الفهرس | Only 14 pages are availabe for public view |
Abstract PURPOSE. The aim of this study was to evaluate the influence of different cement thicknesses of two adhesive cements on resin-zirconia shear bond strength.. MATERIALS AND METHODS. Thirty zirconia discs were prepared from ICE zirconia block.Thirty freshly extracted molars were transversely sectioned at the deep dentin level and bonded to air-abraded zirconium oxide ceramic disks. The specimens were divided into two groups according to cement type: Rely X UniCem or Rely X ARC, and further subdivided into three subgroups according to cement thickness:50 μm,100 μm or 150 μm. All cemented specimens were stored in distilled water for 2 weeks. Then thermocycled between 5oC and 55oC for 1000 cycles with a dwell time of 30 seconds and a transfer time of 2 seconds. All the samples were subjected to a shear test to evaluate their bond strengths. Two-way Analysis of Variance (ANOVA) was used in testing significance for the effect of cement type, cement thickness and their interactions on mean shear bond strength. RESULTS. All failures occurred at the resin-zirconia interface (adhesive failure). RelyX ARC with 100 μm thickness recorded the statistically significantly highest mean shear bond strength. This was followed by RelyX ARC with 50 μm thickness. There was no statistically significant difference between RelyX ARC with 150 μm thickness, RelyX Unicem with 50 μm thickness, RelyX Unicem with 100 μm thickness and RelyX Unicem with 150 μm thickness; all scored the statistically significantly lowest mean shear bond strength values CONCLUSION. Effect of cement type on the shear bond strength more effective than cement thickness. |