13. Denture Teeth Try In and Processing (Quiz 5)

What is the difference between a functional try in vs esthetic try in?

- Functional try-in: when articulation is in question

- Esthetic try-in: when replacing anterior teeth

All of the steps in the image are a part of what technique when processing a denture?

Cold packing technique

All of the steps in the image are a part of what technique when processing a denture?

Injection molding technique

Why is there a denture try-in step?

- To check the prosthetic space/ function (functional try-in)

- To check esthetics and phonetics (esthetic try-in)

What does the vertical prosthetic space include?

Vertical dimension of occlusion

What does the horizontal prosthetic space include?

Related to your bite registration that was obtained either in MIP or in CR. It is especially critical when posterior support needs to be restored by re-establishing a functional dimension of occlusion in centric relation

What esthetic parameters should be checked at tooth try in?

- Midline

- Teeth size, shape, and proportion, contour

- Incisal position and anterior teeth display

- Smile line

- Buccal corridor

- Color

- Space (decreased if overlapping teeth vs increased with diastema)

What is the last opportunity to verify the prosthetic space before processing of the denture?

Functional try-in

How do you check vertical dimension of occlusion (VDO)?

- Facial esthetics

- Interocclusal rest space

- Phonetics (S and F sound)

esthetics and phonetics are mostly related to the ______ teeth

anterior

it is more important for the ______ arch midline to coincide with the facial midline

maxillary

Deviations of less than 1mm can be observed by ____%

14%

Deviations between 1-2mm can be observed by ____%

37%

Deviations of more than 2mm can be observed by _____%

83%

All of the following are characteristics of what teeth?

- Not too big nor too small

- Antero-posteriorly: as it related to phonetics, lip support, and light reflection

- In relation to the symmetry with the midline

- Inciso-cervically; as it related to phonetics, esthetics, gingival display

Anterior teeth

the incisal plane should be parallel with the ______

interpupillary line

the occlusal plane should be parallel with the ______

Camper's plane (ala-tragus)

ideally, the smile line should follow the contour of the ______

lower lip

What parts of the wax need ginigval festooning?

- lingual concavity

- buccal concavity

- gingival margins

What are the 2 conventional methods for processing a partial denture?

- Cold Packing/ Compression Molding/ Acrylic Packing

- Injection Molding

Almost all of the steps in the 2 different conventional methods for processing a partial denture are the same, but what step is different in the Cold Packing/ Compression Molding/ Acrylic Packing method?

resin packing

Almost all of the steps in the 2 different conventional methods for processing a partial denture are the same, but what step is different in the Injection Molding method?

spruing

What are the steps of the Cold Packing/ Compression Molding/ Acrylic Packing method:

- Investing

- Wax elimination

- Resin packing

- Processing

- Deflasking

- Correction of processing errors

- Decasting

- Finishing and polishing

There are few different ways of investing; using 3 or 4 layers and using only stone or stone and elastic materials for the investment. Why do multiple layers help?

Eases deflasking

In the third layer of investing with the cold packing technique, the upper section of the flask is placed in position to verify there is at least ___mm of space present between the second layer of stone and the top of the flask

7mm

how many investing layers are used in the cold packing method?

4

During the wax elimination step of cold packing technique, the flask from the Four-Layer investment technique was placed in boiling water for _____ minutes to soften the wax bases, then removed and a knife has been placed in the slot between the flask sections to separate the flask

5 minutes

During the wax elimination processing of the denture for the cold packing technique, what is placed at the bottom of denture teeth?

Retention holes or diatorics

For the cold packing method, processing is done in a ______

waterbath

During the resin-packing step of the denture for the cold packing technique, what is applied to the edentulous ridge areas of the cast to prevent the resin from fusing to the stone cast?

Gypsum separating agent

Where should you avoid placing gypsum separating agent?

Do NOT apply the agent over denture tooth surfaces

What are two types of presses used in the resin-packing step of the denture for the cold packing technique?

- Pneumatic press

- Flask press

A brush is used to apply a thin layer of ________ to each of the compressed resin surfaces in both halves of the flask to ensure the opposing sections of resin will be securely united with each other.

Monomer

For the cold packing method, for a slow cure, how long and at what temps should you cook the RPD?

