Midterm Flashcards
(162 cards)
1
Q
- distal wall
- facial wall
- lingual wall
- gingival wall
These are all:
A
external walls
2
Q
- pulpal floor
- axial wall
These are both:
A
internal walls
3
Q
What is the thickness gauge of the “heavy” dental dam (pretty sure this is the one we use)
A
.010”
4
Q
The parts of retainers (clamps) used with a dental dam include: (4)
A
- bow
- jaws
- forceps holes
- points
5
Q
Isolation of the operating field is extremely important because a wet field =
A
recurrent caries or failed bond
6
Q
For isolating the operating field in a class II preparation, what teeth would show through the dental dam?
A
one tooth posterior & two teeth anterior to the tooth you’re working on
7
Q
The tooth posterior to the tooth you’re working on that is clamped when using the dental dam is considered the:
A
anchor
8
Q
What are your isolation options when damming anterior teeth?
A
- canine to canine
- clamp on one premolar
9
Q
Sometimes a rubber dam will not work especially in cases with _____ medications (rarely used)
Give examples of these meds
A
Antisialogogue medications
atropine & banthine
10
Q
What instruments are used to remove caries once outline form is achieved?
A
- spoon excavator
- round bur on slow speed handpiece
11
Q
When refining an amalgam class II preparation, why should you plane/bevel the axiopulpal line angle?
A
reduces stress
12
Q
When refining an amalgam class II preparation, why should you plane/bevel gingival margin?
A
This removes loose enamel rods
13
Q
When the placing the wedge with use of a matrix band, what side should the wedge be inserted?
A
place wedge from larger embrasure
14
Q
In a class II amalgam restoration-
- Fill ____ first
- Fill ____ above margins
- Carve ___ of marginal ridge using explorer
- Pre- _____
- Carve with ____
A
- box
- 1.0 mm
- mesial incline
- pre-carve burnish
- hollenback
15
Q
What should you do while removing the matrix band in an amalgam class II restoration?
A
Hold condenser on marginal ridge as you gently remove the band
16
Q
In the proximal outline form of a class II composite restoration, you must break:
A
gingival margin
17
Q
In a class II composite restoration, where should you keep the margins when possible?
A
in enamel
18
Q
In the proximal outline form for a class II composite restoration, the ____ contact should always be broken, while the ____ contact may or may not be broken.
A
lingual; buccal
19
Q
Is a reverse S-curve necessary in a composite restoration?
A
no
20
Q
What bevels are involved with a composite class II restoration?
A
- lingual wall bevel
- gingival bevel
- axial-pupal line angle bevel
21
Q
In what case would you not do a gingival bevel in a class II composite prep?
A
If gingival floor is in dentin/cementum
22
Q
It is more challenging to establish a good contact with a ____ restoration
A
composite
23
Q
What addition steps are needed in a class II composite restoration compared to amalgam?
A
- etch & rinse
- bond
- incremental composite
- light cure each increment
24
Q
For complete etch:
- Place etch on ____ first followed by ___
- Etch ____ for 20-30 seconds
- Etch ____ for 15-20 seconds
- Rinse and gently ____
A
- enamel; dentin
- enamel
- dentin
- air dry
25
What type of etch is typically only done with total-etch and universal bond agents?
complete
26
With selective etch, what is etched and how long?
enamel only; 20-30 seconds
27
What bond agents allow you to selectively etch?
1. Universal (what we use in clinic)
2. Self-etch
28
What is considered evidence of etched enamel?
whitish etched enamel surface
29
Results in collapse of collagen layer and reduced bond strengths
desiccation of dentin
30
what are the typically the solvents in bond agent?
(these evaporate when you gently blow air)
1. acetone
2. ethanol
3. water
31
The most important increment in a class II composite restoration (also the first increment) is at:
gingival wall
32
When adding addition increments after the first composite increment (1mm) you should NOT exceed ____ mm of material per increment
2mm
33
By starting with 1 mm increment of composite and then not exceeding 2mm on additional increments, this method minimizes _____ placed on the material and on the tooth due to ____.
stresses; polymerization shrinkage
34
A flat marginal ridge would ____ (and this is why is should be rounded)
shred floss
35
Finishing and polishing composites functions to:
1. Removes ____
2. Establishes ____
3. Ensures ____
1. oxygen inhibited layer
2. anatomy/final shape
3. a smooth surface
36
What is one MAJOR difference between amalgam and composite restoration steps?
