Frequency of mechanical removal of plaque as it relates to gingival inflammation: a randomized clinical trial

Aim This single blind, randomized clinical trial evaluated the relationship between frequency of mechanical removal of plaque ( MRP ) and gingival inflammation. Materials & Methods Fifty‐two patients (maximum 5% of sites with gingival bleeding and no history of periodontitis) were randomized to different frequencies of MRP : 12, 24, 48 and 72 h. Plaque index (PlI) and gingival index ( GI ) were evaluated at baseline, 15 and 30 days. Intra‐ and inter‐group differences were determined by repeated measures anova and mixed models anova , respectively, both followed by Tukey's test. Results The mean GI between baseline and 30 days remained statistically unchanged in the 12 h (0.51 ± 0.17 versus 0.63 ± 0.23, p  = 0.137) and 24 h (0.43 ± 0.19 versus 0.59 ± 0.21, p  = 0.052) groups, but increased significantly in the 48 h (0.48 ± 0.18 versus 0.84 ± 0.21, p  = 0.001) and 72 h (0.55 ± 0.20 versus 0.94 ± 0.25, p  = 0.000) groups. At 30 days, the average percentage of sites with GI scores of 1 and 2 was significantly higher in the 48 and 72 h than in the 12 and 24 h groups ( p  < 0.05). Conclusions Frequencies of mechanical removal plaque up to 24 h may prevent an increase in the severity of gingival inflammation over a period of 30 days in patients with no history of periodontitis.