AIM The aim of this study was to investigate the influence of three different thicknesses of In-Ceram core on the load at fracture of all-ceramic crowns. METHODS AND MATERIALS Thirty standardized crown-shaped nickel-chromium alloy dies were fabricated using a milling machine. Twenty dies were prepared with a 1 mm shoulder for Groups A and B. The only difference in the ten dies used for Group ...

Statement of problem: A dowel is essential to retain the core in case of severe tooth destruction. However, the placement of a dowel and core may actually weaken teeth and affect their failure pattern depending on their material properties and stress transfer. Purpose: The present study compared the fracture resistance and failure pattern of endodontically treated premolars with different amoun...

PURPOSE OF THE STUDY It is difficult to achieve a reliable bond between the titanium and veneering porcelain. The aim of this study was to evaluate the bond strength between titanium ceramic crowns. MATERIALS AND METHODS The surfaces of titanium copings were divided in two groups. Group A sandblasted with 250 um (n = 10) and Group B without sandblasting (n = 10). Low-fusing porcelain was bond...

In all-ceramic restorations, crack formation and propagation phenomena are of major concern, since they may result in intra-oral fracture. The objective of this study was calculation of damage in porcelain MOD inlays by utilization of a finite-element (FE) implementation of the distributed crack theory. "Damage" is defined as the parameter that describes the local decrease of stiffness caused b...

PURPOSE To investigate the influence of cement film thickness, cement type, and substrate (enamel or dentin) on ceramic fracture resistance. MATERIALS AND METHODS One hundred extracted human third molars were polished to obtain 50 enamel and 50 dentin specimens. The specimens were cemented to 1-mm-thick lithium disilicate ceramic plates with different cement film thicknesses (100 and 300 μm) ...

The purpose of the present study is to evaluate the fracture load of composite-based repairs to fractured zirconium oxide (Z) crowns and to ceramic-fused-to-metal (CM) crowns, comparing different mechanical surface preparation methods. A total of 75 crowns were repaired; samples then underwent dynamic loading and thermocycling. Final fracture load values for failure of the repaired crowns were ...

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The J-based fracture testing technique is newly extended to experimentally determine the tension-softening (a-6) relations in ceramic-matrix composites. The J-based technique originally proposed for concrete has been well established for quasi-brittle materials where the fracture process is primarily dominated by the formation of a fracture process zone and the contribution of the crack tip tou...

results overall, there were 2 (2.7%) mason ii fractures, 21 (28%) mason iii fractures, and 52 (69.3%) mason iv fractures. arbeitsgemeinschaft fur osteosynthesefragen (ao) classification was also determined. of the 85 patients in our study, 75 were available for follow-up. follow-up averaged 41.5 months (range, 4 - 93 months). average scores for the cohort were as follows: morrey, 85.7 (median 9...

This clinical study investigated the practical value of two methods for debonding brackets attached by the adhesive Concise to acid-etched enamel surfaces. Forty-two Ultratrimm Standard metal brackets and 42 Fascination ceramic brackets were collected from juvenile patients undergoing orthodontic treatment. All metal brackets were mechanically debonded by a conventional bracket removal plier, w...