More than one factor causes caries. The primary causative factor is within the tooth; external influences, such as saliva, participate. Teeth attacked by caries invariably show unequal wear caused by traumatic occlusion, which results in a force having a direction that is not parallel to the long axes of the affected teeth. Diet, saliva, etc., affect all teeth more or less generally.To some extent, susceptibility or resistance to caries varies independently for the individual teeth.
Two opposing teeth in malocclusion invariably present evidence of disturbance in the tissues either surrounding or within them. Malocclusion results in stress in a direction that is not parallel to the long axis of the root. Malocclusion often produces changes in periapical tissues, thus causing (a) impingement upon blood vessels, nerves, etc., that enter the roots, and (b) impairment of the functions of the tooth structure, odontoblasts, dentin, etc., nourished and controlled by these blood vessels and nerves. Correction of the bite, by relieving the surfaces of teeth showing wear, results in removal of sensitiveness in teeth attacked by cervical erosion. This correction changes the direction of the stress or force of the bite to one parallel with the long axes of the affected teeth, and restores normal physiological functions to tooth tissues.
Reference: Den. Items Int., 1932.