Combined posterior superior alveolar and anterior middle superior alveolar nerve blocks with labial infiltration versus nerve blocks alone for pain management in minimally invasive non-surgical periodontal therapy: a split-mouth randomized controlled trial.

BACKGROUND: To compare the efficacy of combining posterior superior alveolar (PSA) block, anterior middle superior alveolar (AMSA) block, and labial infiltration of the maxillary central incisor versus PSA + AMSA alone for pain control during minimally invasive nonsurgical periodontal therapy (MINST). METHODS: Twenty-four patients with stage II-III periodontitis were enrolled in the single-center, single-blind, split-mouth randomized controlled trial. The maxillary right and left quadrants were randomized to receive either PSA + AMSA blocks and labial infiltration (test group) or PSA + AMSA alone (control group) during subgingival instrumentation. Pain levels during injection and treatment were assessed using a 100 mm visual analog scale (VAS). Primary outcomes included intraoperative and injection-related pain scores, while secondary outcomes comprised treatment duration, injection time, patient satisfaction, and adverse events. Data were analyzed using GraphPad Prism 9. RESULTS: Twenty-one subjects completed the study. No significant difference in injection pain was observed between groups (test: 22.74 +/- 14.10 mm vs. control: 20.21 +/- 12.27 mm; P = 0.248). However, the test group exhibited a statistically significant reduction in intraoperative pain (test: 11.07 +/- 10.36 mm vs. control: 16.43 +/- 11.55 mm; P = 0.021). Patient satisfaction was significantly higher in the test group [test: 90 (IQR 90-100) vs. control: 90 (80-90); P = 0.004]. No clinically meaningful differences were detected in treatment duration or adverse event rates (P > 0.05). CONCLUSIONS: The combined PSA + AMSA blocks and labial infiltration protocol reduced intraoperative pain and improved satisfaction versus PSA + AMSA blocks, without prolonging treatment. Despite clinical promise, the small sample size limits generalizability, necessitating multicenter trials to validate efficacy and broader applicability. TRIAL REGISTRATION: The trial protocol was retrospectively registered in the Chinese Clinical Trial Registry (ChiCTR2400086566) on 05-07-2024.