In vitro evaluation of the biocompatibility of dental alloys: Fibronectin expression patterns and relationships to cellular proliferation rates

This short-term (72- to 96-hour) in vitro study on fibroblasts evaluated th e biocompatibility of 3 single-phase dental alloys by determining cellular proliferation rates and the expression of a glycoprotein, fibronectin, whic h is involved in cellular adhesion processes. Method and materials: Flow 20 02 fibroblasts were cultured together with 3 single-phase dental alloys of different composition. Proliferation rates were determined by 5-bromodeoxyu ridine incorporation. Fibronectin expression was determined by indirect imm unofluorescence. Results: At 72 hours, cells cultured with the alloy contai ning the lowest amount of noble elements (gold, platinum, and palladium) an d the highest amount of silver exhibited significantly less proliferation t han did controls. At 96 hours, only cultures with the alloy containing the greatest amount of noble elements behaved in a way similar to controls. Fib ronectin organization in fibrils and in focal adhesions was correlated to h igher cellular proliferation rates. Conclusion: Fibronectin organization co uld be a useful tool to determine the biocompatibility of dental alloys. Am ong the noble elements, palladium by itself exhibits very good biocompatibi lity. These indications could be useful for practitioners in the choice of the best alloy for specific clinical applications.