Effects of coloring procedures on shear bond strength between resin cement and colored zirconia.

Abstract

Zirconia has a high fracture strength of more than 1000 MPa, fracture resistance of higher than 2000 N, and fracture toughness of 9–10 MN/m3/2 (1). In addition to these favorable mechanical properties, it is chemically durable (2), biocompatible (3, 4), and displays esthetic advantages (5) over metal-ceramic restorations. However, recent clinical trials have shown that zirconia-based ceramic restorations’ decementation is a common failure. Restoration’s cementation corresponds to restoration durability, and cementation is also an important factor for marginal fit and fracture strength of restorations (6, 7). There are various cementation options for zirconia framework restorations. Cementation of zirconia restorations with traditional luting cements (such as glass ionomer or zinc phosphate cements) provides adequate clinical fixation, but adhesive cementation may be preferred for better retention and marginal adaptation (7-10). In addition, resin cement shows higher compressive and tensile strength than other luting agents, and allows color selection for more esthetic restorations (11, 12).