The effect of different formulations of chlorhexidine in reducing levels of mutans streptococci in the oral cavity: A systematic review of the literature

Objectives The current study undertakes a systematic review of the literature in order to assess how long different formulations (solutions, gels and varnishes) of chlorhexidine (CHX) reduce the level of mutans streptococci (MS) in the oral cavity. Sources A search of the PUBMED and LILACS databases was conducted through October 2005. Study selection Clinical studies evaluating the effects of CHX solutions, gels, or varnishes on MS levels were targeted (n = 52). Conclusions The studies varied greatly in quantity of mouthwash solution used in rinsing, length of rinsing, and treatment frequency and period. CHX mouthwash solution had short-term effect on salivary MS. Most of studies evaluating CHX gel and varnish used a concentration of 1%. The 1% CHX gel showed a significant reduction through intensive treatment (3–4 daily applications over 2 days) or through daily application for 10 and 14 days. It cannot be asserted that 1% CHX varnish provides better results when applied intensively as compared to applications conducted at intervals of 1 or more months. Treatment using 1% CHX varnish displays large variations in the level and length of decreased MS levels. Despite variability in results, 40% CHX varnish has a greater effect on the period of decreased MS levels than does 1% CHX varnish. Studies did not show a statistically significant difference between the gel and the varnish. The effects of CHX treatment must be monitored, given sharp individual variability in response to this treatment.