Effects of SCN-/H2O2 combinations in dentifrices on plaque and gingivitis

Objectives: A 10-week, double-blind, placebo-controlled clinical study on 1 40 male subjects was conducted to determine the effect on plaque and gingiv itis of 5 dentifrices containing various thiocyanate (SCN-)/hydrogen peroxi de (H2O2) combinations. Materials and Methods: The dentifrices consisted of a gel base without any detergents or abrasives (placebo, group A) to which SCN- and/or H2O2 were a dded as follows: 0.1% SCN- (group B), 0.5% SCN- (group C), 0.1% SCN-/0.1% H 2O2 (group D), 0.5% SCN-/0.1% H2O2 (group E) and 0.1% H2O2 (group F). A bas eline examination was performed in which the Silness and Loe Plaque Index ( PI), the Muhlemann and Son Sulcus Bleeding Index (SBI), and the amount of g ingival crevicular fluid (GCF) were recorded using the Periotron 6000 on te eth 16, 12, 24, 36, 32, and 44. The subjects were randomly assigned to eith er the placebo group (n = 40) or one of the test groups (n = 20) and used t heir respective dentifrices over a period of 8 weeks. Finally, each group u sed the placebo for another 2 weeks (wash-out). Re-examinations were perfor med after 1, 4, and 8 weeks and the 2-week wash-out period employing the cl inical parameters used at baseline. Intragroup changes were analyzed with t he Wilcoxon signed-ranks test, using the baseline and wash-out points as re ferences. The Mann-Whitney U test was used for comparisons between the trea tment groups and the placebo group. Results: At the 8-week examination, the plaque index in group E (p = 0.017) and group F (p = 0.032) was lower than in the placebo group. The Sulcus Bl eeding Index in group F after 1 week was increased (p = 0.023) and the SBI in group E after 8 weeks was reduced (p = 0.047) as compared to the placebo group. Conclusion: The results demonstrated that a dentifrice containing 0.5% SCN- and 0.1% H2O2 but no detergents or abrasives inhibited plaque and decrease d gingivitis.