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 )