Finishing and polishing composite
37
_____ is nearly always on the buccal side of a class II amalgam preparation
reverse curve
38
A reverse S curve in a class II amalgam preparation improves:
resistance to amalgam fracture
(because it keeps the narrowest part of prep away from the axiopulpal line angle)
39
In a class II amalgam preparation, this feature allows the preparation to break contact while allowing the buccal wall to meet the tooth surface AT A 90 DEGREE EXIT ANGLE:
Reverse S curve
40
Wall clearances around a class II amalgam preparation:
1. buccal contact is open:
2. lingual contact is open:
3. gingival contact is open:
1. (0.2-0.5mm)
2. (0.2-0.5)
3. at least 0.5mm
41
Enamel rods in a class II amalgam preparation box are inclined:
gingivally
42
In a class II amalgam preparation, an "early" reverse S curve (starts too distal) will result in:
weakening the cusp
43
class II amalgam preparation, a flared too mesially reverse s-curve (late reverse s) leaves amalgam:
prone to fracture
44
What type of S-curve error in a class II amalgam preparation leaves the narrow part of prep adjacent to axiopulpal angle; and makes box walls flare causing obtuse cavosurface angles (weakening amalgam):
NO reverse s-curve
45
In a class II amalgam preparation, a concave axial wall with indistinct internal line angles compromises:
resistance & retention form
46
what are some contraindications to composite restorations?
1. occlusion?
2. restorations extending to root surface
3. deep subgingival margins
47
When comparing amalgam restoration to a composite restoration the _____ may be more forgiving but the _____ is not.
preparation more forgiving; restoration NOT
48
What type of restoration material has the disadvantage of porus and low modulus in elasticity:
composite
49
The sticky uncured layer left on the surface of a composite restoration:
oxygen inhibited layer
50
What are some new aspects you have to consider with composite (opposed to amalgam):
1. inter proximal contacts (he says its harder to achieve these)
2. voids
3. light
4. polymerization stress
51
What step removes the oxygen inhibited layer of a composite restoration?
finishing and polishing
52
What increases the longevity of a composite restoration?
Polishing and finishing
53
The metal adjustable twisty part of the toffelmire:
tofflemire retainer
54
What are the two types of tofflmire retainers?
1. straight retainer
2. contra-angle retainer
55
Inserting band into the tofflemire retainer:
1. Turn the inner nut ___ until slot vice is about ___ from the guide channels
2. Hold the inner and turn the outer nut ____ unit the pointed end of the spindle is free in the slot in the slot vice
3. Double the band back on itself, forming a loop
4. Insert into the slot vice through one of the three guide channels, then tighten spindle
1. counter clockwise; 1/4 inch
2. counter
56
When using a tofflemire matrix band, the wider opening of the loop is toward the _____.
The slot vice is toward the _____
toward the occlusal; toward the gingival
57
What is the most common orientation of the tofflemire band?
most common: retainer on buccal side
58
When carving amalgam, try, if possible, to carve anatomy so that the ____ in maxim intercuspation is in the ___. This will put ___ on the teeth.
occlusal stop; bottom of the fossa; long axis forces
59
Bonding mechanism in which penetration and formation of resin tags within the tooth surface:
mechanical bonding
60
Bonding mechanisms in which chemical bonding to the inorganic components (hydroxyapatite) or to the organic components (mainly type I collagen) of tooth structure:
adsoprtion bonding
61
Bonding mechanisms in which precipitation of substances on the tooth surface to which resin monomers can bond mechanically OR chemically:
Diffusion bonding
62
Acid etching of enamel for 15 second with 37% ____ is considered enamel bonding, also known as ____
phosphoric acid; adhesion
63
What is the fundamental mechanism of enamel bonding?
the formation of resin micro tags within the enamel surface (roughing up the surfaces making high surface energy)
64
Primarily relies on the penetration of adhesive monomers into the filigree of collagen fibers left exposed by etching with 37% phosphoric acid for 15 seconds:
Dentin bonding (adhesion)
65
Compare the strength of dentin bonding to enamel bonding:
dentin bonding is weaker
66
Smear layer = cut ____ surface composed of debris of hydroxyapatite crystals and denatured collagen:
smear layer
67
The smear layer decreases dentin permeability by:
85%
68
Types of etching
1. No phosphoric acid
2. phosphoric acid on enamel
3. phosphoric acid on enamel & dentin
1. self-etch
2. selective-etch
3. total-etch
69
When you use total etch (on enamel & dentin) , you remove the smear layer and this can something cause:
sensitivity
70
Self etch & selective etch leave the ___ in place because you are not etching the dentin
smear layer
71
The state in which two surfaces are held together by INTERFACIAL FORCES which may consist of valence or interlocking forces or both
adhesion
72
A material, frequently a vicious fluid, that joins two substrates together by solidifying and transferring a load from one surface to another:
adhesive
73
The measure of the load-bearing capacity of an adhesive joint:
adhesive strength
74
What factor of adhesion allows the availability of substrate to interact with adhesive?
