LAUSR

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 (△DICDASII 3-6MFT) [β (95% CI): - 0.19 (- 0.37, - 0.01) and - 0.20 (- 0.38, - 0.02), respectively], whereas increment of total carious lesions (△DICDASII 1-6MFT) 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).