CH 47 Laboratory Materials and Procedures

During the pouring procedure, where should the gypsum material be place to flow to all areas of the impression?

• anterior portion

• canine area

• most posterior tooth

• palatal area

A model consists of the ______ portion, which represents the teeth and tissues of the mouth and the ______ portion which forms the base of the cast.

• art; anatomic

• anatomic; foundation

• anatomic; art

• oral cavity; foundation

A trimmed maxillary model will be ____ at the anterior portion and the mandibular model will be ____ at the anterior portion.

• rounded; pointed

• pointed; rounded

• rounded; rounded

• pointed; pointed

What is the recommended water/powder ratio for high-strength stone?

• 100g powder / 45-50 ml water

• 100g powder / 19-24 ml water

• 100g powder / 30-32 ml water

• 100g powder / 10-18 ml water

A common contaminated item found in a dental lab is ______.

• an impression

• a spatula

• a dental model

• an x-ray

Because a dental model shows a three-dimensional view of dental conditions, the dentist can use them to study the patient's mouth from various angles. Dental models are often used for which of the following?

• a. diagnosis of orthodontic treatment

• b. creation of a wax bite

• c. diagnosis and case presentation

• both a and c

• all of the above

How long should you wait before separating a model from the impression?

• less than 10 minutes

• 15-20 minutes

• 45-60 minutes

• 24 hours

What is one specific area of a dental model in which the maxillary and mandibular models are trimmed differently?

• heels

• the buccal surfaces

• the base

• the anterior area

What type of impression is a diagnostic model made from?

• preliminary

• bite registration

• final

• wax impressions

Which of the two models is measured and trimmed first?

• maxillary

• mandibular

• both at same time