NEW MD OPERATIVE Flashcards
1
Q
what is the main component of enamel and dentin?
A
CHA ( carbonate substituted hydroxyapetite)
cha makes more soluble
2
Q
what is critical PH of teeth?
A
5.5
3
Q
what ph is demineralization?
A
below 5.5
4
Q
after applying fluoride, what is the critical pH of teeth?
A
4.5
5
Q
how long does dimenralization remineralization take?
A
10 minute dimeneralization
30 minutes
6
Q
which ion causes dimeneralization
A
H+
7
Q
what does MI paste due to remineralize tooth?
A
releases
Ca+
PO4-
8
Q
3 components of how flupride works?
A
remineralization of tooth structure
dec. enamal solubility
interfere with caries metabolic activity
9
Q
what are the pH of
Dentin and Cementum
Enamel
Enamel FA
A
D and C: 6.2-6.7 ( most susceptible)
enamel: 5.5
FA: 4.5
10
Q
what is keyes-Jordan diagram
A
results of cariogenic oral flora (biofilm) with ( carbs) sugar on tooth surface overtime (host)
11
Q
what is the shape of decay on smooth surface lesions?
A
V-shape
12
Q
shape of decay on puits and fissures ??
A
inverted V shape
13
Q
what is affected dentin?
A
deep, dry, leathery, demineralized decay
14
Q
what is infected dentin
A
superficial, wet, soft, necrotic decay
15
Q
dry, leathery dentin known as what?
A
affected dentin
16
Q
T or F decay is irreversible
A
true
17
Q
how long does it take for enamel cavitation
A
1-2 years
18
Q
what are the steps of lesion progression to cavitation?
A
enamel demineralization -> dentin demineralization -> enamel cavitation (1-2 years) - > dentin cavitation
cavitation steps irreversible !!!
19
Q
upon evaluation of tooth we see smooth surface is opaque white when air dried and disappear when wet
A
incipent !!!! reversible
20
Q
what is a complex restoration?
A
3 surfaces MOD
21
Q
what is a simple resotration
A
1 surface (O)
22
Q
what is a compound restoration
A
2 surfaces MO
23
Q
what is residual caries?
A
caries remain after tooth is prepped
24
Q
what is secondary caries?
A
occur at junction of tooth and restoration (microleakage)
25
rapidly damaging decay that is light-colored, soft infectious called
chronic decay
acute decay
arrested decay
acute / fast
26
demineralized tooth structure that is almost remineralized is called what
chronic decay
acute decay
arrested decay
chronic / slow
27
what type of bacteria is in dentin?
Lactobacilus
28
what type of bacteria in enamel decay
strep mutans
29
what type of decay in root caries
actinomyces
30
what type of bacteria (+/-) is inenamel and what is the enzyme that helps it stick to a tooth
G+
| GTF ( converts SUCROSE to glucans and fructans)
31
what carb in human body is mostly responsible for caries
SUCROSE
32
what are the salivary antibodies that fight against bacteria
sigA
33
what protein does saliva use to elimnate bacteria ?
GLYCOPROTEIN:
| large molecules that elimante bacteria through agglutination and causes swallowing
34
this enzyme in saliva destroys cell walls
lysozyme
35
this protein in saliva activerly binds iron
lactoferrin ( iron inactivator)
36
caries that dissapear while wetting are caleld what?
incipient
37
T or F hypocalcification does not dissapear after wetting
T
38
a patient with 20% mineral loss comes to clinic for tooth #14. Radiographs are not showing anything. why is that?
tooth needs 30-40% loss ot be seen radiographically !!!
39
transillumination is used to detect what?
contact areas of anterior teeth
craze lines
fractures
40
a patient walks in. after examining his amalgam restoration it is found that their is a gap that is >.5 mm. does it need to be restored?
yes.
anything amalgam >.5 is deemed carious or caries- prone
41
amalgam looks bluish. does it need to be re-restored?
no. this is due to corrosion. it is not classified as defective.
42
natural tooth occluding against crown is started to become defected. what is this called>
abrasian
43
hypersensitivity of tooth is resukt of exposure of what?
dentinal tubules in root surface
44
a patient complains about sensitivty. what can you guve them to help occlude dentinal tubules?
GLUMA
45
what is hydrodynamic theory?
pain from dentinal fluid movement stimulates mechanoreceptors near predentin
46
criteria for resotring a tooth is when lesion extends where?
to DEJ !!!!
47
the purpose of preventitive dentistry is to encourage what?
