3D Culture Enhances Osteoblast Mineralization on Dental Implant Surfaces

It has been demonstrated that 3 Dimensional Rotary Wall Vessel (3D RWV) culture techniques enhance mineralization of human preosteoblasts and is capable of forming osteogenic aggregates. Objectives: This study aimed to see if 3D cultured and engineered osseous tissues preserve the higher mineralizing capacity on dental implant surfaces. The hypothesis of this study was 3D RWV culture techniques enhance mineralization and key osteogenic gene expression of human preosteoblasts on dental implant surfaces. Methods: Human preosteoblast cells (HEPM, ATCC 1486) were cultured in both 3D RWVs and on 2D tissue culture plastic plates for 3 days. Aggregates from the 3D chambers and cells from the 2D plates were collected and transferred to commercially pure titanium discs with either 600 grit polished or 50́m aluminum oxide sandblasted surfaces. These were cultured for additional 3 days or 7 days. The aggregates and cells from the discs were collected and prepared for atomic adsorption assay for analysis of mineral content. PCR analysis was done to evaluate expression of key osteogenic genes including Cbfa1 and FAK. Results: After 3 days and 7 days calcium levels were higher in the 3D cultured groups as compared to 2D. The 7 day cultures showed higher levels of calcium versus 3 day cultures. Gene analysis for Cbfa1 indicated no difference in Cbfa1 expression between the 2D and 3D groups. However, at both 3 and 7 days FAK in 3D cultures showed higher expression than 2D cultures. Conclusion: Results from this study may be clinically extrapolated that ‘engineered bone tissues' from human preosteoblasts cultured in 3D RWVs may be used to expedite the osseointegration process on implant surfaces, thus reducing the healing time. This study was supported by the University of Iowa College of Dentistry 2007 Research Seed Grant Program.