Experimental Analysis of Stress in teeth with Different Preparations and Discharges.

The aim of this study was to observe the behaviour of different gingival endings of the restorations and their significance as support agents, with the addition or not of interradicular reinforcement in relation to the possible variants that may come from internal tensions of the teeth committed by a force. The approach that determined the line of research through photoelasticity allowed the visualization itself of the forces, for this purpose an experimental prototype was built which faithfully reproduced a restored dental piece exposed to forces of mastication. The different preparations under similar charges showed different internal grades of tension as indicated by the isochromatic orders, index of the different aptitude to transmit a positive effort according to the case. The preparations without shoulder and without post were the most favourable for presenting the minor concentration of internal tensions, greater uniformity of compression and traction lines and they also had the most favourable results in terms of stress gradient.