Abstract
This article presents specific aspects regarding the role of endodontic medication in the conservative treatment in chronic apical periodontitis. Starting from the bacterial microflora, the etiological factor of the periapical lesions, we discuss about the modalities of identification by the means of in vivo and in vitro tests of the microorganisms present inside the root canal. The characteristics of these methods of microbiological evaluations, as well as their clinical relevance, are reviewed. The general characteristics of endodontic antimicrobial medication are presented, as well as the causes of endodontic failures in treatment in chronic apical periodontitis. It is underlined the essential importance of the rigorous biomechanical treatment, in association with endodontic lavage, which makes the antibacterial medication only have a subordinate role in the treatment of chronic apical lesions.