Effect of Different Restorative Materials on Stress Distribution around Dental Implants.

The purpose of this study was to evaluate the amount and distribution of stress in the implant-supported fixed partial dentures and the surrounding bone in six different models by computer-simulated mastication. Finite element analysis was used to conduct the study. The three-dimensional (3D) model of a 3-unit implant-supported fixed partial denture was created. Six different material combinations were nominated. Full zirconia crown (ZZT), zirconia framework with feldspathic veneer (FZT), full lithium disilicate crown (LLT), lithium disilicate framework and feldspathic veneer (FLT), Ni-Cr framework with feldspathic porcelain veneer (NiCrT), full hybrid ceramic (HHT) and also a type 3 bone was created. The oblique load (534 N) and the horizontal load (76.5 N) were applied on the bridge, and stress values and distribution patterns were examined. The distribution pattern was the same in all the models. The full zirconia crown (ZZT) showed the highest stress values in the bone in both the oblique and the horizontal forces. The highest concentration was around the fixture on the surface of the bone in the cervical area. This study showed that restoration material of the fixed partial dentures does not affect the pattern and the location of maximum and minimum stress concentration. However, as expected, the magnitude of stress values can be changed by switching restoration materials.