Op 1 Flashcards
1
Q
What is the 4 number instrument formula used for?
A
margin trimmers
2
Q
What do these numbers represent: 15-98-10-14?
A
15 = 1.5mm width
98 = angle of cutting edge to long axis of handle
10 = 10mm blade length
14 = angle of blade to long axis of handle
3
Q
What are 3 functions of hand instruments?
A
Removes loose enamel
Smooths preparation
Refines cavity features
4
Q
What are 2 examples of refining cavity features?
A
Retention areas
Line angles
5
Q
What are the 2 metals in hand instruments?
A
Stainless steel
Carbon steel
6
Q
What are the features of stainless steel?
A
Resists corrosion
Dulls easily (need to keep instruments sharp)
7
Q
What are the features of carbon steel?
A
Corrodes
Holds sharpness
8
Q
What are the 3 types of hand instruments?
A
Hand cutting instruments
Restorative instruments
Plastic instruments
9
Q
What are the hand cutting instruments (examples)?
A
chisels, hatchets, hoes, gingival margin trimmers, excavators, carvers
10
Q
What is the most common excavator used?
A
spoon
11
Q
Characteristics of chisels
A
Straight or curved
1, 2, or 3 angles
12
Q
Characteristics of hatchets
A
Cutting edge = in plane parallel with handle
1 or more angles
Do not use with too much force or twist (can easily break)
13
Q
Characteristics of hoes
A
Cutting edge is ⟂ to handle
14
Q
Characteristics of gingival margin trimmer
A
Similar to hatchet, but has curved blades
Cutting edge is at angle to length of blade
15
Q
Characteristics of excavators
A
Remove caries
16
Q
Characteristics of carvers
A
Place anatomy
17
Q
What are restorative instruments used for?
A
Used to place, condense, and carve restorative materials back to normal anatomy of teeth
18
Q
What are restorative instruments primarily made of?
A
Stainless steel
19
Q
What are the restorative instruments (examples)?
A
amalgam carrier, condensers, burnishers, carvers, amalgam knife, composite placement instruments
20
Q
Characteristics of condensers (aka amalgam plugger)
A
Condenses materials
Can be used to gauge cavity width
21
Q
Characteristics of plastic instruments
A
Can be used to carry pliable restorative material to prepped cavity (although typically placed directly by composite gun)
Used to shape material
22
Q
What are the 3 parts of hand instruments?
A
Shaft/handle
Shank
Blade
23
Q
Characteristics of shaft/handle of a hand instrument
A
Can be small, medium, large
Smooth or serrated
24
Q
Characteristics of shank of a hand instrument
A
Connects handle to blade
Straight or angled
(Angled for access and stability)
25
Characteristics of blade of a hand instrument
Working part of the instrument
Beveled to create cutting edge
26
How many bevels can the blade of a hand instrument have?
3
27
Where is the primary cutting edge of the blade of a hand instrument?
on the end
28
Where is the secondary cutting edge of the blade of a hand instrument?
on the sides
29
Can hand instruments be double ended? Or just single ended?
They can be double ended (2 working sides) or a long handle with 1 working side
30
What are the 3 categories for sterilization?
Critical
Semi-critical
Non-critical
31
What does critical mean in regards to sterilization? Give an example
Penetrates soft tissue of bone
Ex: forceps
32
How do we sterilize critical instruments?
Autoclave (most commonly used heat sterilizer in dentistry)
33
What does semi-critical mean in regards to sterilization? Give an example
Does not penetrate, but contacts mucous membranes or non-intact skin
Ex: mirrors
34
How do we sterilize semi-critical instruments?
Autoclave or high level EPA sterilant/disinfectant
35
What does non-critical mean in regards to sterilization? Give an example
Comes in contact only with intact skin
Ex: blood pressure cuff
36
How do we sterilize non-critical instruments?
Intermediate or low level disinfectant
37
How many classes of carious lesions are there? Which one is most and least prevalent?
6 (I-VI)
Most prevalent = Class I
Least prevalent = Class VI
38
Where are caries on Class I lesions?
Pits and fissures on:
-Occlusal ⅓ of molars and premolars
-Occlusal ⅔ of B & L surfaces of molars and premolars
-L surface of upper anterior teeth
-Any other unusually located pit or fissure
39
What is the general rule of pit/fissure lesions? (Class I)
More constricted at enamel surface and wider toward DEJ
40
Where are caries on Class II lesions?
Caries affecting proximal surfaces:
-Molars and premolars
41
What is the general rule of smooth surface interproximal lesions? (Class II)
Wider at enamel surface
42
Where are caries on Class III lesions?
