Date of Award
Doctor of Philosophy
Chemical and Biological Engineering
Thomas D. McGee
The objective of this research was to test both the in vitro and in vivo effects of implant surface properties on soft tissue attachment to a bioactive ceramic tooth root implant. The ceramic material used for the tooth root was a composite of tricalcium phosphate and magnesium aluminate spinel, which is called "osteoceramic." For the in vitro cell attachment assays, pure tricalcium phosphate and spinel materials were used in addition to the osteoceramic. The osteoceramic was treated to produce three different surface structures: smooth, irregular and rough. Characterization of the materials included scanning electron microscopy, elemental dispersive analysis, wetting angle, equilibrium pH and dissolution behavior;Forty osteoceramic tooth roots were implanted in the mandibles of ten dogs for various time periods to evaluate in vivo response. The top portion of the tooth root had various surface structures which were placed adjacent to the gingiva. The tissue response was clinically and radiographically evaluated; however, no significant in vivo differences were found. Histological evaluations, including microradiography, fluorescence microscopy, and light microscopy, also showed no statistically significant in vivo differences between shoulder surface treatments and shoulder heights. Response to the implants showed an increase in the amount of bone surrounding the implants over time with close bone contact to the implant surface. Almost all implants showed inflammation of the soft tissue and generally lacked an effective perimucosal seal formation;For in vitro testing to compare short-term cellular response to the ceramic materials, cell attachment assays were performed using gingival rat epithelial cells and gingival fibroblasts. The various osteoceramic surfaces had a significant effect on in vitro attachment of both cell types. The highest levels of attachment for gingival epithelial cells were observed on the rough osteoceramic surface, whereas the gingival fibroblasts attached least to the rough osteoceramic surface. Cell morphology apparent from the scanning electron micrographs supported these findings;This study found that in vitro cell attachment results do not support in vivo clinical and histological results, which may be due to the many factors affecting clinical trials.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Gabriele Gruss Niederauer
Niederauer, Gabriele Gruss, "In vivo and in vitro evaluations of a bioactive ceramic tooth root implant " (1993). Retrospective Theses and Dissertations. 10313.