The Effectiveness of Manual versus High-Frequency, High-Amplitude, Sonic-Powered Toothbrushes for Oral Health: A Meta-Analysis

Methodology

Studies were eligible if they were randomized controlled clinical trials which evaluated both manual and sonic-powered toothbrushes on plaque or gingivitis reduction over a period of four weeks to three months in subjects without disability affecting toothbrushing. Single-use and clinician supervised studies were excluded.

To identify eligible studies, searches were performed in databases of scientific publications (Embase, MEDLINE, BIOSIS, Inspec, PQ-SciTech, Compendex, SciSearch) as well as the electronic database of IADR abstracts. Data were extracted from qualifying studies, and investigators were contacted when insufficient information was available. To allow for the meta-analysis, data were pooled to compute standardized mean differences (SMD) and 95% confidence intervals (95% CI) using random-effects models to quantify differences in plaque removal or gingivitis reduction for each study as well as for the overall weighted average across included studies. Sources of heterogeneity and risk for bias were assessed.

Results

Overall, 18 studies comprising 1,870 subjects were included. The results demonstrated that high-frequency, high-amplitude sonic-powered toothbrushes resulted in statistically significantly greater reductions in plaque (SMD = -0.89, 95% CI = [-1.27, -0.51]) and gingivitis (-0.67, [-1.01, -0.32]) when compared to manual toothbrushes. In practical terms, this equates to approximately 20% more plaque removal and 10% greater decrease in gingivitis in everyday use. Although heterogeneity was large, sensitivity and subgroup analysis showed that outcomes were robust, and bias was not apparent.

Conclusions

High-frequency, high-amplitude, sonic-powered toothbrushes decreased plaque and gingivitis significantly more effectively than manual toothbrushes in everyday use in studies lasting from four weeks up to three months. 

Standardized Mean Difference and Confidence Intervals for plaque removal and gingivitis reduction.

Results and forest plots for each study with Standardized Mean Difference (SMD) and 95% Confidence Intervals (95% CI) comparing sonic powered versus manual toothbrushes for (left) plaque removal and (right) gingivitis reduction. SMD<0 favors the powered toothbrush. 

Key Characteristics of Included Studies

* Study reported data for natural teeth and implant sites separately