Caries affecting proximal surfaces of:
-Central and lateral incisors
-Cuspids without involving incisal angles
43
Where are caries on Class IV lesions?
Caries affecting proximal surfaces including incisal angles of anterior teeth
44
Where are caries on Class V lesions?
Caries affecting gingival ⅓ of facial or lingual surfaces of:
-Anterior teeth
-Posterior teeth
45
Where are caries on Class VI lesions?
Caries affecting cusp tips of:
-Molars
-Premolars
-Cuspids
46
What is abrasion?
Tooth surface loss from frictional forces
47
What is erosion?
Tooth surface loss from chemico-mechanical action
48
What is attrition?
Mechanical wear from opposition teeth (grinding)
49
What is abfraction?
Cervical, wedge-shaped defects as result of strong eccentric occlusal forces
50
What is fracture?
Can be most difficult and challenging defects in teeth to diagnose and treat
Can be considered incomplete or complete; involving pulp or not involving pulp
51
What are the 4 stages of caries progression?
Demineralization
Cavitation
Infected dentin
Affected dentin
52
What is demineralization?
Loss of mineral from tooth structure, resulting from a chemical process (can be from caries, acid, diet, or gastric)
53
What is cavitation?
Breakdown of surface integrity that can be detected using optical or tactile methods
54
Where can cavitation go?
Can be confined to enamel or extend into dentin via tubular invasion
55
What can cavitation include?
Differing layers of infected and affected dentin
56
How do caries penetrate (shape)?
Penetrate in a narrow or cone shaped channel to DEJ then spread laterally
57
What is infected dentin?
Irreversible, demineralized, and denatured layer with bacterial invasion
Very soft, moist, and easy to remove with spoon excavator
58
What is affected dentin?
Partially demineralized
Leathery/softer than normal
Collagen is not denatured
Contains minimal to no bacteria
59
What are the forms of tooth prep?
Outline
Convenience
Resistance
Retention
60
What is the outline form?
External shape of the prep
61
What do we consider when it comes to outline form?
Access to lesion
Extent of lesion
Restorative material being used
Esthetics
Function
62
What does access to lesion refer to in regards to outline form?
Visualize extent of caries
Allows bur to reach all carious dentin
Creates space for instrumentation and vision
63
You should extend your outline to include all ________ enamel, because enamel rods must be supported by _______ ___.
You also should include the ____ spread of caries at ____. Carious dentin can have ____ overlying dentin; ____ enamel is usually removed.
________ enamel can be considered for ____.
Unsupported; sound dentin
Lateral; DEJ; sound; undermined
Decalcified; inclusion
64
What determines the size of the prep?
Extent of caries in dentin
65
You should design your prep to take advantage of/compensate for what?
For properties of material to be used
66
What do brittle materials like amalgam and porcelain require when creating the outline form?
90° cavosurface margin
67
What do ductile materials like composite and gold require when creating the outline form?
Beveling of margin
68
What do esthetics refer to in regards to outline form?
Restorations in visible areas of mouth dictate cavity design and restoration selection
69
What does function refer to in regards to outline form?
When a restoration alters occlusion, outline may need to be altered
Do not leave occlusal contact on margin of restoration EVER
70
What is the convenience form?
Shape that allows access for the procedure to be done
Allows vision, access, and ease of instrumentation and insertion of restorative materials (influences outline form too)
71
What is the resistance form?
Shape given to prevent fracture of either the restoration or the tooth
72
What are examples of resistance form?
Adequate bulk of amalgam
Rounding of internal line angles
Horizontal pulpal and gingival floors prepared ⟂ to tooth’s long axis
73
What is the consideration of resistance form? What are the 3 reasons?
Prep is placed 0.5mm into dentin (not including enamel) for 3 reasons:
Avoid sensitive DEJ
Provide adequate bulk of restorative material
Take advantage of dentin’s resilience
74
What is the retention form?
Shape that prevents restoration from being displaced by tipping/lifting forces
75
What does retention form include?
Undercuts, truncation, grooves, pits, dovetails, etc.
76
What are the considerations of retention form?
Primary and secondary retention
77
How do we get primary retention?
Converging walls
(and sometimes dovetail)
78
How do we get secondary retention?
Grooves, coves, extensions, skirts, beveled margins, pins, slots, steps, amalgam pins, etchants, adhesives
(sometimes dovetail)
79
What does secondary retention do?
Helps retain restoration in case primary retention fails
80
Which type of retention do we always need?
Must ALWAYS have primary retention; secondary retention is needed when indicated
81
Features that enhance _________ form also enhance _________ form
retention; resistance
82
What is an external wall?
Touches uncut surface/cavosurface margin
83
What is an internal wall?
