Scintigraphic, histologic, and histomorphometric analyses of bovine bone mineral and autogenous bone mixture in sinus floor augmentation: a randomized controlled trial--results after 4 months of healing.

PURPOSE: To test our null hypothesis stating that the mixture of autogenous cortical bone scrapings and bovine bone mineral (BBM) in a ratio of 1:4, compared with BBM alone, would have no significant effect on new bone formation 4 months after maxillary sinus floor augmentation.

PATIENTS AND METHODS: Twenty-four patients presenting with alveolar bone height of less than 5 mm in the narrowest zone between the sinus floor and alveolar crest were randomly assigned to 2 treatment groups in this randomized controlled trial. We augmented 12 maxillary sinuses with a mixture of BBM and cortical autogenous bone graft, which was collected from the lateral wall of the maxillary sinus by a bone scraper, and 12 maxillary sinuses with BBM alone. Four months postoperatively, new bone formation in the augmented sinus sites was evaluated through bone scintigraphy, as well as histologic and histomorphometric analyses of the biopsy specimens obtained during implant placement. Data were statistically analyzed by independent-samples t test.

RESULTS: Scintigraphically detectable new bone formation did not differ significantly between the groups (P > .05). Histologic findings showed that the new bone bridged between BBM particles and BBM underwent resorption by osteoclasts with or without the addition of autogenous bone graft. According to histomorphometric findings, the difference between the percentages of newly formed bone in the sinuses augmented with graft mixture (25.73%) and BBM alone (24.19%) was statistically nonsignificant (P > .05).

CONCLUSIONS: The addition of autogenous cortical bone scrapings to BBM in a ratio of 1:4, compared with BBM alone, does not markedly increase new bone formation 4 months after maxillary sinus lifting.