Motivational Interviewing for Oral Health: Face-to-face Counseling vs. Online Groups

Objectives: This randomized controlled trial compared the effectiveness of two modes of motivational interviewing (MI) (i.e., face-to-face individual counseling and online groups) and prevailing health education (HE) in protecting adolescents' oral health.
Methods: 12 participating secondary schools were randomized into three groups, receiving HE (Group I), face-to-face individual MI (Group II) and online group MI (Group III) respectively. 484 adolescents with unfavorable dental behaviors (toothbrushing less often than twice daily and/or snacking more than three times daily) were recruited; 156, 169 and 159 in Groups I-III respectively. At baseline and after 24 months, Silness-Löe Plaque index and the International Caries Detection and Assessment System (ICDAS) were employed to record participants’ oral hygiene and caries status, respectively. Intention-to-treat analysis was performed. Mixed-effects logistic regression and generalized linear mixed model were constructed to adjust for confounding factors and address the clustering effect (by “school”).
Results: 437 (90.3%) participants were followed up after 24 months. Bivariate analysis showed that the plaque score of Group II and III was significantly lower than that of Group I [mean(SD): 1.00(0.52), 0.84(0.50), and 0.87(0.53) for Groups I-III respectively; both p<0.05]. No significant difference was detected between Group II and Group III. The increment of carious surfaces (△D_ICDAS1-6MFS) was significantly lower in Group II and III, as compared with Group I [mean(SD): 2.37(3.93), 1.57(4.25), and 1.13(3.20) for Group I-III respectively; both p<0.05], while Group II did not significantly differ from Group III. The between-group differences however were not significant in multivariate analysis.
Conclusions: Although 6- and 12-month findings of this trial (reported earlier) supported the superiority of MI in both modes in changing a whole range of behavioral and clinical outcomes, evidence on its 24-month effect on clinical outcomes was less robust. This suggests a need for follow-up counselling session to reinforce the positive changes.