An engineering analysis of dental occlusion principles.

Introduction: The purpose of this study was to develop an analytical model of contacting teeth, based on principles of basic engineering statics. The model would be used to demonstrate the interactions between occlusal contacts and tooth loading (forces and moments) and to critique occlusion-related dogma.

Methods: Free-body diagrams were drawn to depict 2 teeth in occlusal contact. In combination with the concept of the center of resistance, the governing equilibrium equations were derived and used to solve for the forces and moments on the teeth and to investigate the influences of tripod and cusp-fossa occlusal schemes.

Results: With a specific load on a tooth, it was demonstrated that the load on the opposing tooth and the concomitant occlusal scheme dictated crown-crown contact forces that can be computed.

Conclusions: This engineering analysis suggests flaws in widely held notions about the mechanics of occlusion. Loading that is generally considered clinically desirable is certain to produce undesirable loading on the opposing tooth. The complex relationships between the loads on teeth and crown-crown occlusal contacts make it virtually impossible to control tooth loading with occlusal equilibration. For computational and conceptual reasons, it is essential to consider the center of resistance.