Quiz 1: Liners, Bases, Build-ups Flashcards
1
Q
Liner
A
- placed as thin coating on surface of cavity prep
2
Q
Liner
A
Barrier to chemical irritant but NOT for thermal insulation or to add bulk to cavity prep
3
Q
Liner
A
Do NOT have sufficient HARDNESS or STRENGTH to be used alone in a deep cavity
4
Q
Types of Liners
A
- Varishes 2. Calcium Hydroxide 3. Glass Ionomers 4. Resin 5. Resin-modified Glass Ionomer
5
Q
Types of Varnishes
A
- Copalite 2. Duraphat (ColgateOral Pharmaceuticals) 3. Dura-Flor (Pharmascience, Inc) 4. Fluor Protector (Ivoclar Vivadent)
6
Q
Calcium Hydroxide
A
- pH 11 2. Basicity inhibits bacterial growth and neutralizes acidic bacterial byproducts 3. pulpal irritant that stimulates formation of reparative (secondary) dentin –> good for close pulpal exposure 4. extracts growth factors from dentin matrix to produce dentin bridge
7
Q
Types of Calcium Hydroxide
A
- Dycal (dentsply caulk) 2. Prisma VCL Dycal (dentsply caulk) 3. Life (Kerr) 4. TheraCal LC (Bisco): resin-modified calcium silicate- CA 2+ in basic environment
8
Q
Glass Ionomer
A
- Forms IONIC BOND b/w carboxylates and calcium in the dentin and enamel
- Provide sustained Fl release to counter the effects of microleakage
- Should NOT be used as pulp capping agents
- The most common formulations = RMGI
- VERY MOISTURE sensitive
- damaged by desiccation (too much drying), ESPECIALLY during setting
9
Q
Types of Glass Ionomers
A
- Ketac Bond (3M ESPE) 2. Fuji LINING (GC America)
10
Q
Resins
A
- High Compressive Strength
- High Tensile Strength
- Low Solubility
- NOT recommended for DIRECT PULP CAPPING
- LOTS of formulations
11
Q
Types of RMGI - Liners
A
- Vitrebond (3M ESPE) 2. Ketac Bond (3M ESPE) 3. Fuji Lining (GC America)
12
Q
Base
A
Can be considered restorative substitute for the dentin that was removed by caries and/or the cavity preparation
13
Q
Base
A
Generally thicker than liner
14
Q
Base
A
- barrier against chemical irritation 2. Provide thermal insulation 3. Can resist the condensation forces on a tooth when placing a restoration
15
Q
Base
A
Can be shaped and contoured after placement into the cavity preparation
16
Q
Base
A
often used to build out to “IDEAL” in preparation for either the direct or indirect restorative material *fill with a base BEFORE take impression
17
Q
Types of Bases
A
- Reinforced Zinc Oxide and Eugenol (IRM)
18
Q
IRM
A
Do not use under a resin because the eugenol can interfere with hardening and/or cause softening of the polymeric components
19
Q
Zinc Phosphate Base
A
- finishing margins for gold inlays and onlays - has higher acidity and causes greater sensitivity - technique sensitive
20
Q
Polycarboxylate
A
- it is in the permanent cement category but Dr. Taylor use for temporary with Post and core - can only remove with ultrasonic scaler - Durelon can also cement space maintainer -Tylok Plus turns to liquid in distilled water
21
Q
Types of Bases
A
Zinc Phosphate (Flecks)
22
Q
Types of Bases
A
Zinc Polycarboxylate: Tylok Plus, Durelon, Hybond
23
Q
Types of Bases
A
Glass Ionomer: Ketac Fil Plus, Fuji II Core Material
24
Q
Types of Bases
A
Resin: Core Paste, Luxacore, Compcore
25
Types of Bases
RMGI: Vitremer
26
Build Ups
ENHANCE connection of indirect restorative material to existing tooth structure
27
Build Ups
permit the creation of Ideal retention and resistance form in the crown preparation
28
Build Ups
Should help to direct occlusal forces axially
29
Build Ups
Eliminate undercuts to allow a line of draw for the indirect restoration
30
Build Ups
Reduce the volume requirement of the indirect restorative material (more significant if working with AU alloys)
31
Build Ups
Generally involve a greater volume of material than a base
32
Build Ups
Can be place over liners with vital teeth
33
Is a build up necessary if substantial portions of the coronal tooth structure are missing?
