Operative dent (restorative) Flashcards
1
Q
Rake angle determines what?
A
Rake Angle determines how aggressively the bur will cut. Most high speeds rely on speed and use a negative Rake angle, dragging the cutting surface to cut the tooth Slow speed burs sometimes have a positive Rake angle
2
Q
Large diamond particles is for: very fine diamond particles is for:
A
Large diamond particles is for aggressive CUTTING Small diamond particles is for POLISHING
3
Q
material used in high speed (2) =
A
- Tungsten carbide 2. diamond
4
Q
material used in slow speed (2) =
A
- Tungsten carbide 2. Steel
5
Q
Operative dentistry restores (3):
A
Form Function Esthetics
6
Q
conservative dentistry:
A
preparing and restoring tooth with as little damage to healthy surrounding tooth structure, increasing long term function
7
Q
Periodontal structures include (3):
A
Periodontal ligament Bone gingiva
8
Q
3 common choices of restorative material:
A
Gold Amalgam Composite
9
Q
2 most common caries-forming bacteria
A
Strep Mutans Lactobacillus spp.
10
Q
Caries development requires 4 fundamental aspects
A
- Tooth 2. Plaque (bacteria) 3. Food (diet) 4. Time
11
Q
G.V. Black Class I
A
Pits and fissures of teeth
12
Q
lesion in Pits and fissures are Class ?
A
Class I
13
Q
G.V. Black Class II
A
interproximal contact of posterior teeth
14
Q
lesion in interproximal contact of posterior tooth is class?
A
Class II
15
Q
G.V. Black Class III
A
interproximal contact of anterior teeth
16
Q
lesion in interproximal contact of anterior tooth is class?
A
Class III
17
Q
G.V. Black Class IV
A
interproximal contact of anterior teeth involving incisal corner
18
Q
lesion in interproximal contact of anterior tooth that involves incisal corner is a class?
A
Class IV
19
Q
G.V. Black Class V
A
Gingival 1/3 of tooth on buccal or lingual surface of any tooth
20
Q
lesion on the buccal or lingual surface of a tooth in the gingival 1/3rd is a class?
A
Class V
21
Q
G.V. Black Class VI
A
incisal edge of anterior tooth OR worn cusp tip of posterior tooth
22
Q
lesion on incisal edge of anterior tooth is a class?
A
Class VI
23
Q
lesion on worn down cusp of posterior tooth is a class
A
Class VI
24
Q
What are these restorations?
A
Both are Class II (interproximal of posteriors)
25
What class?
Class V (gingival of buccal or lingual)
26
What class of lesion?
Class I (pits and fissures)
27
What class of amalgam?
Class II - because it involves interproximal posterior of tooth
28
what class lesion?
class III - interproximal of anterior tooth
29
What class?
Class IV - interproximal contact involving incisal edge
30
What class caries?
Class V - gingival 1/3 on buccal (or lingual)
31
What class of erosion?
Class VI - incisal edge of anterior
This is erosion and not caries, but it still follows the same classification system
Note: It can be worn cusp tipe of posterior
32
Why do we use rubber dams (4 points)?
1. Moisture control
* saliva contamination
* endo work must be sterile
* dry field for proper bonding
2. Protective barrier (patient and doctor)
* aspiration, choking, and bad tastes
* reduced infectious aerosols
3. Isolation of teeth
* for increased access and visibility
4. Retraction and access
* papilla and gingiva retraction
* keep lips, tongue and cheeks out of way
* soft tissue protection
33
Advantages to rubber dam
Disadavantages
* speeds up work
* keeps mouth open
* reduced aspiration risk
* more efficient than cotton roll
* lattex allergy
* claustrophobia
* time required to place dam
34
Retraction Clamps
* flatter jaws
* hold gingiva out of way
35
stabilization clamp
* jaws are angled downwards
* strong anchorage to tooth
36
Retraction clamp or stabilization clamp?
Stabilization clamp
37
Retraction clamp or stabilization clamp?
Retraction clamp
38
Wings vs. Wingless clamps
* wings hold down rubber dam to give broader work area
* wingless clamps are smaller and easier to place in mouth
39
Five ideal features of cavity prep.
1. Remove all caries and defective pits/grooves
2. **Access form** - Conserve all healthy structure (except in class II)
3. **Retention form** is created to retain restoration
4. All enamel rods are supported by dentin
5. **Resistance form** -material and remaining tooth can resist normal forces
40
Enamel thickness is approximately?
1.5 mm to 2 mm
41
As teeth age, the size of the pulp chamber \_\_\_\_\_\_\_
Size of the pulp chamber decreases with age due to tertiary dentin
42
Minimum mesial ridge thickness of Class I prep?
1.5 mm mesial ridge thickness
43
Define "Cavosurface"
Of or relating to the wall of a cavity preparation and the surface of a tooth.
