Influence of platelet-derived growth factor on osseous remodeling properties of a variable-thread tapered dental implant in vivo.

ABSTRACT

OBJECTIVES: To evaluate the effect of platelet-derived growth factor (rhPDGF-BB) on the promotion of osteogenesis around variable-thread tapered implants in an animal model. MATERIAL AND METHODS: Twenty-four variable-thread tapered implants were inserted in the tibia of 12 rabbits. Twelve sites received additional rhPDGF-BB released from a presoaked xenogenic bone block that was fixed supracrestally. Primary outcomes were bone-to-implant contact (BIC; in % ± SD) and percentage of medullary bone fill around the implants (PMF; in % ± SD) after 3 weeks (PDGF n = 6, no PDGF n = 6) and 6 weeks (PDGF n = 6, no PDGF n = 6). RESULTS: Considerable crestal and medullary bone remodeling could be found around all implants. After 3 weeks, both BIC and PMF values were higher in the no PDGF group (BIC 63% ± 10 with PDGF vs. 85% ± 5 with no PDGF; PMF 57% ± 10 with PDGF vs. 74% ± 4 with no PDGF). After 6 weeks, the BIC difference between the two groups was less distinct (BIC 78% ± 17 with PDGF vs. 72% ± 25 with no PDGF), whereas the PDGF group showed higher PMF values (PMF 77% ± 5 with PDGF vs. 56% ± 10 with no PDGF). CONCLUSIONS: The addition of rhPDGF-BB decreases early osseous crestal and medullar healing properties around dental implants. In a later phase, an increase in the cortical area as well as an increased medullar bone formation was seen. This response is likely to provide stronger secondary stability and stability in suboptimal situations involving poor-quality bone.