To evaluate the influence of surface topography on osseointegration of titanium implants in rat maxillae following systemic bisphosphonate use.
Method:
Twenty Sprague-Dawley rats were divided into two groups - test (systemic bisphosphonate use) and control (no bisphosphonate administered). Bisphosphonate administration began three weeks prior to implant placement with thrice-weekly doses of zoledronic acid (66μg/kg). 40 endosseous implants (two per animal placed bilaterally) with a moderately rough surface (20 implants) or a turned surface (20 implants) were placed in the extraction sockets of maxillary molars. Animals were sacrificed at postoperative times of 14 and 28 days and the implant and surrounding material harvested for histological and histomorphometric analysis. Statistical analysis consisted of unpaired t-test with a level of significance of P≤0.05.
Result:
The quantitative Bone-To-Implant ratio (BIC) analysis (mean±standard error of measurement) of moderately rough surfaced and turned surfaced implants at 14/28 days were: test group -18.94±2.92, 11.42±0.37 / 28.23±2.76, 13.66±2.43; control group - 46.36±2.27, 33.29±3.97 / 72.99±2.95, 47.62±8.14. Histomorphometric analysis indicated higher BIC values on moderately rough compared to turned surfaced implants. Higher BIC values in control group compared to test group was demonstrated to be statistically significant in both implant surfaces and at all time points. Histological observation within control and test groups demonstrated initial bone formation around moderately rough surfaced implants not only at the parent bone, as was the case with the turned surfaced implants, but also along the implant surface itself. Test group specimens illustrated less bone remodeling activity at 14 and 28 days after implants placement, compared with control specimens.
Conclusion:
Surface topography influences osseointegration in pristine bone and following systemic bisphosphonate use. Osseointegration occurs at a higher rate and to a greater extent adjacent to moderately rough surface implants than to turned surface implants.