Clinical Outcomes of a Digital Companion in Periodontal Care: A Randomised Controlled Trial

AIM: To evaluate the efficacy of a digital health companion app as an adjunct to systematic periodontal therapy. METHODS: Seven German university dental centres conducted this multi-centre randomised controlled trial. Adults with periodontitis (n = 194) were assigned to standard periodontal care with or without the Paro-ComPas app. The primary endpoint was the gingival bleeding index (GBI) at baseline, re-evaluation and during supportive periodontal care. Secondary outcomes included plaque and bleeding on probing. Confirmatory analyses used longitudinal mixed-effects regression. Exploratory analyses examined clinical outcomes by app usage cluster. RESULTS: Of the 180 participants, 148 completed the trial. Both groups showed substantial clinical improvements. The unadjusted between-group difference favoured the control group [7.70 pp (0.55; 14.85) at T0-T2]; the adjusted analysis showed no significant difference in the primary endpoint (1.56 pp; p = 0.352) or in secondary endpoints. Implementation fidelity was suboptimal. Exploratory analyses revealed that moderate app users achieved significantly greater plaque reductions compared to low users (-14.95 pp; p = 0.034). CONCLUSIONS: This trial found no significant benefit of a digital companion app as an adjunct to systematic periodontal therapy. Low baseline inflammation, incomplete intervention delivery and inter-examiner variability likely limited detection of small effects. Exploratory findings suggest potential benefits among moderately engaged users. TRIAL REGISTRATION: The study was registered in an international trial register (German Clinical Trial Register number DRKS00031263, registration date 19/06/2023, https://www.drks.de/search/de/trial/DRKS00031263/details).