BIOMECHANICAL INTERACTIONS BETWEEN BONE AND METAL-CERAMIC BRIDGES COMPOSED OF DIFFERENT TYPES OF NON-NOBLE ALLOYS UNDER VERTICAL LOADING CONDITIONS

The purpose of this study was to compare the mechanical properties of three metal-ceramic bridges of different types of dental alloys and to present and evaluate the possible biomechanical interactions between a marginal bone and metal-ceramic bridges during vertical loading. The research was done as an experimental study. A mandible with an intact anterior region was used. The preparation of the remaining teeth for receiving three types of porcelain-fused-to-metal (PFM) restorations was performed. Vita VMK 95 was used for all three metal-ceramic restorations. These three metal-ceramic bridges composed of different alloys, nickel and non-nickel, served as different models: the Niadur-nickelferous model, the Wiron 99-nickel model and the Wirobond C-cobalt-chrome model. The maximum compressive strain of 5% for all three virtual models is observed in the region of central incisors. The Niadur model has the lowest mean strain (2.62%) in comparison with the other two models. The mean strain of Wiron 99 is lower, by 0.10%, than the mean strain of the Wirobond model. Biomechanical behavior of the presented models caused by the vertical-loading conditions is explained as an interaction between the marginal bone and the metal-ceramic bridges. All of them, nickel and non-nickel models, indicate a similar strain (deformation) distribution; however, from the biomechanical perspective, Niadur is more favorable than the other two materials.