Diametral and compressive strength of dental core materials

Statement of problem. Strength greatly influences the selection of core mat erials. Many disparate material types are now recommended for use as cores. Cores must withstand forces due to mastication and para function for many years. Purpose. This study compared the compressive and diametral tensile strength s of 8 core materials of various material classes and formulations (light-c ured hybrid composite, autocured titanium containing composite, amalgam, gl ass ionomer, glass ionomer cermet, resin-modified glass ionomer, and polyur ethane). Material and methods. Materials were manipulated according to manufacturers ' instructions for use as cores. Mean compressive and diametral strengths w ith associated standard errors were calculated for each material (n = 10). Analyses of variance were computed (P < .0001) and multiple comparisons tes ts discerned many differences among materials. Results. Compressive strengths varied widely from 61.1 MPa for a polyuretha ne to 250 MPa for a resin composite. Diametral tensile strengths ranged wid ely from 18.3 MPa for a glass ionomer cermet to 55.1 MPa for a resin compos ite. Some resin composites had compressive and tensile strengths equal to t hose of amalgam. Conclusion. Light-cured hybrid resin composites were stronger than autocure d titanium containing composites. The strengths of glass ionomer-based mate rials and of a polyurethane material were considerably lower than for resin composites or amalgam.