Face-to-face individual counseling and online group motivational interviewing in improving oral health: study protocol for a randomized controlled trial

BACKGROUND Motivational interviewing (MI) has great potential in changing health-related behaviors. In addition to delivery in face-to-face individual counseling, MI can be delivered through online groups, a method that is particularly appealing to adolescents and may offer several benefits. This randomized controlled trial compares the effectiveness of prevailing health education (HE), face-to-face individual MI and online group MI in improving adolescents' oral health behaviors (diet and toothbrushing) and in preventing dental caries and periodontal diseases. METHODS/DESIGN In each of Hong Kong's main districts (Hong Kong Island, Kowloon and the New Territories), three secondary schools will be recruited and randomly assigned to three groups (HE, face-to-face individual MI, and online group MI). A total of 495 adolescents (aged 12 to 13 years) with unfavorable oral health behaviors ("snacking twice or more a day" and/or "brushing teeth less than twice a day") will be recruited: 165 in each group. Two dental hygienists will be trained to deliver the interventions. HE will be provided through an oral health talk. Participants in the "face-to-face individual MI" group will join a one-on-one counseling session. For "online group MI," participants will form groups of 6 to 8 and join a synchronous text-based online counseling session. At baseline and after 6, 12 and 24 months, clinical outcomes (caries increment and gingival health) and oral health self-efficacy and behaviors (toothbrushing and snacking) will be recorded through an oral examination and a questionnaire, respectively. Effectiveness of the interventions will be evaluated and compared. The primary outcomes will be the "number of new carious surfaces" and "gingival bleeding score" (% of surfaces with gingival bleeding). The secondary outcomes will be changes in oral health self-efficacy and behaviors (toothbrushing and snacking frequencies). A preliminary economic evaluation and a process evaluation will be included to analyze the cost of the interventions and the interactions in MI sessions. DISCUSSION Since online group MI is expected to be more convenient, accessible, and time efficient, it might address the practicality issues and pave the way for the application of MI in dental practice. The findings will assist public health workers and dental practitioners to choose effective and viable approaches in delivering behavioral interventions. Since unhealthy diet and poor personal hygiene are common risk factors accountable for many systemic diseases, the intervention scheme identified in this study can also contribute to advancing general health. TRIAL REGISTRATION The HKU Clinical Trial Register #HKCTR-1852 (registered on 13 November 2014).