Autumn midterm: Custom tray

Question 1

what are common difficulties about custom trays

Answer 1

over extended- impinging on tissue or under extended, not covering all areas.

Question 2

what is the material for custom tray we use

Answer 2

triad- visible light cure resin

photopolymerized resin

Question 3

what is the space between the tray and teeth

Answer 3

clearance is 2-3 mm

Question 4

what is triad made of

Answer 4

urethane and dimethacrylate based.

Question 5

what is the unit that we used to harden our trays

Answer 5

VLC (triad 2000, dentsply)

-visible light cure unit for curing material.

Question 6

how long did we cure the trays

Answer 6

2 minutes initially then scoop the wax out. final cure is 6 minutes

Question 7

how far from the gingival margin did we mark/create the lines for the tray borders

Answer 7

3-5 mm from margin

Question 8

what did maximum intercuspation used to be called?

Answer 8

centric occlusion

-cusps of teeth of both arches fully interpose themselves with the cusps of the teeth of the opposing arch

Question 9

what are the “stops” in the custom tray and their purpose

Answer 9

help maintainuniform/even space forthe impression material.

Question 10

where are stops placed?

Answer 10

nonn functional cuspsof 18 and 31, can be angled 45 degrees. not on the prep tooth . also placed between two central incisors

Question 11

what should the thickness of the tray be for rigidity?

Answer 11

2-3 mm of thickness

Question 12

whats the maximum thickness for the wax and what is the purpose of it?

Answer 12

maximum is 3 mm

creates 2-3 mm of space for the impression material

Question 13

what is the purpose of the foil- what else could be used instead

Answer 13

1. easier to clean the tray/ remove the wax
2. residual wax left on the tray may interfere with the impression material.

alternative is using vaseline or something recommended by manufacturer

Question 14

why do we put holes in the tray

Answer 14

for retention of impression material