Effect of anorganic bovine bone to autogenous cortical bone ratio upon bone remodeling patterns following maxillary sinus augmentation

Introduction: Maxillary sinus augmentation is a predictable implant site development technique, although several local and systemic factors may influence outcomes. The aim of this study was to evaluate healing patterns and bone remodeling activity following the use of two different graft mixtures for maxillary sinus augmentation. Materials and methods: Patients in need of maxillary sinus augmentation were randomly assigned to two different groups. A graft mixture using a 50% autologous bone (AB) to 50% anorganic bovine bone (ABB) ratio was used in group 1, while a 20% AB to 80% ABB ratio was utilized for group 2. After a 6-month healing period, bone core biopsies were harvested for histological, histomorphometrical, and immunohistochemical analyses. Results: Twenty-eight subjects participated in this study. No statistically significant differences were found between groups in regards to vital bone and non-mineralized tissue proportions. Higher number of osteoid lines (18.05 +/- 10.06 in group 1 vs. 9.01 +/- 7.53 in group 2; P = 0.023) and higher cellularity, particularly regarding the number of osteocytes (631.85 +/- 607.98 in group 1 vs. 219.08 +/- 103.26 in group 2; P = 0.002), were observed in specimens from group 1. Differences in expression patterns of osteopontin and tartrate-resistant acid phosphatase were also detected between groups. Conclusion: AB to ABB ratio appears to influence bone remodeling patterns and cell content following maxillary sinus augmentation procedures. Similar proportion of vital bone was found in specimens obtained from both groups. More cellular presence was observed in samples containing higher proportions of AB.