Impressions are _______ reproductions of the tooth structures and models are _______ reproductions.
negative; positive
100
What is the irreversible hydrocolloid material that is most widely used for preliminary impressions?
Alginate
100
How are elastomeric impression materials supplied?
Base and Catalyst
100
Which type of tray is used to cover the anterior portion of an arch?
Section trays
100
Which type of bite registration is particularly useful when diagnostic casts are being trimmed?
Wax bite registration
200
What are the three types of impressions taken in the dental office?
preliminary, final, and occlusal (bite registration)
200
Which component of alginate is used as a thickening agent?
Potassium alginate
200
Which form of elastomeric impression material is used for its ability to flow into and around the details of the prepared tooth?
Light-bodied
200
Trays should allow for ___-___mm of material between the tray itself and the incisal or occlusal edges of the teeth.
2-3mm
200
How is polysiloxane supplied when used for bite registration?
Paste system and as cartridges
300
Which type of impression is used for diagnostic models, custom trays, provisional coverage, ortho appliances, and pre and post treatment records?
Preliminary
300
What is it called when the alginate absorbs additional water and expands?
Imbibition
300
Which term means that the material was changed and will not regain its previous shape?
Permanent deformation
300
What kind of lock is created when the material oozes through the holes of a perforated tray?
mechanical
300
What is used when a more durable material is needed for a bite registration?
ZOE
400
Which type of impression produces the most accurate reproduction of the teeth and surrounding tissue?
Final
400
What causes a reversible hydrocolloid to change from one physical state to another and what is the term used to describe this change?
A change in temperature; hysteresis
400
What are the two disadvantages to rubber base material (polysulfide)?
Strong odor and it can easily stain clothing
400
How is the impression material held securely in place in a smooth surface tray?
An adhesive is used to line the tray
400
The easiest technique in wax bite registration employs a softened _____ ______.
Baseplate wax
500
Bite registrations provide the dentist and lab with an accurate registration of the patient's _______ relationship between maxillary and mandibular arches.
Centric
500
When conditioning the reversible hydrocolloid material, what is the second bath used for?
Storage
500
Which material is easy to handle when taking final impressions and has no taste or odor, making it acceptable to patients?
Polysiloxane
500
How long before use should a tray be painted with an adhesive?