Dental Materials Chapters 43-46 Flashcards
1
Q
What has to be done prior for dentin bonding to be successful
A
etching to remove the smear layer
2
Q
etching a tooth is to remove
A
the smear layer - Thin layer of build up blocking tubules
3
Q
bonding agents should be cured for
A
20-30 seconds
4
Q
tooth whitening comes in what percentages
A
10,16,22
5
Q
where do you place a dentin bond
A
on the dentin of a prepped tooth
6
Q
Enamel bond can only be placed on what surface
A
intact enamel surfaces
7
Q
What are 3 types of enamel bonds
A
sealants, ortho brackets, resin bonded bridges
8
Q
Dental bonding reduces the ____ which reduces chance of ___
A
microscopic gap, microleakage
9
Q
How does bonding improve retention
A
creates a Micromechanical retention between structure and restoration
10
Q
3 precautions of using acid etch
A
it is corrosive, protect the pulp, avoid contact with soft tissue
11
Q
What is the procedure for etch
A
- Dry cavity prep
- apply etch and leave for 15-30 seconds
- rinse and dry thoroughly
12
Q
How does a successful etch make the tooth look
A
chalky or frosted
13
Q
If saliva contaminates acid etch what do you have to do
A
repeat the process from step one
14
Q
3 forms of acid etch
A
liquid/gel
maleic acid
phosphoric acid
15
Q
How is amalgam placed in the tooth
A
placed in prep in small increments, condensed after each increment is added
16
Q
why is amalgam condensed when placed
A
to tightly pack into the tooth, and to rise excess mercury to the top to be scraped off
17
Q
for a small amalgam restoration a __mg capsule is used
A
600mg
18
Q
for a large amalgam restoration a ___Mg capsule is used
A
800mg
19
Q
What separates the powder and liquid components of a capsule
A
a thin membrane wall
20
Q
What aids in mixing inside a capsule while in the trituration machine
A
a pestle
21
Q
Trituration is
A
the process in which mercury and alloy powder is mixed to form amalgam
22
Q
Trituration is AKA
A
amalgamation in an amalgamator
23
Q
Scrap amalgam (non contact amalgam)
A
leftover pieces, capsules, etc
24
Q
Trap amalgam (contact amalgam)
A
suction filter containing particles from mouth
25
How would you properly dispose of amalgam waste
in properly labelled wide mouth containers, with a tight sealing lid
26
Mercury Absorption is
absorbed directly through skin contact or inhalation of vapours
27
Two most common controversies of mercury
1. Potential harm to patient
| 2. Toxicity level to DHCP
28
the amount of mercury released from pressure of chewing is
extremely small, you're exposed to more in day to day life
29
What makes the mercury in amalgam restorations almost harmless
when its combined with the other materials the chemical nature changes
30
mercury is part of amalgam to make the mixture more ___
workable/pliable
31
Physical characteristics of mercury
liquid at room temp
vaporizes at high temp
gives plasticity
highly poisonous
32
what are the 4 metals found in alloy powder
silver, tin, copper, zinc
33
a 1:1 ratio of amalgam is the
Eames technique
34
What are the percentages of mercury to alloy
43-54% mercury, 57-46% alloy powder
35
Direct restorations are
applied/created directly in the mouth
36
what 5 materials are used for direct restorations
```
amalgam
composite
glass ionomers
tooth whitening
temporary restorative materials
```
37
Indirect restorations are
created in a lab, bonded or cemented in place
38
4 Materials for indirect restorations
nobel alloys, basic metals, ceramic, porcelain
39
what is an example of a indirect restoration
ceramic crown, PFM crown, FG bridge
40
Polymerization is
the process of resin changing from a pliable state to a hardened restoration
41
Hybrid (comp resin) is a
combination of large and small particle, strong and shiny
42
Microfilled
tiny and shiny, small particles (anterior teeth)
43
Macrofilled
strong and dull, large particles (posterior)
44
what 4 things is resin composed of
organic resin matrix
inorganic fillers
coupling agent
pigment
45
organic resin matrix is a
fluid monomer called dimethacrylate
46
BIS-GMA stands for
dimethacrylate
47
the coupling agent in composite resin is for
bonding filler to the resin matrix creating strength
