The physical properties of a machinable resin composite for esthetic restorations.

To investigate the pre-clinical relevancy of a machinable composite, its physical properties were evaluated and compared with a machinable ceramic and two indirect composites. A machinable resin composite (GN-I composite, CO), a machinable ceramic (GN-I ceramic, CE), and two resin composites (Artglass dentin, AG; Estenia dentin, ET) were used. Compressive strength, diametral tensile strength, flexural strength, elastic modulus, and fracture load of standardized, premolar crown-shaped specimens were determined. In terms of compressive strength, diametral tensile strength, and flexural strength, AG showed significantly lower values than the other three materials. In terms of fracture load, specimens with 1.5 mm thick wall showed a higher value than those with 1.0 mm thick wall, and the value decreased in the order of ET, CE, CO, and AG. Marginal tipping was also observed in ET and CE. Within the limits of the current study, CO showed physical properties favorable for constructing esthetic restorations.