A lingual approach for a conservative Class III preparation for a composite resin requires
maintenance of the incisal contact area.
a retentive internal form.
parallelism of the incisal and gingival walls.
All of the above
1 explanations
oneguy
Idea conservative Class III composite resin cavity preparation:
(1) Gingival margin: 1mm above gingival, incisal margin: just below proximal contact (maintenance of the incisal contact area), facial margin: parallel to facial surface, at junction of facial and middle 1/3
(2) Incisal and gingival walls parallel to each other with ideal depth of 1-1.25mm (incisal wall: 1.25mm, gingival wall: 1.0mm)
(3) Internal line angle: Round with approximately 90 degree
oneguy