Comparative analysis of the effect of two chlorhexidine mouthrinses on plaque accumulation and gingival bleeding

The aim of the present study was to evaluate the effect of two chlorhexidine rinsing solutions (0.12% and 0.2%) on plaque and gingival bleeding. Ten dental students participated in this double-blind, cross-over study, rinsing twice a day, for one minute, with each one of the tested solutions for fourteen days. A wash-out period of one week between treatments was observed. In order to assess gingival bleeding, the van der Weijden et al.(1) (1994) index was used. The plaque indexes used were those of Quigley, Hein(2) (1962) and Silness, Löe(3) (1964). In the pre-experimental period, subjects received oral hygiene instructions and dental prophylaxis. The results revealed no significant differences between both concentrations in relation to plaque and gingival bleeding. Mean values (+/- standard deviation) of the Quigley & Hein index were 0.25 +/- 0.16 for the 0.12% solution and 0.23 +/- 0.26 for the 0.2% solution (p = 0.4838). Mean values (+/- standard deviation) of the Silness-Löe index were 0.12 +/- 0.10 for the 0.12% solution and 0.11 +/- 0.11 for the 0.2% solution (p = 0.7592). The bleeding index mean values at the end of the study were not different for both concentrations with mean values (+/- standard deviation) of 14.93% +/- 6.68% and 13.95 +/- 9.24% for the 0.12% and 0.2% solutions, respectively. Although an increase in gingival bleeding was observed, both concentrations were able to control dental plaque.