operative final study guide material Flashcards

1
Q

Class III:

A

Interproximal caries on anterior tooth

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2
Q

class IV

A

“chipped tooth” (fractured incisal edge)
III and IV similar but IV missing incisal edge

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3
Q

which III or IV
more extensive bevel to increase retention and esthetics

A

IV
Bevel must cover at minimum the same amount of enamel that is missing due to the fracture
ground(bevel) enamel improves the adhesive bond to enamel by 18% over unground enamel

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4
Q

lingual enamel margins not beveled in class IV when:

instead:

A

heavy centric contact on margin

Use dovetail with no bevel on lingual to compensate for retention without beveling

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5
Q

thin covering (often to hide under layer)

A

veneer

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6
Q

Direct Veneer Preparation (composite):
1
2

A
  1. incisal lapping preparation
  2. window preparation
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7
Q

Preparation includes incisal edge
Indicated when tooth needs to be lengthened or incisal defect is present and needs to be correct
(some clinicians do minimal tooth preps, which result in overcontoured (bulky) veneers)

A

incisal lapping preparation
-direct veneer prep (composite)

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8
Q

type of direct veneer:
(what we did)
Most often recommended
Remove only enough tooth structure to achieve optimal contours with final restoration
Incisal edge remains intact

A

window preparation

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9
Q

Intra-enamel preparation with window prep in direct veneer

A

Necessary to provide space for materials to achieve max esthetics
Removes outer, fluoride rich layer (resistant to etching)
Roughens surface for improved bonding
Establishes definite finish line

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10
Q

Identify common mistakes associated with veneers:

A

-Failure to do wax-up prior to prepping
-Failure to address gingival asymmetry
-Failure to communicate effectively with patient
-Everyone must have same expectations
-Dont start a case that should have never been started (learn to say no)

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11
Q

made OUTSIDE of mouth):
Porcelain

A

indirect veneer

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12
Q

indirect porcelain veneer adv

A

Excellent aesthetics
Color match
High bond strength
Conducive with periodontal health
Low wear/abrasion on porcelain restoration

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13
Q

indirect porcelain veneer disadv

A

Multiple appointments
Expensive
Must have adequate room for preparation
Requires laboratory involvement and fee
Difficult to keep provisional seated

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14
Q

made in mouth veneer

A

direct composite

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15
Q

adv of direct comp veneer

A

Mask discoloration
Cheaper than indirect
Can easily correct rotated tooth or diastema
One appointment

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16
Q

direct comp veneer disadv

A

Susceptible to wear
Margin fracture/stain
Discoloration
contours

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17
Q

Understand which materials will give a better esthetic result

A

porcelain
has better esthetics and color match compared to composite veneer

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18
Q

different treatments available to help patients with esthetic concerns and tools for communicating with them

A

Alternate treatment:
-Bleaching for discoloration
-Microabrasion and macroabrasion (polishing) for discoloration
-Direct composite veneers
Microfill composite resin polishes best
-Full coverage porcelain crown or porcelain veneer
-Orthodontics (rotation or diastema)

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19
Q

veneer indications

A

Intrinsic stain
(Tetracyclie, fluorsis)
Extrinsic stain
(Coffee, wine, smoking)
Wear patterns
Poor restorations
Diastema closure
Rotated and misaligned teeth

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20
Q

Veneer contraindications

A

Severely malpositioned teeth
Ortho
Denuded dentin (from bruxism)
Poor oral hygiene
Beware of highly fluoridated teeth
Issue with bonding
No primary teeth!
Pregnancy
Oral habits
Bruxism

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21
Q

used with LARGE restorations and less than ideal supporting tooth structure
Typically amalgam (because it relies on mechanical retention)

A

accessory retention
(Understand the purpose of pin placement and when it is appropriate or inappropriate to place a pin)

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22
Q

Indications for pins:

A

Improve retention as a last resort
Large restorative that are missing cusp(s)
Prognosis of tooth is uncertain (unstable perio)
Unable to access pulp canals (sclerosed tooth) for needed additional retention

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23
Q

Contraindications for pins:

A

Severe loss of tooth structure
Endodontically treated teeth
-Teeth too brittle
-Alternatively use post or amalgam core
Large pulp canals (children)
Difficult access for placement
Tooth serves as abutment for RPD

