Regeneration of rabbit calvarial defects using biphasic calcium phosphate and a strontium hydroxyapatite‐containing collagen membrane

Objectives Biphasic calcium phosphate ( BCP ) composed of 10% hydroxyapatite ( HA ) and 90% beta‐tricalcium phosphate has been developed. Recently, a strontium hydroxyapatite‐containing collagen membrane ( S r) was shown to stimulate early bone formation in rat calvarial defects at 4 weeks postoperatively, as compared with a cross‐linked collagen membrane, for guided bone regeneration ( GBR ). The objective of this study was to evaluate these novel biomaterials for GBR in relation to a non‐cross‐linked collagen membrane ( BG ) and deproteinized bovine bone mineral ( BO ). Materials and methods Twenty N ew Z ealand rabbits were used in this study. Four defects of 7 mm in diameter were created in each rabbit, and three of the defects were treated with BG / BO , Sr/ BO , and Sr/ BCP . Ten rabbits were sacrificed at 12 and 24 weeks, respectively. Histological and histomorphometric analyses were conducted. Volumetric densities of mineralized new bone ( MNB ), bone marrow ( BM ), residual grafting material ( RG ), and non‐mineralized connective tissue ( NCT ) were determined for each group. Results After 12 weeks, S r/ BCP yielded more MNB than BG / BO and S r/ BO with no significant difference among the three groups. After 24 weeks, however, Sr/ BCP demonstrated significantly more MNB than BG / BO and Sr/ BO . Both after 12 and 24 weeks, Sr/ BCP showed significantly less RG than BG / BO and Sr/ BO . There was a significant increase in MNB in Sr/ BCP from 12 to 24 weeks. Conclusions In defects grafted with BCP , more MNB was formed while less RG remained, than in defects grafted with BO . The Sr membrane was as effective as BG when comparing Sr/ BO with BG / BO .