clean substrate
75
What factor of adhesion allows the adhesive to maintain intermolecular contact with dental surface
wetting ability
76
Acid etching = increases surface free- energy =
improves surface wetting
77
Spreading capacity of adhesive onto dental surface:
viscosity
78
Viscosity depends ont he surface tension of:
tension of liquid (adhesive)/ solid (substrate)
79
Surface roughness- irregular surface increases the bonding ability by: (2)
1. increases area for bonding
2. increases adhesive interlocking
80
increases the surface available for bonding and intermolecular contact for adhesive:
acid etching
81
Penetration of resin adhesive and formation of hybrid layer/ or resin tags within the tooth surface after polymerization- entanglement=
mechanical bonding
82
micro mechanical interlocking within the tooth surface:
resin tags
83
Chemical bonding to the inorganic component (hydroxyappntitie) or organ components (mainly type I collagen) of tooth structure:
chemical/adsoprtion bonding
84
Precipitation of the substances on tooth surfaces to which resin monomers can bond mechanically or chemically:
diffusion bonding
85
What are the mechanisms of bonding? (4)
1. mechanical
2. chemical/adsorption
3. diffusion
4. combo of all
86
- 97% mineral (mainly hydroxyappetite)
- 1-2% organic (amelogenin and enamelin)
- 2% water
composition of enamel
87
Origin of enamel:
epithelial
88
The structure of enamel is:
prisms
89
Enamel can be described as a ____ substrate
homogenous
90
The bond strength of dentin can be described as:
unpredictable
91
The origin of dentin:
conjunctive
92
- ~55% mineral (mainly hydroxyapatite)
- 30% organic (mainly type I collagen)
- 15-20% water
composition of dentin
93
structure of dentin:
tubular
94
Dentin can be described as a ____ substrate:
very heterogeneous (challenging)
95
chemical drilling=
acid etching
96
Fundamental mechanism of adhesion:
micromechanical bond
97
type of etching pattern on enamel described as "honeycomb" and accomplished through dissolution of prism cores:
Type 1
98
type of etching pattern on enamel described as cobblestone and accomplished through dissolution of prism peripheries:
Type II
99
Occlusal and Middle thirds of teeth is where what types of etching patterns are best accomplished?
Type I and II
100
type of etching pattern on enamel which is a combination of type I and II:
Type III
101
type of etching pattern on enamel that can be described as "pitted"
type IV
102
type of etching pattern on enamel that can be described as "prism less" and flat and smooth:
Type 5
103
____ & ____ enamel allows for bonding performance to have stronger retention and be more predictable:
Incisal third & middle third
104
Location of prism less enamel- where there are fewer and shorter resin tags after bonding:
cervical third
105
Gingival floor beveling in enamel in class II preparations allows for the reduction of:
micro leakage at cervical and ascending walls
106
T/F: You want to bevel the gingival floor in a deep class II prep
False- probably no enamel present once you get deep
107
When do we not bevel the gingival floor?
deep class II preps
108
Critical area to bond to enamel includes:
1. perpendicular prisms
109
As we known perpindicular prisms are a critical area to bond to enamel, where might we find these?
1. cavosurface margins of class I prep
2. bevels of class II preps
3. ends of enamel rods
110
- fluid filled
- enclosed cellular extension (odontoblasts)
- connect pulp to DEJ
dentin tubules
111
What type of dentin is being described?
- higher organic content
- collagen rich zone
intertubular dentin
112
What type of dentin is being described?
- surrounding the tubules
- highly mineralized
peritubular dentin
113
Dentin tubules get larger as you near the:
pulp
(because more fluids and less intertubular dentin)
114
Impairs effective bonding and must be removed with acid etch:
smear layer
115
After acid etching, ___ are exposed
Adhesive penetrates the encapsulates of ____
collagen fibrils (for both)
116
After polymerization of collagen fibrils by adhesive this creates an intermingled layer of collagen + resin called the:
hybrid layer
117
- the key for dentin bonding
- the base for all composite restorations
hybrid layer
118
stability and longevity of composite restorations relies on the stability of:
hybrid layer (collagen + adhesive resin)
119
agents that bond (micro mechanically and/or chemically), the restorative material (or luting agent) to tooth substrate through an interface:
adhesive systems
120
What adhesive technique would you use for a class I-VI carious lesion, traumatic defects and the esthetic restorations such as full or partial resin veneers
direct restoration
121
The primer in an adhesive system is _____ while the adhesive bonding resin/agent is ___
hydrophilic; hydrophobic
122
In the polymerization process, what are the 3 steps?
