Gene expression and morphometric parameters of human bone biopsies after maxillary sinus floor elevation with autologous bone combined with Bio-Oss® or BoneCeramic®

Abstract

Objectives: Although the clinical success of Bio-Oss(®) and BoneCeramic(®) has been corroborated by histologic and histomorphometric findings, the biological events that occur during healing after maxillary sinus floor elevation (MSFE) are unknown. Here, we evaluated biopsies of grafted bone with a mixture of autologous bone and Bio-Oss(®) or BoneCeramic(®) after two different healing time periods to understand the molecular process underlying bone formation after MSFE.

Material and methods: Seven patients, following a bilateral split-mouth design model and needing a MSFE to allow implant placement, were recruited for this study. Right or left sinuses were grafted with autologous maxillary bone combined either with Bio-Oss(®) or BoneCeramic(®) , respectively. Twenty biopsies were taken at the time of implant insertion after 4-5 months or 6-8 months of MSFE, and analyzed by micro-computed tomography (microCT) and gene-expression analysis.

Results: MicroCT analysis revealed no differences in the morphometric parameters or BMD either after 4-5 months or 6-8 months of MSFE between Bio-Oss(®) and BoneCeramic(®) . At molecular level, a higher expression of bone forming gene Runx2 was observed after 4-5 months of MSFE in the Bio-Oss(®) compared with the BoneCeramic(®) group.

Conclusions: Our results indicate that differences found at the molecular level between Bio-Oss(®) and BoneCeramic(®) are not translated to important differences in the 3D microstructure and BMD of the grafted bone.

Keywords: bone graft; clinical study; dental implant; gene expression; maxillary sinus floor elevation (MSFE); micro-computed tomography (microCT).