48
3 examples of inorganic fillers
quartz, glass, silica
49
composite resin bonds to the natural structure, therefore it
moves fluidly with contact and expanding movements
50
there are how many classes of glass ionomers
6
51
what is the most versatile dental material
glass ionomer
52
2 advantages of glass ionomers
chemically binds to the surface
| releases fluoride
53
Type I glass ionomer is for
cementation of indirect restorations
54
type II glas ionomer is
class V restorations near gingiva and root surface
55
type III glass ionomer is
Liners and bases
56
Sealants are a class ___ glass ionomer
IV
57
Ortho bands and brackets are a class __ glass ionomer
V
58
Type VI glass ionomer is for
core build up restorations
59
Glass ionomer is a ___ base
insulating
60
polycarboxylate is a _ and _ base
protective and insulating
61
A non irritating cement to the root would be
Polycarboxylate
62
can polycarboxylate be used under direct or indirect restorations
yes
63
Poly carboxylate bonds to
enamel
64
Zinc phosphate Type II (medium grain) is used for
insulating base of Deep cavity preps
65
Zinc phosphate type I (fine grain) is used on
permanent cementation of indirect restorations
66
Castings / cast restorations are AKA
indirect restorations
67
zinc phosphate is ___ to the pulp
irritating
68
what would you use before a zinc phosphate cement to protect the pulp
a liner or desensitizer to counteract the acidity
69
what should the temp of a glass slab be while mixing zinc phosphate
68 degrees F
70
what is the cool glass slab intended to do while mixing
dissipate the heat and increase working time
71
when mixing zinc phosphate the powder must be added to the liquid in
small increments
72
ZOE type III (IRM) is used for
placement of Temporary restorations (primary teeth, emergencies, regenerative)
73
ZOE cavity liner is class
IV
74
ZOE type II is for
permanent cast restorations or appliances
75
why is ZOE type II stonger than type I
it has added reinforcements to create strength to hold a permanent
76
ZOE type I (temp bond) is for
temporary cementation/provisional coverage
77
ZOE stands for
zinc oxide eugenol
78
IRM stands for
intermediate restorative material
79
eugenol is oil from
cloves that have a soothing/sedative effect on the pulp
80
what is the fulcrum
finger rest
81
what tools are used in the removal of cement
explorer, mirror, scaler, floss
82
Variable that effect cementation are
temp, humidity, mixing time, liquid/powder ratio
83
Permanent Luting agents are used for
long term cast restorations
84
long term cast restorations (indirect) are
crowns, bridges, veneers, inlays, onlays, fixed ortho appliances
85
when seating crowns, luting agent must be evenly filled and equally __
distributed
86
Temporary luting agents are used for
when a restoration needs to be removed later on (intermediate)
87
What would you use a temp luting agent on
a temporary crown, bridge, veneer
88
what is the consistency of a temporary luting agent
thick putty like, tacky and able to be rolled into a ball
89
luting cement has a consistency of
syrup, should create a string when lifted
90
luting agents act as a
glue holding tooth structure and casting together
91
Dental cements come in forms of
luting agents, liners & bases, IRM
92
Sedative bases
soothe damaged or irritated pulp
93
Zinc oxide eugenol is a ___ base
sedative
94
Insulating bases are
placed in deep preps to protect from thermal shock
95
zinc phosphate, polycarboxylate and glass ionomer are all ___ bases
insulating
96
Protective bases
reduce post op sensitivity and damage to pulp
97
Which base is protective and insulating
polycarboxylate
98
dental bases are applied after liner to provide
pulpal protection from acidic cements
99
when applying desensitizer you use a
cotton tip applicator and apply on exposed dentin
100
What can you use in place of a varnish that does not need any prep
desensitizer (primer)
101
desensitizer is used to seal tubules from
oral fluid getting between tooth and restoration
102
HEMA and glutaraldehyde are found in
desensitizers
103
HEMA stands for
hydroxethyl methacrylate
104
Cavity varnish can only be used under which material
