Abstract
Aim
Antimicrobial photodynamic therapy (aPDT) has been proposed as a locally acting adjunct to subgingival instrumentation for periodontitis. This umbrella review aimed to synthesize and critically appraise systematic reviews of adjunctive aPDT during active nonsurgical periodontal therapy, with emphasis on methodological confidence, clinical importance, and overlap of the evidence base.Method
PubMed/MEDLINE, the Cochrane Library, Epistemonikos and Google Scholar were searched from inception through 24 July 2026, supplemented by backward and forward citation searching. For Google Scholar, the first 200 relevance-ranked results were screened, and exact-title and author searches were used to identify additional review reports. Systematic reviews with or without meta-analysis were eligible when they evaluated aPDT added to subgingival instrumentation and reported separable clinical evidence for adults receiving active nonsurgical treatment. Reporting followed PRISMA 2020 and PRIOR. Methodological confidence was appraised with AMSTAR 2; ROBIS domains were used as an interpretive framework rather than as a formal domain-by-domain rating tool. One reviewer completed selection, extraction and appraisal using a prespecified form and a structured second source-check pass for eligibility and numerical data.Results
Fifteen systematic reviews published from 2010 to 2025 were included. After recalculation using the AMSTAR 2 decision rules, four reviews had high methodological confidence, three had moderate confidence, three had low confidence, and five had critically low confidence. The 2024 Cochrane review included 50 randomized trials and 1407 adults. During active treatment at 6 months, adjunctive aPDT produced an additional PPD reduction of 0.52 mm (95% CI 0.31-0.74; 15 studies, 452 participants) and CAL gain of 0.44 mm (95% CI 0.24-0.64; 13 studies, 414 participants); both were very low-certainty and judged unlikely to be clinically important. BOP improved by 5.72 percentage points (95% CI 1.62-9.81; 5 studies, 171 participants), also with very low certainty. No aPDT-related adverse effects were reported in 24 active-treatment studies involving 639 participants, while pocket closure, satisfaction, quality of life and economic outcomes were sparsely reported.Conclusion
Adjunctive aPDT may produce small short-term improvements in PPD and CAL after nonsurgical periodontal therapy, but the most reliable evidence remains very low certainty, and the observed mean differences have not been shown to translate into patient-important or treatment-changing benefit. Current evidence does not support routine adjunctive use; standardized trials should prioritize pocket closure, patient-reported outcomes, long-term effectiveness and economic outcomes.Prospero registration
CRD420261468530.