REMINERALIZATION of incipient SMOOTH surface lesions
48
what is a smooth surface lesion?
lesion where there is no pits or grooves
49
preventitive dentistry for pits and fissures?
sealants
50
excavators used for what part of tooth?
enamel
dentin
calculus
dentin ( spoon)
51
chisels used for what part of tooth?
enamel
dentin
calculus
enamel
52
10-90-7-14
what does the 10 tell you?
width of blade ( 10=1mm)
53
10-90-7-14
what does the 90 tell you?
cutting angle
sometimes 90 is missing
54
10-90-7-14
what does the 7 tell you?
legth of blade (7= 7mm)
55
10-90-7-14
what does the 14 tell you?
angle of blade
56
what do the 4 numbers on isntrument tell you?
10-90-7-14
width-cutting angle- length- blade angle
57
slow speed vsmed speed vs high speed RPM
slow: 12,000
med: 12,000 - 200,000
High : >200,000
58
for cutting efficacy do you want 6 blades or 40 blades?
6 blades
59
for smoothness do you want 6 blades or 40?
40
60
dimensions of 245 bur and shape
pear shaped
| 3 mm x .8 mm
61
dimensions and size of 330 carbide
pear
| 1.5 x .8
62
tapered fissure bur is what bur
169L
63
what is worse in terms of C factor class 4 or class 1?
class 1
64
what are the internal prepped walls?
Axial
| Pulpal
65
what is a line angle?
junction of 2 walls ( step)
point angle is junction of 3 walls
66
what always gets .5 mm of clearnace?
gingival floor
67
does all demineralized enamel need to be removed?
yes b/c bonding agent not as affective
68
resistence vs retention
resistence: prevention of tooth or restoration fracture from occlusal forces
retention:
prevention of displacement of restorative material
69
2 primary retention features for restoration?
convergent walls
| dovetail
70
2 primary resistence forms for resotration?
flat pulpal gingival floor
| rounded internal line angles
71
restoration that has <1mm exposure and is asymtpomatic, what would you do?
direct pulp cap
72
resoration has >1 mm exposure and symtpomatic what do you do?
RCT
73
what is a sealer used and an example?
sealer used for senesitibity ( desenstitiver)
occludes dental tubules
GLUMA
74
what do you use for direct or near direct exposure and example?
Liner
| CaOH or RMGI
75
what are 3 fxns of liner?
| 2 examples?
- electrical insulation
- thermal protection
- pulpal treatment (formation teritary dentin)
caoh rmgi
76
this is used for METAL restorations whenever liner is used
example
RMGI or GI cememnt
77
what does base do for protection
thermal protection ( amalgam or gold restorations)
78
what to use for amalgam with remaining dentin thickness (RDT) of
>2mm
.5-2 mm
sealer
base, sealer
liner base sealer (glumma seals dent. tubes)
79
what to use for composite with remaining dentin thickness (RDT) of
> .5 mm
< .5 mm
bond
| liner, base , bond
80
what to use for gold or CERAMIC with remaining dentin thickness (RDT) of
>2mm
.5-2 mm
cement
| cement ( 2 mm thick) \liner, base, cement
81
what is secondary resistence and retentive forms?
retentive grooves (amalgam)
beveled enamel margin
slots
pins
82
dimensions of slot
1 mm deep
1 mm long
.5 mm inside DEJ
83
type of bur to use fir smooth walls?
carbide
84
for RETENTION on amalgam prep, does occlusion converge or diverge?
converege
85
what degree does pin have to be for retention?
2
86
for resistence of amalgam, what depth does it have to be for adequate thickness
1.5- 2 mm deep
87
type of bur to use to roughen walls
coarse diamond
88
what does composite resotration not need compared to amalgam
retentive, occlusalal convergence, uniform depth
89
for gold onlay describe how the skirt and collar should look like
skirt: feather-edged
collar: beveled shoulder around capped cusp
90
what is eames ratio?
50% mercury
| 50% metal alloy ( tin, copper, zinc)
91
```
which metal helps with corrosion?
silver
tin
zinc
copper
```
tin
92
```
which metal helps wotj strength>
silver
tin
zinc
copper
```
zilver/ copper
93
```
which metal is a deoxidizer
silver
tin
zinc
copper
```
zinc
94
strongest type of mercury?
gamma 2, gamma 1, gamma
gamma 1
95
trituration of mercury that comes out wet, soft is indication of what?
over-trituration
96
trituration of mercury that comes out dull, crumble is indication of what?
under-trituration
97
normal titration mix is supposed to look how?
shiny, smooth
98
alloy that is low in copper has what percentage of copper and results in what gammas?
<12%
| y, y1, y2
99
alloy that is high in copper has what percentage of copper and results in what gammas?
> 12%
| y and y1 ( less corosion and less creep)
100
```
spherical alloy vs admixed
- which is easier to condense?
-which is stronger?
better proximal contact?
- which sets faster?
```
spherical is easier, stronger, sets faster
admixed: better proximal contact
101
restorative material to use when isolation is hard?
amalgam
102
5 reasons marginal ridge fractures?
