Form, function and strength in the restored dentition.

The masticatory system is a biomechanical engine for the reduction of food before final absorption by the alimentary canal. These demands may lead to biological changes dominated by wear, fracture, or plastic deformation. This in turn lead to the loss of hard tissue, which is detrimental to the primary function of the oral cavity. The primary roles of restorative dentistry are to restore what is lost and to preserve remaining hard tissue, which is served by conservative techniques and the development of materials that recover the function of lost tissue. The criteria for new restorative materials should be based on the structure-property-function relationships of the hard tissues. An understanding of these relationships may lead to better methods of assessment and provide clues for the development of better synthetic analogues for enamel and dentine.