composites Flashcards
(193 cards)
1
Q
Direct restoration
A
restoration inserted as soft material
2
Q
Indirect restoration process
A
FAbricated outside the mouth
Cemented or bonded to the tooth
3
Q
Full coverage indirect restoration
A
Zr
4
Q
Partial coveration indirect restorations
A
Veneers, ceramic inlays and onlays
5
Q
Examples of Direct tooth colored restoratiosn
A
Composites
Glass Ionomer
6
Q
Functions of tooth-colored material
A
REstorations
Bases and liners
Cemeents
7
Q
Tooth colored materials from high fluoride to low floride
A
Glass Ionomers Resin Modified Glass Ionomers Low Fluoride: Compomers Composites
8
Q
Base of Composites
A
Polymer base
9
Q
Base of Glass Ionomers
A
Water base
10
Q
Changing of COmposites
A
Static
11
Q
Functional roll of GI
A
Fluoride REservoir (dynamic)
12
Q
Mech properties of Composites
A
Comparable to Amalgam
13
Q
Mech Properties of GI
A
Decrease Mech properties
14
Q
Wear resistance of Composites
A
Was a conern (especially for older compostes)
15
Q
Retention of composites
A
Micromechanical retention - resin tags and hybrid layer
16
Q
GI wear resistance
A
Good
17
Q
Retention of GI
A
Chemically bond (ionic - not strong)
18
Q
Where is the hybrid layer found
A
In dentin
19
Q
Advantage of Posterior Composites
A
Esthetic
Conservation of tooth
Easier Prep
20
Q
Disadvantage of Posterior Composites
A
Tequnique sensitive
Effect of Polymerization shrinkage
21
Q
Indication for Posterior Composites
A
Small/moderate sized Class I and CLass II preps
22
Q
Contraindications for Posterior Composites
A
Complete Moisture control is inadequate
Heavy occlusal stresses
LArger preps
More posterior
23
Q
effect of Resin shrinkage
A
Won’t create microleaks, but will put stress on the polymerization
24
Q
Why are Class II composites hard
A
Doesn’t hold itself well to be pressed due to putty consistency
25
What must be done with Class II composites
Restore proximal contour of posterior teeth and recreate the proximal contact
26
Resin matrix for dental compsite
Bis-GMA and TEGMA
27
What makes up the Filler of Dnetal composite
Irregular or spherical particles( ranging in size)
28
What is the Coupling agent in a dental compsite
Silane
29
What is the Resin matric of Composite Resin
Small Oligomers, Bis-GMA and TEGMA
30
How to minimize gaps in Composite
Incremental layering technique to reduce bulk volumetric shrinkage
Placing a low viscosity material such as flowable composite prior to composite "elastic Theory)
31
Roll of FIller in composites
Improve in mechanical behavor
also helps match color
With thermal coefficient
32
Result of MOre Filler in composite
Less resin, less polymerization shrinkage, decreaed Coefficient of thermal expansion
33
What is the Filler made of in Resin
Glass particles and spheroidal silical particles
Shape: spherical, irregular, combo
Size: ranges
34
Too little of filler leads to
Slump and sticky
35
Too much small particles of filler leads to
Hard to handle
36
Macrofill size
10-50 um
37
Microfill size
40-50nm
38
Hybrid fill size
10-50 um + 40nm
39
Nanofill size
5-100nm
40
Mini-fill size
.6-1um + 40nm
41
Midifill size
1-10um + 40nm
42
Examples of MAcrofill
Adaptic
| Concise
43
Characteristic of Macrofill
Very large filler particles
Particles plucked out forming a rough surface
Low wear resistance
44
Filler size for Homogenous microfill
Small size filler: .04/40nm
45
Characteristic for Homogenous Microfill
Small fillers
| Polishability and wear resistance optimal
46
Where are Homogenous Microfills Indicated
esthetic non-stress bearing area in young patients
47
Filler loading in Homogenous Microfills
25-42% vol
48
Did Homogenous Microfills work on posterior composites
No
49
What research was doen to try and get Homogenous Microfills to work as posterior composite
Increased Filler content
| Increased Nanoparticles
50
Problems with High FIller Content of Posterior Homogenous Microfills
High-viscosity - difficult handling
Clustering/agglomeration
- large cluster compromises esthetics
51
How are HEterogenous microfills for Posterior composites made
Cured microfill composites then crushed and incorporated in uncured Composites
52
What does Heterogeneous Microfills for posterior composites contain
PPF (prepolymerized fillers)
53
Problem with using PPF with posterior composites
Bond between PPF and cured composite was weak leadign to debonding
54
What are Conventional Hybrids
