Stress Pattern Variations in Operatively Prepared Human Teeth, Studied by Three-Dimensional Photoelasticity

Abstract

Three-dimensional photoelastic stress analysis was used to investigate the design of Class I cavity preparations. Enlarged, epoxy resin models of the mandibular first molar were modified with variations of Class I preparations. The models with stresses "frozen" into them were sectioned on predetermined planes. The resulting fringe patterns demonstrated that significant stresses exist in planes remote from loads, and that rounding internal line angles reduces stresses significantly.