Cholesterol as an Aetiological Factor of Persistent Asymptomatic Apical Periodontitis

Abstract

Objectives: Microbial colonization of the root canal system has been shown to be the prime cause of apical periodontitis. Therefore, the main goal of the endodontic treatment is to eliminate microorganisms present in the root canal system, remove disintegrated pulp tissues that could serve as substrate for microbial growth, and fill the endodontic space to preclude bacterial recolonization, so as to prevent apical periodontitis or allow its healing. Microbial infection persisting in the root canal and/or periapex is also considered to be the most significant factor that affects the outcome of endodontic therapy. However, there are also other biological factors that lead to asymptomatic radiolucencies persisting after root canal treatment, such as extraradicular infection, generally in the form of periapical actinomycosis; extruded root canal filling or other exogenous materials that cause a foreign body reaction; accumulation of endogenous cholesterol crystals that irritate periapical tissues; cystic lesions, and scar tissue healing of the lesion. Conclusion: The purpose of this article is to review the causative factors of non-resolving periapical lesions - persistent apical periodontitis that are radiographically seen after endodontic treatment of devitalized teeth as asymptomatic radiolucencies - specifically the presence of cholesterol crystals in these lesions.

Keywords

• cholesterol crystals
• persistent apical radiolucency
• non-healing apical periodontitis
• asymptomatic apical periodontitis
• foreign body reaction