Motivational interviewing for caries prevention in adolescents: a randomized controlled trial

Objective: The objective of this study is to investigate the effectiveness of motivational interviewing (MI) in changing health behaviors (snack and toothbrushing) and preventing dental caries among adolescents.

Methods: Five hundred and twelve adolescents with unfavorable caries-related behaviors ("snacking three times or more a day" and/or "toothbrushing less often than twice a day") were randomly assigned to three groups. Group I received prevailing health education (oral health talks and pamphlets). Participants in group II joined a one-on-one face-to-face MI session. In group III, a patient communication tool (Cariogram) was incorporated to facilitate the MI process. At baseline and 24 months post-intervention, a self-administered questionnaire gathered information of participants' sociodemographic characteristics and oral health self-efficacy and behaviors. Their oral hygiene and tooth status were assessed by a blinded examiner.

Results: After 24 months, 460 (89.8%) participants were followed up. Compared with group I, (i) restriction of frequent snacking was more likely in group II [OR (95% CI): 3.91 (1.48-10.33)] and group III [OR (95% CI): 6.33 (2.46-16.27)], whereas group III tended to adopt the behavior of toothbrushing twice a day [OR (95% CI): 4.80 (1.79-12.85)]; (ii) no significant between-group difference in plaque score reduction was found (p > 0.05); and (iii) groups II and III developed fewer cavitated teeth (△D_{ICDASII 3-6}MFT) [β (95% CI): - 0.19 (- 0.37, - 0.01) and - 0.20 (- 0.38, - 0.02), respectively], whereas increment of total carious lesions (△D_{ICDASII 1-6}MFT) was lower in group III [β (95% CI): - 0.63 (- 1.24, - 0.02)].

Conclusion: MI outperformed prevailing health education in improving oral health behaviors and preventing dental caries among adolescents.

Clinical relevance: Incorporating MI into dental care for caries-prone adolescents contributes to optimal health outcomes.

Trial registration: HKUCTR-1852 ( http://www.hkuctr.com/ ) (Hong Kong, 2013).