High Yield Prosth Flashcards
What is the weakest porcelain?
Feldspathic porcelain
What can cause porosity in porcelain?
inadequate condensation
What can cause porcelain to turn green?
Silver; copper in cervical 1/3rd
What should be the first thing checked when seating a crown?
Esthetics -> contacts
What is the most technique sensitive part of placing veneers?
Preparation
What can cause dark stain near the margin of veneers?
Microleakage
What is the proper reduction for veneer prep?
.5mm
What is the proper process for bleaching with veneers?
Bleach, wait 2-3 weeks, prep veneers
Which fluoride should be used with veneers?
Sodium fluoride
What is the ideal reduction for PFM crown?
1.5-2mm
T/F: The functional cusp bevel in a crown prep is for retention form.
False
Resistance
T/F: The modified ridge lap pontic has minimal contact with the residual ridge.
True
When should an ovate pontic be used?
Anterior teeth that were recently extracted.
Which dimension is most important for strength of FPD connectors?
occlusogingival width
What is advantage of fiber post?
Has same modulous elasticity as dentin
What is the purpose of post?
Retain the core
What is the most important when selecting shade?
Value
T/F: Value is the black-white spectrum of a color.
True
When you have a color index of 100, which is effected?
Value
T/F: Adding a complimentary color increases the value.
False.
Decreases. You cannot increase value
T/F: Wavelength is associated with hue.
True
What are the rules for balancing, working, and protrusive contacts?
Balancing - BULL
Working - LUBL
Protrusive - DUML
In non-working movements, the lingual incline of buccal cusps of mandibular molars should hit what?
Buccal incline of lingual cusps of maxillary molars
Wear facets are seen on lingual inclines of maxillary lingual cusps and facial inclines of mandibular facial cusp on the left side of the mouth. During what movement is there an interference?
Left working or right non-working interference
Wear is seen on buccal cusps of maxillary premolars? What movement is causing this?
Working
When should the BULL rule be utilized in selective grinding?
When there is a non-working side interference
When should LUBL be utilized in selective grinding?
When there is a working side interference
When should DUML be utilized?
When there is a protrusive interference
The mesial angle of the ML cusp of maxillary 2nd molar occludes with what on mandibular 2nd molar?
Distal of MB cusp
T/F: Tooth contact will result in inaccurate terminal hinge record.
True
What position are the condyles in in CR?
Superior-anterior-medial
If both condyles break, what will be the result?
Posterior open bite
The __________ is the angle formed by the non-working condyle and the sagittal plane during lateral movement.
Bennett angle
What kind of bond is used by composite?
Mechanical bond (micromechanical)
Most likely cause of post-op composite pain?
Hyperocclusion
What determines the depth of occlusal composite?
Depth of decay
T/F: Class 1 composite preps should contain only pit and fissure carries.
True
No extension
What two factors determine successful posterior composite?
Type of resin and type of prep
What is the disadvantage of a large MOD posterior composite?
Occlusal wear
Which type of prep has the highest C-factor?
Class 1 and Class 5 (both are 5 walled preps, so C factor = 5)
Which type of caries is transillumination most useful?
Class III
Which part of composite stains the most?
Gingival proximal
What is the best material for a pt with a lot of cervical caries?
GI
MOD amalgam prep goes 1/3 the distance of the cusp height. What should you do?
MOD onlay
T/F: Indirect restorations (onlay/inlay) have better marginal seal than direct composites.
False
What is the main reason for the failure of posterior composites?
Case selection and technique
What are some causes for sensitivity after composite placement?
Occlusion, debonding
What is the most common reason for replacing anterior composites?
Color change
How long after bleaching should you wait before bonding composite?
1 week
Pt has pain to cold and chewing after Class I composite filling? You ditch it out with a bur and the pain is gone. What was the cause?
Polymerization shrinkage
What is the highest chance of leakage with a rubber dam?
Holes punched too close
What are the steps for adding composite to porcelain?
