QUESTION: Is Cosmetic Dentistry Evidence-Based?
In the 1970s and early 1980s, the widespread “cosmetic revolution” in dentistry began with the introduction and development of new materials and techniques that allowed for simpler and more predictable cosmetic dental procedures. In the late 1980s and 1990s, cosmetic dentistry truly blossomed. Public awareness and desire for elective cosmetic dentistry was increasing, a whole new and improved generation of adhesives and tooth-colored materials were introduced, and dentists began marketing cosmetic dentistry as never before. It seemed that all clinicians suddenly became “cosmetic dentists.” The initial euphoria and mystique surrounding cosmetic dentistry, as well as the lucrative profits it afforded, led many clinicians to perform cosmetic procedures using techniques and materials with little or no evidence-based support. Sometimes these procedures worked and sometimes they did not. In effect, many of these materials and techniques were being tested on our patients, and still are today. This is not entirely the dentists’ fault. Dental manufacturers are introducing new adhesives, porcelains, composites, whitening agents, and other cosmetically oriented materials at such a prolific rate that research simply cannot keep up. It is not uncommon for researchers to present data on materials that no longer exist or are replaced by “newer and improved” versions of those same materials by the time the research is published. The fact is many of the materials and techniques dentists use for cosmetic procedures have no long-term clinical track record simply because they have not been around long enough to have established one. While these materials and techniques may demonstrate initial success, they should not be classified as evidence-based until they demonstrate long-term predictability. Certainly there are cosmetic procedures and materials that meet both the clinical and scientific requirements to be classified as evidence-based. It is up to individual clinicians to objectively examine their own clinical successes and failures, read the literature and research, and attend reputable CE programs, in order to make evidence-based treatment choices for their patients.
From its inception in the 1990s, this popular buzz phrase has caused excitement for some researchers and academicians and frustration for numerous clinicians. One of the leaders who initiated the concept of “evidence-based medicine,” Canadian David Sackett, MD, stated that “...(EBM) is the conscientious, explicit and judicious use of best evidence in making decisions about the care of individual patients. The practice of EBM means integrating individual clinical experience with the best available clinical evidence from systematic research.” (BMJ. 1996;312:71-72). As the phrase “evidence-based dentistry” evolved, many eagerly reacted to it as though we never had any evidence before. Evidence-based journals started, conferences were conducted, and the phrase began to permeate books and articles. In my considered opinion, American dentistry has somewhat misinterpreted the concept. Sackett and others stated that neither available external evidence (research) nor individual clinical experience (observation) alone is enough. Both must be present. In my opinion, we have deviated from that interpretation, looking primarily at the science only.
I have observed many examples when the scientific evidence was proven to be diametrically opposed to the real-world observations after a period of clinical use. Both scientific evidence and clinical observation must be present and those individuals involved in each area must mutually respect one another.
So yes, most phases of cosmetic/esthetic dentistry are evidence-based if the original definitions are considered. There are hundreds of research and clinical observation articles on all areas of cosmetic dentistry. Conscientious clinicians should use resources such as Google Scholar, PubMed, Cochrane Collaboration, and others to find the scientific information, blend it with their own clinical observations, and only then make a truly “evidence-based” decision.
I recently attended the ADA Evidence-Based Champions Program in Chicago. I like to think, as we all do, that I base my clinical decisions on evidence. After the conference, I realized that I had room for improvement.
The problem is that many dentists do not understand what evidence-based dentistry really is. They tend to think of it as something used by insurance companies to limit their reimbursement. The ADA EBD website states that EBD is based on three important domains: the best available scientific evidence, a dentist’s clinical skill and judgment, and each individual patient’s needs and preferences. I agree with that statement. Evidence is what we use to inform our diagnoses and treatment plan, but not to decide a specific course of treatment. We also need to factor in our own clinical judgment as well as our patient’s needs. If we think about the three domains as overlapping circles, then EBD is right in the center where all three circles overlap.
Many articles suggest a simple approach to addressing a clinical question: (1) ask an evidence-based question; (2) search MEDLINE and/or the ADA website for the best evidence; (3) critically appraise the evidence; and (4) apply the evidence to the patient. When evaluating the best evidence, it is important that articles be limited to human and randomized controlled trials (RCTs) when possible. When RCTs are not available, we can turn to case-controlled studies, case reports, expert opinion, or bench studies, in that order.
Many dentists base their cosmetic decisions on expert opinion and/or peer feedback. This is valuable if, along with it, the above-mentioned approaches are included. My hope is that the “experts” are at least making an effort to base their recommendations on evidence and not just personal preference or limited feedback from other clinicians. Over the years, we have experienced major failures in cosmetic materials and techniques. These include composite to metal crowns; fiber-reinforced bridges; cast-ceramic posts; and esthetic ceramic bridge material, to name a few. If we had taken a more EBD approach to these cosmetic procedures we would have saved a lot of time, effort, money, and inconvenience to our patients.
About the Authors
Gary Alex, DMD
Long Island Center for Dental Esthetics and Occlusion
Gordon J. Christensen DDS, MSD, PhD
Founder and Director of Practical Clinical Courses (PCC) and Senior Consultant for Clinicians Report(CR).
Gerard Kugel, DMD, MS, PhD
Associate Dean for Research
Tufts University School of Dental Medicine.