statement of the problem: by introducing the coloring liquids, it is claimed that it is possible to make the color of frameworks fabricated from zirconium oxide extremely close to the natural tooth color. purpose: the purpose of this research was to evaluate the effect of two staining techniques on value changing in zirconia crowns. materials and method: three groups a, b, and c, each containin...

Using three-dimensional finite element analysis (3D-FEA), stress distributions in the remaining radicular tooth structure were investigated under the condition of varying diameters of fiber post for fiber post-reinforced composite resin cores (fiber post and core) in maxillary central incisors. Four 3D-FEA models were constructed: (1) fiber post (ø1.2, ø1.4, and ø1.6 mm) and composite resin cor...

The aim of the study was to evaluate the core veneer bond strength of graded zirconia combinations and compared those to conventional zirconia combinations after thermal and mechanical tests. Conventional zirconia-veneer combinations and graded zirconia-veneer combinations were made into cylinders. Prior to shear bond testing, half of each group was subjected to thermal and mechanical cycling t...

the purpose of this ex- vivo study was to evaluate the fracture resistance of simulated immature teeth, obturated with gutta-percha or resilon and reinforced by either composite resin or fiber post.eighty-four human maxillary incisors were divided into seven groups (n=12). teeth in all groups were prepared until peeso #5 (1.5mm) could be passed through the apex. root ends received 4mm of mta pl...

conclusions: The restoration of root canal treated teeth – because of the significant loss of tooth structureis often achieved with post and core. However, posts may generate stresses, which lead to vertical root fracture and the loss of the tooth. Since post design, materials used and post space preparation has significant influence on vertical fracture prevalence, broad investigation is in pr...

This article presents a literature review on the resin bond to zirconia ceramic. Modern esthetic dentistry has highly recognized zirconia, among other ceramic materials. Biocompatibility of zirconia, chemical and dimensional stability, excellent mechanical properties, all together could guarantee optimal therapeutical results in complex prosthodontic reconstruction. On the other hand, low therm...

AIM The purpose of this in vitro study was to assess and compare the retention of zirconia copings luted with different luting agents onto zirconia and titanium abutments. MATERIALS AND METHODS Titanium and zirconia abutments were torqued at 35 N/cm onto implant analogs. The samples were divided into two groups: Group A consisted of four titanium abutments and 32 zirconia copings and Group B ...

INTRODUCTION Esthetic post and core systems were recently introduced. There are few reports regarding their behavior under cyclic loading. OBJECTIVES This study compared the effect of cyclic loading on survival rate, residual strength and mode of fracture of endodontically treated teeth restored with esthetic and direct metallic post systems subjected to mechanical cyclic loading. MATERIALS...

AIMS AND OBJECTIVES The fiber post type used in restoring endodontically treated teeth may affect the dental expert decision in the case of dental malpractice. The aim of this study was to evaluate the low-cost commercial fiber post in comparison with a higher cost or well-known documented fiber post system. MATERIALS AND METHODS A total of 20 premolars were selected for the study; following ...

This study aimed to compare the biomechanical behaviour of functionally graded structured posts (FGSPs) and homogenous-type posts in simulated models of a maxillary central incisor. Two models of FGSPs consisting of a multilayer xTi-yHA composite design, where zirconia and alumina was added as the first layer for models A and B respectively were compared to homogenous zirconia post (model C) an...