Strain Behavior of Implant-Supported Full-Arch Fixed Dental Prostheses Supported by Four or Five Implants

Strains transferred to the supporting simulated bone structure by implant-supported full-arch fixed dental prostheses (FAFDPs) were analyzed by digital image correlation (DIC).

Polyurethane models were made using 3.75 × 11-mm implants and divided into the following groups with different implant numbers and design: EH5 (five implants/external hexagon), MT5 (five implants/internal taper), EH4 (four implants/external hexagon), and MT4 (four implants/internal taper). Both qualitative and quantitative (one-way analysis of variance [ANOVA] statistical comparison) analyses were performed by the DIC method after the application of a 250-N load in the central fossa of the mandibular first molar. Different regions of interest were selected in the polyurethane model for comparison between groups.

Compressive strains were found in the cervical region of the models, and tensile strains were found in the apical region of the models. Significant differences were found in the different analyzed regions of interest for the different number of supporting implants and implant designs (P < .05).

Groups with five implants showed more regions with less strain concentration compared to groups with four implants, but strain distribution was similar between groups. The different tested implant designs showed similar strain concentration and distribution to the supporting structures.