Does NOT touch uncut surface/cavosurface margin
84
What is a bur?
Rotary cutting instrument with bladed cutting head
85
What are most burs made up of?
Carbide head to steel neck
86
Describe carbide
Stiffer/stronger than steel
Holds up better at high speeds
Less prone to dull
87
Describe steel
Decreased cost of fabrication
Freedom in design
88
What does the arbitrary 2 part numeral code of burs indicate?
Size and shape
89
What are the basic shapes of burs?
Round
Inverted cone
Pear
Straight fissure
Tapered fissure
90
Features of round burs
Initial entry into tooth
Expansion of prep
Retention features
Caries removal
91
Features of inverted cone burs
Rapidly tapered cone with apex of cone directed TOWARD shank
Head length = head diameter
Undercuts in tooth prep
92
Features of pear burs
Slightly tapered cone with small end of cone directed TOWARD shank
245 = elongated pear bur for amalgam preps
330 = small version of 245
93
Feature of straight fissure bur
Elongated cylinder
94
Features of tapered fissure bur
Slightly tapered cone with small end of cone directed AWAY from shank
Used for indirect restorations
95
What are the 3 parts of a bur?
Shank
Head
Neck
96
What does a shank of a bur do?
Fits into handpiece
Accepts rotary mutation from handpiece
Provides bearing surface to control alignment and concentricity of instrument
97
How many classes of bur shanks are there? How many are important to us?
5 total classes; 3 are important to us
98
What are the 3 classes of bur shanks that we care about?
Straight
Right angle latch
Friction grip
99
What are straight bur shanks for?
Rarely used for prepping teeth
Used for oral surgery and polishing indirect restorations
100
What are right angle latch bur shanks used for?
Used in slow speed handpieces
Fits into D-shaped socket at bottom of bur tube instead of a chuck
101
What are friction grip bur shanks used for?
Used in high speed handpieces
Small size allows for improved access with molars
Held in place using friction between shank and chuck within handpiece
102
What is the neck of a bur?
Intermediate portion that connects the head to the shank
103
What is the function of the neck of a bur?
Transmits rotational and translational forces
104
How does the neck of a bur taper?
Tapers from shank diameter to smaller size by the head (improves access/visibility)
105
What is the head of a bur?
The working part of the bur
106
What does the head of the bur have?
Cutting edges/points that perform desired shaping of tooth structure
107
What part of the bur has the greatest area of variability based on intended application and technique?
Head
108
What is the primary retention feature for an amalgam restoration?
Converging B and L walls
109
What is the secondary retention feature for an amalgam restoration?
Retention grooves and dovetails
110
What must be included in the Class I prep outline form?
All caries and defective pits/fissures
111
In Class I preps, you should prep _____mm into _____ and _____ grooves to create nicely shaped dovetails in _______ and ______ ______ by also going slightly toward B and L (outline form)
0.5
B
L
M
D
Fossa
112
What is the retentive feature in Class I preps?
Dovetails
113
If the dovetail includes B and L grooves, is it considered primary or secondary retention?
Primary
114
If the dovetail is not part of the initial prep design, but instead is part of the extension feature, is it considered primary or secondary retention?
Secondary
115
What should be preserved unless undermined or crossed by a fissure in Class I preps?
Oblique and transverse ridges
116
Why do we direct the bur around cusps in Class I preps?
To conserve tooth structure
Remember we want:
No sharp angles
Gently flowing curves and distinct cavosurface margins (outline form)
117
What is the width in Class I preps?
1/5 to 1/4 (1.0 mm) of intercuspal distance
118
Why is the width of Class I preps 1/5 to 1/4 (1.0 mm) of intercuspal distance?
Conserves tooth structure
Facilitates carving for amalgam restorations
Reduces occlusal interferences
119
How should you center Class I preps?
On central groove (outline form)
120
What should the B to L width be in Class I preps?
No more than 1.0 - 1.5 mm (outline form)
121
What size should marginal ridges be in Class I preps?
1.5 mm (outline form)
122
How should the pulpal floor look in Class I preps?
Pulpal floor is flat and ⟂ to long axis of tooth (resistance form)
123
Why should the pulpal floor be flat and ⟂ to long axis of tooth (resistance form) in Class I preps?
At right angle to direction of occlusal forces
Helps resist fracturing/shearing forces
124
What is an isthmus? How is it created?
Narrow anatomic part/passage connecting 2 larger structures
Created by preparing occlusal width/outline
125
What does the isthmus of a Class I prep contribute to?
Retention and resistance form
126
Where is the isthmus of a Class I prep?
Central portion of prep between M and D-most aspects/dovetails
127
Where is the isthmus of a Class II prep?
