Bone Stress Around Tilted Implants and Splinted Prostheses. FEA-3D

Objectives: The purpose of this study was to analyze the stress distribution on maxillary bone tissue around implants with different angulations (0º, 17º, and 30º) supporting splinted prostheses by three-dimensional finite element method.
Methods: All methodology was based on study of Almeida et al. (2014). Six different configurations with three implants each were simulated with single unit crowns (model 1 – 0°; model 2 – 17°; model 3 – 30°) and splinted crowns (model 4 – 0°; model 5 – 17°; model 6 – 30°).Two load applications (400 and 200 N at the occlusal surfaces [50N by each cusp] in the axial and oblique directions, respectively), were applied. The maximum principal stress (σmax) criteria and microstrain (µstrain) at the cortical bone crest were measured around the implants for each situation. Stress patterns on the bone tissue around the implant were analyzed qualitatively.
Results: Under axial loading, the stress concentration was moderate around all implants for simulated models. There was slight increase in stress whenthe implants were tilted. The splinted models (4,5,6) showed better stress distribution among the implants. Under oblique loading, the stress was higher, increasing as the implants were tilted. The single crowns models (1,2,3) showed higher stress concentration in the molar region.The models with splinted crowns showed increased of the stress according to the implants inclination; however, the stress was better distributed between the three implants for all models.
Conclusions: In conclusion, within the methodology limitations, rehabilitations with tilted implants tend to increase the stress concentration around the implants, mainly under oblique loading. The splinting dissipated uniformly the stress on bone around implants for all inclinations and loadings.