1. adhesive/primer (involves a chemical reaction)
2. reaction (activator converts initiators into a free radical that starts the polymerization reaction)
3. Light
123
Our light activator in the polymerization process is _____ and our initiator is ___ & ___
activator= blue light
initiator- camphoquinone (photosensitized) and DMAEMA (amine)
124
self-etch (compared to etch and rinse) is good for:
dentin
125
self etch is not chemically compatible with:
dual cure composites
126
A material containing atlas two components (phases) with distinct chemical and physical properties that after blended show unique and SUPERIOR properties as compared to the individual components:
Composite
127
Tooth-colored restorative material containing an organic resin matrix phase (monomers) reinforced by dispersed filler particles phase bound to the resin by a silane coupling agent and initiator-accelerator system:
Dental composite
128
What is the coupling agent in dental composite?
silane
129
What is the organic phase of dental composite?
resin matrix
130
What is the inorganic phase of dental composite?
fillers
131
- tooth-colored restorative material (direct or indirect restorative technique)
- bonding agents (filler may be present)
- composite resin luting agents (cement)
- resin-modified glass ionomer materials
- light -activated liner mateirals
- CAD/CAM blocks
- resin endo sealers
reasons you would use dental composite
132
Components of dental composite include: (5) RFCAP
1. resin matrix
2. filler particles
3. coupling agent
4. activator-initiator system
5. pigments and other components
133
Bis-GMA and UDMA are types of:
resin matrix
134
Describe resin matrixes Bis-GMA and UDMA: (3)
1. high molecular weight monomers- diluents necessary (bisGMA)
2. low viscosity
3. low flexibility
135
TEGDMA is a resin matrix that is a high fluid monomer and used as a diluent for high molecular monomers such as BisGMA.
The amount of TEGDMA =
polymerization shrinkage
136
Bis-GMA, UDMA, and TEGDMA are all:
difunctional monomers
137
The 2 reactive ends of difunctional monomers (Bis-GMA, UDMA, and TEGDMA) all for:
cross-linking
138
- Crystalline silica (quartz)
- Ba
- Li
- Al silicate glass
- amorphous silica
These are all
filler particles
139
- dispersed resin matrix
- distribution varies depending on the material
- percent expressed by weight or by volume
filler particles
140
The benefits for filler particles include:
1. reinforcement of ___
2. DECREASED ____
3. DECREASED ___ and ____
4. ______ control
5. DECREASED ____
6. INCREASED ____
1. resin matrix
2. polymerization shrinkage
3. thermal expansion and contraction
4. viscosity
5. water sorption
6. radiopacity
141
Bond between the two phases of the composite:
coupling agent
142
Silane functions as:
coupling agent
143
strongly binds the filler to the resin matrix:
interfacial bridge (from coupling agent)
144
Allows for better stress distribution between resin matrix and filler particles:
coupling agent (silane)
145
Improves the mechanical properties and decreases the water sorption along filer-resin interface:
coupling agent (silane)
146
Composites must be converted from monomers to polymers, and this processes is triggered by ____ from ____
free radicals from chemical activation, heat or light
147
Activator = tertiary amine
Initiator = benzoyl peroxide
together these = free radicals
chemical or self-cure
148
activator= blue light (465nm)
initiator= camphorquinone (photosensitized) and DMAEMA (amine)
together these = free radicals
light-cured
149
- prevents spontaneous polymerizaton
- stops polymerization from brief room light exposure (reacts with free radicals)
Polymerization inhibitor
150
Once the blue light is used, all the inhibitor is quickly consumed =
polymerization chain reaction starts
151
What increases the shelf-life of the composite resins?
polymerization inhibitor
152
Butylated hydroxytoluene (BHT) and Hydroquinone are both:
polymerization inhibitors
(BHT is a food preservative that reduces oxidation)
153
Optical modifiers = (2)
pigments and opacifiers
154
metal oxides=
pigments
155
- titanium an aluminum oxide
- control opacity or translucency
- brand difference
- dentin vs. enamel composite shades
opacifiers
156
Composites are classified based on:
1. filler particle size and distribution
2. handling characteristics
3. type of polymerization
157
Classification by filler wise and distribution (categories: 4)
1. macrofill
2. midfill
3. microfill
4. hybrids
158
The hybrids of fillers =
1. midi-micro hybrid
2. mini-micro hybrid
3. mini-nano hybrid
159
What category of fillers are not really used much today due to rough surface finish, not good size distribution, and prone to staining:
macro & midfill composites
160
- 0.01-0.1 micrometers, colloidal silical 40-60% weight
- excellent finish
- low mechanical hardness surface properteis
- use for esthetic, low-stress sites (class 3, layer over hybrid, kit systems)
Microfill composite
161
- high strength
- universal composites for anterior and posterior
hybrid composites
162
