Final Exam Flashcards
Elastic impression materials are…
Used in dentistry for construction of metal castings, ceramic restorations,bridges, implant restorations,partial denture frameworks and complete dentures
Elastic Impression materials are also used for what?
Both edentulous and dentistry patients having under cuts
Inelastic(rigid) materials are used…
Only with edentulous patients having NO or shallow under cuts
Elastic impression materials:
- Agar colloid (reversible)
- alginate colloid (Irreversible)
- Polyvinyl silicoxane (reversible)
- Polyether (reversible)
Inelastic (rigid) impression materials: (reversible)
- Plaster of Paris
- Impression compound
- Zinc Oxide Paste
- Impression waxes
Composition of alginate:
Agar (seaweed)
Composition of Polyvinyl:
??
What type of trays do poly vinyl use?
- Stock
- Disposable
- Tri-Tray
Trays used for alginate:
- Metal perforated trays
- Disposable
- Stock
Trays used for polyether:
Custom
Negative Impresssions
Impressions of the patients mouth
Positive impressions:
Poured impression in the stone known as the diagnostic cast
Sizes of Maxillary trays:
1-5 (5 is largest)
Sizes of Mandibular trays:
20-25 (20 is largest)
Parts of model trimmer:
- Grinding wheel
- Casing
- Platform
Classifications of gold alloys:
- precious crowns
- non-precious crowns
- inlays
- onlays
Waxes used In lab:
Box
Borders of Diagnostic cast and how they are trimmed:
1. Anterior Maxillary: 30 degrees ( D of canine to M of central) Mandibular: rounded 2. Lateral Maxillary: 65 deg. Mandibular: 55 deg. 3. Posterior (90 deg.) 4. Posterior corners(115 deg.)
Stone of choice for pouring impressions:
Microstone- it’s less porous and gives greater detail
Classifications of gypsum material:
- Impression plaster
- Model plaster
- Dental stone
- Dental stone (High strength/Low expansion)
- Dental stone (High strength/High expansion)
Diagnostic Cast:
Casts generally made from dental plaster or stone
Used for: Pt. Education, treatment, planning, and tracking the progress of treatment
(Also known as study models)
Direct restoration
When the material is put in immediately (in the office)
Ex: amalgam and composite
Indirect restoration
When the restoration is made outside of the office (the restoration is not placed immediately)
Metals used to fabricate partials:
Colbalt chronium alloy
Metals used to fabricate implants:
Titanium
Sealants
Unfilled/lightly filled resins
Composition of sealants:
- bis-GMA
2. UDMA
Steps in application for sealants:
- Isolate(cotton roll or rubber dam)
- Pumice
- Rinse/Dry
- Etch (60 sec.) (chalky appearance)
- Rinse 30 sec./ air dry
- Place sealant (use explorer to move material down in grooves)
- Light cure (20 sec.)
- floss inter-proximally
- Check occlusion