Dental Plaque Scores After 2 or 3 Minutes Toothbrushing: A Systematic Review and Meta-Analysis

Compared to the standard recommended brushing duration of 2 min, what is the effect of a 3 min on dental plaque scores, based on data from single toothbrushing exercises?

CRD42023445354.

MEDLINE-PubMed, Cochrane-CENTRAL and Embase databases were searched up to May 2025 to identify eligible studies. Extracted data were summarised in a descriptive and, if possible, a meta-analysis using difference of means (DiffM) or standardised mean difference (SMD) as outcome measures. The methodological quality of the included studies was scored using the RoB 2. Separate analyses were performed to evaluate participants' toothbrushing (PART) and professional toothbrushing (PROF), considering both manual (MTB) and powered (PTB) toothbrushes as distinct groups for subsequent comparisons. The certainty of the evidence was assessed using the GRADE approach.

Based on the selection criteria, the search identified 6 unique eligible publications providing 20 comparisons. The meta-analysis revealed statistically significant differences (p ≤ 0.05) for PART-MTB at the end scores, and for PROF-PTB at end scores in favour of 3 min brushing.

Based on the descriptive and meta-analyses as found in single brushing experiments there is, with moderate certainty, a very small to no difference in plaque removal, as measured in dental plaque reduction scores in favour of 3 min brushing rather than 2 min. Given the small effect size of the difference, the clinical relevance was estimated as negligible.