A system of practice that integrates clinically relevant scientific evidence, clinical experience, and the patient's treatment needs and preference, taking into account the patient's oral and medical condition and history. The strength of the scientific evidence available can be ranked in a hierarchical order and should be taken into account when assessing its validity.
Richards D. Not all evidence is created equal—so what is good evidence? Evidence-Based Dentistry 2003;4:17–18.Evidence based dentistry for effective practice, ed. J. Clarkson et al. Martin Dunitz, 2003.
http://www.cebm.net/index.aspx?o=1025 Levels of evidence defined by the Centre for Evidence based Medicine.
Hierarchy of evidence