly stated so pragmatic levels of care can be defined.

Many people have encouraged me to pursue my thinking about the current oral health situation. I am very grateful to Professors Ake Zillen and Clive Wright, Drs Graham Mount, Hein Ngo, John McIntyre and Peter Dennison for their willingness to entertain my arguments and give timely advise and comment.