Results: In Model 1 (control), maximum stresses occurred at the coronal third of the buccal (2.32 × 107 Pa) and palatal aspects of dentin. The stress peak value of the model (2.45 × 107 Pa) occurred on the palatal aspect of the enamel at the level of the cementoenamel NVP-BEZ235 junction. With the insertion of dowels with thin cement layers (Models 2 and 3), stress concentrations in radicular dentin decreased,

while they increased in the dowel/cement/dentin interface. These models exhibited the greatest stress peak values in the incisal margin of the gold alloy core (18.9 × 107 Pa) and in the cement layer (4.7 × 107 Pa). In Model 4, stress peak value was observed in the porcelain crown (4.62 × 107 Pa), and there was no stress concentration inside the cement layer. Conclusions:

Within the limits of this study, the results suggest that the use of dowels and cements with mechanical properties similar to those of dentin, and an increased cement layer thickness, results in mechanical behavior similar to the physiological behavior of a sound tooth. “
“Purpose: check details This study compares the stress distribution in the structure of a loaded endodontically treated maxillary extracted canine restored with either custom-made zirconia (Cercon) or cast gold dowel and core. Materials and Methods: Standard treatments were implemented to prepare the gutta-percha-filled root canal

and dowel space. The tooth along with the dowel and core fabricated pattern resin were prepared to receive an all-ceramic (Cercon) crown. An impression was made for the tooth preparation with the zirconia milled dowel and core in place to fabricate the Cercon crown using CAD/CAM. The restored canine was scanned, and from the scan two models were constructed with the surrounding AZD9291 in vivo ligament and bone. Three-dimensional finite element elastic analysis was then carried out for the stress distribution within the different regions of the two models due to a concentrated force of 100 N applied at the mid-lingual area. Analyses were made for three load angulations, vertical, buccolingual horizontal, and an in-between oblique force at 45o. Each region of the models was assumed isotropic and homogeneous. The two restored canines with zirconia and gold were compared in terms of the resulting maximum tensile, compressive, and Von Mises stresses. Results: Generally, there were no significant differences in the maximum stresses in most regions for both models. Von Mises stresses for zirconia dowel and core was 8.966 MPa and for cast gold dowel and core was 8.752 MPa. The maximum tensile stress for zirconia dowel and core was 9.326 MPa, and for cast gold dowel and core was 8.166 MPa. Conclusions: The present work validates the use of CAD/CAM zirconia material for ceramic dowel and cores.