Combined the micro fillers with the macrofilled
55
why were conventional hydrids used as a posterior composite
Improved the mechanical properties
56
Filler size for Microhybrids
less than 1.0 microns
57
Properties of Microhybrids
60% loading capacity
| Good handling properties
58
where were microhybrids used
anterior and posterior restorations
59
Examples of Microhybrides
Point 4 (kerr)
Herculite XRV (Kerr)
Esthet-X (Dentsply)
TPH spectra
60
What is the Filler for Nanocomposites
No glass fillers
| Only silica particles in the range of 5-100nm and aggregations of Silica particles (Nanoclusters)
61
Examples of Nanohybrids
```
Herculite Ultra (kerr)
Tetric Evoceram (Ivodar)
Reflectys (Itena)
N'Durance (Septodont)
Premise (Kerr)
```
62
Conventional consistency
Putt like consistency
63
Flowable Consistency
Lighy Consistency
64
Packable consistency
Condensable/Moldable/HD
65
The Number of Carbon double bonds C=C of monomer that are converted to single bonds C-C to form polymers
Degree of Conversion
66
Distance of Curing tip
abour 1 mm
67
Thickness of Composite for Curing
1.5 mm
68
Bulk Fill
One bulk fill placement up to 5 mm
69
How do Bulk Fill Capsules engage
In a slow speed
70
What does the slow speed do for Bulk fill Compsites
Vibrates to make the material less viscous during Extrusion
71
what keeps bulk fill from pulling from cavity walls
Stress Relievers
72
what aids in depth of cure
Special photo-initiator
73
Types of Retainer System
Tofflemire with Circumferential bands
Retainless MAtrix system in the absence of matrix retainer
Sectional matrix
74
Roll of Rings
Prongs on the rings produce separation between the teeth for a class II prep
75
Pre contoured sectional matric band thickness
thin af .001inch
76
Materials for Circumferential bands
Metal
| Polyester - clear or blue
77
Thickness of circumferential bands
```
Thin: 0.0015 inch
Ultra thin (dead soft): .001inch
```
78
Types of Wedges
```
Wedge wands
Wizard wedges
Anatomical wooden wedges
Light trasmitting Wedges
Wedge guard
```
79
Roll of Wedges
Seal gingival margin to prevent overhand
| wedges adjacent teeth to compensate for the band's thickness
80
How tall should a wedge be
Be of a height that does not prevent the formation of proximal contact
81
Techniques for wedging
Piggy back- 2 wedges on top of each other
Double wedge - one wedge on each side of the tooth
wedge wedging - one at a 90 degree angle to the other
82
Step
1. Examine the margins of the prep, having a plan
2. Profound Anesthic + shade selection + check occlusion
3. Isolate
4. Etch 37% phosphoric acid for 15 s, Rinse thoroughly, gently dry and never desiccate
5. Apply 1‐2 coats of avadhesive, lightly dry it, cure for 20s
6. Apply selected shade of composites in increments, cure for 20 s
83
What is the etch used
37% phorphoric acid
84
What happens to Enamel if over dried
Doesn't have much collagen so it is find
85
What happens to Dentin if I over dry
Ton of collagen so fibers collapse if over dry and adhesive won't infiltrate
Removes water out of tubules leading to bite sensitivity
86
Roll of Etching
Removes smear Layer and smear plugs
| Opens Dentin Tubules
87
Steps of Total etch system
Etch
Rinse
Apply Adhesive
88
pH of total etch system
2
89
When to use total etch system
When there is enamel margins
90
2 step Total etch system
2 bottles,: etch, prime+bond
91
3 step Conventional Total etch system
3 bottle etch prime, bond
92
pH of self Etch adhesive
3.5
93
TWo step self etch adhesive
2 bottle acidic primer, bonding agent
94
1 step self etch adhesive
1 bottle acidic primer and bonding agent
95
Total etch system
Optibond solo plus (Kerr)
96
self etch adhesive
Scotch bond universal 3M
| Clearfil (kuraray)
97
Composite instrumers
Contact fomer
BBL
CVIPC
8A
98
What is done after curring
Remove Rubber dam
Evaluate the margins - Check for excess and deficiencies
Check for Proximal contact
Check occlusion with articulating apaper and miller forceps
Adjust occlusion with rotary carbide finishing burs
99
How Does RMGI seal
Good seal due to chemical bonds
100
Mech properites of RMGI
Not as good as composite
101
Solubility of RMGI
less soluble than GI
102
Moisture effect on GIC
affected by moisture due to slow setting reaction
103
Acid and GIC
Acid Vulnerability
104
Sollubility of GIC
Initial solubility
105
GIC strength
Brittle
106
Moisture on RMGIC
Not affected by moisure
107
Solubility of RMGIC
