Purpose: This review of six clinical trials provides a comprehensive overview of the results of statistical analyses to explore between-brush differences, specifically in the lingual, gingival marginal, and approximal ("hard-to-clean") areas, in post-brushing plaque removal of oscillating-rotating (O-R) power toothbrushes compared to either a marketed sonic power toothbrush or a manual toothbrush control.
Methods: All studies were single-center, randomized and controlled, and examiner-blind. Four trials were four-period crossover design with replicate single-use brushing, while two studies were parallel group investigations (4 or 12 weeks) with multiple brushings and assessments at each visit. Generally healthy subjects were enrolled. Plaque evaluations were via the Turesky Modification of the Quigley-Hein Plaque Index (TMQHPI) or the Rustogi Modification of the Navy Plaque Index (RMNPI). At each evaluation visit, subjects brushed with either the randomly assigned O-R power brush [Oral-B Professional Care Series 4000 (Triumph) or Oral-B Vitality with Floss Action or Precision Clean brush head] or a control brush [Sonicare FlexCare with ProResults brush head (three trials) or an American Dental Association (ADA) reference manual toothbrush (three trials)]. ANCOVA and ANOVA analyses subsequently evaluated specifically the 'hard-to-clean' tooth surfaces for between-brush differences.
Results: In total, 462 subjects completed the trials and were evaluable. While all toothbrushes provided significant post-brushing versus baseline plaque removal efficacy, the magnitude of the reduction was consistently superior for the O-R brush compared to either the sonic power or manual brush control in all the 'hard-to-clean" region-specific analyses. Adjusted mean RMNPI or TMQHPI benefits favoring the O-R brush relative to the sonic brush control were collectively 18% to 34% greater on lingual surfaces (P < or = 0.044), 32% to 49% greater on lingual approximal surfaces (P < 0.001), and 32% and 31% greater in lingual mandibular and lingual mandibular anterior regions, respectively (P < or = 0.005). Post-brushing whole mouth adjusted mean reduction RMNPI or TMQHPI benefits favoring the O-R brush compared to the manual brush control were collectively 31% to 206% greater on lingual surfaces (P < or = 0.001), 29% to 217% greater on lingual approximal surfaces (P < or = 0.001), and 67% to 526% greater in lingual gingival margin regions, respectively (P < or = 0.001). All study toothbrushes were well-tolerated.