Effectiveness and safety of water laser-assisted endodontic-periodontal therapy: A retrospective controlled study.

ObjectiveCombined endodontic-periodontal lesions are challenging to manage because complete debridement is often difficult to achieve with conventional root canal therapy and scaling and root planing alone. This study aimed to assess the effectiveness and safety of adjunctive water laser therapy in improving pulp-periodontal outcomes.MethodsThis single-center retrospective controlled study included 634 teeth with 12 ± 3 months of follow-up, including 295 treated with adjunctive water laser treatment and 339 treated according to a conventional nonlaser regimen. Propensity score overlap weighting was used to balance baseline characteristics, with all standardized differences <0.10 after weighting. The primary endpoint was pulp-periodontal composite success. Secondary endpoints included changes in probing depth and clinical attachment level, bleeding on probing negativity, and acute exacerbation within 7 postoperative days. Safety was assessed using a Miettinen-Nurminen noninferiority test with a 5% risk-difference margin.ResultsThe water laser group showed a higher composite success rate than the control group (risk ratio = 1.22, 95% confidence interval: 1.10 to 1.36; risk difference = 13.88 percentage points, 95% confidence interval: 6.97 to 20.34;