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

J Appl Oral Sci. 2010 Sep-Oct;18(5):515-21. doi: 10.1590/s1678-77572010000500015.


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% 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% 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% of test surfaces presented calculus, whereas calculus was observed in 4.52% in control surfaces.

Conclusions: The presence of plaque increased 0.12% CHX side effects. These results strengthen the necessity of biofilm disruption prior to the start of CHX mouthrinses in order to reduce side effects.

Trial registration: NCT00818376.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Chlorhexidine / adverse effects
  • Chlorhexidine / analogs & derivatives*
  • Dental Calculus / chemistry
  • Dental Calculus / etiology*
  • Dental Plaque / chemistry
  • Dental Plaque / drug therapy*
  • Dental Prophylaxis / adverse effects
  • Gingivitis / physiopathology
  • Humans
  • Male
  • Mouthwashes / adverse effects*
  • Periodontal Index
  • Single-Blind Method
  • Surface Properties
  • Time Factors
  • Tooth Discoloration / etiology*


  • Mouthwashes
  • chlorhexidine gluconate
  • Chlorhexidine

Associated data