Take an impression for study models


This unit of competency describes the skills and knowledge required to take an accurate impression of the teeth and their supporting structures for the construction of study models as prescribed by the dental practitioner.

This unit applies to dental assisting work.

The skills in this unit must be applied in accordance with Commonwealth and State/Territory legislation, Australian/New Zealand Standards and industry codes of practice.

Elements and Performance Criteria



Elements define the essential outcomes

Performance criteria describe the performance needed to demonstrate achievement of the element.

1. Assess the patient

1.1 Confirm patient’s medical history

1.2 Provide full details of the procedure to the patient or carer

1.3 Obtain and document consent following ethical and legal requirements

1.4 Select the equipment and instruments for the impression

1.5 Prepare personal protective equipment for the patient and members of the dental team

2. Select appropriate impression tray

2.1 Check the position of the dental chair and patient for the procedure

2.2 Check the tray for size and modify the impression tray to ensure accuracy and comfort

2.3 Instruct patient on participation during the procedure

3. Prepare impression material

3.1 Select impression material in accordance with desired outcome

3.2 Mix the impression material to the correct consistency and quantity required according to manufacturers’ instructions

4. Perform impression-taking procedure

4.1 Implement standard precautions during impression-taking

4.2 Use syringe to remove saliva from the occlusal surfaces

4.3 Load tray with an appropriate amount of impression material and seat the tray from the back using gentle pressure

4.4 Ensure the impression extends to and surrounds dental hard tissue structures

4.5 Ensure the impression has adequate extension into the buccal sulcus and vestibule

4.6 Carry out muscle trimming after seating the impression

4.7 Monitor and reassure the patient throughout the procedure

4.8 Remove the impression when set

4.9 Examine the patient’s mouth for injury and impression material debris following removal of the impression

4.10 Restore the patient’s comfort and appearance

5. Assess the impression

5.1 Assess the quality of the impression for the required study model

5.2 Identify common impression-taking problems

5.3 Document details of the procedure in accordance with standard procedures and relevant guidelines

6. Decontaminate the impression

6.1 Implement standard precautions during impression-taking

6.2 Rinsethe impression or denture in cold running tap water to remove all traces of saliva and blood

6.3 Clean the impression in an appropriate solution

6.4 Rinse the impression until all visible contamination is removed

6.5 Identify and correctly label impression and record procedure

Evidence of Performance

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 undertaken 10 impression procedures for study models ensuring patient safety.

Evidence of Knowledge

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

• national and State/Territory legal and ethical requirements and considerations for dental assisting work including:

­ codes of practice

­ discrimination

­ duty of care

- informed consent and statutory requirements of consent

- practice standards – dental guidelines on infection control

­ privacy, confidentiality and disclosure

­ records management

­ work role boundaries – responsibilities and limitations

­ work health and safety

• fundamental oral anatomy:

- 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

• principles and practices which underpin interpersonal communication

• principles of quality assurance and work effectiveness

• rationale and objectives for the taking of impressions for study models

• impression materials suitable for creating impressions for study models

• appropriate responses to patient’s reactions during impression taking procedure.

Assessment Conditions

Skills must have been demonstrated in the dental clinic workplace with the addition of simulations and scenarios where the full range of contexts and situations cannot be provided in the workplace. The following conditions must be met for this unit:

• use of suitable facilities, equipment and resources including:

- dental chair and unit

- impression material and equipment

- syringe suitable for saliva removal

- materials and mixing equipment

- operator and assistant personal protective equipment

- waste disposal equipment

- Dental Board of Australia guidelines on infection control on which the candidate bases the planning process

• modelling of industry operating conditions including access to real people for simulations and scenarios in dental assisting work.

Assessors must satisfy the Standards for Registered Training Organisations (RTOs) 2015/AQTF mandatory competency requirements for assessors.

In addition, assessors must hold a minimum of 5 years clinical experience in dental assisting work.

Foundation Skills

The Foundation Skills describe those required skills (language, literacy, numeracy and employment skills) that are essential to performance.

Foundation skills essential to performance are explicit in the performance criteria of this unit of competency.