This randomized controlled trial (RCT) aims to evaluate the clinical efficacy of Nd:YAG laser adjunctive therapy and its impact on the subgingival microbiome in patients with stage III-IV periodontitis. The study addresses two key questions: (1) Whether Nd:YAG laser combined with scaling and root planing (SRP) yields significantly greater improvements in periodontal parameters compared to SRP alone; and (2) How subgingival microbial dynamics correlate with therapeutic outcomes.
Participants were randomized into two groups: the SRP group (mechanical debridement only) and the Nd group (mechanical debridement with Nd:YAG laser therapy). Clinical parameters-including probing depth (PD), clinical attachment level (CAL), and gingival index (GI)-were assessed at baseline and 3 months post-treatment. Subgingival plaque samples were analyzed via 16S rDNA sequencing to characterize microbial community shifts.