Efficacy of topical application of simvastatin gel combined with a collagen sponge carrier in preserving alveolar ridge dimensions: a triple-blind randomized clinical trial

Alveolar ridge atrophy is an inevitable consequence following tooth extraction, leading to substantial vertical and horizontal bone loss and frequently complicating subsequent prosthetic rehabilitation. Simvastatin (SIM), known for its osteoinductive and anti-inflammatory properties, has shown promise in promoting local bone regeneration. This study aimed to evaluate the efficacy of topical application of a novel 1.2% SIM gel in preserving alveolar ridge dimensions following the surgical extraction of mandibular third molars, compared with a placebo. A randomized, triple-blind clinical trial (RCT) was conducted involving 40 patients (n = 20 per group) requiring mandibular third molar extraction. Patients were randomly assigned to receive either the active 1.2% SIM gel (test group) or a placebo gel (control group). In both groups, the assigned gel was delivered using a collagen sponge as a carrier scaffold placed directly into the extraction socket. Cone Beam Computed Tomography (CBCT) scans were obtained pre-extraction (T0) and 12 weeks postoperatively (T1). The primary outcome was the dimensional change in vertical alveolar bone height (ΔH). Secondary and exploratory outcomes included changes in bone width (ΔW), bone density (Mean Gray Value), postoperative pain, and swelling. The primary outcome analysis included 38 sockets (n = 19 per group). The Test Group (SIM) showed significantly greater vertical bone preservation, with a mean change in height of − 0.30 ± 1.79 mm (indicating preservation/gain), compared to the Control Group’s mean loss of 1.28 ± 1.50 mm (p = 0.006). No statistically significant difference was observed in exploratory bone width preservation (p > 0.05). The SIM gel demonstrated an excellent safety profile, with no significant differences regarding postoperative pain or swelling compared to the placebo. The topical application of 1.2% SIM gel significantly improved vertical alveolar bone height preservation at 12 weeks compared to the placebo. This primary finding confirms the clinical benefit of local simvastatin delivery in maintaining the vertical dimension required for successful prosthetic treatment, while exploratory densitometric data also suggested an improvement in coronal bone mineralization. This simple, low-cost pharmacological approach is highly effective in mitigating post-extraction vertical bone loss.