A Multicentre Randomised Controlled Trial Evaluating the Efficacy of the SMILE™ Module for Improving Short-term Periodontal Outcomes, Compliance, and Acceptability Among Clinical Dental Students

This multicentre randomised controlled trial aims to evaluate the efficacy and safety of the SMILETM (Siwak Method for Integrated Lifestyle Enhancement) module in improving short-term periodontal outcomes, oral hygiene behaviour, and safe siwak practice among clinical dental students. Conventional toothbrushing will serve as the control intervention. Eligible participants will be randomly assigned to either the SMILE intervention group or the conventional toothbrushing control group. Both groups will receive professional oral prophylaxis, standardised oral hygiene education, structured training according to their allocated intervention, and digital monitoring throughout the 21-day study period. The study will assess changes in plaque accumulation, gingival health, and bleeding on probing, as well as participant compliance, behavioural outcomes, acceptability of the SMILE module, and intervention-related adverse events. It is hypothesised that the SMILE module will effectively improve short-term periodontal outcomes, promote better compliance with the recommended oral hygiene practice, and achieve favourable acceptability while maintaining participant safety.

Inclusion Criteria: 1. Adults aged 18 - 24 years 2. Clinical dental students enrolled at one of the participating universities. 3. Participants with a maximum diagnosed with plaque-induced gingivitis according to the 2018 Classification of Periodontal and Peri-Implant Diseases and Conditions, without clinical attachment loss attributable to periodontitis. 4. Have adequate oral hygiene (ranging from good to fair; score from 0 to 1.9 according to Silness and Löe plaque index (1964) 5. Possess at least 28 natural teeth. 6. Able to understand study procedures and provide written informed consent. 7. Willing to comply with all study procedures, intervention instructions, and follow-up assessments. Exclusion Criteria: 1. Using braces and dental prosthesis. 2. Presence of systemic diseases known to influence oral and periodontal health 3. Use of antibiotics for the last 3 months or any medication or known to affect oral and periodontal tissues or salivary flow 4. Moderate or high dental caries risk 5. Severe tooth malposition that may interfere with plaque assessment or oral hygiene procedures 6. Participants presenting with moderate - severe dentin hypersensitivity 7. Participants with mucosa/ gingival trauma/recession and tooth wear 8. Pregnancy or breastfeeding 9. History of allergy or hypersensitivity to any material used in the study 10. Cognitive, psychiatric, or physical conditions that may impair compliance with study procedures