Evaluation of poly lactic-co-glycolic acid-coated β-tricalcium phosphate for alveolar ridge preservation: A multicenter randomized controlled trial

Abstract

Background: Alveolar ridge preservation via socket grafting (ARP-SG) is indicated to attenuate physiologic alveolar bone resorption as a consequence of tooth extraction. However, a specific bone grafting material that is patently superior has not been identified yet. The aim of this randomized controlled trial was to evaluate the efficacy of a moldable alloplastic graft, Poly Lactic-Co-Glycolic Acid-Coated β-Tricalcium Phosphate (PLGA-β-TCP), for ARP purposes [Group A] compared to freeze-dried bone allograft (FDBA) particles covered with a rapidly absorbable collagen dressing (RACD) (Group B) in function of a panel of radiographic, histomorphometric, and implant-related outcomes.

Methods: Patients in need of extraction of a single posterior tooth (premolar or molar) and subsequent replacement with a dental implant were recruited and randomly allocated into one of the two treatment groups. Follow-up visits took place at 1, 2, 4, 8, and 16 weeks. Cone-beam Computed Tomography (CBCT) scans were obtained at baseline and at 16 weeks. Sites were re-entered at 20 weeks for bone core biopsy harvesting and subsequent implant placement. After delivery of the final implant-supported restoration, follow-up visits were scheduled at 6 and 12 months to monitor peri-implant tissue health and marginal bone levels using standardized intraoral periapical radiographs.

Results: A total of 45 patients were initially enrolled in the study, of whom 43 received an implant and 32 completed the study. Healing was uneventful in all sites after ARP-SG and implant placement. No site required bone augmentation to allow for implant placement. CBCT scan analyses showed no statistically significant differences between groups in terms of reduction of horizontal width, midbuccal / midlingual height and ridge volume. Histomorphometric assessments revealed a statistically significant difference between both groups in terms of mineralized tissue formation (Group A = 27.0% ± 22.1% versus Group B = 38.2% ± 12.5%; P < 0.05). On the contrary, no significant differences were observed regarding percent of remaining bone grafting material and non-mineralized tissue. No implant failed throughout the study period and marginal bone level change was negligible in both groups.

Conclusions: Although a higher proportion of mineralized tissue was associated with the use of FDBA+RACD compared to PLGA-β-TCP alone, both ARP-SG approaches rendered comparable outcomes in terms of maintenance of alveolar bone dimensions, feasibility of implant placement, implant survival, and peri-implant bone level stability up to 12 months post-loading.

Keywords: alveolar bone grafting; alveolar process; cone-beam computed tomography; dental implantation; histology.