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Evaluation of Retention of two Different Cast Post-Core Systems and Fracture Resistance of the Restored Teeth | ||
| Journal of Dentistry | ||
| مقاله 10، دوره 16، شماره 2، شهریور 2015، صفحه 121-128 اصل مقاله (195.82 K) | ||
| نوع مقاله: Original Article | ||
| نویسندگان | ||
| Amir Ali Reza Khaledi1؛ Shekufe Sheykhian* 2؛ Arash Khodaei2 | ||
| 1Dept. of Prosthodontic, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. | ||
| 2Students’ Research Committee, School of Dentistry, International Branch, Shiraz University of Medical Sciences, Shiraz, Iran. | ||
| چکیده | ||
| Statement of the Problem: The survival of pulpless teeth restored with different post and core systems is still a controversial issue.Purpose: This study compared the retention of two different post and core systems and also the fracture resistance of teeth restored with these systems.Material and Method: Eighty endodontically treated maxillary central incisors were sectioned perpendicular to the long axis at a point 2mm incisal to the cemento-enamel junction (CEJ) and then the root canals were obturated.The restored teeth were randomly divided into two equal groups of 40. One group was restored with Nickel-Chromium (Ni-Cr) post and core system and the other group with Non-Precious Gold alloy (NPG) system. For evaluation of fracture resistance of the restored teeth, the specimens (n=20 per each group) were mounted in acrylic resin blocks and a layer of polyvinyl siloxane was applied to cover the roots. Loads were applied at an angle of 45 degrees to the long axis of the teeth and measured with a universal testing machine.The axial retention values of the studied groups (no=20) were measured on an Instron testing machine at a crosshead speed of 0.5 mm/min. Statistical analyses were performed using SPSS version 19.00 and student’s t-test (α=0.05).Results: Although retention failure load for Ni-Cr system was lower than NPG system, there was no significant difference between the two systems (p= 0.7). However, fracture resistance of the teeth restored with Ni-Cr post and core system was significantly higher than NPG group (p= 0.000).Conclusion: There was no significant difference between the retention of the studied post and core systems. Although significantly higher fracture thresholds were recorded for Ni-Cr post and core group, the failure loads of both systems may rarely occur clinically. | ||
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