1. Custom Trays Individualized trays for making final impressions
Made on a diagnostic cast

2. Purpose of a Custom Tray
Improve retention (border molded)
Minimize:
Impression material distortion
Uniform thickness
Rigid tray

3. Purpose of a Custom Tray
Minimize:
Tissue distortion
Less viscous material
Accurately adapted tray
Costs
less impression material used

4. Custom Material Light-cure resins (Triad)
Auto polymerizing acrylic resin (e.g. SR-Ivolin)
Fume hood
Vacuum-form poly vinyl
Thermoplastic materials

5. Monomer Hygiene
Autopolymerizing resins have a liquid monomer that should be used in a fume hood
Light cure materials for students

6. Extension 3-4 mm short of the peripheral role
Diagnostic casts usually overextended (irreversible hydrocolloid)

7. Extension Outline the depth of vestibule
vertical portion turns toward horizontal
Through hamular notches across vibrating line
Provide room for frenal attachments

8. Block-Out Undercuts Baseplate wax Prevent tray from locking onto cast
Lubricate cast (Petroleum jelly or Alcote)

9. Wax Spacer One thickness of base plate wax over the cast
Trim line in vestibule
Trim to“butterfly” configuration glandular tissue

10. Wax Spacer Minimizes hydraulic pressures
Do not place relief over blockout
Already space from tissue
Provides room for impression material

11. Triad Resin Light-cure Heat will melt wax spacer Cure under water
Cures on exposure to ambient light

12. Triad Resin Exposed surface has air inhibited layer
Air Barrier Coating
Cytotoxic
Must be thoroughly removed
Cure under water

13. Triad Resin Wear gloves to minimize exposure to material
Hypersensitivity potential minimal

14. Tru-Tray Material Remove from wrapper Adapt the resin over the spacer
Palatal area adapted first

15. Large Casts Use portion of another sheet Adapt well until seam is gone
Reclose material in wrapper, tape shut
Infection control

16. Tru-Tray Material Trim excess with a scalpel, then readapt
Cut down through resin
Pulling blade will tear resin

17. Trimming the Tray

18. Handle Addition Small vertical handle Add before curing
Does not pull vestibule
Add before curing

19. Auxiliary Handles Mandible
For stabilization
Orientation the tongue
Area of 2nd premolars / 1st molars

20. Curing in Water Prevents wax meltdown Water hazard Ensure:
Top of container well sealed
Outer container surface dry

21. Cure Time
4 minutes
Cooling effect of water may extend cure time

22. Finish Arbor-bands and acrylic burs Round and smooth edges
Mask and eye protection

23. Finish
Do not polish - adhesion
No holes until border molded

24. Tray for Border Molding with Partner
More difficult than edentulous border molding
Removal from teeth & undercuts
Easier to lock in place
Hybrid design

25. Tray Design