The cavosurface angle is the angle (boundary) between the cavosurface and the sound tooth structure
44
List 5 points that should be done to carious lesions prior to resorting to restroring
1. attempt to reminieralize
2. polish early lesions
3. smooth off enamel defects
4. increase oral hygiene
5. assess diet for high risk cariogenicity
If all else fails, then you restore
45
4 objectives to cavity preperations
1. remove all defects and give protection to the pulp
2. Create margins of the restoration that are as conservative as possible
3. Cavity form is created in a way that will not fracture the tooth or restoration under masticaticatory forces
4. Cavity prep allows for the esthetic and functional placement of restorative material
46
Three biological consideration to cavity prep
1. maintain pulp health
2. prevent recurrent caries
3. prevent gingival inflammation
47
Three mechanical consideration to cavity prep
1. Type of restorative material used
2. Remaining enamel structure is sufficient and strong
3. Masticatory stress (occlusion) is considered to avoid damage
48
Factors influencing outline form
1. extent of decay
2. extent of demineralization
3. undermined enamel
4. esthetics
5. locate the margin on smooth cleansable surface
6. avoid terminating margin on cusp tip or fissure
NOTE: **outline form** is the outline of where you're working whereas **access form** is cutting through good tooth structure to access decay
49
Define: Resistance form
Resistance agaisnt fracture - the shape and placement of cavity walls that enable both the RESTORATION and the TOOTH to withstand functional forces
50
principles of resistance form
1. flat floors (perpendicular to long axis) - prevents masticatory forces at oblique angles
2. Do not over extend buccal-lingual (isthmus too wide)
3. Slight rounding of internal line angles to reduce concentration of stresses
4. eliminate weak areas of tooth structure
5. Allow for enough thickness of restorative material
6. Avoid occlusal contacts with margins of cavity - opposing tooth should contact natural tooth or tooth and filling (not just the filling)
51
Define: Pulpal axial line angle (PALA)
The angle between the gingival floor and the axial wall (the internal wall of the box)
Class II prep should have a PALA that is rounded
52
principles of Primary Retention Form
* convergent walls (class I, II, III, V)
* Dovetailing outline (class II) - wraps around cusp to lock restoration in mesial-distal direction
Primary rention form involves the shape and form of the prep, while secondary retention form involves grooves and pins
53
Completely clearing proximal contact on a Class 2 prep is an example of:
a. Outline form
b. Resistance form
c. Retention form
d. Convenience form
a. Outline form
54
Extending your prep from the Class 2 box onto the occlusal surface with a dovetailing pattern, is an example of:
a. Outline form
b. Resistance form
c. Retention form
d. Convenience form
c. Retention form
55
Rounding off the PALA, is an example of:
a. Outline form
b. Resistance form
c. Retention form
d. Convenience form
b. Resistance form (against fractures)
56
what is used for Caries removal bur?
Slow speed rounded bur - avoids over heating pulp and only removes soft dentin
57
Pulp protection after caries removal (4 types)
Pulp capping
Cavity liners
Bases
Resin modified glass ionomer cement (RMGIC)
58
Define: secondary retention form
The placement of additional features to help retain restoration
```
mechanical: undercuts or retention grooves
acid etching (micro mechincal)
accessory features (pins and pin slots) - rarely used nowadays
```
59
Three aspects of restoring a tooth
restore proper FORM, FUNCTION, and ESTHETICS
60
Amalgam advantages (4 points)
* Easy to handle
* excellent longevity in small-medium lesions
* inexpensive
* tolerant of poor handling technique
61
Amalgam disadvantages
* Poor esthetics
* Difficult to restore full anatomy
* High wear factor for larger restorations
62
Composite advantages
* very esthetic
* very polishable
* various types available for different tasks
* Wear factor is acceptabple
* relatively inexpensive
63
composite disadvantages
* requires high degree of skills for placement technique
* difficult to restore full anatomy
* difficult to bond to dentin
* water absorbing
* longevity is not great
64
Advantages of Indirect technique (restorations fabricated outside mouth - ie crowns, bridges, veneers)
* Good control of occlusal and interproximal anatomy
* excellent esthetics
* good seal if cemented properly
* good longevity
* excellent wear results
* gold = enamel
* porcelain is more abrasive
65
disadvantages of Indirect technique (restorations fabricated outside mouth - ie crowns, bridges, veneers)
* costly
* requires multiple appoitnments
* a lot of good tooth structure may need to be removed
* technique sensitive
66
Three steps to amalgam placement
1. condensation
2. carving
3. burnishing
67
Treatment hierarchy
1. no treatment (watch it, and modify factors)
2. polish it and apply fluoride
3. sealant
4. Enameloplasty (depth: 0.25mm) and sealant
5. Preventive Resin Restoration (PRR)
6. Conventional restoration (amalgam or composite)
68
Five reasons for class V resotrations
1. caries
2. replacement of faulty restorations
3. erosion (chemical)
4. abrasion (caused by excessive brushing and may have gingival recession)
5. abfraction (caused by grinding or clenching)
69
Abrasion
* mechanical tooth damage (ie: hard tooth brush or rigorous brushing)
* V-shape notch (deepens faster once softer dentin is reached)
* not usually associated with caries
* may be associated with gingival recession
*
70
Erosion
* non bacterial chemical demineralization
* smooth, dull, shallow depressions; margins are not sharply demarcated.
