Producing A Light Cured (Secondary) Tray

Question 0

Steps: (5-7)

Answer 0

5) Adapt resin to wax spacer.
- Apply a light coat of separate to the wax spacer (generally baby oil)
- Fill stops with resin and then adapt sheet of resin over wax spacer. - - Do not overwork to ensuyre even thicness over model
- Trim excess around sulcae & palate (avoid extending too posteriorly)

6) Shape handle with excess resin
- Position at midline of tray
- At level of occlusal plan, tray is to be angled at 45-60degrees
- Allows for easier manipulation
- Ensure it does not obstruct patient lip or nose and etc.

7) Perforations
- Place evenly distributed small perforations over the resin
- Perforations released excess material during impression taking
- Avoid placing perforations at occlusal stops and periphery of tray

Question 1

Steps: (1-4)

Answer 1

1) Preparation of model
- Where we make sure model angulation is suitable for thermoforming
materials by minimising undercuts by blocking them out with wax.
- Ensure sulcular anatomy is identifiable

2) Briefly soak model in water

3) Identify occlusal stops
- To ensure adequate space for impression material and stability of
tray.
- Occlusal stops are generally placed on the 3s and 6s or 3s and
7s only if premolars are extracted.
- Ensure that the occlusal anatomy over the teeth of concern are not
used as occlusal stops.

4) Spacer Wax
- Adapt a heated double-layer of spacer wax onto the model,
extending into the sulcae.
- Note not to overwork the wax as it can cause uneven thickness.
Space required for alginate is 3mm, thus 3mm thickness is required.
- Trim occlusal stops or boxes and excess wax over non-anatomical
areas (i.e. the land)

Question 2

Steps: (8- b)

Answer 2

8) Curing
- 5mins on model
- Removal tray from model and then cure 5mins off model to ensure
curing of palatal and lingual surfaces, particularly occlusal stops.

9) Finishing
- Ensure that there is a 2-4mm clearance between tray and sulcus/
attachments.
- Trim, round and smooth sharp/rough edges with an acrylic bur
- Ensure perforations are through and through using a round tungsten
carbide bur
- Assess stability on model

9) Clean, Disinfect, Store and before placing into patients mouth, disinfect again.