You are employed at A.B & C.D. Dental as a dental assistant. You are assisting the dentist with the following patient:

Matt is 14 years old and has attended the dental practice for a discussion about orthodontics. After discussion with his parents, the dentist has decided to take preliminary impressions for study models.

You have been asked to describe to the new employee the technique for pouring the model for the patient. Refer to the 'HLTDET001 - Assignment Attachment - Manufacturer's Instructions Gypsum Plaster X' to complete the following tasks.

GYPSUM PLASTER X Manufacturer Usage Instructions Colour Blue Mixing Time 35- 45 seconds Working Time 5-6 minutes Initial Setting Time 9-11 minutes Final Setting Time 45-60 minutes Water ratio 40 ml water/100g Gypsum Plaster X powder

Mixing instructions Mix 40ml of water per 100g of Gypsum Plaster X powder in a clean bowl Stir the mixture using the provided spatula for 15-20 seconds to combine the materials Using a rapid mixing action, stir the mixture for an additional 20-25 seconds to ensure a consistent mix Inspect the mixture for any air bubbles Flatten any air bubbles using the provided spatula Inspect the mixture before pouring to ensure the mixture is consistent and appears thick and creamy Place the bowl containing the mix on a vibrator and run the vibrator for at least 30 seconds

Pouring instructions

First Stage Pour: Place the impression on the vibrator. Then, starting at one corner, deliver a small amount of the plaster into the molar tooth impression, allowing it to flow into the impression. Repeat this step until all the tooth impressions are filled. The plaster should flow around the arch of the impression, completely filling one tooth at a time. Carefully check for bubbles. The vibrator should eliminate these; however, if a bubble appears and does not go away with vibration, pop it with a small instrument. Allow the mix in the impression to reach the 'initial set'. This usually occurs between 9-11 minutes and will be several minutes after the plaster loses its glossy appearance. Second Stage Pour: When the tooth depressions have filled, add plaster in larger amounts to a level slightly above the impression walls. Continue to vibrate to ensure complete coverage.

Blend the pours together with the spatula to make a continuous connection. While holding the handle of the impression tray, use the spatula to shape the sides of the model material around the first pour. Avoid placing the wet material from the base onto the impression tray because this would cause a mechanical lock that is difficult to separate when set.

Place the remaining model material onto a tile, forming a mound slightly wider than the impression

Add the base to the top of the filled impression by inverting the impression onto the base

The final setting time is between 45-60 minutes from the start of the second pour

Storage instructions

Gypsum Plaster x can be safely stored in its sealed packaging. Ensure packaging is correctly sealed after usage.

The shelf life of the plaster is 12 months from the date of manufacture

Gypsum Plaster must be stored in a dry environment away from direct sunlight

Once mixed, any unused Gympusm Plaster x must be disposed of appropriately

You have been asked to train the new employee at your workplace on how to finish the model that you have poured in scenario 3. Complete the following questions to describe the processes for this new employee.

1. Describe the process you will follow to carefully separate the model from the impression.

2. Describe what 4 defects you will check the model for

3. Describe why you will trim the model?

4. What equipment will you use to trim the model?

5. What may require trimming on the model?

6. Why would a master model be duplicated?

7. How can a master model be duplicated?