Estudo fotoelástico da distribuição de tensões em implantes hexágono externo interconectados por resina acrílica e metal

Abstract

The clinical success of dental implants has as important factor the way the mechanical stress is transferred from the implant the surrounding bone tissue. This transference and its magnitude may be related to the material of the screwed the prosthesis to the implants, risking the longevity of osseointegration. This study has as proposal to determinate the stress distribution of the region of implants, to compare the energy level to obtained when they are interconnected by bar constructed metallic alloy or in acrylic resin activated chemically, using the photoelastic method. For that it was constructed two photoelastic models with to implant positioned and united by bars in metal and acrylic resin activated chemically. The load of 2 kgf was applied in the center of bars (A point), on the implant B and in one extremity of point C, distance 10,0 mm of implant. The reading of distribution and location of stress was made from photographs that register the images after the applied loads. The results show, qualitatively, that when the load was applied in A point, it was distributed symmetrical along them and the high stress concentration occurred in the distal portion of implants; when applied over the implant (B point), it was noted an increase of stress levels; loads applied in one extremity (C point), distance 10,0 mm of implant center, produced the highest stress level, showing more solicitation of implant in the side that the load is applied, generation distortion in the geometry producing more level of energy, being that the distortion of resin bars more that metal bars. The consequence is: for situations of one extremity (cantilever), where the biggest values are found, the distortions generate high stress levels in the first lines and to the long one of the line next to the apex to the implant and no depends of the type of bar, but the point application of the load.