Enamel is an active protective tissue and in undergoing deformation, by attrition, equilibrium of the tooth as a whole is assured. Caries is evidence of structural fatigue, the consequence of mechanical conditions. The sites at which caries occurs are referable to inequalities of attrition.
Under physiological conditions, dental structures once elaborated do not change, and their configurations present a history of the physical forces which have determined their characteristic forms. Such configurations constitute the linkage between the external and internal environments, and supply ” graphs ” of the motions of the dental organs, and thus afford an explanation of the eruption of teeth. The history of forces which occasion the pathological state of existence, or “caries dentium,” is also manifested by the disorganized configuration. The lesion is due to the imposition of undissipated stress, which primarily affects the metabolic processes within a sphere of defined areal limitation, and ultimately causes collapse of the structure by ” fatigue.” The patho-histological phenomena are fully explained by the mechanical theory.
References: Proc. Aus. Den. Cong., 1930, 1935, 1937.