There is no doubt in anyone’s mind that dentistry should be practiced according to evidence-based scientific principles. In theory this premise makes sense, but the theory is actually difficult to crystalize into practice.
What exactly are the evidence-based scientific principles? How should they be applied? A good place to start is ADA’s definition of Evidence-Based Dentistry1:
“Evidence-based Dentistry is an approach to oral health care that requires the judicious integration of:
- Systematic assessments of clinically relevant scientific evidence, relating to the patient’s oral and medical condition and history, together with
- The Dentist’s Clinical expertise and
- The Patient’s Treatment Needs and Preferences”
Let’s discuss the clinical applications of each point.
First, is the problem of finding clinically relevant scientific evidence as found in academic journals. What constitutes evidence? “Much of the scientific literature, perhaps half, may simply be untrue,” says Richard Horton, Editor of Lancet2. He notes that a great deal of scientific literature is “afflicted by studies with small sample sizes, tiny effects, invalid exploratory analyses, and flagrant conflicts of interest, together with an obsession for pursuing fashionable trends of dubious importance.” According to Tina Saey of Science News3 there are twelve reasons why research goes wrong:
- Pressure to publish
- Impact factor mania
- Bad math
- Sins of omission
- Biologic variability
- Peer review doesn’t work
- Some scientists don’t share
- Research results unreported
- Sloppy procedures
“This is chilling information,” says Gil Ross, former Executive Director of the American Council on Science and Health: “Our edifice of scientific progress, the peer-reviewed medical / scientific literature, is a can of worms rather than the gold standard we thought it to be.4” One cannot look at academic literature without consideration of underlying agendas. It is important to uncover why the research was done, who funded the research and what motivated publication of the article.
Astute clinicians also recognize that statistical results usually create a bell curve, with the majority falling in the middle. “Statistics embody averages, not individuals” says Dr. Jerome Groopman5, author of How Doctors Think. What about those individuals on the outskirts of the bell curve? The treatment protocol as outlined in the research may not be suitable for outliers.
The second ingredient for evidence-based dentistry is the dentist’s clinical expertise. It is so important that a dentist be well rounded with multiple treatment options to offer patients — or at least to know about them for appropriate referral. It is becoming increasingly common for dentists to concentrate on proficiency in a specialized area of dentistry. While it is great to be an expert in one treatment modality, dentists should avoid becoming a “one-trick” pony. It is not uncommon for experts to overstretch their discipline rather than to offer alternatives or referrals that might be better. There is an alarming trend of extraction and implant placement for teeth that can be saved easily with classical crown and bridgework. Many dentists are not confident with crown and bridgework and they feel much more comfortable placing implants. But lack of proficiency in crown and bridge is not a justification for extraction and implant placement.
A common joke is that dentists call their vocation “practice” because maybe one day they will get it “right.” While the joke is guaranteed for a chuckle, it is the absolute truth. Dental Practice is a continual striving for excellence in order to do better work.
Sadly, the conversation today is often less about excellence and restoration longevity and more about economics and quick fixes.
The famous educator from the University of Wisconsin, IC Davis, outlined in the 1930s several key elements required to approach clinical practice in a scientific way6:
- A willingness to change opinion on the basis of new evidence
- A desire to search for the whole truth without prejudice
- A concept of cause and effect relationships
- A habit of basing judgment on fact
- The ability to distinguish between fact and theory.
Patient Needs and Preferences
The third ingredient in evidence-based practice is consideration of the patient’s needs and preferences. Dr. David Sackett, the father of evidence-based medicine7 emphasizes that “the transfer of science into clinical practice remains a challenge because practitioners often face individual needs and demands that are not reflected in the required rigors of “randomized controlled clinical trials”. Many practitioners long for a “cookbook” approach to treatment planning where computers make the decision. Some proponents of the evidence-based dentistry movement are intent on creating flow-charts to determine how dentists should deliver care for every clinical problem in dentistry.
But cookbook flowcharts can never happen in the real world. Dental practitioners have to address an infinite array of individual patient needs and preferences. Of paramount importance is accepting that procedures on patients can have multiple outcomes. Dr. David Hamlin, founder of Contract Dental Evaluations, emphasizes that “experience with similar cases, the patient’s needs and desires, medical history and other considerations are factors that must be carefully considered in choosing the best treatment approach. Critical thinking and intensive investigation are absolutely essential ingredients for success8.” In order to uncover the best treatment plan for an individual patient, practitioners need to take time to listen. “If only the doctor would sit down, shut up, and listen!” exclaims author and physician Oscar London. “The patient will eventually tell him the diagnosis9.” After listening, the doctor’s job is teach. The patient needs to know possible treatment solutions and outcomes, as well as the doctor’s recommendation in order to make the best choice. The title of “Doctor” actually derives from the Latin verb docere, which means to “teach.” It does not mean to “sell.” Intensive investigation may be necessary to arrive at an answer for difficult cases and it is best to avoid snap decisions.
Answers may require extensive case analysis, research, simulating possible outcomes, and consultation with specialists. A great doctor is someone who searches out the best answer for each patient. A good treatment plan should include a contingency plan to handle potential complications.
Evidenced-Based Clinical Practice
There are some guidelines that clinicians can use to ensure evidence-based practice:
- Key Principles of evidence-based practice cannot be based on unproven assumptions. It is a terrible mistake, says scientist Tom Siegfried10 to assume anything. “When an assumption is clearly stated at the outset, it’s easy to go back and check to see if that assumption skewed the results. But when the assumption is invisibly ingrained into the scientist’s mind, a seemingly certain conclusion may actually be fatally flawed”.
