The role of superstructure material on the stress distribution in mandibular full-arch implant-supported fixed dentures. A CT-based 3D-FEA.

This study evaluated the stress distribution in mandibular full-arch implant-supported fixed dentures with different veneering and metallic infrastructure materials, using three-dimensional finite element analysis. Ten models were obtained from an edentulous human mandible with a complete denture fixed by four implants. Acrylic resin (RES) and porcelain (POR) teeth were associated with infrastructures of titanium (Ti), gold (Au), silver-palladium (AgPd), chrome-cobalt (CoCr) and nickel-chrome (NiCr). A 100-N oblique was applied. The von Mises (σvM) and maximum (σmax) and minimum (σmin) principal stresses were obtained. The RES-AgPd group showed the lowest σvM values, while the RES-Ni-Cr group showed the highest. In the bone tissue, the RES-Au group was the only one that showed different σmax values with a 12% increase in comparison to the other groups which had similar stress values. In the implants, the groups with Ti, Au and AgPd infrastructures, either with porcelain or resin teeth, showed σvM values similar and lower in comparison to the groups with CoCr and NiCr infrastructures. The tooth veneering material influenced the stress values in metallic infrastructures, in which the acrylic resin had the highest values. The veneering and infrastructure materials have influence on stress values of implant-supported dentures, except for the peri-implant bone tissue.