Crown Lengthening

Question 1

Crown coronal to the alveolar crest.

Answer 1

Clinical crown

Question 2

Crown coronal to the CEJ

Answer 2

Anatomical crown

Question 3

Supra-marginal dentin engaged by the restoration.

Answer 3

Ferrule

Question 4

Crown lengthening can be done for ________ caries or this type of resorption.

Answer 4

Subgingival; root

Question 5

Indications for crown lengthening.

Answer 5

1) Short clinical crown
2) Improve esthetic appearance (gummy smile)
3) Subgingival caries or root resorption
4) Reduce excessive gingival display
5) Subgingival margins
6) Root fracture in the coronal third
7) Pin or post perforations in the coronal third

Question 6

Contraindications to crown lengthening.

Answer 6

1) Inadequate tx plans
2) Poor oral hygiene
3) No strategic value for the tooth
4) Severe periodontitis

Question 7

Biological width

Answer 7

CT attachment + JE

Question 8

Biologic Width measurement

Answer 8

2.04 mm

Question 9

Biologic width starts at the bottom of what?

Answer 9

The gingival sulcus

Question 10

T/F:

You don’t usually need to do osseous reduction around the entire circumference of the tooth.

Answer 10

True

Question 11

You want at least ___ mm of tooth structure below the margin.

Answer 11

1

Question 12

You want ___ mm of root structure above the bone height.

Answer 12

3 (2 mm for biologic width and 1 mm for sulcus depth).

Question 13

Types of crown lengthening

Answer 13

1) Gingivectomy
2) Flap surgery
3) Orthodontic extrusion

Question 14

A gingivectomy does not lengthen what?

Answer 14

Clinical crown

Question 15

How many mm of keratinized gingiva do you need for a gingivectomy?

Answer 15

4 mm

Question 16

How long is the recovery period for crown lengthening?

Answer 16

6 weeks

Question 17

Final gingival contour is dictated by:

Answer 17

1) Underlying osseous configuration
2) Surface anatomy of the root.
3) Post-operative flap placement