Algae-derived hydroxyapatite behavior as bone biomaterial in comparison with anorganic bovine bone: A split-mouth clinical, radiological, and histologic randomized study in humans.

Abstract

To analyze a modified biphasic phycogenic biomaterial in comparison with anorganic bovine bone in maxillary sinus floor elevation in humans. Eight male patients in need of bilateral two-stage sinus floor elevation were consecutively recruited for this randomized split-mouth study. A combination of autogenous cortical bone (ACB, 20%) and anorganic bovine bone (ABB, 80%) (ACB+ABB group) or ACB (20%) and modified biphasic phycogenic material (BP, 80%) (ACB+BP group) were randomly assigned to graft each sinus. Patients were followed up for 6months post-surgery when bone samples were collected for analysis. Radiographically, bone height gain was statistically higher in the ACB+ABB versus the ACB+BP group. While the analysis of the biological compartments showed differences in non-mineralized tissue (39.15±20.97% vs. 65.87±28.59%, ACB+ABB vs. ACB+BP respectively; p=.018) and remnant biomaterial particles (22.62±17.01% vs. 7.96±8.57%, respectively; p=.028), the percentage of mineralized tissue (38.23±17.55% vs. 24.14±24.66%, respectively; p=.398) showed no statistically significant difference. In contrast, ACB+ABB biopsies showed higher Musashi-1-positive cells per mm2 compared to ACB+BP biopsies (811.49±875.30 vs. 236.90±280.81; p<.018), where the fusiform cells corresponded mainly with fibroblasts, as demonstrated by ultrastructural analysis. Both combinations of materials exhibited bone formation after 6months of healing in the maxillary sinus cavity. However, the combination with biphasic phycogenic biomaterial induced a higher radiographical vertical resorption and graft collapse in comparison with the combination with anorganic bovine bone, possibly due to a higher remodeling of the graft.