Fracture resistance of pressable glass–ceramic fixed partial dentures

Abstract

The aim of the present study was to evaluate the mechanical strength of the Empress2 system, which is based on the use of a high-strength glass--ceramic core of lithium disilicate, and the fracture resistance of fixed partial dentures fabricated with this material. To evaluate mechanical strength, four types of ceramic materials were tested for four-point flexural strength and diametral tensile strength: Empress2 core material, Empress2 layering porcelain, conventional Empress material and Dicor. Then, using Empress2, conventional Empress and Dicor, actual clinical type anterior fixed partial dentures were fabricated for fracture testing. The results showed that the Empress2 core material, at 329 MPa, has more than twice the flexural strength of conventional materials and at 271 MPa, more than four times the diametral tensile strength of conventional materials. Furthermore, fixed partial dentures fabricated with Empress2 had a fracture resistance of 1424 N. That is, they were more than twice as fracture resistant as fixed partial dentures made with conventional materials.

A study on the fracture strength of collarless metal-ceramic fixed partial dentures

“…Several experiments used loading points that simulated the centric occlusion of the incisor 9,31,33-36. The points were located on the palatal surface 1 - 4 mm below the incisal edge.…”

A study on thein-vitrowear of the natural tooth structure by opposing zirconia or dental porcelain

“…Due to this trend, there has been increasing clinical application of the all-ceramic crown, which is more esthetic and bio-friendly, whereas there has been decreasing clinical application of the metal ceramic crown, which is less esthetic due to the metal coping. As the all-ceramic crown has relatively higher embrittlement and lower tensile strength, its application has been particularly limited to fixed partial dentures 1-4…”

Wear properties of dental ceramics

“…The IPS e.max Press material can be used to form a core or an entire crown. Flexural strength values for the IPS Empress 2 core are reported to be approximately 329 MPa ( Nakamura et al, 2002). A two-year clinical evaluation (Taskonak and Sertgöz, 2006) of IPS Empress restorations showed a 100% success rate for crowns and a 50% success rate for fi xed partial dentures.…”

“…A benefi t of both Procera AllCeram and the IPS e.max Press ceramic systems is high strength (Nakamura et al, 2002). However, common ceramic problems, such as surface degradation, cracks, wear and material loss (Etman et al, 2008;Etman, 2009;Etman and Woolford, 2010) still exist and uncertainties remain concerning long-term clinical performance (Haselton et al, 2000;Etman et al, 2008;Etman and Woolford, 2010).…”