A stable, healthy gingival margin and adequate exposure of the clinical crown is necessary prior to crown preparation to prevent exposure of the crown margin and root surface after the crown is placed.
This procedure would develop an adequate area for crown retention without extending the crown margins deep into the periodontal tissues.
Gingival inflammation and bone loss will occur if the margin of the crown is placed in the junctional epithelium and connective tissue attachment.
- Average (CT) Connective Tissue Attachment is 1.07mm
- Average (JE) Junctional Epithelium is 0.97mm
- CT+JE=Biologic Width
The biologic width (2.04mm) and the sulcus (0.67) always grow back, so we have to keep enough space for these re-establishment. Otherwise, there will always be inflammation and halitosis in the area of the violated biologic width. Bone loss with gingival recession will occur where alveolar bone surrounding the tooth is thin.
Correction of Biologic Width
Surgical removal of bone away from the proximity to the restoration margin.
Orthodontically extrude the tooth, thus moving the margin away from the bone.