| Objective. This study aims to compare several mechanical and optical properties between three different CAD/CAM materials. The properties tested are: flexural strength, modulus of elasticity, hardness, translucency and surface gloss. Background. Typically, CAD/CAM restorations are either ceramic based or resin based. A new resin-ceramic hybrid material has recently been introduced and is thought to combine the advantages of both materials. Methods. Samples were divided into three groups, leucite-reinforced porcelain (IPS Empress CAD), lithium dicilicate (IPS e.max CAD) and resin-ceramic hybrid material (Vita Enamic). Twenty-six bar-shaped specimens were fabricated for each group by cutting standard CAD/CAM blocks. 3-point bending test and Vickers diamond pyramid indenters were used to test the flexural strength and microhardness respectively. Seven veneers were fabricated for each material with a thickness of 0.5 mm using a CAD/CAM milling machine. These veneers were used to test the optical properties via spectrophotometry and gloss-meter analysis. One-way ANOVA, and the Tukey HSD post hoc test were used for statistical analysis between the groups (P<0.05). Results. No significant difference was found between IPS Empress CAD and Enamic for flexural strength and surface gloss. However there was a significant difference when comparing IPS e.max CAD to the other materials. When comparing hardness and translucency of Enamic to the other materials there was a significant difference, however, no difference was found between IPS Empress CAD and IPS e.max CAD. Conclusion. Based on the result of this study, the current commercially available hybrid resin-ceramic material (VITA Enamic) showed, for the most part, similar properties to the machinable leucite-reinforced porcelain (IPS Empress CAD). Nevertheless, it does not appear to have any significant advantages over existing all ceramic materials, which may prove to be more esthetic with time. Therefore, the use of this class of material might be suitable for simple conservative indirect restorations. Grants. This study was funded by HPD grant. |
