Edition V03N03 | Year 2013 | Editorial Literature Review | Pages 36 to 54
This study aims at presenting the properties of chlorhexidine used as an auxiliary chemical substance for endodontic instrumentation: structure and mechanism of action, substantivity, tissue solvent effect, chlorhexidine x sodium hypochlorite interaction, cytotoxicity, action over biofilm, antibacterial activity, antifungal activity, intracanal dressing, rheological action and allergic reactions. In Dentistry, chlorhexidine has been proved effective and safe against bacterial plaque since 1959. In Endodontics, it has been recommended in liquid or gel form, at different concentrations (usually 2%), as root canal irrigant and dressing (alone or associated with other substances). Additionally, it may be applied as an antimicrobial agent at all stages of root canal preparation, including disinfection of the operative field, removal of necrotic tissues before determining the root length, chemical-mechanical preparation before foraminal clearance and enlargement, disinfection of obturation cones; to shape the main cone with gutta-percha, to remove gutta-percha during retreatment, to disinfect the prosthetic space; etc. It is reasonable to conclude that chlorhexidine, at different concentrations, has an antimicrobial activity against Gram-positive as well as gram-negative bacteria and fungus. Its antimicrobial activity, increased by the substantivity effect, does not have the ability of solving tissues, which is overcome by the rheological action of its gel form that lubricates the endodontic instrumentation used. Its biocompatibility is acceptable with relative absence of cytotoxicity.