MAYBE
34
Is a build up necessary if over 1/2 of coronal tooth structure is missing?
YES
35
If require a build up ask:
1. can this tooth be predictably restored without a post? 2. will pis or retentive grooves/pot holes be necessary
36
T/F do pins and posts strengthen the teeth
FALSE: they simply enhance the connection
37
T/F do you put a post in an untreated tooth
FALSE: only put a post in an endo treated tooth. However, just b/c there is endo does NOT mean require post if not indicated
38
T/F Do posts fracture teeth
TRUE
39
T/F Do pins put micro crack in tooth
TRUE
40
T/F Crown Prep w/ parallel walls + taper + height + 1-2 mm Ferrule + no violation of biological width are clinically SUCCESSFUL regardless of material chosen for definitive crown
TRUE
41
T/F non vital builds up require a post
FALSE: non vital build ups MAY or MAY NOT need a post
42
T/F cut away tooth structure to fit a post
FALSE: don't cut away tooth structure b/c that is most important ally. Put in the post that fits
43
Post Facts
1. Unnecessary when adequate coronal tooth structure is present to retain core 2. do not remove additional tooth structure in order to construct a stronger post 3. thinnest post with adequate strength is recommended 4. for best retention, post surfaces SHOULD NOT be smooth 5. remaining coronal tooth structure has the highest correlation in regard to success of final restoration of endo treated teeth
44
What is the the survival of edno treated maxillary anterior teeth, restored with full coverage ceramic crown dependent on?
Retaining 3-4 walls of coronal tooth structure vs. the shape of the post
45
Is there a difference b/w parallel and tapered glass-fiber posts?
Little Difference
46
what type of post should be used for maxillary incisors with compromised roots?
Cast Posts had fracture strength more than 2x that of the fiber post groups. BUT all fracture result in unrestorable roots! \*prefabricated posts + resin filling in space b/ post and flared root walls = 60-80% of the failures resulted in non-restorable root fractures
47
T/F cast posts have higher fracture resistance than fiber posts
TRUE - in premolar teeth with WIDE ROOT CANALS, cast metal dowels had highest fracture resistance, BUT 90% specimens had non-repairable fractures
48
What should endo treated canines with glass fiber posts + 2mm ferrule be restored with?
Metal Ceramic Crowns b/c they have higher fracture strengths than all -ceramic crowns, independent of ferrule
49
What is the ideal length of ferrule
-minimum of 2 mm! doesn't have to be uniform. One side can be 2 mm and the other 3 mm -enhances the fracture strength of custom cast post-core restored endo treated teeth - fracture threshold higher for quartz fibers, glass fiber, glass fiber + zirconia, and zirconia posts dowels
50
T/F ferrule doesn't have to be on tooth structure
FALSE: ferrule HAS to be on the tooth. A build is not going to create a ferrule
51
What is the strongest combination for badly broken tooth?
Cast post and core and a PFM crown with a 2mm ferrule
52
How does ferrule effect endo treated teeth?
positively affects the fracture strength of fiber post
53
What is the worst combination for cast post and core?
fiberglass reinforced composite posts in teeth without maintaining supragingival structures.
54
Is there an Ideal Post length?
No, ferrule effect and stiffness of the post, NOT post length, has a critical effect on levels of stresses in dentin
55
Where is the most shear stress in cast post and core?
