Class III Composite Preparation / page 3

Due to greater access from the facial, the facial-approach preparation preserves more of the facioproximal line angle than the lingual-approach preparation which usually requires removal of most of the linguoproximal ridge in the area of the caries.

RETENTION FORM Beveling of accessible enamel margins is performed to expose enamel rod ends to acid conditioning for resin bonding. In facial appoach preparations, beveling of the facial margin may enhance blending of the resin over the enamel surface.  However, in lingual approach preparations, beveling of the facial margin is often deferred to maintain the integrity and beauty of sound enamel.

Lingual approach

Facial approach