Operative Dentistry Flashcards
1
Q
What is the main component of enamel and dentin?
A
- carbonate-substituted hydroxyapatite (CHA)
2
Q
How does Fluoride help with tooth health?
A
- remineralization of tooth structure
- decrease enamel solubility (lowering critical pH)
- interfering with the metabolic activity of cariogenic bacteria
3
Q
What is the critical pH of tooth structure?
A
- enamel (FA) - 4.5
- enamel (CHA) - 5.5
- dentin and cementum - 6.2-6.7
4
Q
What is the order of progression of a cavity?
A
- enamel demin
- dentin demin
- enamel cavitation
- dentin cavitation
5
Q
3 cariogenic bacteria
A
- streptococcus mutans (contains glucosyltransferase) - enamel caries
- lactobacillus (dentinal caries)
- actinomyces (root caries)
6
Q
What is the most toxic form of mercury?
A
- methylmercury (digestion of seafood)
7
Q
What form of mercury is found in dental amalgam?
A
- elemental
8
Q
Characteristics of low-copper amalgam
A
- <12% Cu
- results in all 3 phases (gamma, 1 and 2)
9
Q
Characteristics of high-copper amalgam
A
- > 12% Cu
- results in only 2 phases (gamma and 1)
- this is better, less corrosion and creep
10
Q
Characteristics of spherical amalgam particles
A
- easier to condense
- stronger
- sets faster
11
Q
Characteristics of admixed amalgam particles
A
- requires more condensation forces
- better proximal contacts
12
Q
Common causes for marginal ridge fracture of amalgam
A
- axiopulpal line angle not rounded
- marginal ridge left too high
- occlusal embrasure form is incorrect
- improper removal of matrix
- overzealous carving
13
Q
Commonly found in primers, HEMA can cause what if touching the skin?
A
contact dermatitis
14
Q
What is the purpose of a primer?
A
prevent collagen collapse
15
Q
Self-cure composite initiator? and activator?
A
- benzoyl peroxide = initiator
- tertiary amine = activator
