Class III caries are found on the proximal surfaces of anterior teeth. As with most interproximal lesions, class III lesions begin just gingival to the interproximal contact area. Due to the cosmetic location of these lesions, tooth-colored restorative materials are generally indicated.
Access to the proximal lesion is first determined based on location of the lesion relative to sound tooth structure. When the lesion is centered faciolingually, access from the lingual surface is preferred to maintain the cosmetic facial enamel surface. However, if caries or other defect is displayed toward the facial, a facial approach may be indicated to remove these areas and conserve the lingual ridge.
For a lingual approach, a conservative entry to the caries is made through the linguoproximal ridge. With a 330 or 1 round bur aligned perpendicular to the tooth surface, tooth structure is removed to expose the caries. The outline form follows the caries. Likewise, the axial depth is determined by the depth of caries into dentin. An ideal outline for an incipient lesion would be semi-circular looking from the proximal view, and rectangular from the lingual view.