Initial solubility is low
108
Acid and RMGIC
LEss acid Disintegration
109
What is done first for CLass I deep cavity preps
Condition and Based with GI before placing the composite
110
What is done with CLass II with Enamel margins
Use a total etch system to allow for shorter etching time for dentin
Rinse thoroughly
Lightly dry leaving damp dentin
Apply adhesive layer/air gently/cure
111
how to do composite for Class II with enamel margins
1 layer to build up proximal contour and contact
| 1 layer to build up occlusal anatomy
112
what technique is used with Class II with dentin margins and deep gingivally
Use Open Sandwich technique
113
Do you add etchant to the Restorative base
No, it is not essential
114
How different are composite restorations in preclinic
No different
115
Criteria for Composite restoration
Can be v. conservative
Remove defective areas
Remove all caries
No grossly unsupported enamel in high stress bearing areas
116
when can you be most conservative with composite restorations
if you're first
117
Advantages of Composte for inital caries
```
Preparation conservative (only infected area
Small volume (shrinkage stress minimized
Contact area small (wear minimized)
Good Longevity ( like that of sealants or amalgams
```
118
Composite technique
```
Prep
Consider a base or liner
Place band
Apply adhesive
Apply composite
Finish and Composite
```
119
Types of Matrix bands
```
#1 Adult universal (normal)
#2 Adult MOD wide (has 2 humps in middle)
#1 Pedo universal ( has 2 humps at the side)
```
120
What is done with matric band once wedges have been placed
Burnished
121
initial preps are likely to encounter what
Tubular dentin
122
Problem with the smear layer
Inhibits Good adhesion by keeping the resin from penetrating into the dentin
123
What makes up the smear layer
GRound bits of HA, Collagen, Bacteria, Salivary proteins
| Smear Plugs
124
What is Etchants
INorganic acid (35% phosphoric Acid)
125
Roll of Etchants
Completely remove smear layer and plugs
Demineralized surface Dentin
Leaves Collagen rush surface with numerous pores
126
Steps of Total Etch
Etch and Rinse
Primer
Adhesive
127
How does the Primer for Total etch feel about Water
Hydrophilic
128
How does the adhesive in Total etch feel about water
Hydrophilic or Hydrophobic
129
Steps of forming na hybrid layer
Etch enamel and dentin for 15 sec, rinse for 15 sec, gently air drying
Apply adhesive
Air thin for 3 sec, avoiding pooling, light cure
Pace composite and light cure
130
What is the Hybrid layer
Between the unaffected dentin and adhesive resin
131
Zone of the Hybrid layer
Interdiffusion zone
| Interpenetration zone
132
Photoinitiator peak absorption wave length
468nm
133
Types of curing lights
Halogen lights
Plasma Arc lights
Argon Lasers
LED lights
134
What type of Curing light is ideal for Composites
LED
135
power intensity of LEDs
intensity similar to highest QTH but lower than lazer and xenon arc
136
Benifits of LED curing lights
Small compact and light weight
Battery powered and cordless
Long bulb life
137
Problem with LED curing units
Power output narrow
| TIp design limited
138
ideal degree of converstion
100%
139
Maximum degree of curing
65%
140
what is the top layer of a curred composite
O2 inhibition layer
141
What is light intesnity proportional to
the distance squared
142
What is the air inhibited layer
Unreacted double bonds avilabe for the next layer that does not cure-tacky
143
The sea cretarure thing used to polish
Sof-lex ( i think brown first followed by purple )
144
Approach to primary occlusal caries treatment in posterior teeth for composites
Keep prearations as small as possible
145
when to do composite or amalgam on post teeth
Composite: small
| Amalgam if large: location and patient desire also important
146
Consequences of class 2
Adjacent tooth damage
Reduced Tooth stiffness
Introduce stress Concentration that lead to fracture
Margins in caries susceptible locations
147
Percent of teeth with adjacent tooth damage for class II
60-100%
148
Reduced tooth stiffness for MOD
60%
149
Incidence in vital posterior teeth of stress concentrations that lead to fracture
70/1000
150
Endo tx post teeth fracture for MOD at 7 years
50-60%
151
where do amalgams fail
Margins of class II (94%) due to caries
152
Where do Composites fail
Margins of class II (62%) due to caries
153
How to prep a slot
330 bur
