Biological width

Question 1

Crown lengthening

Answer 1

Glossary of Periodontal Terms defines clinical crown lengthening as a surgical procedure that aims at exposing sound tooth structure for restorative purposes via apical repositioning of the gingival tissue, with or without removal of alveolar bone

Question 2

Biologic width

2.04 mm

Answer 2

Biologic width is the healthy gingival tissue above the alveolar crest representing the sum of JE (0.97mm) and connective tissue (1.07mm).

Question 3

CLINICAL RELEVANCE OF BIOLOGICAL WIDTH

Answer 3

1. Irreversible loss of periodontal attachment
2. Pocket formation
3. Inflammation
4. Osseous resorption
5. Occasionally root resorption
6. Gingival recession

Gingival recession usually seen in thin gingival tissue biotype (gingival thickness is less than 1.5mm
Inflammation and periodontal pocketing is usually seen in thick gingival biotype (gingival thickness more than 2mm)

Question 4

SIGNS OF BIOLOGICAL WIDTH INVASION

Answer 4

Chronic progressive gingival inflammation around the restoration
Bleeding on probing
Localized gingival hyperplasia with minimal bone loss
Gingival recession
Pocket formation
Clinical attachment loss
Alveolar bone loss

Question 5

EVALUATION OF BIOLOGICAL WIDTH VIOLATION

Answer 5

A). Clinical Method
B). Bone Sounding
C). Radiographic Evaluation

Question 6

METHODS TO CORRECT BIOLOGICAL WIDTH VIOLATION

Answer 6

1. Surgical Crown Lengthening
2. Gingivectomy
   = External bevel gingivectomy
   =Internal bevel gingivectomy
3. Apical repositioned flap surgery
   =Apically repositioned flap without osseous resection
   =Apically repositioned flap with osseous resection
4. Orthodontic technique

Question 7

Indications of crown lengthening

Answer 7

1. Inadequate clinical crown for retention due to extensive caries, subgingival caries or tooth fracture, root perforation, or root resorption

2. Short clinical crowns.

3. Placement of sub gingival restorative margins.

4. Unequal, excessive or unaesthetic gingival levels for esthetics.

5. Planning veneers or crowns on teeth with the gingival margin coronal to the cemeto enamel junction (delayed passive eruption).

6. Teeth with excessive occlusal wear or incisal wear:

7. Teeth with inadequate interocclusal space for proper restorative procedures due to supraeruption.

8. Restorations which violate the biologic width.

9. In conjunction with tooth requiring hemisection or root resection.

10. Assist with impression accuracy by placing crown margins more supragingivally

Question 8

Contraindications of crown lengthening

Answer 8

1. Deep caries or fracture requiring excessive bone removal.

2. Post surgery creating unaesthetic outcomes.

3. Tooth with inadequate crown root ratio (ideally 2:1 ratio is preferred)

4. Non restorable teeth.

5. Tooth with increased risk of furcation involvement.

6. Unreasonable compromise of esthetics.

7. Unreasonable compromise on adjacent alveolar bone support.