Lecture 2

Question 1

what is fabricated from master casts?

Answer 1

maxillary and mandibular triad base plates with occlusal wax rims with starting measurements of
22mm maxillary
18mm mandibular

Question 2

why are we concerned about the space btween edentulous ridges?

Answer 2

room to swallow
room to chew
room to enunciate words
room for maxillary and mandibular baseplates
room for maillary and mandibular denture teeth
room to look and feel comfortable

Question 3

what are the important structures to be aware of in the master cast?

Answer 3

the frenum notch int the premaxilla area must be visible
retromolar pad areas should not be cut short
hamular notch areas should not be cut short
all land areas of the cast should be 3-4mm wide
the cast in the tongue space should be reduced flat to access the lingual undercuts
all land area should be reduced to access undercuts
cast should be 13mm thick in palate space and tongue area

Question 4

what is the definition of border molding?

Answer 4

shaping of an impression material by manipulation or action of tissue adjacent to the borders of an impression tray

Question 5

what is the objective of border molding

Answer 5

to determine the contours, height, and width of the borders of a complete denture

Question 6

what technique is used to make impression of the vestibule during function?

Answer 6

selective pressure technique

to manipulate the tissues to get them extended to allow maximum movement before engaging the denture and movign it

Question 7

why is the border molding compound tempered?

Answer 7

3-5 sec in water bath to avoid serious burns
the temperature of the tempering bath varies with the type of compound used but is always a few degrees above the fusion temperature of that compound - so the compound is still plastic when tray is placed in the mouth

Question 8

what is the final impression taken in?

Answer 8

elastic impression material (not alginate)

Question 9

is the wax spacer removed before border molding?

Answer 9

no- retained inside custom tray while border molding is performed

Question 10

border molding with pvs

Answer 10

use a heavier body impression material in place of the green stick compound

Question 11

what is the magnetic strip used for?

Answer 11

a base to enclose an edentulous impression that will preserve the vestibular contours of the final impression, and to create a land area to protect the cast and to establish an area to process against

Question 12

what is the method to make the base?

Answer 12

1:1 plaster/pumice mixture- enough water added so the mix is smooth and creamy
then push impression into the base until only 4mm is exposed evenly all around

Question 13

what is beading wax used for?

Answer 13

heat seal two strips of beading wax evenly around the peripheral borders of the entire edentulous impresssion

Question 14

what is boxing wax used for?

Answer 14

heat seal two strips of boxing wax evenly around the peripheral borders of the entire edentulous impression

Question 15

what will overvibrating cause?

Answer 15

separation of the wax

Question 16

what is done after removing the exterior wax?

Answer 16

immerse the entire cast and plaster/pumice matrix in very hot water for 15mins to soften the total impression and the utility wax ysed to to define the land area

Question 17

what is the master cast?

Answer 17

an accurate replica of the residual ridge areas and other parts of the dental arch upon which a complete denture prosthesis can be fabricated
the cast must be protected by blocking out all undercuts before making the base plates

Question 18

what is the most commonly seen problem that have resulted from undercuts on casts being insufficiently blocked out or insufficiently lubricated before making the base plate?

Answer 18

broken or marred surface of the cast

Question 19

what is the downfall of blocking these undercuts?

Answer 19

dealing with lack of retention of the temporary base plate during patient treatment

Question 20

what are occlusal rims?

Answer 20

wax pillars placed on base plates which are adjusted to record the patient’s interocclusal jaw relationship and serve as guides for setting the teeth in proper position and establishing the proper contour of the denture base

Question 21

what are templates/base plates?

Answer 21

create temporary intermediate structural base plates representatie of the contours of the final denture

Question 22

what do you want to do with the occlusal wax rims and base plates?

Answer 22

adjust base plates and occlusal wax rims to the clinical proportions acceptable to the pt
22mm maxillary
18mm mandibular