Comparison of Proliferation and Differentiation of Human Osteoblast-Like Cells Harvested During Implant Osteotomy Preparation Using Two Different Drilling Protocols

Purpose: Autogenous bone grafts are considered a "gold standard." The success of autografts mainly depends on their ability to promote an osteogenic response. The aim of this study was to collect autogenous bone during implant osteotomy preparation using two different drilling protocols and to evaluate and compare the proliferation and differentiation ability of the collected bone particles. Materials and Methods: Autogenous bone particles were harvested from 20 patients during implant osteotomy preparation using two different drilling protocols: (1) standard drilling protocol with saline irrigation (according to the manufacturer's recommendation) and (2) low-speed drilling protocol without saline irrigation (speed 200 rpm). Collected bone samples were cultured in growth medium, and after 2 to 3 weeks, cells that grew out from bone grafts were cultured in the normal medium as well as in osteogenic medium for days 0, 4, 7, and 20. Scanning electron microscopy, alizarin red/toluidine blue staining, DNA, ALP, and calcium content measurements were performed. Repeated measures analysis of variance (ANOVA) with Bonferroni's test was employed to analyze the data of this study. Results: The total DNA content was significantly higher for the low-speed drilling samples compared with the standard drilling on day 4 (P .05), day 7 (P .01), and day 20 (P .001) in the normal medium and on day 7 (P .01) and day 20 (P .01) in the osteogenic medium. Besides, calcium measurements and mineralized matrix formation observed with alizarin red/toluidine blue staining were significantly higher for the low-speed drilling group compared with the standard drilling group. Conclusion: Osteogenic efficacy (differentiation and proliferation) of autogenous bone particles collected using low-speed drilling was superior compared with standard drilling samples. Keywords: bone graft(s), bone remodeling/regeneration, cell differentiation, dental implants, mineralized tissue/development, osteoblast