A novel CAD/CAM resin composite block with high mechanical properties

To determine the mechanical properties of a newly-developed CAD/CAM resin composite block and compare with other resin composite blocks and a polymer-infiltrated ceramic block.

Experimental composite block was formulated by our proprietary resin and filler technologies and cured via Hot Isostatic Pressing (HIP). Bar-shaped specimens (1 × 4×12 - 13 mm, n = 10) for flexural strength, flexural modulus and modulus of resilience were sectioned from block materials and measured in accordance to modified ISO-6872. Cylinder specimens for compressive strength (2 × 4 mm, n = 8) and for diametral tensile strength (6 × 3 mm, n = 8) were milled from the block materials and tested according to ASTM-D695 and ANSI/ADA-Specification #27, respectively. Block specimens (5 mm, n = 3) for Vickers hardness were polished and measured for five indentations on each specimen. The data was analyzed by one-way ANOVA and post-hoc Tukey tests (p ≤ 0.05).

Experimental composite block showed higher or significantly higher flexural strength, flexural modulus, modulus of resilience, compressive strength, diametral tensile strength and Vickers hardness than the other commercially available block materials except Vita Enamic for flexural modulus and hardness and Cerasmart for modulus of resilience. Some positive correlations were observed among the different mechanical properties.

New composite block exhibited higher mechanical properties as compared to commercially available composite block materials. Superior mechanical properties for resin composite block materials were obtained by composite and curing processing technologies. Resin composite blocks with higher mechanical properties are good options for the fabrication of CAD/CAM indirect restorations.