* ie: bulimia, acid reflux, acidic diet (sodas, citric)
71
Abfraction
* Excessive occlusal stresses causing flexure of the teeth with forces concentrated in cervical area.
* Leads to micro cracks within the cervical enamel making it more susceptible to abrasion or erosion (theory postulates that toothbrush abrasion works in combination with bruxing)
* lesions tend to be much worse on the buccal surfaces of the premolars and the canines where patients are likely to place the most brushing force. It becomes progressively worse from the posterior teeth to the anteriors
72
When do we treat an abrasion or erosion type lesion ?
* Esthetics
* Sensitivity
* To prevent further tooth loss that could otherwise lead to pulpal damage or structural weakness
* Caries secondary to the erosion or abrasion
* Compromised periodontal health
73
Dimensions of class V prep
axial depth:
* gingival: 1.0 - 1.25 mm
* occlusally 1.25 - 1.5 mm
Inciso-gingival dimension: 1.5 - 2.0 mm
**Note**: must stay within line angles of tooth and follow curvature of DEJ ( causes divergent walls, thus RETENTION GROOVES are important)
74
Define: Reverse Curve
* The result of blending together the proximal and occlusal portions of the prep, the outline resembling a backwards “S”
* The reverse curve circumvents the cusps, conserving tooth structure and helps to create proximo-facial cavosurface angles that are as close to 90 degrees as possible
75
Gingival Axial Line Angle (GALA)
The angle created between the axial wall and gingival floor (of the box)
NOTE: Accentuate the GALA with handtool to create retention groove
76
Class II dimensions
1. Axial depth (horizontal distance from cavosurfce to axial wall):
* premolars: 1.0-1.25 mm
* molars: 1.25-1.5mm
2. Axial height (vertical dimension of axial wall from gingival floor to pulpal floor):
* 1.25-1.5 mm from pulpal floor
77
Retention Form for Class II (3 points)
## Footnote
* Parallel or slightly convergent buccal & lingual walls in both occlusal & proximal box portions
* Pulpal & gingival floors at right angles to axis of the tooth crown, this to preclude any lateral displacement
* Buccal & lingual retentive grooves in proximal boxes as appropriate. (ONLY in slot preps)
78
Resistance Form for Class II
* Minimal thickness for restorative material on occlusal surface 1.5 mm.
* NO undermined enamel at any cavosurface margin
* Smooth cavosurface margins
* 90 degree angle of amalgam at cavosurface, no flash (excesses), no ditching
* Maximal Width of prep 1/3 intercuspal distance
* Rounded pulpal-axial line angle, internal line angles
* Rounded junction of occlusal & box portions, no sharp points
* “Reverse S” where appropriate
* Each portion of prep (occlusal & proximal) should be self-retentive, this to minimize stress at isthmus
79
Define: Isthmus
The narrowest portion of the cavity preparation between the occlusal portion and the box portion
80
Class II outline form
There is no predetermined shape for class II
The outline form is determined by:
- occlusal morphology
- proximal contact
- extent of caries
81
Enamel spur results in strong or weak:
- retention form
- resistance form
Weak resistance form (enamal easily breaks off)
Strong retention form (amalgam holds into place)
Note: if cavosurface is greater than 90 degrees it results in strong resistance form but weak retention form. Therefore make it 90\*
82
Three reasons for clearing contact in class II prep
1. Ensure removal of caries
2. Allow for proper carving & finishing
3. Allow for follow up inspections
Exceptions to the rule: Conservation of tooth structure
83
Classic signs of mercurialism
1. Psychosomatic symptoms
2. Alterations in affect or emotional lability
3. Insidious loss of mental capacity (progressively affecting memory and logical reasoning)
4. Motor effects (in the arms, progressing to incoordination, imbalance, and tremor in muscles that perform fine motor control)
84
Three forms of mercury associated with disorders
1. Hg gas (mercury vapor)
2. Hg2 salts (inorganic form)
3. Methyl mercury (organic mercury)
NOTE: Methyl group increases solubility in blood and lipids, thereby increasing distribution and bioavailability.
85
Mercury exposure in amalgams occurs during the following:
* Removal of old amalgam
* Placement of amalgam
* Release of un-reacted mercury
* Chewing
* Proportional to surfaces and corrosion behavior
A peak is observed the day after removal or placement of amalgam filling.
86
Diseases linked (?) to mercury poisoning from amalgam
* Autism (no - not linked to vaccine)
* Chronic fatigue Syndrome
* Alzheimer's Disease (no - no difference with edentulist)
* Multiple Sclerosis
* Auto-immune diseases
* Amyotrophic Lateral Sclerosis (ALS)
