Photoelastic Stress Comparison of Three Different Post Systems

The purpose of this study was to compare and analyze the stress magnitude of a novel post versus two different post systems.

Methods:

A total of 30 canals were prepared in a photo elastic material (PSM 1, Vishay Measurements Group). The canals were divided into three groups: Spirapost (Zenith/DMG)—Group 1; Flexi Post (Essential Dental Systems)—Group 2; and Fiber Post (Bisco,)—Group 3. Luxacore (Zenith/DMG) was used to cement the posts and cores. The cores were built using size 6 copper bands. Each sample was subjected to 30 kilograms of stress twice: once at an incline of 30 degrees and once vertically; using an Instron machine (model 4202). Three areas were chosen in which to measure the stress: lateral right, lateral left and apical areas of the post region. The magnitude of the stress was then analyzed by measuring the fringe orders with a null balance compensator under a polariscope (Model 080 series Teaching Polariscope system, Vishay Measurements). The data was analyzed using one-way ANOVA and Scheffe's test.

Results:

The magnitude of stress in Group 1 was significantly lower (p<0.05) than Groups 2 and 3 on lateral left and apical areas. There was no difference on the lateral right areas between Groups 1 and 2 (p>0.05). A significant difference was noted only at the apical area when comparing Groups 2 and 3.

Conclusion:

Overall, the statistical analysis of the test results showed that the mean values of the stress caused by Group 1 (Spirapost) were significantly lower than those of Groups 2 (Flexi Post) and 3 (Fiber Post). Supported by a grant from Zenith Dental /DMG