The effect of local application of chlorhexidine on plaque and gingivitis

This study compared the effects on plaque accumulation and gingival inflammation, of a 0.2 percent chlorhexidine solution applied with an interdental brush, with the effects of the interdental brush with control solution. Thirty-three subjects with at least one tooth-bounded edentulous space were chosen. The trial was of a double-blind, cross-over design with two, 28-day active periods separated by a 21-day rest period. The experimental solution was 0.2 percent aqueous chelorhexidine, and 0.1 percent quinine solution was used as the control. Prior to the commencement of the trial, plaque accumulation at the sites to be tested was recorded using the Plaque Index. Gingival condition was recorded using the Gingival Index. The surfaces were carefully scaled and cleaned to reduce the Plaque Index to 0. Subjects cleaned the selected tooth surfaces on a day using the interdental brush with the appropriate solution. After 28 days, the Plaque and Gingival Indices were recorded again. Normal oral hygiene was resumed during the rest period. The second trial followed the same format as the first, but with each subject using the alternative solution. Results were analysed using Wilcoxon signed-rank tests for matched pairs. 1. The mean Plaque and Gingival Index scores were reduced over the 28-day trial period for both experimental and control groups. 2. Although the Plaque Index scores were slightly lower after treatment with chlorhexidine when compared with the control, the difference was not statistically significant. 3. The reduction in Gingival Index was significantly greater for the chlorhexidine group than for the control group. The results indicated that 0.2 percent aqueous chlorhexidine, applied with an interdental brush to tooth surfaces adjacent to edentulous spaces, produced a significantly greater improvement in gingival health than the interdental brush with a placebo quinine solution, but the reductions in plaque accumulation were similar with the two solutions.