Antimicrobial Activity and Dose/Concentration Concerns with Chlorhexidine Mouthrinses - A Literature Review

Abstract

Bacterial plaque is the main etiological factor in chronic inflammatory periodontal disease. Removal of supragingival plaque is a critical strategy in the prevention or control of periodontal disease. Mechanical cleaning is the most widely and effectively used method of suprgingival plaque control. Evidence exists that the degree of motivation and skill required with this oral hygiene technique are often far beyond the ability of the majority of patients, especially in groups of handicapped, juvenile, and elderly individuals. Thuse much attention has been focused on the chemical inhibition of plaque formation. Chlorhexidine has been extensively studied and used clinically as an antiseptic for over 40 years with no reports of adverse systemic effects or local bacterial resistance following ingestion of the compound. Due to its supreme antiplaque activity, favorable chemical characteristics of substantivity(5hours), and persistence of action, it is now generally recognized as the primary agent for chemical plaque control; its clinicall efficacy and some minor side effects are also well known to the dental profession. Chlorhexidine is a large dicationic molecule, [16-di(4-chlorphenyl-diguanido)] hexane, with a positive charge distributed over the nitrogen atoms on either side of the hexamethylene bridge. The chlorthexidine molecule has the ability to adsorb onto negatively charged surfaces, such as bacterial cell walls, where it exerts its bacteriostatic and bactericidal effects. The present article reviews and summarizes antiplaque and/or antibacterial activities of chlorhexidine mouthrinses, their relationship to the administered dose or concentration, mechanisms of action, indications of usage, systemic safety and toxicity, and de-optimizing effect of other oral hygiene products.