High Yield Restorative Flashcards
At what pH does enamel start to demineralize?
5.5
What is best indicator of future caries?
Hx of caries
T/F: Frequency of sugar intake is more important than amount of sugar intake.
True
What is the earliest sign of a carious lesion?
Change in enamel opacity
Describe the process by which S. mutans adheres?
Converts sucrose -> dextrans via enzyme glucosyltransferase
T/F: Lactobacillus contributes to carries formation.
True
T/F: Lactobacillus initiates caries formation.
False
Helps it progress
Which race has the most prevalent caries risk in children?
Hispanic
What type of caries has seen the most increase in caries incidence?
Root caries
What racial population has the most unrestored caries?
Black
What is the best diagnostic indicator of root caries?
Soft spot
What are some characteristics of remineralized enamel?
Darker, harder, more resistant to acid
What will an arrested lesion look like?
Brown, leathery, hard
What is the most common areas for caries?
Pit/fissure
When do you treat caries?
Upon Cavitation
Fluoride works best on which type of caries?
Smooth surface
T/F: Consistency of sugar intake is most important for caries
True
Describe the differences in the shapes of smooth surface carries vs pit/fissure caries?
Smooth surface = Cone with apex facing pulp
Pit/fissure = two triangles, both bases at DEJ
T/F: A sealant over carries will lead to the carries getting worse.
False
Will lead to arrested caries
What is the mechanism of caries indicating dyes?
Bind to denatured collagen
How do you calculate incidence of caries?
(this years caries pts - last years caries pts)/total patients
What zone of carries is seen in a radiograph?
Body zone
What is the DMFS?
Decayed, missing, filled surfaces. Includes 3rd molars.
What is the DMFT?
Decayed, missing, filled teeth. Only permanent teeth, no 3rd molars
What race has the highest F in the DMFT index?
White
What is the deft?
Decayed, extracted, filled teeth. PRIMARY dentition
What is the difference between the 330 and 245 burs?
330 = 1.5mm long 245 = 3mm long
What are some pear shaped burs?
245, 330
How wide is the 245 and 330 bur at the tip?
0.8mm
What is the best bur for creating convergent walls?
245
What are the pros and cons of more blades on a bur?
Pro = smoother Con = less efficient
What is the RPM for high speed?
200,000 RPM
T/F: When excavating caries, you should start in the center and go towards periphery.
False
Use large bur and start at periphery
What is the difference between gingival margin trimmer and enamel hatchet?
GMT has angled blade
Which instruments are used to bevel occlusal floor?
15, 80
What would cause displacement of odontoblastic processes?
Thermal
What method of sterilization does not corrode burs?
Dry heat
Steam heat = BAD
What are the first signs of mercury poisoning?
Hair loss and muscle weakness
Where is the most common place for an amalgam to fracture?
Isthmus
What is the most common reason for amalgam failure?
Improper design (depth)
What is the corrosive phase of amalgam?
Mercury/tin
What is the function of zinc in amalgam?
Deoxidizer
What is the most toxic mercury?
Methyl mercury
Elemental mercury is what is in dental amalgam
What type of amalgam must be condensed the most?
Shperical
What happens when you over titrate amalgam?
Decreases setting expansion, increases strength
T/F: Moisture contamination has no effect on amalgam.
False
Decreases strength
When is it acceptable to leave unsupported enamel?
Class V
T/F: The required isthmus is the same for an inlay and amalgam.
True
What are the top two factors for retention form in an amalgam prep?
- BL walls converge
2. Retention groove/dovetail
What is the top factor for resistance form in an amalgam prep?
Flat floors and rounded angles
Doc says all amalgams should be replaced because they are toxic. What ethical principal is being violated?
Veracity
T/F: Gold is both malleable and ductile.
True
Deforms under compressive and tensile strength
Why bevel gold inlay?
Better marginal adaptability
What is the weakest part of a cast gold restoration?
Cement layer
When is a base metal recommended over gold?
FPD
When can galvanic shock happen to tooth with gold crown?
When there is another metal on opposing tooth
When should a cusp be included in the prep?
> 1/3 wide between cusps
T/F: Axial walls are convergent on inlay and onlay preps.
True
What is an indication for an inlay/onlay?
Low caries risk
What are some indications for rubber dam use?
Adhesive procedures, quadrant dentistry, teeth with challenging preps, difficult patients
What do the three different numbers indicate when identifying a hand instrument?
1st number: width of blade in 0.1 mm
2nd number: blade length in mm
3rd number: blade angle relative to long axis of handle
*sometimes a 4th number in-between 1st and 2nd indicates primary cutting edge angle
For a dental hand instrument with a formula of 10-8.5-8, the number 10 refers to?
Width of the blade, in tenths of a mm
T/F: During a Class I amalgam prep on a mandibular molar, the bur should be held parallel to the long axis of the tooth.
False
Long axis of the crown! The crown has a lingual tilt.
What is the standard axial wall depth in a class II amalgam prep? What if the gingival floor goes into cementum?
Standard: 0.2-0.5mm internal to DEJ
Gingival floor in cementum: 0.75-0.8mm
T/F: An occlusal bevel is often utilized to add to retention form of a Class I composite.
False
Retention from converging walls and bonding
T/F: In a Class V amalgam, walls should converge and retention grooves should be placed at DEJ.
False
Walls often diverge in Class V amalgam. Retention grooves should be placed internal to DEJ.
T/F: Amalgam preps should always result in amalgam and enamel margins at 90 degrees.
False.
Amalgam must be at least 90 degrees. Enamel should be at 90 degrees but sometimes this is not the case.
What are some possible reasons for increased sensitivity after an amalgam restoration has been placed?
Hyperocclusion, voids, poor condensation (leads to voids), inadequate dentinal sealing
T/F: Deep occlusal carving in amalgam is appropriate.
False
Can create weak points
When carving amalgam at the cavosurface margin, what should the discoid carver rest on?
Should rest on unprepared enamel and be moved parallel to margin.
In what sized increments can composite be polymerized?
1-2mm increments
What happens during the trituration of amalgam?
The entire allow particle is coated in mercury, and a product being formed
What is the half-life of mercury in the body?
55 days
T/F: Self-etch removes less of the smear layer than total etch.
True
T/F: Self-etch creates a weaker bond with enamel than total etch.
True
T/F: Self etch requires a wet bonding.
False
May be required in some total etch
T/F: Self etch systems take much less time to apply than total etch.
False
Although there are less materials, self etch often requires multiple applications. So self and total etch take about the same amount of time.
What are the indications for restoring a cervical notch?
Moderate-severe sensitivity, esthetics, symptomatic
T/F: Age is an indication for restoring a cervical notch.
False
T/F: Slots and pins give similar retention.
True
What is the proper depth of a slot for retention?
1mm
What bur should be used to make a slot?
Inverted cone
What is the only constant contraindication for composite?
Inability to isolate
T/F: A cervical lesion being very sensitive is an indication for restoring.
True
What are some characteristics of eburnated (sclerotic) dentin?
Darkened, firm, rough. Often seen in older patients. Indicates good oral hygiene
A beveled shoulder design around a capped cusp of a gold only is termed a _______.
collar
Provides bracing
What is a “skirt”?
Mini crown prep placed around a line angle in an onlay prep. Done with diamond bur. Increases retention and resistance. Contraindicated in esthetic areas.
