Unit 1
Powder into water or water into powder?
Powder to water
An impression is a ___ reproduction, a study model is a ___ reproduction
Impression- Negative
Study model- Positive
Water and powder ratio for mandibular and maxillary impressions?
MX- 3:3
MN- 2:2
Which cement must be mixed on a cool glass slab? Why?
Zinc Phosphate, due to exothermic heat
Amalgam capsules come available in 3 sizes. What are they?
400 mg
600 mg
800 mg
More/cold water= ___ setting time
Less/warm water= ___ setting time
More/cold- Longer
Less/warm- Shorter
Define mixing time, working time, and setting time
Mixing time- Time to mix a material
Working time- Time material can be manipulated before initial set
Setting time- Time from initial set of mix until no indentation can be made to the material
What elastomeric impression material is used most frequent? Advantages?
Polyvinylsiloxane (VPS)
High dimensional stability, low tear resistance
Can LDAs remove excess temporary and permanent cement? What level of supervision is this?
Yes, indirect supervision
Can LDAs place a temporary restoration? Under what level of supervision?
Yes, general supervision
Initial set should appear ___, final set should appear ___
Initial- Glossy
Final- Chalky
What is border molding and what is the purpose?
Utility wax around border of tray to extend to 3rd molars and high palate
What instrument to remove permanent cement? Temporary cement?
Permanent- Scaler
Temporary- Explorer
What are the types of glass ionomers?
Type I- Luting
Type II- Restoration
Type III- Liners and bases
Type IV- Sealants
Type V- Ortho bands and brackets
Type VI- Core build-up
Particle sizes of composite resins? Which is most commonly used?
Macrofill, Microfill, Hybrid
Hybrid most commonly used
Name the 3 pour methods for models
Double-pour
Box pour
Inverted-pour
Syneresis- Open air causing shrinkage
Imbibition- Water causing expansion
What are the 3 classifications of impression taking?
Preliminary, final, bite registration
What are the 3 different uses of a base?
Protective
Insulating
Sedative
Compositions of amalgam and uses?
Silver- Strength
Tin- Workability
Copper- Corrosion resistance
Zinc- Suppress oxidation
Types of gypsum? (5 types)
Type I and II- Impression/model plaster
Type III- Dental stone
Type IV- Die stone
Type V- High strength stone
Name 3 maxillary structures and 3 mandibular structures
MX- Labial frenum, rugae, raphe, tuberosities, soft palate, buccal attachments, incisive papilla
MN- Lingual frenum, retromolar area, mylohyoid ridge buccal frenums, retromolar area
What are the 4 classes of viscosity?
Class I- Putty
Class II- Heavy-bodied
Class III- Regular/medium-bodied
Class IV- Light-bodied
What are the 4 types of pulpal stimuli? Define each
Physical- Thermal changes
Mechanical- Grinding teeth, improper occlusion
Chemical- Acidic materials reaching pulpal tissues
Biologic- Bacteria and saliva reaching pulpal tissues
What indirect restorative material is most commonly used in dentistry? What are the advantages?
Porcelain
Strength, translucency, good insulator, low coefficient of thermal expansion