The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the theoretical technique, finite element stress-analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia ceramic crown were prepared and 1.5 mm ferrule height was provided. Each model contained...

BaO -SiO2-Al2O3 glass ceramics containing K2O and B2O3 were prepared using conventional melting of powered batches, quenching in water and crystallization of sintered glass. XRD patterns introducehexacelsian and celsian as two major crystallized phases in sintered glass-ceramics. Presence of K2O enhances crystallization of hexacelsianin comparison withB2O3.Observations showed sintering temperat...

silane to improve the adhesion of phosphate monomer-based (MDP) resin cement to glass ceramic. Resin and feldspathic ceramic blocks (n=48, n=6 for bond test, n=2 for microscopy) were randomly divided into 6 groups and subject to surface treatments: G1: Hydrofluoric acid (HF) 9.6% for 20 s + Silane + MDP resin cement (Panavia F); G2: HF 9.6% for 20 s + Silane + Heat Treatment (oven) + Panavia F;...

Dental materials need to be thoroughly examined in order to assess their long-term therapeutical value. Chemical degradation of dental ceramic material enhances its roughness, leading to the wear of the opposing natural tooth or restorative material, greater plaque attachment to ceramics, weakening of the ceramic structure causing the critical ion exchange at the surface and enhancing the sensi...

OBJECTIVES This study evaluated the effect of three different surface conditioning methods on the bond strength of a Bis-GMA based luting cement to six commercial dental ceramics. METHODS Six disc shaped ceramic specimens (glass ceramics, glass infiltrated alumina, glass infiltrated zirconium dioxide reinforced alumina) were used for each test group yielding a total number of 216 specimens. T...

A YSiAlON glass has been studied by mechanical spectroscopy, through the glass transition. The a-relaxation peak observed in the YSiAlON glass can be interpreted well by a formalism of hierarchically correlated molecular mobility through the glass transition. In particular this formalism accounts for the observation of unusually high apparent activation energy. The viscoelastic properties of th...