Fabrication and analysis of a multiple-phase infused ceramic matrix

Abstract

In-Ceram is an all-ceramic restorative material with improved resistance to crack propagation. Ceramics of various compositions are widely used as restorative materials in dentistry. In-Ceram has an alumina core that is infiltrated with glass to achieve a high strength substructure that can support crowns and bridges. This material belongs to the class of interpenetrating phase materials. The objective of this study was to determine flexural strength and fracture toughness of the alumina core infiltrated with resin, glass, and resin/glass combined, as well as to evaluate crack propagation through different layers of the material. Four-point flexural strength values of bend bars were 355.54 [plus or minus] 49.83 MPa for In-Ceram infused glass, 245.1 [plus or minus] 18.62 MPa for In-Ceram infused resin, 21.41 [plus or minus] 3.5 MPa for In-Ceram sintered alumina and 278.2 [plus or minus] 26.94 MPa for In-Ceram infused glass and resin (dual infused). Fracture toughness values were 3.20 MPa.m[1/2] for In-Ceram infused glass with 5 Kg load applied and 10.56 MPa.m[1/2] for In-Ceram infused resin with 20 Kg load applied. SEM evaluation indicated inhibition of crack propagation throughout the layers of glass and resin of a dual infused sample, when the crack was initiated on the glass infused layer.