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MyView: OMG: What is EBD?

February 06, 2012

By John Thompson, D.M.D.

Here we go again. The ADA has another set of acronyms that are supposedly meaningful to a practicing dentist. For some reason, the ADA keeps sending me surveys to take online. I think I have been identified as obsessive-compulsive (OCD) and they know I will most likely respond to the survey if it is not too long. Yesterday I received an email requesting that I complete an online survey on "evidence-based dentistry." Well, I've been practicing dentistry for 40 years and one of my favorite lines that I drop on my staff when we change procedures or materials is "studies show," therefore: I know all about evidence-based dentistry.

If you can "flunk" a survey, I did! What is a meta-analysis? What is the EBD Champions Conference? Have you visited the online ADA Center for Evidence-Based Dentistry? Why should I?

Today my JADA arrived with a cover story, "Exploring the Effectiveness of Articaine and Lidocaine as Pulpal Anesthetics." I immediately know I am going to read this "studies show" article. The editorial by Dr. Michael Glick, "Justifying Changes in Clinical Practice," was the first thing I read and the dots began to connect. Dr. Glick wrote, "A baffling but interesting trend has emerged in medicine and other scientific fields whereby outcomes from studies performed years ago no longer can be replicated. This phenomenon has called into question, not only the validity of available evidence, but also the prevailing scientific method, which is grounded on the reproducibility of study results. Some of the most revered doctrines in dentistry—G. V. Black's principle of extension for prevention, for example—have been supplanted by the introduction of new materials, techniques and novel methodologies for evaluating clinical outcomes." If you can no longer trust the principles of Dr. Black, who can you trust?

Dr. Glick goes on to say, "Unquestionably, clinical practice should be supported with the best available evidence...There are several sources professionals can draw upon for evidence-based information regarding oral health care, including the ADA's own website on evidence-based dentistry (EBD)." I think he just answered yesterday's question of "Why should I?" While reading the cover story, "The Pulpal Anesthetic Efficacy of Articaine Versus Lidocaine in Dentistry," I see that the subtitle is "A Meta-Analysis." I did not know what it was yesterday and now I am going to find out by Googling the term in Wikipedia:

"In statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. In its simplest form, this is normally by identification of a common measure of effect size, for which a weighted average might be the output of a meta-analysis. Here the weighting might be related to sample sizes within the individual studies. More generally there are other differences between the studies that need to be allowed for, but the general aim of a meta-analysis is to more powerfully estimate the true 'effect size' as opposed to a smaller 'effect size' derived in a single study under a given single set of assumptions and conditions."

Now I think I know what I am about to read and how to value the final paragraph on implications for practice. The bottom line was that I had just read an unbiased review of validated studies from multiple resources that provided a logical conclusion that would affect the purchase of local anesthetics for our practice.

The dental literature is rife with advertising that allows manufacturers to make certain claims based on limited or flawed studies. I began to look through a number of throw-away publications that come across my desk on a daily basis and observed that the claims for one-step bonding systems were very attractive. The question was, "How accurate are the claims being made?" I decided to test the ADA's EBD website for an answer.

For me, the test of bond strength to dentin is the class five composite restorations in the esthetic zone. Therefore I went to EBD and under systematic reviews/restorative dentistry/materials, the first reference I found was, "Clinical Performance of Cervical Restorations—A Meta-Analysis" from Dental Materials 2010:26. The abstract was easy to read and cut straight to the chase with a closing that provided this very pertinent information:

"SIGNIFICANCE: The clinical performance of cervical restorations is significantly influenced by the type of adhesive system used and/or the adhesive class to which the system belonged and whether the dentin/enamel is prepared or not. 2-Step self-etching- and 3-step etch&rinse systems shall be chosen over 1-step self-etching systems and glass ionomer derivates. The dentin (and enamel) surface shall be roughened before placement of the restoration."

Since I agree with this statement, I am very impressed with this resource from the ADA that provides relevant clinical research data in a usable and easy to access format. What if I did not agree with the conclusion of the ADA's EBD research? When I consider what I just read, I see "shall" used two times in this three-sentence paragraph. Having chaired the committee that was charged with writing "Parameters of Care for Dentistry" when Kentucky decided to have health care reform in the mid '90s, I vividly recall the discussions that took place regarding "should" and "shall." Should is a recommendation and shall is a dictum.

The continuum of care that we provide our patients will not always be consistent with "best practices" or "evidence-based dentistry" and we have to use our diagnostic skills and sound clinical judgment when circumstances force us to deviate in the treatment we provide. The weight of the American Dental Association should not be armament for a plaintiff's attorney when sound care, skill and judgment do not result in the intended outcome. Based on what I now know about EBD, I am completely in favor of the information this service will provide the practicing dentist as a counter to the plethora of claims made on the conclusions drawn from biased research.

It is my hope that we shall soon see evidence-based dentistry as an indispensable service provided by our most prestigious professional organization and not as another layer of governance. I always feel better when I find something new and beneficial, and I think I have. I hope you are having a good day and bring on the next ADA survey.

Dr. Thompson is the editor of the Kentucky Dental Association. His comments, reprinted here with permission, originally appeared in the July/August 2011 issue of KDA Today.