Application of Liposomal Bupivacaine in Pain Management After Immediate Implant Placement

Abstract

To evaluate the analgesic efficacy, safety, and clinical value of liposomal bupivacaine for pain management following immediate dental implant surgery. This prospective, single-center, two-group, parallel-arm superiority randomized controlled trial was registered at [ISRCTN](registration number: redacted for peer review). We randomized 32 eligible patients undergoing immediate implant surgery between September 2025 and February 2026 to an experimental group ( n = 16) and a control group ( n = 16). The experimental group received subperiosteal and peri-incisional infiltration of 3–5 mL of liposomal bupivacaine (1.3%) post-surgery, whereas the control group received no long-acting local anesthetic. We used a repeated-measures ANOVA to analyze longitudinal visual analog scale (VAS) scores and pain relief rates and account for intra-subject correlation; we applied the Benjamini–Hochberg false discovery rate method to correct for multiple comparisons across six time points and multiple endpoints. We performed formal statistical assumption tests, including normality, homogeneity of variance, and residual diagnosis, before statistical analysis. We conducted sensitivity analyses and per-protocol and intention-to-treat robustness analyses to verify result stability. We recorded pain relief rates and VAS scores at fixed time points (2, 6, 12, 24, 48, and 72 h). Rescue analgesic use, swelling degree, and patient satisfaction (Cronbach’s α = 0.86) were assessed. Ordinal data were analyzed using the Wilcoxon rank-sum test. At 24, 48, and 72 h post-surgery, the experimental group had significantly lower VAS scores and higher pain relief rates than the control group (P < 0.05) after multiple comparison adjustment. At 72 h, the VAS score dropped to 0.680 ± 0.310 (95% CI: 0.518–0.842), significantly lower than the score of 1.960 ± 0.620 (95% CI: 1.631–2.289) in the control group ( t = 7.115, P < 0.001). Cohen’s d effect size was calculated as 1.78, indicating a large clinical effect. The experimental group had a significantly lower rescue medication rate (12.50%) and total frequency (3 times) than the control group (56.25% and 21 times, respectively; P = 0.009). Additionally, the experimental group exhibited milder swelling ( Z = 2.105, P = 0.035) and higher satisfaction (93.75% vs 62.50%; χ 2 = 4.571, P = 0.033). Subperiosteal infiltration of liposomal bupivacaine (3–5 mL) targets the postoperative pain peak, significantly reduces tissue swelling, and minimizes the systemic analgesic burden. As exploratory provisional evidence, supported by rigorous statistical assumption testing, repeated-measures modeling, and multiplicity correction, it shows promising clinical application potential for immediate implant postoperative pain management. However, it cannot be generalized as an optimal universal clinical strategy at present.