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Follow the links below to find material targeted to the unit's elements, performance criteria, required skills and knowledge

Elements and Performance Criteria

1. Elements define the essential outcomes
2. Prepare model
   • Read and interpret the work order
   • Block out undesirable undercuts
   • Design the custom tray for the patient’s dentition and the intended impression material and technique
   • Apply spacer material when required
3. Select and prepare materials
   • Select custom tray materials in accordance with the work order
   • Prepare equipment for processing
   • Provide appropriate mixing vessels and templates when required
4. Construct custom impression tray
   • Apply appropriate separating medium in accordance with manufacturer’s instructions
   • Mix or manipulate materials in accordance with the manufacturers’ instructions
   • Adapt tray material to the model to the pre-determined peripheral outline
   • Construct handle and attach according to operator requirements
   • Process custom tray using the correct method for the correct material
   • Separate the tray from the model in a manner that prevents damage and remove spacer material
   • Trim the outline of the tray to shape
5. Finish custom impression tray
   • Smooth and refine the peripheries, handle and other surfaces of the tray
   • Decontaminate the custom impression tray according to infection control guidelines
   • Dry the custom tray and place in a sealed container for dispatch

Performance Evidence

The candidate must show evidence of the ability to complete tasks outlined in elements and performance criteria of this unit, manage tasks and manage contingencies in the context of the job role. There must be evidence that the candidate has:

• read and correctly interpreted 4 work orders

• used standard precautions and safe work practices to fabricate custom trays, using a range of materials, for 4 different dentitions with desirable properties and design features including one each of the following (must be a combination of maxillary and mandibular arches):

- full dentition

- edentulous

- partial dentition including

o bounded saddle

o free end saddle

• critically evaluated the 4 custom impression trays produced to meet technical laboratory and clinician requirements.

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Knowledge Evidence

The candidate must be able to demonstrate essential knowledge required to effectively complete tasks outlined in elements and performance criteria of this unit, manage tasks and manage contingencies in the context of the work role. This includes knowledge of:

• Australian/New Zealand Standards, workplace health and safety (WHS) policies, current Dental Board of Australia guidelines on infection control, Commonwealth and State/Territory legislation requirements and organisation policies relating to dental laboratory work

• Fundamental oral anatomy including:

- dentition – arrangement of the teeth, naming and coding of teeth

- structures of the oral cavity – hard and soft palate, lateral and posterior borders of the oral cavity, tongue and floor of the mouth

- teeth form and function

• properties of custom tray materials including:

- acrylic resins

- light-cured composite

• rationale for using space filling materials

• desirable properties and design features of custom impression trays including:

- a design that holds the impression material in the correct position in the mouth

- a design that supports the lips and cheeks so that the functional depth and shape of the sulcus is recorded

- a design that allows for positioning of the handle to avoid the lip during impression taking

- rigidity, strength, dimensional stability and smoothness

- spacing to permit the correct thickness of the impression material to be used.

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