Comparison of two different forms of bovine-derived hydroxyapatite in sinus augmentation and simultaneous implant placement: an experimental study.

PURPOSE: The aim of this study was to compare two different forms of bovine-derived hydroxyapatite (HA) in sinus augmentation and simultaneous implant placement.

MATERIALS AND METHODS: The schneiderian membranes of 12 domestic pigs were elevated bilaterally through an extraoral approach. One sinus of each pig was grafted with bovine-derived granular HA (GHA) and the other was grafted with bovine-derived spongiosa block HA (BHA) (Unilab Surgibone). One dental implant was placed simultaneously into each grafted sinus. Animals were sacrificed after 6 months of healing. Primary implant stability (ISQi) and secondary implant stability (ISQf) were measured by resonance frequency analysis. Undecalcified sections were prepared for histomorphometric analysis.

RESULTS: Mean ISQi values for implants placed in sinuses grafted with BHA and GHA were 68.8 +/- 5.0 and 68.2 +/- 3.7, respectively (P > .05). The mean ISQf value for implants in GHA increased to 72.0 +/- 5.1 and for implants in BHA decreased to 52.3 +/- 8.8 (P < .01). There was a statistically significant difference between ISQi and ISQf values for implants placed in BHA (P = .03) and GHA (P = .037). Mean bone-implant contact (BIC) in residual bone was 61.3% +/- 2.1% for BHA and 61.2% +/- 1.7% for GHA (P > .05). In augmented bone, mean BIC percentages were 20.6% +/- 2.1% and 35.6% +/- 1.8% for BHA and GHA, respectively (P = .002). Mean percentages of connective tissue were 61.9% +/- 9.5% and 48.4% +/- 10.7% (P = .036), new bone formation percentages were 12.8% +/- 5.5% and 27.9% +/- 4.6% (P = .012), and percentages of graft material around the implants were 25.3% +/- 5.8% and 22.4% +/- 6.2% (P > .05) for BHA and GHA, respectively.

CONCLUSION: The form of graft material affects the osseointegration of implants in sinus augmentation and simultaneous implant placement.