Lecture 5-Mouth Preps Flashcards
For a TOOTH SUPPROTED segment (class III), how “tall” occlusal-gingival should the guide plane be?
2 to 4 mm
For an extension base (class I and II), a guide plane should be how “tall” occlusal-gingival?
1.5 to 2 mm (vs 2-4mm for class III)
What do you do first: Polish your guide plane or take an impression/pour to check correct angles?
Impression/pour THEN polish
What is the recommended bur to use for a cingulum rest?
an inverted cone
What is the preferred bur for an incisal rest?
round ended tapered diamond
An occlusal rest seat is basically _______ in shape
triangular
All features of the rest seat are gently _________.
rounded
You freggin missed this one PAY ATTENTION: How wide should the rest seat prep be in a BUCCAL-LINGUAL direction?
1/2 of the occlusal table (at its WIDEST-on the marginal ridge)
The enclosed angle formed by the floor of the rest seat and the proximal surface of the tooth must be less than _____ degrees
90
The preparation is finished using a ______ stone in a low-speed handpiece.
green
The preparation is then polished using a _________- containing rubber point in a low-speed handpiece
carborundum
T/F-you take off more when preparing a tooth that will hold a survey crown.
TRUE. You prep in the rest area for consistent metal thickness
When making a PFM survey crown, how far (in mm) should metal borders extend beyond the proposed rest borders?
1mm
What are the dimensions of the handle on your custom tray?
20mm x 20mm
Impression types: The surface contour of the ridge when it is not supporting a load
Anatomic
Impression types: The surface contour of the ridge when it is supporting a functional load
Functional
Which impression type represents the hard and soft tissues at rest

Anatomical Impression
Which type of impression is a pressure less impression?
Mucostatic
What are the two types of functional impressions?
1.physiologic 2. selective pressure
Which type of impression? (2 descriptors!)…This technique places an occlusal load on the impression tray while the impression is being made; therefore, placing pressure on the ridges
physiologic OR functional impression
Which impression type is accomplished by providing relief in the tray in certain areas and letting the tray contact the tissue in other areas?
Selective Pressure
When making our MASTER CAST, which type of stone do we use?
die stone
What are the three metals used in the casting of RPDs? What %weight do these three metals comprise in MOST dental restorations?
Chromium, Cobalt, Nickel…they account for 82-92%wt of most alloys used for dental restorations
What is the breakdown for the amount of the BIG THREE metals in VITALLIUM???
1.Chromium-30% 2.Cobalt 63% 3.Nickel-0%
