Osseointegration with Ceramic Coated Implant / 대한척추외과학회지

PURPOSE: This study was designed to clarify the osseointegration of the titanium screw coated with CMP, in regard to the time schedule, through the characteristic of early osseointegration. MATERIALS AND METHODS: Mechanical, radiological and histomophometric measurements were performed in 28 rabbit tibial proximal metaphyseal cortical bone screws 6, 12, 26 and 52 weeks after surgery for the in vivo comparison of the osseointegration of titanium screws (3.75 mm diameter, 5 mm length) with different surface treatments: CMP coating group, with the sol-gel method (experimental group) and uncoated group (control group). RESULTS: 1. Radiology: There were no differences between the two groups without a radiolucent line or in regard to the time schedule. 2. Histology: There were no differences between the two groups without a fibrous tissue intervening surface or in regard to the time schedule. 3. Torque test: The test results for the CMP coated group were 1.5 times higher than those for the uncoated group, which was statistically meaningful, but there was no difference in regard to the time schedule. CONCLUSION: CMP coating is an option to increase the osseointegration of the titanium screw.

Cellular Biocompatibility and Stimulatory Effects of Calcium Metaphosphate on Osteoblastic Differentiation of Human Bone Marrow-derived Stromal Cells / 대한정형외과연구학회지

PURPOSE: The in vitro biocompatibility of Calcium Metaphosphate (CMP) with human bone marrow stromal cells (HBMSCs) and its effect on osteoblastic differentiation have been evaluated. MATERIALS AND METHODS: The effects of CMP on the HBMSCs undergoing osteoblastic differentiation were evaluated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Morphologies of the HBMSCs were examined using scanning electron microscopy and confocal laser scanning microscopy. Osteoblastic differentiation of the HBMSCs was analyzed by alkaline phosphatase (ALP) staining and RTPCR. RESULTS: The CMP powder and disk did not exert cytotoxic effect on the HBMSCs. In addition, the HBMSCs were adhered on the surface of CMP disk as successfully as on the culture plate or HA disk and displayed similar actin arrangement and cellular phenotypes. Furthermore, the HBMSCs grown on three different matrices were able to support osteoblastic differentiation of the HBMSCs as accessed by ALP staining. However, the CMP disk compared to the HA disk has a better ability to induce expression of osteoblast-related genes such as ALP, osteopontin (OPN) and osteoprotegerin (OPG). CONCLUSION: The results demonstrate that, in addition to biocompatibility of the CMP with the HBMSCs, the CMP has an ability to stimulate osteoblastic differentiation of the HBMSCs in vitro.