Tooth Deformation under a Load of Occlusal Force.

The purpose of this study was to evaluate the relationship between tooth deformation and functional occlusal loading. Vertical length of buccal tooth surface was measured with a newly-developed submicron transform detector. Deformations of upper canines and first premolars of 13 adult volunteers were evaluated under different occlusal conditions. Buccal tooth surface was contracted with buccal cusp loading and expanded with palatal cusp loading. The median of the first premolar deformation was-171 nm/mm/ 100 N with buccal cusp loading and 34 nm/mm/100 N with palatal cusp loading.Maximum clenching at eccentric occlusion exhibited significantly larger tooth deformation than that of intercuspal occlusion. The experimental occlusal interference exhibited relatively large tooth deformation, while insignificant deformation was seen with mastication. The results suggested that tooth structure may receive more harmful influence from occlusal imbalance and bruxism, and that tooth deformation analysis may have potential to a evaluate a clinically ideal occlusion.