amalgam
105
cavity varnish interferes with bonding and setting reactions of which materials
composite resin and glass ionomers
106
cavity varnish is used to
seal dentin tubules, reduce micro leakage, and a barrier from highly acidic materials
107
Calcium hydroxide is known as
dycal
108
calcium hydroxide is used to
protect pulp from chemical irritation
109
when would you use dycal
when pulp exposure is expected or seen (red spots)
110
Cavity liners are used to line the
deepest portion of the prep and seal tubules
111
cavity liners regenerate the production for
dentin
112
Physical pulpal responses are
thermal and electrical
113
mechanical pulpal responses are from
handpiece vibration and improper occlusion
114
chemical pulpal responses are from
acids in dental materials
115
biological pulpal responses are from
bacteria in saliva contaminating the exposed pulp
116
vibration from a handpiece on an irritated tooth can cause a
mechanical pulpal response
117
what dictates the dental liner/base to be used
depth of prep
118
what is utility wax used for
extending the length and height of an impression tray
119
bite registration wax is used to
take a bite impression
120
inlay casting wax is to form patterns of
indirect restorations on model
121
casting wax is used for
single tooth direct restorations
122
when trimming models you should always
wear goggles/mask
soak in water for 5 minutes prior to trim
start trimming biggest arch and then match
use proper angles on art portion
123
which impression model material uses the most water
plaster
124
Anatomic portion
teeth of model
125
art portion
base of model
126
3 types of gypsum products
stone, high strength stone, plaster
127
high strength stone is AKA
densite or improved dental stone
128
3 types of Occlusal impressions
ZOE bite registration paste
wax bite
polysixoline bite registration paste
129
Hydrophobic
impressions that dislike moisture
130
syneresis
alginate impression looses moisture and shrinks
131
imbibtion
alginate impression absorbs water and expands
132
smearing
additional alginate in undercuts, occlusal, inter proximal, palate
133
glazing
smoothing surface of alginate by wiping moist finger across surface
134
2 types of alginate impression material
fast and normal set
135
maxillary alginate has
more powder and water
136
alginate is a
irreversible hydrocolloid
137
alginate beading is the use of __ to extend tray
utility wax
138
2 types of impression trays
stock and custom
139
final impressions are taken to make
indirect restorations, dentures, implants
140
preliminary impressions are used for
custom trays, diagnostics, provisional coverage
141
Impressions are the ___
negative
142
gypsum products are used to make the ___
positive
143
3 types of curing
auto cured, light cured, dual cured
144
Retention
the ability to hold two things firmly together when they don't naturally adhere
145
why are retention cuts used in amalgam
it docent naturally adhere, cuts add more stability
146
wetting
ability of liquid to flow over a surface into irregularities
147
viscosity
property of a liquid not able to flow easily
148
surface characteristics
a liquid flows easier on a rough surface than smooth
149
film thickness
thinner the film better the adhesion
150
adhesion
how well a product sticks
151
flow
how a product moves within a tooth when placed
152
solubility
substance dissolving in another
153
corrosive factors
temp, humidity, saline, foods
154
4 application properties
adhesion, flow, retention, curing
155
2 corrosive properties
solubility, corrosive factors
156
galvanic action
electric shock
157
what causes electrical shock
interaction of multiple metals in the mouth
158
thermal change
rapid temp change causing contraction and expansion
159
ductility
metal stretched by tensile force without fracture
160
malleability
metal extended in all directions without fracture
161
shear stress (grinding) is
two forces parallel sliding in opposite directions
162
compressive stress (chewing) is
two forces pushing towards eachother
163
tensile stress (tog of war) is
two forces pulling away from eachother
164
mechanical forces are
biting forces and stress & strain