- Evidence for techniques must be based on years of follow-up at hygiene re-care visits. Practitioners who check patients carefully at hygiene visits find out quickly what works and what doesn’t. The measure of a success is how well a treatment works for the majority of patients—especially on medically compromised patients, and patients with susceptibility to periodontal bone loss and decay.
- Clinical analysis of techniques must be measured in parameters that clinicians can follow and interpret. One of the most important parameters clinicians have for measuring success is X-Rays, because the X-Rays measure the levels of periodontal bone around the roots. The level of periodontal bone ultimately determines whether natural teeth or implants will last in health. Years of X-Ray follow-up therefore provide valuable insight into whether a particular type of treatment is successful. X-Rays must be taken in a consistent manner in order to compare with previous sets of X-Rays.
- Cases that succeed must be analyzed to uncover the reasons for success. In order to properly evaluate a treatment, successful cases must be analyzed to uncover the factors that contributed to longevity and prevention of disease. Sound principles of engineering and healthy architecture are major contributing factors in successful outcomes.
- Cases that fail must be analyzed to uncover the reasons for failure. No practitioner likes failures, but failures are inevitable when dealing with the human body. Operating room surgeons accept the fact that in spite of their best efforts, some of their patients will die. A true scientist confronts failures to learn how to prevent future ones.
When to Try Something New
Practitioners are continually attracted to new techniques, products and equipment that promise better treatment outcomes, improve diagnosis and treatment planning, increase efficiency and enhance profit margins.
Dr. Rena Vakay, a practitioner from Haymarket Virginia, believes that integrating a new device, technique or material also prevents “routine-it is”—doing something because you have always done it that way11.
Some devices, techniques and products are definite improvements and can be safely implemented. But others are gimmicks that mesmerize dentists and patients alike but deliver disappointing results that could potentially cause harm. It is important to realize that there is no device or product that is going to be a panacea for all dental problems.
A new treatment should satisfy several criteria before it is used on patients:
- First, it does no harm [Hippocrates]
- It conforms to accepted principles of health
- It has scientific evidence for its efficacy
- Reputable individuals recommend its use
Initial patients for new treatments should be carefully selected. In addition, staff members must be coaxed to embrace change. “There is never a perfect time to implement new techniques, materials, or devices because change is difficult,” says Dr. Vakay. “Approaching change as a benefit to all and implementing it in small increments may help the dental team be more inclined to embrace it with open arms.”
Evidence-based practice is not something formal that can’t be applied by everyday clinicians. Practitioners need to adopt the persona of scientists in order to be great doctors. Dr. Richard Simonsen, former Dean of Midwestern University College of Dental Medicine says that evidence-based practice is “simply having a scientifically based reason for doing what [you’re] doing12. A good yardstick to follow is the golden rule. If you would accept the same treatment for yourself given the same circumstances and you have the clinical experience and scientific evidence to support that treatment, then you are on solid ground.
1 www.ada.org/goto/ebd The ADA’s Evidence-Based Dentistry Website offers abstracts of published systematic reviews on dental topics as well as links to national and international sources of valuable information (e.g. the Cochrane Oral health Group and Pubmed libraries).
2 Ross, Gil; “Science Publication is Hopelessly Compromised, Say Journal Editors;” https://www.acsh.org/news/2015/05/19/sciencepublication-is-hopelessly-compromised-sayjournal-editors; May 19, 2015.
3 Saey, Tina Hesman; “Repeat Performance: Too many studies, when replicated, fail to pass muster,” Science News, Jan 12th, 2015. https://onlinelibrary.wiley.com/doi/abs/10.1002/ scin.2015.187002014
4 Ross, Gil; “Science Publication is Hopelessly Compromised, Say Journal Editors;” https://www.acsh.org/news/2015/05/19/sciencepublication-is-hopelessly-compromised-sayjournal-editors; May 19, 2015.
5 Groopman, Jerome MD; How Doctors Think, Houghton Mifflin Company, ©2007; p. 6.
6 Trefil, James; Why Science?; Teachers College Press, 2008; p 119.
7 Sacket, David, William MC, Rosenberg, JA Muir Gray, R Brian Haynes and W. Scott Richardson, “Evidence-Based medicine: What it is and what it isn’t”; BMJ 1996; 312, 71-72.
8 DiMatteo, Allison; “Does Office Based Equal Evidence-Based?”; Inside Dentistry; Feb 2008, Vol 4, No. 2; https://www.aegisdentalnetwork. com/id/2008/02/
9 Oscar London, MD, WBD, Kill as Few Patients as Possible and 56 other Essays on How to be the World’s Best Doctor
10 Siegfried, Tom; “Assumptions are Repulsive, especially about gravity,” Science Matters; April 13, 2006.
11 Bacall James DMD; Cohen, David DMD; Vakay, Rena DDS; “When is it Appropriate to Integrate a New Device, Technique or Material in Clinical Dentistry;” Compendium of Continuing Education in Dentistry; Volume 40, No. 6; June, 2019; p338-340.
12 DiMatteo, Allison; “Does Office Based Equal Evidence-Based?”; Inside Dentistry; Feb 2008, Vol 4, No. 2; https://www.aegisdentalnetwork. com/id/2008/02/
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