Properties and cyclic fatigue of glass infiltrated tape cast alumina cores produced using a water-based solvent

Abstract 

Objective

The purpose of this study was to investigate the properties of tape cast alumina composite produced using a water-based solvent and its possible clinical use as an all ceramic crown system in a fixed partial denture. Durability of the system will be measured by fatigue test to simulate the masticating conditions of the oral cavity.

Methods

The optimal weight ratio of water-based alumina tape was determined by tensile strength, shrinkage ratio and durability. The coefficient of thermal expansion, fracture toughness, biaxial flexural strength and flexural strength after fatigue test of a composite produced from alumina tape at optimal weight ratios were determined and compared to In-Ceram alumina core (control).

Results

The weight ratio of alumina/(alumina+binder+plasticizer) of 0.84 and binder/(binder+plasticizer) of 0.5 was observed to be the optimal composition for achieving excellent composite properties. Coefficient of thermal expansion of the sintered alumina tape was observed to be 7.3×10⁻⁶/°C, and this value was increased to 7.5×10⁻⁶/°C after infiltrating the sintered tape with glass. The fracture toughness and biaxial flexural strength of glass infiltrated alumina tape was observed to be 4.6MPam^1/2 and 498MPa, respectively. After cyclic loading for 10²–10⁶ cycles, no significant change in the biaxial flexural strength was observed between the glass infiltrated alumina core and the In-Ceram alumina core (p>0.05).

Significance

The observed properties provide evidence that the water-based tape cast alumina–glass composite is suitable for clinical use as an all ceramic crown system in a fixed partial denture.

Keywords: All ceramic crown, Alumina tape, Tape cast, In-Ceram, Cyclic fatique, Biaxial flexural strength