Experimental comparison of bovine derived block hydroxyapatite and granule hydroxyapatite graft materials in sinus augmentation and simultaneous implant placement procedures

Maxillary sinus augmentation is a surgical procedure, which is performed in order to increase the inadequate bone height in posterior maxillary region prior to or in conjunction with implant placement. The success of bovine derived granule hydroxyapatite (GHA) in sinus augmentation was reported in most of experimental and clinical studies. The effects of solid bovine derived block HA (BHA) on implant stabilization, osseoentegration, new bone formation and advantages and disadvantages of BHA when compared with GHA in sinus augmentation procedure are not clear in the literature. In this research, the success of two different forms of bovine derived HA in sinus augmentation and simultaneous implant placement procedures were compared by means of resonance frequency analysis (RFA) and histomorphometric methods.In this study, 12 adult domestic pigs were used. The maxillary sinus membranes of the pigs were elevated bilaterally via extraoral route. One sinus of each pig was grafted with 3cc bovine-derived GHA, the other with bovine-derived spongiosa BHA (20x20x10mm). One dental implant was placed simultaneously per grafted sinus via extraoral route. The animals were sacrificed after 6 months of healing. Primary and secondary implant stability were measured by RFA. The implants and bone-graft complex around implants were removed in block forms. Undecalcified sections were prepared for histomorphometric analysis. The data were analyzed statistically.Although both bovine derived HA grafts used in this study are manufactured from the same materials, the form of the grafts influenced osseoentegration of the implants. The implants placed into bovine derived GHA showed better stabilization and osseoentegration when compared to the implants placed into bovine derived BHA in sinus augmentation and simultaneous implant placement procedures after 6 months of healing.