Lecture 2: Final Impressions->Wax Rims Flashcards
_______: Records selected tissues in a displaced (functional) position
Selective Pressure
_______: Records the soft tissues in the undisplaced (resting) position.
Mucostatic
How long should the patent leave out their current denture before your final impression appointment?
24 hrs
CUSTOM TRAY- Mark this line ________ and extend ______mm past it when making your custom tray.
vibrating line (jxn of hard & soft palate)…2-3mm
_________: Shaping of an impression material by the manipulation or action of tissues adjacent to the borders of an impression tray
border molding
What are the 2 categories and 4 OPTIONS for border molding materials?
Categories: 1. Modeling Compound (Options: 1.Green or 2.Red Stick Compound) 2.Elastomeric (Options: 1.Polyether 2.PVS-Heavy Body)
________ : Negative registration of an area over which the complete denture will be worn
Final Impression
What are the three types of final impression material?
- Zinc Oxide-Eugenol 2.Polysulfide 3. Polyether/PVS
What material am I? Main use is for full-mouth edentulous impressions with no or very minor undercuts for complete denture
Zinc Oxide-Eugenol
What material am I? Accuracy of soft tissue impressions (low viscosity)…Stable after setting….Inexpensive
Zinc Oxide-Eugenol
What material am I? Disadvantages: Messy….Variable setting time (temperature/humidity)….Non-elastic (fracture if undercuts are present)….Irritating to soft tissue…Can not be disinfected using Birex (Phenols)
Zinc Oxide-Eugenol
What material am I? Widely used for full mouth edentulous impressions for complete dentures
Polysulfide
What material am I? Advantages: Long working time (4-7 min)… Good tear strength, flow, and reproduction of surface detail….High flexibility for easier removal around undercuts….Low cost compared to polyether
Polysulfide
What material am I? Disadvantages: Need custom tray (distortion)…Bad odor/taste…Tendency to run down to the patient’s throat(low viscosity)
Polysulfide
Holy cow: how long am I keeping PolySulfide in the Pt mouth for final impressions?
7-8 min
How long do you have to pour a PolySulfide impression?
1 hour before distortion
What material am I? Used for accurate full-mouth edentulous impressions without severe undercuts Advantages: Pleasant handling and easy of mixing…Good surface detail reproduction and easily poured in stone…If kept dry, good dimensional stability for up to 1 WEEK

Polyether
What material am I? Disadvantages…High cost…Storage of impression is critical (water/humidity affect)…Taste objectionable to some patients
Polyether
Interesting…Choose a PVS material that has the best ______ qualities.
hydrophilic
What material am I? Advantages: Ease of mixing and dispensing…No odor…Ease of clean-up…Stable – does not have to be poured immediately
PVS
What material am I? Expensive…Not as hydrophilic…Excessive flow
PVS
What are the 4 instructions to give the patient during the maxillary impression?
AFTER 1 MINUTE: Gently pucker…smile…move jaw side to side…forward and back
_______: Enclosing an impression to produce a base, to preserve the vestibular contours of the final impression, and to create a land area to protect the cast
BOXING
land area must be __-__ mm wide, the base is __-__mm thick
4-5mm..10-15mm
What do I use to lute the boxing wax to the impression? How far do you put it from the border of the impression?
sticky wax..3 mm
WHEN BOXING THE MAXILLA: The palatal shelf should be oriented parallel to the bench top and approximately __-__mm below the superior periphery of the boxing wax.
15-20mm
WHEN BOXIND THE MANDIBLE: The ________ should be oriented parallel to the bench top and approximately 15-20mm below the superior periphery of the boxing wax
alveolar ridge
How long do I wait after pouring the boxing master cast? What do I need to do before separating it?
45min to 1 hour..put it in HOT water bath for 5 min
_______: A replica of the prepared tooth surfaces (where necessary), residual ridge areas, and/or other parts of the dental arch used to fabricate a dental restoration or prosthesis
MASTER CASTS
How thick should the master cast base be?
15mm
How deep should the peripheral roll be around the vestibule on the master cast?
1-3mm
________: A temporary device representing the base of a denture and used for making jaw relation records/teeth arrangement
Record Base
________: An occluding surface usually made of wax
placed on a record base for making jaw relation records and arranging artificial teeth
Wax Occlusion Rims
How long do you soak your cast before mounting?
2-3minutes
