Week 4 - Record Bases and Wax Rims

articulate master casts

What do occlusal wax rims allow you to do?

to make guidelines for proper placement of the denture teeth

Why do we mark our master casts?

Facial surface of maxillary central incisors

The incisive papilla is marked on the maxillary final cast to position which teeth?

Mid-palatal suture

When placing the transparent ruler over the center of the incisive papilla, the front edge of the ruler should be perpendicular to what structure?

Place a dot anterior 2/3 of the height of each retromolar pad (make dots/reference points on side of casts while holding cast at eye level and look at it from the facial aspect)

Where do you place a dot on each retromolar pad?

height of posterior occlusal plane

Retromolar pads are marked in order to determine what?

- Crest of the residual ridge

- Determine the bucco-lingual placement of posterior teeth

- The central fossae of the premolar and molar denture teeth are placed directly over the crests of the mandibular residual ridges

After marking the retromolar pads, what are the 2nd markings on the mandibular casts?

No tooth placed distal to this

When we mark the ascending rami on the mandibular cast, what does this indicate for tooth placement?

guideline for positioning facial surfaces of max. central incisors

Why do we mark the incisive papilla and the lines on the left and right land areas beneath the incisive papilla?

Teeth/denture will lean outward and cause cheek biting

It is important that we mark the crest of the mandibular ridge correctly because, if we set teeth too buccally, what would happen?

Teeth/denture will tip too lingual and reduce space for tongue

It is important that we mark the crest of the mandibular ridge correctly because, if we set teeth too lingually, what would happen?

incisive papilla

What is 1?

lower border of papilla (crest of anterior aspect of ridge)

What are 3 and 4?

center of papilla

What is 2?

Retromolar pads

What are 5 and 6? (What do the oval indicate?)

ant. 2/3 of retromolar pads

What are 7 and 8?

Height of occlusal plane (at level of ant. 2/3 of retromolar pads)

What are 9 and 10?

crest of residual ridge (posterior)

What are 11 and 12?

crest of residual ridge (anterior)

What are 13 and 14?

Where the ascending rami begins

What does this line mark?

anterior ridge crest

What are 17 and 18?

1. Left + right undercuts in the anterior area

2. Above both tuberosities posteriorly

Where are there undercuts on the max arch clinically?

1. Labial aspect of the mandible

2. In both retromylohyoid areas

Where are there undercuts on the mand arch clinically?

Vaseline

What should you coat on the impression cast before placing the triad?

- Height

- Width

- Contour

Ideal border molder determines the proper ________, ________, and ________ of the final complete denture

Peripheral rolls

For this project, we will assume that our impressions are perfect. Therefore, the triad material should completely fill the entire __________ of your final edentulous casts.

Hamular notch

When fabricating the maxillary record bases, be sure that the material completely fills the ___________ areas and is straight across the posterior aspect of the cast.

10 mm

On the back portion of the maxillary triad, how wide anterio-posteriorly should this area be?

minimize acrylic shrinkage

With a Vaselined finger, thin the back edge of the record base to about one-half of its original thickness. What does thinning the back edge of the triad on the maxilla do?

2 minutes cure on the casts > take off casts and flip > 6 minute cure

What is the reccomended curing time of the triads?

Pineapple acrylic bur

What bur can you use to smooth and round-off all of the peripheral edges of both record bases?

no more than 2 mm

For the maxillary posterior area, how much space is allowed without having to remake?

Makes room for teeth set-up (this should be done before adding wax)

What does thinning the anterior aspect of the record base do?

anterior inclination

What is a key feature of the anterior portion of the maxillary wax rims?

22 mm

What is the measurement at the area of the lateral incisors for the maxillary wax rim?

3 mm (flat and smooth)

How wide is the incisal plane at the anterior portion of the maxillary wax rim?

peripheral roll

The buccal surface of the maxillary wax rim should be smooth and sloping towards what?

palate

The lingual surface of the maxillary wax rim should be smooth and sloping towards what?

Over the crest of the maxillary ridges

Where should the posterior maxillary wax rim be located over?

Midline

For the fabrication of the max posterior wax rim, it should have a lingual wax smooth and sloping towards the ________

maxillary mean foundation plane

What should the posterior maxillary wax rim be parallel to?

5 mm

How wide should the maxillary wax rims be in the bicuspid areas?

10 mm

How wide should the maxillary wax rims be in the molar areas?

Where you expect the junction of the 1st + 2nd molars to be - put about a 45 degree angle on this cut

Where should you cut the posterior ends of the maxillary wax rim?

18 mm

How high is the anterior mandibular wax rim?

3 mm

How wide is the anterior mandibular wax rim?

flat and straight anterior portion

What is a key feature of the mandibular wax rim?

5 mm

How wide is the occlusal surface of the mandibular wax rims in the bicuspid area?

10 mm

How wide is the occlusal surface of the mandibular wax rims in the molar area?

Peripheral rolls

The facial and lingual walls of the mandibular wax rim are flat with a slight flare as they feather toward the _________

mean foundation plane

What is the occlusal plane of the mandibular wax rim parallel to?

No

Is there a buccal inclination of the mandibular wax rim?