Nd: YAG laser-assisted treatment of subgingival microbiota composition in stage III-IV periodontitis: a randomized controlled study.

OBJECTIVES: Nd: YAG laser, a near-infrared laser, offers advantages such as sterilization, hemostasis, and tissue ablation, making it a promising adjunctive tool for minimally invasive periodontal treatment. This study aimed to evaluate the clinical efficacy of Nd: YAG laser-assisted nonsurgical treatment in stage III–IV periodontitis and its impact on the subgingival microbial community structure using 16 S rRNA sequencing. MATERIALS AND METHODS: A total of 20 patients with stage III-IV periodontitis were randomly divided into a subgingival scaling and root planning (SRP group) (n = 10) and a Nd: YAG laser-assisted SRP group (Nd group) (n = 10). Clinical parameters were compared before and after treatment for 3 months, and subgingival plaque samples were collected for 16 S rRNA microbial analysis. RESULTS: Both groups exhibited significant improvements in periodontal clinical parameters after treatment (P < 0.01), with greater gains in the Nd group (P < 0.05). Alpha diversity decreased after treatment in both (P < 0.05), more markedly in the Nd group (P < 0.01). Beta diversity analysis showed that significant clustering was formed in the subgingival plaque samples before and after treatment in both groups, with larger microbial shifts in the Nd group(P < 0.05). After treatment, the relationship network was significantly simplified. CONCLUSIONS: Non-surgical treatment significantly improved periodontal parameters in stage III-IV periodontitis patients, reducing subgingival microbiota diversity and optimizing its composition. CLINICAL RELEVANCE: Nd: YAG laser-assisted SRP demonstrated superior clinical outcomes versus SRP alone, with microbiological analysis confirming its adjunctive benefits and enhanced clinical efficacy.