PPT 2 Flashcards
What are the standard starting measurements for the occlusal wax rims?
22 mm maxillary
18 mm mandibular
What are the chances the wax rims will not need adjustments?
Slim to none
Why are we concerned about space?
- room to swallow
- room to chew
- Room to enunciate words
- Room for max and mand arches
- Room for max and mand teeth
- Room to look and feel confortable
What must be visible in the premaxillary area in your cast
Fremum notch
What 2 structures must you be especially careful not to cut short?
Retromolar pad area and Hamular notch area
How wide should the land areas of the cast be?
3-4 mm
What should you do to the tongue space of the cast and why?
Tongue space should be reduced flat to access the lingual undercuts
Why should land areas on the cast be reduced?
To access undercuts
Why must you take extra care to preserve your casts?
Because they are used in processing the final dentures
How thick should the cast be in the palate and tongue area?
13mm
What must be done prior to the second patient visit?
The preliminary casts must be poured and a custom tray made
During the 2nd patiend visit (final impression appt), the tray is tried in the mouth and adjusted to be ________, then border molded with ______, and then a ______ is taken
Adjusted to 2 mm short of the vestibule; Border molded with compound; Final impression taken
What should you find during the 2nd (final impression) appt.
If possible, find the location of the posterior palatal seal and scribe it into the maxillary master cast
What should be done directly after the 2nd (final impression) appt?
The impression must be boxed and poured,
the master cast must be trimmed,
and a record base and occlusal rims are made
Why do we insist upon using a single sheet of base plate wax for the spacer?
To ensure an even thickness of the impression material (1mm specifically)
What impression material is used for the final impression?
PVS (elastic impression material)
How can you make sure that the custom trays are at least comfortable for your patient (5 things)?
- Remove all undercuts
- No rough edges
- No sharp edges
- No scraping tissue
- Stable seating is accomplished
What is the procedural order for bordermolding?
- obtain green stick
- insert green stick into fire
- goop melty green compound onto custom tray
- Dunk in water bath
- Put in patient’s mouth
What is the definition of border molding?
Shaping of an impression material by the manipulation or action of tissues adjacent to the borders of an impression tray
What is the objective of border molding?
To determine the contours, height and width of the borders of the complete denture
During border molding we use the ____ technique to make an impression of the vestibule during function
Selective pressures technique
What is the objective of the selective pressures technique?
To manipulate the tissues in such a way as to get them extended so that the patient may be allowed to perform maximum movements before actually engaging the denture and moving it.
Is wax spacer kept in during border molding?
Yes!
Is wax spacer kept in during impression taking?
No!
What are the two sources of fire we use to melt green compound?
- Bunson burner
2. Hanau torch
What do we do before placing gooey green compound into patient’s mouth
Always temper the compound in a water bath 3-5 seconds before placing in the mouth to avoid serious burns
What is the temperature of the water bath?
140 degrees
Why is the water bath 140 degrees?
140 is slightly HIGHER than the FUSION temp of the compound, so the compound will still be PLASTIC when placed in the mouth
What happens if you take too long between tempering and putting try in patients mouth?
The compound hardens and you have to peel it of and start over
What size increments should the compound be?
Small
What should be placed in the area where you will do border molding prior to using the PVS specifically?
Adhesive
After completing border molding, what is the next step?
Scrape excess compound and remove the wax spacer
What is the purpose of triad stops
To keep tray from over-seating
What should you add after removing the wax spacer?
Adhesive
Which PVS should you use in place of the green compound (border molding)?
Heavy body
What should the second wash impression cover?
The original border molding
How do you make a supportive base?
1:1 plaster:pumice mixture with enough water for the mix to be smooth and creamy
What should the size of the land area be when creating a supportive base?
4mm even racetrack land area exposed
What is the purpose of the supportive base?
- To enclose an endentulous impression
- To preserve the vestibular contours of the final impression
- To protect to cast
- To create a land area
- To establish an area to process against
Define luting
A substance used to pack and seal pipe joints, and other connections, or coat a porous surface in oder to make it tight (A SEAL)
Describe the luting process
Lute (heat seal) 2 strips BEADING wax exenly around the peripheral borders of the entire edentulous impression (including tongue area) before pouring in stone
What will over-vibrating cause?
separation of the wax while pouring the stone
Should you crowbar your cast/pumice-plaster matrix apart?
No, soak in hot water for 15 minutes to soften the total impression and wax used to define the land areas
What happens if you break or over-trim your master cast
Must retake the final impressions with border molding
What is a master cast for complete dentures
An accurate replica of the residual ridge areas, and other parts of the dental arch upon which a complete denture prothesis is fabricated
What must be done to the master cast before making the base plates?
Protect cast by blocking out all undercuts
What causes a marred (broken) surface of the master cast?
Not blocking out undercuts or properly lubing cast before making the base plates
What is the downfall of the REQUIRED step of blocking our undercuts?
Lack of retention
What are the 7 names for base plates?
Base plate Occlusal rim Record bases Wax rims Templates Interim bases Record rim
What are occlusal rims?
Wax pillares places on base plates
Adjusted to record patient’s interocclusal jaw relationship
Serve as guides for properly setting teeth
Serve as guides to establish proper contours of denture base
Since we are doing split mounting, what should be done to the cast?
Put grooves in the bottom for retention to articulator
