Early types of metal-free ceramics did not enjoy success in dentistry, especially in the posterior region (Shimada et al., 2002). The high crystalline content ceramic systems have been developed in an attempt to improve the strength of metal-free restorations as well as deliver more esthetic results than conventional metal-fused-to-ceramic restorations (Ozcan et al., 2001; Valandro et al., 2006...

BACKGROUND Recasting the base metal alloys is done as a routine procedure in the dental laboratories whenever there is casting failure or to decrease the unit cost of a fixed partial denture. However, this procedure may affect the metal ceramic bond. Furthermore, it is unclear, as to which test closely predicts the bond strength of metal-ceramic interface. The aim was to compare the bond streng...

The aim of this study was to evaluate the shear bond strength of Co-Cr and Ni-Cr metal alloys and a specific ceramic, submitted to different thermocycling immersion times. Sixty metal-ceramic specimens were confectioned and standardized in cylindricalformat. Three thermocycling conditions were evaluated: without thermocycling, 3,000 cycles (5 degrees C/55 degrees C+/-1) with 30s of immersion ti...

Metal-on-ultra-high molecular weight polyethylene (UHMWPE) total hip replacements have been the most popular and clinically successful implants to date. However, it is well documented that the wear debris from these prostheses contributes to osteolysis and ultimate failure of the prosthesis, hence alternative materials have been sought. A range of 28 mm diameter bearings were investigated using...

Osteolysis is due to particulate wear debris and is responsible for the long-term failure of total hip replacements. It has stimulated the development of alternative joint surfaces such as metal-on-metal or ceramic-on-ceramic implants. Since 1988 the second-generation metal-on-metal implant Metasul has been used in over 60 000 hips. Analysis of 118 retrieved specimens of the head or cup showed ...

I thank Dr. Tony Pensak for his interest and comments on my article on gingival response to crowns.1,2 Dr. Pensak is suggesting that the poor gingival response of the 2 maxillary central incisors to the metalceramic crowns (Fig. 1) had more to do with the metallic content of these crowns than their marginal fit and contour. The literature is rich with evidence of longterm success and longevity ...

The biologic response to polyethylene particulate debris generated from metalonpolyethylene bearing surfaces is thought to be largely responsible forperiprosthetic osteolysis and aseptic loosening in total joint arthroplasty. As a result, there has been an interest in developing polyethylene with improved wear characteristics, as well as a renewed interest in alternative bearing surfaces for to...

INTRODUCTION Zirconium is a metal with excellent biocompatibility, which when oxidized is converted to the ceramic, zirconia. Composite-bearing materials have recently become available consisting of a metal zirconium core with an oxidized zirconia surface. The metal-ceramic composite has the wear characteristics of a ceramic bearing but with a much lower propensity for fracture. This dual advan...

BACKGROUND The optimal type of bearing for hip arthroplasty remains a matter of debate. Ceramic-on-polyethylene (CoP) bearings are frequently used in younger and more active patients to reduce wear and increase biocompatibility compared to Metal-on-Polyethylene (MoP) bearings. However, in comparison to metal heads, the fracture risk of ceramic heads is higher. In addition, ceramic head fracture...

Metal transfer has been observed on retrieved THA femoral heads for both CoCr and ceramic bearing materials. In vitro wear testing has shown increased wear to polyethylene acetabular liners with the presence of metal transfer. This study sought to investigate the extent of metal transfer on the bearing surface of CoCr and ceramic femoral heads and identify prevalent morphologies. Three bearing ...