Maintain proximal contacts if possible to make it easier to restore
Break out enamel with hand instruments
154
Can you bevel a tooth prep
Possible if non occlusal to increase retention
155
What needs to be done for Restorations
Sensitivity free
Good proximal contacts
good margins for the perfect seal
156
How to minimize sensitivty
```
Reduce etch time on dentin
Do not over dry
Use RMGI base or liner
Apply Gluma or rewet dentin
Apply adhesive for 15 sec (diffusion)
Multiple layers of adhesive
```
157
When would one use a base
Large deep restorations
Proximaal margins on cementum
High carier risk patients ( but still want tooth colored and indirect is too expensive
158
why use a base with preps with proximal margins on cementum
best seal
159
Why use RMGI as a base
REsists microleakage as well as any material
Release fluoride
Neutralize acid when disolved
160
Liner used
Vitrebond
161
How to prep a liner
Powder/liquid hand mixed
162
Base used
Fuji 2 LC
163
How to prep a base
Activated Capsule
Amalgamator 11-14 secs
Apply by injections
164
What kind of cure is done for REsin Ionomer set reaction
TRipple cure
165
Parts of the Cure of Resin Ionomer
Resin component LC, SC - free radical rxn occurs rapidly
| GI component acid-base reaction - slow
166
Part of the tooth most susceptible to recurrent decay
Deep Proximal Margins
167
Why Deep proximal Margins are the most susceptible to recurrent decay
No enamel
Poor bonding potential
Difficult to wedge without collapsing band
168
Why use the open sandwich
Good seal around high risk area
Layer minimizes shrinkage stress on box floor
Good tissue response
Helps to achieve good contacts and form
169
NEgative consequences of Open sandwich
If not well adapted can leave bacterial niche
| Some increase sirk of composite fractue
170
Elastic modulus (stiffness of Dentin, Composite, RMGI
Dentin:16-18 Gpa
Composte: same as dentin
RMGI: lower than composite or dentin (6-10GPa)
171
How does GI and RMGI adhere to tooth
Water based materials that use an acid base set reaction to adhere directly to the tooth
172
How does Compomers and Composites adhere to the tooth
Polymer based materials that work by a free radical set reaction and require adhesives
173
What are Conditions
Mild organc acids
174
Roll of Conditioners
```
Solubizes smear layer
Removes smear layer
Leaves smear plugs intact
Does not demineralize dentin or enal
Cleans surface
```
175
Acid difference between Etchand and conditioner
Etchant: strong acid 35% H2PO4
Conditioner: weak acid of 10% polyacrylic acid
176
Penetration depth of Etchant vs Conditioner
Etch penetrates much farther
177
Effect of Etchant vs Conditioner on Dentin
Etchant: cleans smear layer, Removes smear plugs and demineralized Dentine
Conditioner: Cleans smear layer, leaves intact dentin
178
What is Found in GI and RMGI powder
CaFAIsiO2, glass CalciumFluoroaluminosilicate
Acid Soluble glass
Non-silanated
179
What is found in GI liquid
50% water
50% polyacid copolymers (Long chain polymers, Carboxylic acid reactive groups)
pH=1
180
How are GI and Resin Polymers different
GI: polymers are hydrophilic and can chelate with metal ions
181
What is Found in RMGI LIquid
35% water
35% MEthacryltae modified polyacid copolymers (long chain polymers, Carboxylic acid reactive groups, Methacrylate reactive groups )
30% HEMA
ph=2
182
Glass Ionomer Reaction
Acid MAtrix dissolves periphery of glass
Glass releases ION (Ca, Al, F)
Divalent Ca ions quickly chelate with acid polymer chains
Next 24-72 Hours: Al replaces Ca to increase strength and F released
Acid side groups also can chelate with glass and with HA
183
Speed of GLass Ionomer reaction
Slow
184
GI's sensitivity to Moisture
Very sensitive early stages giving a soluble and rough appearance
185
Appearance of GI
opaque
186
RMGI reaction
Acid MAtric dissolves periphery of glass
| GLass releases Ion (Ca, Al, F
187
Reseasons for size changes of RMGI
Polymerization shrinkage
| Swelling from water sorption
188
What is used to aid in proximal contact formation
Sectional matrix
189
Problem with Composite in High caries risk patient
4x greater risk of recurrent decay
190
Problem with Adhesive
Can sometimes lead to sensitivity
191
What rubber dam clamp would you use to isolate a class V
212
192
what increases strength of composites
More filler
| Smaller filler
193
What type of composite for Class I and Class II
Nanofilled/Nanohybride Composites