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24
Q

Self threading Pin (size, depth, properties)

A

Pin hole 0.002” smaller than pin
Pin self-threads into dentin (with hand wrench or latch grip on slow speed 5000rpm)
2 mm in dentin, 2 mm outside of dentin

5-6 times as retentive as cemented pin
High crestal and apical stresses; crazing and microleakage
-greater stresses in dentin
Also, SELF SHEARING: break off on own as you turn them

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25
Know where pins should be placed in relation to tooth structures and in relation to other pins
-Pin is always placed in DENTIN -At least 1 mm of dentin around pin hole (0.5mm both sides) -2mm deep into dentin -Should be placed 5mm apart from each other -(Minimum of 3mm apart) -Should be 1mm from wall of prep -(Minimum 0.5mm from wall to allow for room for condensation of amalgam around pin) -Place in line angle -Placed along long axis of tooth -If using multiple, angle in slightly different directions -AVOID bending pins
26
Twist drill sizes
Regular: 0.027 (gold) minim : 0.021 (silver) most frequent used Minikin: 0.017 (red) Minutia 0.013 (pink)
27
Types of twist drills
Standard Self-limiting: drill stops itself from drilling too deep of a pilot hole
28
how to know if pin is the correct height and how to troubleshoot if not
Must be 2mm of amalgam over top of pin If not: amalgam will fracture Too tall: -reduce with handpiece stabilized by forceps to cut perpendicular to pin -Check when done to make sure not lose -Bend slightly using provided pin tool (preferred) -Helps avoid excessive stress
29
Where not to place pins:
Avoid pulp exposure: -MF (MB) corner of max and mand 1st molar -D mand molars -L max molars -mid-F, mid-M, mid-D furcations of max 1st and 2nd molars Concavities: -M over max 1st PM -mid-L and mid-F of mand 1st and 2 molars -Mid-F, Mid-M, and Mid-D furcations of max 1st and 2nd molars
30
Disadvantages of pins:
1. Introduces stress into dentin which can lead to fracture 2. Pins reduce the compressive and transverse strength of amalgam 3. Possibility of pulp or PDL perforation -Pulpal exposure is preferred to PDL exposure a. Pulpal -Direct pulp cap with calcium hydroxide or endo b. PDL -Results in abscess -Treated by removing pin that is perforating tooth and plugging with amalgam -Less predictable prognosis 4. Microleakage around pin 5. More difficult to restore and carve anatomy
31
Know advantages and disadvantages of indirect restorations
Advantages: Esthetics Better control of restoration contours Strength of material Disadvantages: Expensive Requires two appointments (if sent to lab) Impression needed (digital or with impression material)
32
Indication for inlay:
1. Indirect restoration that is placed within the cusp tips 2. NO cuspal protection 3. Used on teeth with minimal caries -Occlusal must be acceptable -Buccal and lingual cusps must be strong
33
Indications for onlay:
1. Large carious lesions or existing defective restorations 2. Cracked teeth 3. Endodontically treated teeth -Must have sufficient tooth structure to retain the only and allow for removal of undercuts -When enough facial and lingual are relatively intact; otherwise do a crown
34
Why use an ONLAY instead of Inlay:
1. When the bucco-lingual width of the cavity preparation is: ½ way between central groove and cusp tip- CONSIDER ONLAY ⅔ way between central groove and cusp tip-SHOULD ONLAY 2. Where cusps are undermined after caries removal 3. Where occlusion of tooth must be altered (inlay acts as wedge, onlay protects)
35
Advantages of gold:
Strength Wear resistance Will maintain smooth surface (no tarnish or corrosion) Better control of contact and contour Potential for greater longevity
36
disadv of gold
esthetics
37
Advantages of ceramic:
Esthetics Wear resistance Reduced polymerization shrinkage compared to direct composite restoration
38
disadv of ceramic
Require removal of more tooth structure for adequate material bulk Ceramics require dry field to bond Expense (compared to direct composite) TECHNIQUE SENSITIVE Wears on opposing dentition Low potential for repair
39
Inlay preparations:
Cannot have any undercuts (walls are DIVERGENT) Restoration fits PASSIVELY NO SHARP LINE ANGLES
