Class IV Composite Preparation, page 1

Class IV Classification: Cavities and restorations of the proximal surfaces of anterior teeth that involve the incisal edge.  These can occur from traumatic injuries and caries undermining the incisal corner and edge.

These teeth have suffered accidental fracture including both proximal surfaces and incisal edges.  While some dentin is exposed, most of the exposed tooth surface is enamel.  Enamel and dentin shades, and incisal translucency is recorded after pumicing of teeth, and before rubber dam placement.

The outline form includes removing all friable and unsupported enamel to establish a firm foundation (resistance form).  Beveling of the enamel surface provides exposure of enamel rods for improved adhesive bonding (retention form), and enhances cosmetic blending of the composite resin to the undamaged and unprepared enamel surface.