Análise fotoelástica da influência da aplicação de carga no padrão de distribuição de tensões em implantes dentários

Abstract

The aim of this study was to evaluate and compare stress distribution around implants using platform switching technique with conventional diameters, using the photoelasticity method in internal and external hex-type implants. Five models were fabricated using photoelastic resin kit FLEXIBLE G3 (POLIPOX Ind. E Com, Sao Paulo Brazil) with a single-body implant in each of them. These models were as follows: MODEL A - 4.1mm platform with 4.1mm external hex implant-abutment connection; MODEL B - 5.0mm platform with 4.1mm external hex implant-abutment connection; MODEL C - 5.0mm platform with 5.0-mm external hex implant-abutment connection; MODEL D - 4.5mm platform with 4.5mm internal hex implant-abutment connection; and MODEL E - 4.5mm platform 3.8mm internal hex implant-abutment connection. An axial load of 100N was applied in a plane polariscope to verify isochromatic fringes. The images were photographed with a digital camera CANON EOS DIGITAL REBEL XTI and viewed with software specially developed for this study. The values for total maximum shear stress for implant HISW was 20.16 kPa, HI 20.64 kPa, 21.84 kPa HESW, HE 21.70 kPa and 20.74 kPa for control implant. The internal hex implant showed better load distribution and lower stress values when the platform switching technique was used and no system was able to eliminate stress on some thirds.