40
gold inlay prep
-If walls are longer: more divergence acceptable (5-7 degrees) -If walls are shorter: walls should be closer to parallel (2 degrees) -Bevel gold inlay preparations -Occlusal, axiopulpal, gingival bevels -1mm bevel at 45 degree Flared exit angles -Contacts broken at least 0.5mm I-f 2 surface (MO or DO) -Dovetail is present -No reverse S curve (gold strong enough)
41
Ceramic Inlay preparation:
-Occlusal depth: 1.5-2.0mm -Isthmus 2.0mm -NO BEVEL -Flared exit angles -Contacts broken at least 0.5mm -No sharp line angles -Smooth, flat walls -If 2 surface (MO or DO) Dovetail is present
42
Gold onlay preparation:
1. Cut depth cuts into cusp 1.5mm reduction on functional cusp 1.0mm reduction on nonfunctional cusp 2. Add bevels 1mm functional cusp 0.5mm nonfunctional cusp 3. Ferrule margin (same as light chamfer?)
43
Ceramic onlay: specifications
2mm reduction functional cusp 1.5mm reduction nonfunctional cusp 90 degree cavosurface angles Smooth line angles No external bevels Need adequate (0.5mm) clearance from adjacent teeth for die separation
44
ceramic materials used at UMKC and their basic properties
Nano resin ceramic (weakest) Enamic, lava ultimate 140-200 MPa Feldspathic porcelain Vita and Sirona blocks 154 +/- 15 MPa Leucite Reinforced IPS Empress 160 MPa Lithium Disilicate Ivoclar e.max Starts in an intermediate phase and must be crystalized Flexural strength 360 MPa Shortened firing cycle may cause loss of strength and color shift Zirconia (strongest) Flexural strength 600-900 MPa Strong, less aesthetic (very opaque)
45
Inlay seating:
-Cannot have any undercuts (walls are DIVERGENT) -Restoration fits PASSIVELY -NO SHARP LINE ANGLES
46
Very predictable bonding= 25-30MPa
enamel
47
Chemical drilling 30-40% phosphoric acid most effective for enamel retention Removes about 10 um enamel
enamel etching
48
enamel etching: Place for ___ seconds prior to rinsing Creates porous layer 5-50 microns deep Rinse with water for ___seconds after etching To remove acid and leave enamel surface clean for bond
15 seconds rinse 10 seconds
49
Etching raises the surface free energy to exceed the surface tension of bonding material Produces spaces where resin can penetrate to form resin tags
micromechanical bond
50
Mechanical interlocking is formed between polymerized resin and porosities in etched enamel
micromechanical bond
51
Flows into microporosities Polymerizes to micromechanical bond
after etching, you apply bond agent resin (low viscosity)
52
Variation in enamel bonding
Incisal third and middle third enamel Predictable and strong Cervical enamel Less strong Shorter and fewer enamel tags Due to presence of prismless enamel
53
Bond strength perpendicular to enamel
ends of enamel rods 25MPa
54
Bond strength parallel to enamel
sides of rods 7-10 MPa
55
Challenging bonding= bond strengths vary
dentin
56
______dentin has higher bond strength than ___ dentin
superfical dentin than deeper dentin (near pulp)
57
if you don't use____, you are not getting smear layer off)
etch
58
bond systems
Etch and rinse (total etch) 1. etch separate 2. prime 3. bond (or prime and bond together- do at UMKC) 3 step (2 bottle) total etch Etchant Primer Bond agent 2 step (1 bottle) total etch Etchant Primer and bond agent combined self etch -no phsophoric acid etch step -acid part of primer or primer/bond agent 2 step: Acidic primer Bonding agents Acidic primer partially dissolves smear layer, allows penetration of bond resin 1 step: All in one (most variable/least predictable) Acidic primer and bond resin, one solution Many require mixing selective etch : etches enamel only with phos. acid
59
adv of total etch
More predictable, stronger bond Enamel adequately prepared
60
disadv of total etch
-Collagen collapse is possible (user error) -Etched zone is often deeper than hybrid layer Exposed demineralized, collagen fibrils Post-operative sensitivity
61
self etch adv
No separate etch: overdried demineralized collagen not a problem Etched zone and hybrid layer comparable width; however, some exposed collagen Low post operative sens Time efficient
62
self etch disadvan