```
axiopulpal line angle not rounded
high MR
incorrect occlusal embrasure
improper matrix rmeoval
overzealous carving
```
103
how are walls prepped in vlass V amalgam ?
divergent
four corner coves ( occlusal and gingival line angle grooves or circumfrential grooves are all equally effective for retention)
104
if mercury spills how do you clean it up?
vacuum
| SULFUR POWDER
105
acute mercury toxicity symptoms
hypotonia
alopecia
weight loss
exhaustion
low muscle, low hair, low weight, low energy
106
what is the most toxic form of mercury
elemental mercury
methlymercury
mercury salt
methylmercury ! ( from seafood)
107
what type of mercury is in amalgam
elemental mercury
methlymercury
mercury salt
elemental mercury ( liquid)
108
what type of mercury is inorganic
elemental mercury
methlymercury
mercury salt
salt
109
what is more reliable, dentin or enamel bonding?
enamel
110
why is dentin bonding more difficult?
```
in terms of
composition
structure
depth
smear layer
```
enamel: 90% mineral/ 2% organic
Dentin: 50% mineral/ 25% organic
enamel: rods parallel
Dentin: collagen bowl of spaghetti
Dentin: dentinal tubules larger and more numerous
smear layer decreasesd dentin permeability
111
etch:
type of acid?
how long to etch for?
what does it do to dentin and enamel
how long to rinse for?
phosphoric acid/ 15 seconds
enamel: creates MICROPOROSITIES
dentin: exposes COLLAGEN , widens dentinal tubules
10 seconds. LEAVE MOIST
112
more likely to get contact dermatitis from what? **
primer ( HEMA)
113
function of primer ?
prevents COLLAGEN COLLAPSE
infiltrates enamel prisms and dentinal tubules
114
this chemically binds to underlying primer to overlying composite resin
Bond/ adhesive
though MMA BOND (optibond solo pluss)
air dry to evaporate solvent and leave monomer
115
what happens when you air dry bond?
evaporates solvent and leaves monomer( MMA bonds)
116
what is the hybrid layer?
| how does it function?
interference b/w tooth and adhesive
resin tags: adhesive resin locks into microporosities of etched enamel and intertubular dentin
117
what is the key to adhesive dentistry
micromechanical bond
118
gold standard etchant generation? how many steps?
4th
3 steps
acid
primer
adhesive
119
what 3 things is Composite resin made of?
```
Bis-GMA ( resin matrix)
FIller particles ( silica)
coupling agent ( silane; combines top 2)
```
120
what is better. macro fill or microfill composite?
macrofill
80% filler ( larger composite= more strength)
hgier filler= less water absorption
121
self cure vs light cure composite?
initators ?
self:
2 paste system
initatior: BENZOYL PEROXIDE
activator: tertiary amine
light cuure:
single system
- photoinitiator: camphorquinone
468 nm light needed to initiate poymerization
122
nm of light to initate light cure composte
468
123
initiate for self-cure vs light cure
self cure: benzoyl peroxide
| light xure: camphorquinone
124
what is better. High C factor or lower ?
Higher = less bound surfaces so higher amount of shrinkage
better: low
125
c factor for class 3 ?
3(bound): 3 (unbound) = 1
126
what has the worst C factor?
```
class 1:
C factor of 5
```
5(bound surfaces): 1 (unbound suraface)
127
what is the best C factor?
```
class 5
1:5 = cfactor of .2
```
128
```
GI vs CR
made of ?
bonding?
which is stronger?
fluoride release?
```
```
GI ( salt-matrix) :
ACID. BASE !! : polyacrylic acid/ Fluorsilicate glass
self-adhesion
CHEMICAL BOND
fluroside release
weaker
```
CR (resin matric) :
MATRIX FILLER !: Bis-GMA / silicate glass
LIGHT/ SELF CURE MICROMECHANICAL BOND
no fluoride release
129
RMGI is set by what?
acid-base rxn ( from GI)
free-radical addition ( resin)
more rapid polymerixation thanks to free radical
130
when should Compomers ( polyacid Modified resin composite) be used and how is it different thatn CR and GI
Orthodontics !!
it is anyhydrous ( no water!!)
slower polymerization allows more time to clean up excess
fluroide releasin
131
```
which of the following materials are used for ortho?
GI
RMGI
Compomers
Ionomer Modified composite
```
componers
132
```
which of the following materials has slow polymerization making it ideal to clean up excess?
GI
RMGI
Compomers
Ionomer Modified composite
```
componers
133
```
which of the following materials has rapid polymerization?
GI
RMGI
composite
Compomers
Ionomer Modified composite
```
RMGI ( from free radical addition polymerization from resin)
134
```
which of the following materials has no fluroide release ?
GI
RMGI
composite
Compomers
Ionomer Modified composite
```
CR
