الفهرس | Only 14 pages are availabe for public view |
Abstract Aim: to assess the difference in tensile bond strength between (PEEK) and lithium disilicate endocrowns cemented to natural extracted teeth after thermocycling . . Methodology: 22 recently extracted human maxillary first molar teeth from diabetic patients ranging from 20 to 50 years old were collected from the Oral and Maxillofacial Surgical Department of Faculty of Dentistry, Cairo University. All teeth were subjected to standard endodontic treatment and mounted into resin pattern. Cavity preparation with butt joint design was made with copious water cooling using CNC special milling machine . The specimens were divided into 2 equal groups (n=11). 11 endocrowns were allocated to be constructed from lithium disilicate and others were allocated to be constructed from PEEK All endocrowns were cemented on their corresponding teeth using cementation loading device. All samples were subjected to thermal cycles(6000cycles,5-55c) . Tensile load was applied using universal testing machine .Retention was measured by Materials Testing Machine with a loadcell of 5 kN ) Stereomicroscope was used to investigate the the mode of failure . Data was statistically analyzed used Kolmogorov-Smirnov and Shapiro-Wilk tests & Student’s t tests (α = 0.05) and failure mode (%) by the Fisher exact test & chi2 test (p≤0.05). Results: The mean ± SD values of tensile bond strength were recorded for lithium disilicate group (2.683±0.56 MPa) meanwhile the mean ± SD value recorded with PEEK endocrown group(2.119±0.37 MPa) . It was found that lithium disilicate group recorded statistically significant higher tensile bond strength mean value than PEEK group.Conclusions: It was found that lithium disilicate endocrown group recorded statistically significant higher tensile bond stregth mean value than PEEK endocrown group after thermal loading . |