La preparazione del margine cavitario in restauri diretti di denti anteriori: aspetti teorici

The angle of enamel cavity is not properly defined by the CSA, which also refers to the dentinal walls: we propose to refer only to the angle of residual enamel (Enamel's Residual Angle, ERA) which will be 90° in butt-joint and lower inclination in the bevels with progressively higher cut of the enamel surface. The increase of the enamel area available for the adhesion with the use of bevel or chamfer with respect to the butt-joint can be demonstrated with simple geometric calculations. We show that, in theory, the transformation of a bevel at 45° with enamel extension of 1 mm in a chamfer with the same sides and the design of 1/4 of a sphere increases the percentage of available surface area of 11.03%. Since are not reported in the literature universally accepted media by the thickness of the enamel of thefrontteeth, this requires new studies and/or the design of equipment available experimentally and clinically for this purpose.