-Not compatible with self-cure, dual cure composite Acidic monomers, low pH, kills basic amine activator -Will not etch unprepared enamel -Self etch primer systems Long term bond strength questionable -Self etch adhesives (all in one) Lower bond strength Long term breakdown Collagen degradation overtime
63
Primary bacteria in caries
S. mutans (initiator) Lactobacillus (responsoble for progression of caries) Actinomyces V.
64
Where caries progresses most rapidly in tooth
hydroxyapatite(enamel) demineralizes at pH<5.5 Dentin demineralizes at pH<6.2 Proteolytic enzymes (MMPs) removed organic partition (collagen) so remineralization may not be possible Fluorapatite demineralizes at pH<4.5
65
Dietary habits that affect caries
Frequent snacking/drinking of carbohydrates(primarily sucrose) in between meals increases caries risk Consuming sugar without chewing does not stimulate saliva and increases caries risk
66
When to place sealants
Sealants are placed on pit and fissure areas on NON CAVITATED TEETH PRR(preventive resin restorations) done on teeth that have initial caries but NOT in dentin Caries must be removed first
67
Be able to describe a properly placed rubber dam system
Prep work: 1. Punch holes in rubber dam 2. Check contacts for floss shredding Smooth contacts if necessary 3. Mark occlusion before placing dam 4. Place clamp on tooth 5. Place dam over entire clamp Can do with or without frame in place 6. Stretch dam through contacts Floss between contacts 7. Invert dam Delicately blow air around cervical area and push rubber into sulcus with plastic instrument 8. Ligate anterior tooth Ligate with ligatures or piece of rubber dam cut and placed interproximal 9. Rubber dam is optimal method of isolation
68
enamel rod orientation § Including in relation to one another
Larger diameter near surface, smaller near dentin borders DO NOT LEAVE UNSUPPORTED ENAMEL Enamel rods are perpendicular to long axis and radiate outward from dentin
69
Thickness varies by location and tooth types 90-92% hydroxyapatite STRONG AND BRITTLE
enamel
70
Largest portion of tooth Located in both coronal and root portions of tooth 50% hydroxpap
dentin
71
dentin harder near ____
near DEJ than at pulp larger and more at pulp than DEJ
72
Fluid movement in tubules=
dentinal sensitivity
73
Class III preps
1. approach from lingual when possible (esthetics) May be acceptable to leave unsupported enamel facial or incisal 2. Preserve a portion of incisal contact 3. Outline form is created PERPENDICULAR to long axis of tooth (not lingual surface) 4. Inciso gingival height 1.5mm on lateral 2.0mm on central 5. Mesial distal width 1.0mm on lateral 1.5mm on central 6. Gingival contact broken 7. Retention points/groove added only in dentin at depth of ¼ round bur Point is incisal Groove is gingival 8. 1 mm, 45 degree bevel placed on lingual (or facial) 9. Facial contact is minimally broken so it can be seen slightly from facial
74
importance of axis of entry on preparations
Important for retention form to insure proper convergence Also important to ensure that enamel rods are not undermined
75
Recall the purpose of the reverse S in amalgam preparations
helps resist fracture of amalgam restoration by increasing the bulk of amalgam, reducing its brittleness and increasing its strength
76
proper tofflemire retainer and matrix band placement
Slots face gingiva Choice 1 Retainer on the buccal side Band emerges from one of the side guide channels MOST COMMON
77
Obtaining good contact with toffle
Loosen band quarter turn after wedging Burnish band against proximal surface of adjacent tooth Pack material hard against matric band in contact area
78
proper Class II composite placement and why
Place composite incrementally to achieve proper contact and maintain good margins
79
problems that may occur if occlusion is not considered when restoring a tooth
Pain on biting Fractured cusp Fractured restoration Premature wear on tooth Trauma to PDL Trauma to TMJ
80
identify cause of amalgam marginal ridge failure after matrix band removal
Premature removal of matrix band can cause marginal ridge fracture removing matrix band occlusal and not taking off tofflemire first
81
now where the handpiece motor is located
in the actual handpiece