Staining and calculus formation after 0.12 percent chlorhexidine rinses in plaque-free and plaque covered surfaces: a randomized trial

ABSTRACT

OBJECTIVES: Studies concerning side effects of chlorhexidine as related to the presence of plaque are scarce. The purpose of this study was to compare the side effects of 0.12 percent chlorhexidine gluconate (CHX) on previously plaque-free (control group) and plaque-covered surfaces (test group). METHODS: This study had a single-blind, randomized, split-mouth, 21 days-experimental gingivitis design, including 20 individuals who abandoned all mechanical plaque control methods during 25 days. After 4 days of plaque accumulation, the individuals had 2 randomized quadrants cleaned, remaining 2 quadrants with plaque-covered dental surfaces. On the fourth day, the individuals started with 0.12 percent CHX rinsing lasting for 21 days. Stain index intensity and extent as well as calculus formation were evaluated during the experimental period. RESULTS: Intergroup comparisons showed statistically higher (p<0.05) stain intensity and extent index as well as calculus formation over the study in test surfaces as compared to control surfaces. Thus, 26.19 percent of test surfaces presented calculus, whereas calculus was observed in 4.52 percent in control surfaces. CONCLUSIONS: The presence of plaque increased 0.12 percent CHX side effects. These results strengthen the necessity of biofilm disruption prior to the start of CHX mouthrinses in order to reduce side effects.