Implant stability following septal expansion in immediate mandibular molars: a pilot randomized clinical trial comparing piezoelectric surgery and osseodensification

Abstract Background Immediate implant placement (IIP) in mandibular molars is challenged by wide extraction sockets and limited septal bone support. This pilot feasibility randomized clinical trial evaluated primary and secondary implant stability following septal expansion using piezoelectric surgery (PISP) compared with osseodensification (OD) using Densah ® burs. Methods Twenty patients were randomly allocated (1:1) to either PISP group or OD group for immediate mandibular molar implant placement. The primary outcome was implant stability quotient (ISQ), measured immediately and at 3 months. Secondary outcomes included insertion torque, osteotomy preparation time, and postoperative pain assessed using a visual analogue scale (VAS) during the first postoperative week. Normality was evaluated using Shapiro–Wilk tests and Q–Q plots. Between-group comparisons were performed using independent t-tests, while VAS scores were analyzed using Mann–Whitney U and Friedman tests (α = 0.05). Results No statistically significant differences were observed between groups in primary or secondary ISQ ( p > 0.05). Both groups demonstrated a significant increase in ISQ at 3 months compared with baseline ( p < 0.001). The mean insertion torque was significantly higher in the PISP group (40.33 ± 3.24 Ncm; p = 0.004) compared to the OD group (35.00 ± 3.53 Ncm). Osteotomy preparation time was significantly longer in the PISP group (9.00 ± 0.94 min) than in the OD group (6.00 ± 0.82 min) ( p < 0.001). Postoperative VAS pain scores were significantly lower in the PISP group throughout the first week ( p < 0.05). All implants achieved clinical stability with no intra- or postoperative complications. Conclusions The preliminary findings of this pilot feasibility trial demonstrated that PISP achieves comparable biomechanical stability to OD, establishing its clinical feasibility for immediate molar implant placement in anatomically complex posterior regions. Trial registration NCT06957860 ; registered May 5, 2025.