Fixed I - Waxing the Complete Crown

What are requirements of an adequately trimmed die?

- preservation of uncut neck of tooth

- access to create good emergence profile

What is an emergence profile?

gingival contour of a restoration which enables the tooth to give the appearance that it's emerging out of the soft tissue

True/False: the margin of the die should be marked with a graphite pencil

False

True/False: the margin of the die should be marked with a colored pencil

True

A graphite pencil shouldn't be used to mark the margins of the die BECAUSE it can be incorporated into the wax pattern and can cause miscasting

A) statement true, reason false

B) statement true, reason true

C) statement false, reason true

D) statement false, reason false

B) statement true, reason true

What can be used on the margin after marking it?

cyanoacrylate

True/False: you should use a contrasting colored pencil vs. the color of the wax to mark the margin

True

What is the cement space?

area between prep and under the surface of the crown

What is the optimal cement space dimension?

A) 10-20 microns

B) 20-40 microns

C) 40-50 microns

D) 60-80 microns

B) 20-40 microns

The internal diameter of the crown should be ___ larger than the prepared tooth

A) 20-40 microns

B) 40-80 microns

C) 80-100 microns

B) 40-80 microns

Die spacer should be placed ___ mm away from the margin

A) 1

B) 2

C) 3

D) 4

A) 1

True/False: die spacer can be used to artificially create a cement space

True

True/False: die spacer can be placed on the margin

False

What are ways to increase cement space?

- impression shrinkage

- investment expansion

- die spacers

- metal removal

True/False: investment material expands

True

What are ways to reduce cement space?

- reduced impression shrinkage

- resin or electroplated dies

- alloys with higher melting temps

- reduced investment expansion

- W/P ratio

- burnout temp

What are desirable properties of inlay wax?

- color contrast

- easy to carve

- strong/rigid

- stability

- complete burnout

What are desirable properties of inlay wax?

A) color contrast

B) easy to carve

C) strong/rigid

D) stability

E) complete burnout

F) all of the above

F) all of the above

What type of inlay wax is used in casting?

A) type I

B) type II

B) type II

What type of wax is direct?

A) type I

B) type II

A) type I

What type of wax is indirect?

A) type I

B) type II

B) type II

Inlay wax has what percentage of paraffin?

A) 20-40%

B) 40-60%

C) 60-80%

B) 40-60%

Carnauba wax in inlay wax

A) increases melting temp

B) prevents flaking

A) increase melting temp

Ceresin wax in inlay wax

A) increases melting temp

B) prevents flaking

A) increases melting temp

Candelilla in inlay wax

A) increases melting temp

B) prevents flaking

A) increases melting temp

Beeswax dammar resin in inlay wax

A) increases melting temp

B) prevents flaking

B) prevents flaking

True/False: the function of beeswax in inlay wax is to prevent flaking

True

What is wax memory?

elasticity of wax unless thoroughly liquified

True/False: margins don't need to be reflowed before investing

False

What is the sequence of waxing a complete crown?

- internal surface

- proximal surface

- axial surface

- occlusal surface

- margin finishing

Put the steps of waxing a complete crown in the correct order:

1. margin finishing

2. internal surface

3. axial surface

4. proximal surface

5. occlusal surface

A) 1, 2, 3, 4, 5

B) 5, 4, 3, 2, 1

C) 2, 4, 3, 5, 1

D) 2, 4, 5, 3, 1

C) 2, 4, 3, 5, 1

True/False: you only need to lubricate your die once and that's sufficient every time waxing

False

What type of instrument should be used to make a wax coping?

large, blunt instrument

True/False: the wax coping should be remelted

True

True/False: excess wax from making the wax coping should be removed

True

True/False: when removing the wax coping, you should push your fingers together before pulling them apart

True

True/False: after pulling your wax coping off and seeing margin irregularities, you can continue because these won't affect your final crown

False

Most posterior teeth have contact at what part of the tooth?

A) gingival 1/3

B) middle 1/3

C) occlusal 1/3

C) occlusal 1/3

True/False: when waxing occlusal contacts, you should follow the cuspal/fossa relationship

True

How many cusps are on tooth #30?

A) 1

B) 2

C) 3

D) 4

E) 5

E) 5

True/False: you should always reflow margins before investing

True

The maximum faciolingual width is generally no more than ___ mm larger than the width at the CEJ

A) 1

B) 2

C) 3

D) 5

A) 1

The maximum faciolingual width is generally no more than 1 mm larger than the width at the ___

A) height of contour

B) CEJ

C) DEJ

B) CEJ

The facial height of contour is usually located where?

A) occlusal 1/3

B) middle 1/3

C) gingival 1/3

C) gingival 1/3

The facial height of contour shouldn't bulge more than ___ mm facially beyond the CEJ

A) 0.5 mm

B) 1.0 mm

C) 1.5 mm

D) 2.0 mm

A) 0.5 mm

True/False: the facial height of contour shouldn't bulge more than 1 mm facially beyond the CEJ

False

The lingual convexity is less than ___ mm beyond the CEJ

A) 0.5

C) 1.0

D) 1.5

E) 2.0

A) 0.5

True/False: the lingual contour can be 0.75-1.0 mm beyond the CEJ in maxillary molars

False

True/False: the lingual contour can be 0.75-1.0 mm beyond the CEJ in mandibular molars

True

The proximal contacts are usually located in the ___

A) gingival 1/3

B) middle 1/3

C) occlusal 1/3

C) occlusal 1/3

What are the exceptions to the rule that proximal contacts are usually located in the occlusal 1/3?

A) maxillary premolars

B) mandibular premolars

C) maxillary 1st and 2nd molars

D) mandibular 1st and 2nd molars

C) maxillary 1st and 2nd molars

The proximal contacts of the maxillary 1st and 2nd molars can be located in the ___

A) middle 1/3

B) gingival 1/3

C) occlusal 1/3

D) junction of the occlusal and middle 1/3

E) junction of the gingival and middle 1/3

D) junction of the occlusal and middle 1/3

True/False: the proximal surface is always flat or convex B-L

False

The proximal surface is always flat or ___ B-L

A) convex

B) concave

B) concave

True/False: transitional line angles are straight for the lingual of maxillary molars

False

True/False: transitional line angles of teeth are usually straight

True

The transitional line angles are usually

A) straight

B) convex

C) concave

A) straight

The transitional line angles of maxillary molars are usually

A) straight

B) concave

C) convex

C) convex

True/False: marginal heights must be of equal height

True

True/False: marginal ridges should converge lingual to buccal

False

Marginal ridges should converge

A) lingual to buccal

B) buccal to lingual

B) buccal to lingual

What should be the minimum distance between the restoration margin and the crest of bone?

A) 1 mm

B) 2 mm

C) 3 mm

C) 3

True/False: mistakes don't need to be corrected in wax because they are easier to fix in metal

False

Mistakes should be fixed in wax BECAUSE they can be easily fixed

A) statement true, reason true

B) statement false, reason false

C) statement true, reason false

D) statement false, reason true

A) statement true, reason true