Personal oral hygiene and dental caries: A systematic review of randomised controlled trials

Objective: To conduct a systematic review of randomised trials assessing the association between personal oral hygiene and dental caries in the absence of the confounding effects of fluoride. Background: Dental caries continues to affect close to 100% of the global population. There is a century-old conflict on whether dental caries is caused by poor oral hygiene or poorly formed teeth (ie, teeth with dental defects). Resolving this conflict is of significant public health importance as these two hypotheses on dental caries aetiology can lead to different prevention strategies. Methods: A systematic search for randomised trials was conducted using predefined criteria in 3 databases. The impact of personal oral hygiene interventions on coronal dental caries incidence was evaluated using random-effects models. Results: Three randomised studies involving a total of 743 participants were included. Personal oral hygiene interventions failed to influence the incidence of dental caries (Δ Decayed, Missing and Filled Surfaces (DFMS) = −0.11; 95% confidence interval: (−0.91, 0.69; P-value <.79)) despite meticulous deplaquing of teeth. There was no significant heterogeneity in the trial results (heterogeneity chi-squared = 1.88, P =.39). The findings were robust to sensitivity analyses, including consideration of the results of nonrandomised studies. Conclusion: Personal oral hygiene in the absence of fluorides has failed to show a benefit in terms of reducing the incidence of dental caries.