UNIT 3

The first step is choosing the proper (a)   , based on the reason for the impression.

The consistency you want when mixing dental stone is like:

• Honey

• Peanut butter

• Water

• Cement

The next task after taking the impression is:

• Preparing the tray

• Trimming the model

• Pouring up the model

• Polishing the model

Answer explanation

After taking the impression, the next task is pouring up the model. This involves filling the impression with a gypsum material to create a replica of the patient's teeth and gums.

What is the purpose of Type IV gypsum in dental models?

• For taking impressions

• For fixed and combined prostheses

• For mounting and models

• High strength and high expansion models

What is the goal when pouring dental models?

• To practice pouring techniques

• To produce an exact replica of a patient's teeth

• To create a rough model

• To make a temporary model

What is the purpose of bite registration in dentistry?

• To clean the teeth

• To record a patient's occlusal scheme

• To take X-rays

• To apply braces

Which material was the first used for bite registration?

• Plaster of Paris

• Thermoplastic modelling compounds

• Acrylic resins

• Waxes

What is the main disadvantage of acrylic resins for bite registration?

• Difficult to use

• High cost

• Low accuracy

• Contracting on curing

What is the main advantage of elastomers for bite registration?

• Difficult to use

• High resistance to mandibular closure

• Low dimensional stability

• Easy to trim when cured

What material is used for wax bite registration?

• Acrylic resins

• Elastomers

• Plaster of Paris

• Dental waxes