The overall objective of this project is to investigate the hypothesis that osteoblast function, specifically biosynthesis of extracellular matrix, and mineralization are affected by the magnitude and frequency of strain present at the implant-tissue interface. Support for this hypothesis is provided by the fact that placement of dental implant within bone will change the local biomechanical environment, which in turn will affect the healing and integration of the device. Excessive loading or non-loading of bone will result in fibrous tissue or bone resorption respectively around the implant instead of osseointegration. Since tissues grow in intimate contact with implant surfaces in vivo, it is essential to study how cells respond to implant surface strains under well characterized loading conditions and thus develop bone matrix at the tissue-implant interface. This information is critical as immediately loaded implant systems are designed. To study this hypothesis, a custom cell culture strain plate will be used to apply known magnitudes of strain and frequency of loading to osteoblast cells growing on an implant alloy in vitro. This strategy is important since it provides the means to measure and assess biomechanical interactions between cells and materials on a local level under in vivo-like conditions. The nature of such interactions cannot be determined by other means. In this two year study, the expression of osteoblast markers and production/secretion of matrix will be evaluated and compared to unstrained control cells over a five day interval. The hypothesis will be evaluated by measuring osteoblast extracellular matrix production parameters such collagen type I and osteocalcin by ELISA, and mineralization by alkaline phosphatase activity and calcium deposition by colorimetric and microscopic analyses. The significance of this study will be to provide critical information on the role that the local biomechanical environment plays in thge formaiton of the implant-tissue interface. Furthermore, it may also be useful in identifying loading parameters that promote osteointegration.
|Walboomers, X F; Elder, S E; Bumgardner, J D et al. (2006) Hydrodynamic compression of young and adult rat osteoblast-like cells on titanium fiber mesh. J Biomed Mater Res A 76:16-24|