Histological and histomorphometric evaluation of anorganic bovine bone used for maxillary sinus floor augmentation: a six-month and five-year follow-up of one clinical case.

Background: Anorganic bovine bone (ABB) is widely used in maxillary sinus floor augmentation procedures. Nevertheless, long-term human clinical cases data are very rare but still important to understand the behavior of the xenograft. The objective of this study was to analyze and to compare the histological and histomorphometric results of maxillary sinus floor augmentation using ABB at 6-month and 5-year post surgery on the same human clinical case.

Methods: Bone samples from a single patient received slight specific decalcification process before histologic and histomorphometric analyzes.

Results: At 6-month postoperative, the histological section showed numerous remaining ABB particles integrated inside the newly formed bone architecture. The histomorphometric results were 21.1% of newly formed bone, 30.5% of ABB xenograft, and 48.4% of marrow/connective tissue. At 5-year postoperative, small residual particles of ABB were surrounded by large areas of newly formed bone. The histomorphometric mean rates were 44.0% ± 0.1% of newly formed bone, 3.5% ± 0.3% of ABB xenograft, 6.8% ± 0.7% of bone marrow, and 45.8% ± 0.1% of connective tissue.

Conclusions: The 6-month and 5-year postoperative histomorphometric data of this clinical case confirmed the long-term continuous ongoing resorption process of the ABB and increasing newly formed bone rate.