Magnesium-enriched hydroxyapatite versus autologous bone in maxillary sinus grafting : combining histomorphometry with osteoblast gene expression profiles ex vivo

Background: Many biomaterials are proposed for sinus floor lifting and grafting in the posterior maxilla for insufficient bone volume (BV). The aim of this study was to compare the use of magnesium-enriched hydroxyap-atite (mHA) versus autogenous bone graft (AB) for maxillary sinus lift procedures by histomorphometric and in vivo gene expression profiling. Methods: Fifteen patients requiring bilateral maxillary sinus augmentation received autologous bone particles (group A) and mHA (group B) (split-mouth design). Five months later, implants were placed, and biopsies were obtained. Bone specimens were analyzed by histomorphometry, BV and vital bone (VB) percentages were calculated, and ex vivo osteoblast expansion followed by highly sensitive osteoblast specific gene expression profiling for cbfal, osteocalcin, osteopontin, collagen type I, receptor activator of nuclear factor-kappa B ligand (RANKL), and osteo-protegerin (OPG) by quantitative real-time reverse transcription-polymer-ase chain reaction (RT-PCR) were performed. Comparisons were made using the Student t test. Results: After healing with no complications, B V was comparable in the two groups (80.79% \ub1 14.27% for autologous versus 76,72% \ub111,47% for mHA; P= not statistically significant), but VB was lower in the mHA group (29.65% + 9.81% versus 78.40% \ub1 16.72%; P