The effects of oscillating-rotating electric toothbrushes on plaque and gingival health: A meta-analysis

Purpose: To compare the effects of oscillating-rotating (O-R), sonic (side-to-side), and manual toothbrushes on plaque and gingival health after multiple uses in studies up to 3 months. Methods: A meta-analysis was conducted on randomized clinical trials (RCTs) up to 3 months in duration to evaluate O-R electric toothbrush effectiveness regarding gingivitis reduction and plaque removal versus sonic and/or manual toothbrushes. To ensure access to subject-level data, this meta-analysis was limited to RCTs involving O-R toothbrushes from a single manufacturer conducted from 2007 to 2017 for which subject-level data were available and that satisfied criteria of duration, parallel design, examiner-graded, etc. For gingivitis studies, a one-step individual subject meta-analysis was used to assess direct and indirect treatment differences and to identify any subject-level covariates modifying treatment effects. In the two-step meta-analysis, individual participant data were first analyzed in each study independently using the last timepoint (up to 3 months), producing aggregate data for each study. Then forest plots were produced using these aggregate data with random-effects models. For plaque studies, the efficacy variables were standardized so direct comparisons could be generated using the 2-step meta-analysis. Network meta-analysis was performed to assess the indirect plaque comparisons. Results: 16 parallel group RCTs with 2,145 subjects were identified assessing gingivitis via number of bleeding sites. In five and 11 gingivitis studies assessing O-R brushes versus manual and sonic brushes, respectively, a change in the average number of bleeding sites of -8.9 (95% CI: -15.9, -1.9) and -3.1 (95% CI: -3.8, -2.4) was observed (P <= 0.008). These reductions equate to a 50% and 28% bleeding benefit for O-R technology versus the respective controls. The sonic brush bleeding change versus manual was -5.9 (P= 0.062), a 34% bleeding benefit. Utilizing individual bleeding scores, subjects with localized or generalized gingivitis (>= 10% bleeding sites) had 7.4 times better odds of transitioning to generally healthy (< 10%, RMNPI). In eight and 12 plaque RCTs assessing an O-R brush versus manual and sonic brushes, respectively, standardized changes in average plaque scores of -1.51 (95% CI: -2.17, -0.85) and -0.55 (95% CI: -0.82, -0.28) were observed (P < 0.001). These plaque reductions by O-R equate to a relative 20% and 4% greater benefit, respectively. The change for sonic versus manual was -0.93 (95 bleeding sites) after using an O-R brush versus manual. 20 parallel design RCTs with 2,551 subjects assessed plaque (TMQHI % CI: -1.48, -0.38); (P< 0.001) which equates to a 12% plaque benefit.