Effects of low-dose rhBMP-2 on peri-implant ridge augmentation in a canine model.

ABSTRACT

AIMS: The aim of this study was to investigate the potential of low-dose rhBMP-2 combined with Hydroxyapatite (HAp)/ß-tricalcium phosphate (TCP)/ Collagen (Col) composite in repairing the peri-implant critical size defect and to determine the optimal rhBMP-2 concentration. MATERIALS AND METHODS: Fifty saddle-type alveolar defects (10 mm mesiodistally and 4 mm apicocoronally) were surgically prepared on edentulous ridges in ten beagle dogs. Following implant placement, the defects with vertically exposed implant fixtures either received (a) no graft, (b) HAp/TCP/Col composite, (c) HAp/TCP/Col +0.02 mg/ml rhBMP-2, (d) HAp/TCP/Col +0.08 mg/ml rhBMP-2 or (e) HAp/TCP/Col +0.2 mg/ml rhBMP-2. After healing for 4 or 8 weeks, bone regeneration and mineralization were assessed through radiography, micro-CT, fluorescence labelling and histologic analyses. Implant stability was measured through resonance frequency analysis. RESULTS: It was evident HAp/TCP/Col with 0.2 mg/ml rhBMP-2 manifested strong osteogenic potential in this large animal model, as significantly more and faster new bone formation with better implant stability was identified compared to the HAp/TCP/Col-alone control group (adjusted p < .05). CONCLUSIONS: Our results highlight the constructs of HAp/TCP/Col +0.2 mg/ml rhBMP-2 without barrier membranes as a promising tool for peri-implant ridge augmentation.