- 8 hours at 160℉

- 1 hour at 212℉

For the cold packing method, for a quick cure, how long and at what temps should you cook the RPD?

- 1 hour at 165°F

- 30 minutes at 212℉

During the deflasking step of the denture for the cold packing technique, a plastic-headed hammer is used to tap on the round insert located in the center of the lower portion of the flask. What does the tapping cause?

The tapping causes the investing stone to separate itself from the lubricated flask

What can be used to adjust areas of heavy occlusal contact in the cold packing technique?

A small-tipped rotary instrument

When is the centric occlusal relationship adjusted until?

Until the incised guide pin comes into contact with the blue incised guide table, indicated adjustment has now returned the RPD to its original vertical dimension of occlusion

What step of the cold packing technique is this?

1st: Cut off abutment teeth:

- A bur is used to cut the grooves through the stone to separate the abutments from the base of the cast.

- Once the abutments are separated from the base of the cast, sometimes the RPD will come off the base of the cast.

- Other times, the base of the cast will need to be sectioned

Decasting

An __________ bur is being used to remove the resin flash present at the perimeter of the base and to produce a rounded form to the border

Acrylic resin

A __________ is used to trim the slight amount of resin flash that was expressed beyond the internal finish line on the framework and over the polished internal surface of the lingual bar major connector. The junction of the resin base and the internal finish line will then be very carefully adjusted with a small rotary instrument until the transition between the resin and the metal is smooth

Scalpel

What can be used to finish and polish the denture in the cold packing technique?

- Fine pumice with a wet rag wheel

- Bristle brush with fine pumice

- Resin buffing compound and clean rag wheel

What is the resin base made of?

Methyl Methacrylate

which procedure is at risk of chemical shrinkage of methyl methacrylate during polymerization resulting in inaccuracies?

Cold Packing/ Compression Molding/ Acrylic Packing

The ________ controls the heat/pressure polymerization, during which the exact amount of material keeps flowing into the flask to compensate acrylic shrinkage

Ivocap Injection System

What are the steps of the Injection Molding method:

- Investing upper member

- Spruing

- Investing lower member

- Wax elimination

- Processing

- Deflasking

- Correction of processing errors

- Decasting

- Finishing and polishing

What is the powder to liquid ratio for the resin packing step in the cold packing method?

3:1

When heat-polymerized resin is mixed, it progresses through a series of stages. Which stage do you want to pack the resin at?

A) Sandy

B) Stringy

C) Dough-like

D) Rubbery

E) Stiff

C) Dough-like

ID the phase:

investing

ID the phase:

wax elimination

ID the phase:

resin packing

ID the phase:

deflasking

ID the phase:

decasting

which procedure eliminates the chemical shrinkage of methyl methacrylate during polymerization, resulting in more accuracy?

Ivocap injection Molding

What procedure is the following?

- A method to process dentures

- Controls the heat/pressure polymerization, during which the exact amount of material keeps flowing into the flask to compensate acrylic shrinkage

ivocap injection system

What procedure is this image from?

ivocap injection system

What is an example of a reductive manufacturing technique used in RPD fabrication?

Milling

In additive manufacturing for RPD frameworks, what technique uses resin as the primary material?

Sterolithography

Selective laser melting (SLM) is primarily used to fabricate RPD frameworks made of what?

Metal

In additive manufacturing for RPD frameworks, what technique uses plastic, glass, or ceramic?

Selective laser sintering

What materials are used in conventional RPD fabrication?

- Co-Cr

- Titanium

- PMMA (Polymethyl Methacrylate)

What materials are used in first generation RPD fabrication?

- Polyamide (nylon)

- Acetal resin

All of the following are used in what type of RPD fabrications?

- Polyaryletherketone (PAEK),

- Polyetheretherketone (PEEK)

- Polyetherketoneketone (PEKK)

- Aryl Ketone Polymer (AKP)

Newer methods

What is needed to improve 3D and CAD/CAM methods in RPD?

- Further development in usage, workflow, and accuracy needed

- Primarily follow RPD design but consider property of new material

Does the use of 3D and CAD/CAM methods in RPD still require conventional methods?

Yes