Evidence-based dentistry: reality and dilemmas.

The concept of evidence-based practice (EBP) relies on rendering treatment, the effectiveness is solidly demonstrated by rigorous research, not just empirical experience. The aim of this paper is to review the foudation of EBP and the reality of its application. Evidence is commonly ordered up in a “hierarchy” from expert opinion to case report, case series, case-control study, cohort study, randomized controlled trial, and systematic review/meta-analysis. We stratify this hierarchy into 3 categories ascending from perspective, to investigation then synthesis. Depending on the type and feasibility of research, the higher levels of evidence do not negate the value of lower strata. The application of evidence is illustrated in two representative areas of dentistry: timing of early orthodontic treatment and immediate loading of osseointegrated implants. The clinician faces dilemmas in the need to ground treatment into unquestionable basis and the difficulty of relating this basis to the individual treatment. Reasons for this dichotomy include the scale of variation around mean results delivered by the most sophisticated research and the potential for new more encompassing research to deviate from prior findings. While research sets central tendencies, individual variation favors interpretation of the evidence. In the face of viewpoints on EBP ranging from support to rejection, the clinician should not indict a needed process, but rather use judgment to apply the average response shown in investigations to the individual circumstances of patients.