Microetch, etch, silanate, bond
T/F: Etchant provides a chemical bond.
False
Mechanical
What is the difference between self-etch and total etch?
Self-etch = etch and primer are together, not as strong of an etchant, does not always remove smear layer
Total etch = separate phosphoric acid used for etch and rinse technique
Which type of etch is less reliable?
Self-etch
What is the function of filler in composite?
More filler = higher strength, less shrinkage, do not polish as well
T/F: HEMA composites can cause contact dermatitis.
True
What are the components of GI cements?
Polyacrylic (polymeric) acid.
Silicate glass.
What is the purpose of mixing GI cement on a glass slab?
Incorporate more powder
T/F: Impression inaccuracies will cause the crown to fit poorly on the master cast.
False
Will fit die, will not fit in mouth
What should be used to cement all ceramic crowns?
Composite resin
T/F: GI should be used to cement all ceramic crowns.
False
Expansion can cause cracking of porcelain
What is the most radiopaque aspect of composite?
Barium
Which type of composites have the most color stability?
Light cure due to TEGDMA
T/F: Microfill composites have a smoother finish than hybrid composites.
True
Less staining
What is the significance of their being less nitrates in light cured composite?
Shade balance
What is the wavelength of visible light?
380-740nm
T/F: Glass ionomer forms an ionic bond.
True
What is most critical in a direct pulp cap?
Place hard liner/base over CaOH
What is a negative of GI cements?
low pH can cause pulp irritation/sensitivity
T/F: GI has less surface hardness, compressive strength, and tensile strength than composite.
True
Zinc oxide eugenol can be strengthened with what?
Methyl methacrylate
IRM/Reinforced ZOE
What do you fill primary tooth RCT with?
ZOE w/o catalyst or accelerator
What does BIS-GMA do when added to PMMA?
Adds strength, crosslinking. Gives doughy texture - increased working time
T/F: An excessive amount of monomer can cause shrinkage.
True
What happens if you increase water:powder ratio in alginate?
Increase working time. Decrease expansion.
What will increase expansion (decrease working time) of gypsum?
- Longer spatulation time.
- Decrease water:powder ratio
- Hot water
What is used if angioedema to alginate?
C1 esterase inhibitor
Why does alginate still shrink in 100% humidity?
Syneresis
What is a disadvantage of polyether?
Sticks to teeth
What is the most rigid impression material?
Polyether
What is the most stable elastic impression material?
Additional silicone
How many mg of fluoride in 1 liter of water at 1ppm?
1mg
What does fluoride replace in hydroxyappetite?
Hydroxyl group
T/F: Fluorapatite is less soluble than hydroxyapatite.
True
T/F: Fluoride increases strength of collagen.
False
T/F: Fluoride lowers pH of oral cavity.
False
How long should fluoride trays (foam) be applied?
4 minutes
At what age should supplemental fluoride be started?
6 months
What is a toxic dose of fluoride?
5-10 mg/kg
What is the average concentration of fluoride in water?
1 ppm
EPA maximum allowed concentration of fluoride in water?
4 ppm
How is fluoride administered in schools?
.2% weekly
How should you supplement a 4 y.o. fluoride use when she only gets .28 ppm daily?
Systemic supplement
What are the teeth most likely to be effected by early childhood caries?
Max anterior and primary molars
What is the effectiveness of water fluoridation?
20-40%
How many people/cities have fluoridated water in U.S.?
65-70%
What is the difference between primary, secondary, and tertiary treatment of caries?
1 - prevention (fluoridated water)
2 - eliminate/reduce disease (filling)
3 - rehabilitation (dentures/c&b)
T/F: Fluorosis inhibits remineralization.
True
How is severity of fluorosis determined?
Look at 2 worst teeth
T/F: Acidulated fluoride will wear away GI.
True
Which fluoride will not stain veneers?
Sodium fluoride
What is the bleaching agent used for home bleaching?
10% carbamide peroxide