Evidence-based dentistry is the practice of making treatment decisions based on the best evidence available about a particular issue, the dentist’s own experience, and the wishes of the patient. The practice outlines five basic steps when a patient’s condition is being assessed: question, find, appraise, evaluate, and act. There is also a hierarchy of types of evidence that a dentist can use to delineate the most desirable information from the least desirable when researching an issue. It is a methodical way to consider and choose the best treatments when practicing dentistry.
The hierarchy used in evidence-based dentistry has seven levels of information and research. The highest levels are: meta-analysis, systematic review, randomized controlled trial, and cohort study. Lower levels include case-control study, case series or case report, and animal research or laboratory study. Top-level evidence is believed to provide the best solution to a question about patient care. The lower the level of the hierarchy, the less reliable is the information collected.
Meta-analysis is the top level of the evidence-based dentistry hierarchy. It consists of a group of data compiled from multiple small-scale studies. When this information is not available, the next level down in the hierarchy is systematic review. This method covers a wider, international range of research findings found via a rigidly systematic search.
When the top levels of the hierarchy are not available to the medical practitioner, the next step is to research randomized controlled trials, which contain evidence from an array of clinical trials. The next step is to refer to a cohort study, which considers a group of people who have a condition similar to the patient. After that, a case-control study can be consulted. This involves comparing a control group without the condition in question with previously collected information about a group that has had the problem.
The next level, case series or case report, involves examination of the files of patients who have previously had the treatment in question in order to learn common reactions and to determine if it is the appropriate method for the current patient. When research is not available at any of these levels, the medical professional will typically resort to animal research or laboratory study. While the results from this level do not necessarily directly apply to human subjects, they do reflect a caliber of research that may be sufficient in determining the appropriate course of treatment.