-post end area, which increases with decrease of post length - shear stress usually directed at 135 degrees to long axis of tooth -increased post length decrease shear stress at apical end of post -shear stress decreases as post length increases
56
how long should the post length go?
3/4 of the length of the root offered the greatest rigidity and least root deflection
57
how much gutta percha must remain to preserve apical seal?
4-5 mm
58
T/F a post should have minimum diameter to maximize preservation of remaining dentin
TRUE
59
What do you need to be careful of in deciding post length?
1. many factors influence post length 2. curved roots 3. navigating canal with post drills 4. Ideal post length PROBABLY 2/3-3/4 of the total length of the root 5. HAVE to maintain 4-5 mm of gutta percha at apex
60
Ideal post shape?
well-adapted, passively luten, parallel-sided post provided the MOST retentive post with least stress; PARALLEL SERRATED AND VENTED POST = uniform stress along length \*taper post produce greatest stress at coronal shoulder \*parallel posts generated greatest stress at apex of canal
61
What shape of post is NOT recommended?
Tapered self threaded screws
62
How do you reduce dentin stresses with posts?
1. bonding the dowel 2. increasing modulus of elasticity of the dowel (glass fiber?) 3. increasing diameter of the dowel 4. increasing length of the dowel 6. parallel sided dowels
63
what is the most universally appropriate post shape?
Parallel post with a tapered apical end
64
What is the most superior method placement for most cements?
lentulo Spiral
65
What do you NOT use a lentulo spiral with?
RelyX Unicem
66
Other than lentulo spiral what can be used to place luting agent in the canal?
Needle tube
67
What is best cementation for fiber post?
Etch-and -rinse adhesives + dual-cure resin cements (ex. photo bond + compcore) \*self adhesive resin cement could improve glass fiber post
68
T/F/ bond strength formed by self adhesive cements is noticeably lower in comparison to bond strength formed by resin cements with etch and rinse adhesive
True
69
What is RelyX Unicem?
Self adhesive cement
70
Should RMGI used for cementing posts?
NO, because of the post-set expansion
71
for Glass fiber posts should you choose self adhesive resin cement OR regular resin cement?
Self adhesive resin cementer are less technique sensitive when luting
72
T/F delayed cementation of fiber post (at least 24 hours post Endo) resulted in HIGHER retentive strengths using lentulo sprial
TRUE
73
when cementing posts, what should the thickness of the resin cement be?
cement layer should oversize post spaces but not larger than .3 mm
74
Should core-build material be used as post luting cements?
NO, unless in oversized canal when core build up material is probably indicated
75
T/F self-adhesive resin cements exhibited significantly higher bond strengths than self-etching resin cement
True
76
what is most important in having long term success of post endo restorations?
preservation of tooth structure, presence of ferrule effect, and adhesion
77
T/F the more biomimetic behavior of fiber-reinforced composite posts reduces risk of vertical root fractures
True
78
T/F achieving stable adhesion to intraradicular dentin is more challenging than to coronal dentin
True, this affects fiber posts debonding
79
What is a good alternative to metal posts in endo treated teeth?
Fiber posts
80
T/F preservation of tooth structure is a must
True
81
T/F posts should not be used with intention of reinforcing the tooth
True
82
What additional force should be review prior to restoring a tooth?
Functional and parafunctional forces
83
What causes technical failures in fixed prosth?
Fatigue failures: these occur at the weakest point or where maximum stress occurs
84
What affect do non axial forces cause?
put tooth, cement, and restorative material at risk for fatigue fracture
85
What is more important for survival of structurally compromised teeth: favorable occlusal prosthesis design OR type of post used?
Occlusal prosthesis design
86
What technique should be used forf cast post and core?
1. remove all damaged tooth structure including caries, fractures, etc. 2. test the integrity of any remaining pillars of tooth structure by applying moderate lateral forces with an instrument 3. WHERE POSSIBLE, eliminate non-axial loading of build up against tooth
87
What should be removed prior to core build up?
weakened axial walls
88
how should build cores be supported?
flat tooth structure that delivers a purely compressive force upon axial loading
89
How do you eliminate non-axial loading?
