The effectiveness of three different strengths of chlorhexidine mouthrinse.

Dental caries in dentate elderly patients may be controlled with chlorhexidine. The purpose of this study is to establish the effectiveness of two low-concentration chlorhexidine mouthrinses in reducing the microbial counts of cariogenic bacteria in a sample of institutionalized elders. Stimulated saliva samples from all subjects before treatment produced counts greater than or equal to 105 colony-forming units (CFU)/mL of lactobacilli and/or mutans streptococci. Treatment consisted of daily rinsing with 4.0 mL of mouthrinse before bed for 14 days. Bacterial counts were re-assessed two weeks after commencing treatment. The mean reduction in mutans streptococci counts in subjects receiving the regular-strength chlorhexidine mouthrinse (Group B) was significantly greater than for subjects using either of the low-concentration rinses (Groups A and C). These findings failed to demonstrate the effectiveness of the lower-concentration mouthrinses (Groups A & C).