Interdental mutans streptococci suppression in vivo:: A comparison of different chlorhexidine regimens in relation to restorative material

Purpose : To evaluate the suppressive effect of four different chlorhexidine (CHX) regimens on the interdental levels of mutans streptococci (MS) on enamel and various restorative materials in a group of adults. Materials and Methods: 128 subjects with high salivary MS counts were allocated to (A) a single professional tooth cleaning with a 1% CHX gel, (13) duplicate applications of a dental varnish containing 1% CHX and 1% thymol, (C) a single application of a 40% CHX varnish, (D) daily tooth brushing with a 1% CHX gel for 2 weeks. Interdental plaque samples were collected at baseline, I week, and 3 months after termination of CHX treatment. Results: The baseline MS levels were significantly higher in plaque from composite surfaces than in plaque from enamel surfaces, All methods decreased the interdental MS levels compared with the baseline on enamel, composite and amalgam surfaces. On both clinically sound enamel and amalgam surfaces, the outcomes in Groups B, C and D were similar and significantly better than in Group A. On composite surfaces, the 40% CHX varnish (C) and the CHX brushing (D) were significantly more effective in decreasing MS than the low-CHX varnish (13) and the professional CHX cleaning (A).