1. create near horizontal and vertical planes of tooth structure w/ NO SHARP LINE ANGLES and they can create points of stress in build up and dentin 2. slight truncation is favorable for build up retention 3. spicules of dentin less than 2 mm in width are best to eliminate
90
after extensive loss of tooth structure, vital teeth can be completely built up with \_\_\_\_\_\_\_\_\_\_\_\_\_.
Composite restoration material sometimes use of additional retentive features such as pins, potholes, and grooves is indicated
91
endo treated MULTI-ROOTED teeth build ups
build up entirely with composite, utilizing the pulp chamber and root canal access for retention
92
single rooted teeth build ups
post is usually necessary to reinforce the retention or coronal tooth structure to root (?)
93
T/F preparation must be modified to make use of remaining tooth structure in severely damaged tooth with cast restoration
True, bozes, isthmuses, grooves and pin (preexisting and new ones) employed to provide adequate retention and resistance
94
What can be used when destruction of coronal tooth structure is greater than 1/2 of the clinical crown?
1. pin retained amalgam core 2. composite resin core --\> either core to build up for a cast restoration
95
What are the 3 types of pins?
1. cemented 2. friction locked 3. threaded
96
Steps of pin placements
1. advise patient that pins put tooth at endo risk 2. place ONLY when absolutely necessary 3. be aware of DENTAL ANATOMY 4. best locations are LINE ANGLES 5. .5-1 mm inside of DEJ with 1/4 round pilot hole 6. PARALLEL to outer surface of root 7. HAND PLACEMENT ONLY! do not drive in with slow speed motor! less likely to strip threaded dentin and less internal stresses introduced to dentin 8. bend pin to be contained largely within core of build up if necessary
97
Drill Technique for posts
1. use 1/4 round pilot hole 2. place tip of pin drill into pilot hole 3. orient angulation , M/D B/L to avoid PDL and pulp 4. at slow speed, penetrate into dentin 1/2 depth of threads on pin drill 5. pull out 6. again at slow speed, penetrate now to full depth and remove 7. DO NOT OVER PREPARE!
98
Pin Types
1. Stabilok- titanium small diameter
99
Post Preparation
1. start with gates glidden #2 or #3 2. keep minimum of 5 mm of gutta percha to maintain apical seal 3. confirm with radiograph if necessary 4. watch for gutta percha at end of drill to help confirm position within canal 5. allow drill to follow path of least resistance
100
Bonding the post
1. condition of tooth surface for bonding, including the canal 2. thoroughly dry tooth, including canal with paper points 3. mix cement (self-adhesive resin cement) and apply according to manufacturer's instructions 4. insert post
101
What can be used as matrix for core build up?
1. Copper Band 2. Tofflemire 3. Rubberized core former 4. Other: premier blue cure thru squeez matrix band \*MAKE SURE WHICHEVER USE TRIM AND ADAPT MATRIX
102
what is an example of dual cured dental bonding agent?
Clearfil Photo bond: 1. apply bonding agent 2. thin with gentle air stream 3. cure for several seconds Use prior to placing core material
103
What is an example of core material?
CompCore AF dual cure composite core build up
104
After matrix placement what are the steps?
1. trim adapt matrix 2. place dual cure bonding agent 3. fill with core material 4. light cure and allow to completely set 5. remove matrix 6. begin tooth prep for final restoration OR trim and smooth excess build up material and adjust occlusion
105
- placed as thin coating on surface of cavity prep
Liner
106
Barrier to chemical irritant but NOT for thermal insulation or to add bulk to cavity prep
Liner
107
Do NOT have sufficient HARDNESS or STRENGTH to be used alone in a deep cavity
Liner