Between 2 proximal flares or 1 proximal flare and dovetail
128
How deep should the pulpal floor be in Class I preps?
At least 1.5mm (resistance form)
129
The pulpal floor depth of 1.5mm resists ________ force to prevent _________. It also avoids sensitivity at the _______.
Occlusal; fracturing; DEJ
130
What angle should all cavosurfaces be at in Class I preps?
90 degrees
131
How should all line and point angles look in Class I preps?
Rounded, but defined, to avoid stress concentrations (resistance form)
132
How should B and L walls look in Class I preps?
B and L walls should converge pulpo-occlusally (retention form)
133
Converging B and L walls create an ____ angle with the ____ floor. This provides ____ retention. The degree of convergence should be ____ degrees.
Acute; pulpal; primary; 6
134
How should M and D walls look in Class I preps?
M and D walls should diverge pulpo-occlusally (resistance form)
135
Diverging M and D walls create an ____ angle with the ____ floor. This prevents undermining of the _____ _____.
Obtuse; pulpal; marginal ridge
136
Once you start carving, you _________ add to amalgam
CANNOT
137
If you have a void, fracture, or under-contoured area, you must drill out all amalgam in ________
Clinic
138
If you have a void, fracture, or under-contoured area, you must start a new tooth in _________
Lab
139
What are the causes for amalgam restoration failure?
140
What are the instruments used for amalgam occlusal anatomy?
1. condenser
2. egg burnisher
3. acorn burnisher
4. cleoid/discoid
5. refine with acorn burnisher
141
What is the condenser used for when placing occlusal anatomy in amalgam?
Condenses amalgam into cavity
142
What is the egg burnisher used for when placing occlusal anatomy in amalgam?
Pre-burnishes amalgam, further condenses, and aids marginal adaptation
143
What is the acorn burnisher used for when placing occlusal anatomy in amalgam?
Places initial anatomy
144
What is the cleoid/discoid used for when placing occlusal anatomy in amalgam?
Carves and removes excess amalgam
145
What is the acorn burnisher used for when REFINING occlusal anatomy in amalgam?
Refines anatomy, improves smoothness, produces a satin (not shiny appearance)
Groove pattern can shine, BUT NOT the entire restoration
146
What are the 3 P's of preventing injury?
Postural awareness
Positioning strategies
Periodic stretching and exercise
147
What does postural awareness consist of?
Neutral posture
Increases comfort and productivity
Decreases tension, numbness/tingling, joint discomfort, muscular problems, circulatory problems
Conserves energy
148
What do positioning strategies consist of?
Patient, dentist, lighting, OP setup
149
What does periodic stretching and exercise do?
Reduce fatigue, relieve stress, and increase stamina
150
Definition of musculoskeletal disorders
Soft-tissue injuries caused by sudden or sustained exposure to repetitive motion, force, vibration, and awkward positions
151
What can musculoskeletal disorders affect?
Muscles, nerves, tendons, joints and cartilage in your limbs, neck, and lower back
152
Advantages/disadvantages of lathe-cut alloy
High "positive pack" handling quality ("crunchy") to provide good proximal contacts
Relatively > mercury required
Require early condensation with a small condenser
Irregular in shape, so higher packing forces needed during condensation
Minimal material-related post op sensitivity
153
Advantages/disadvantages of spherical alloy
Lower condensation pressure require to achieve same strength
Larger condenser required
Shorter working time, fast set, and high early strength
No positive pack because they move away from the condenser when packing (tendency to poor contacts and more overhangs because they can slide under the matrix band)
Greater risk of post op sensitivity
Advantage: you could work on the tooth the same day after restoring it with this type of amalgam
154
Advantages/disadvantages of admixed alloy (lathe-cut + spherical combined)
This is the type of amalgam we have!
Combine best of both geometries
High packing pressure with small condensers still required
Positive interproximal contact obtained
Slightly faster setting
Low post op sensitivity
155
Overall disadvantages of alloy
Not esthetic
Low tensile strength in thin sections under masticatory forces
It does not bond to tooth structure
Utilizes mercury
156
What is dental amalgam?
Metallic restorative material composed of a mixture of silver-tin alloy and mercury
157
What does the FDA say results from removing intact amalgam fillings?
Unnecessary loss of healthy tooth structure and a temporary increase in exposure due to additional mercury vapor released during the removal process
158
Has mercury in amalgam been found safe and beneficial as a direct restorative material?
Yes
159
Amalgam is _______ as a _____ lasting restorative material. It is ______ resistant to ______ caries as compared to bonded composite restorations.
Successful; long
More; recurrent
160
Amalgam is ______ for _______ restorations and when subsequent addressing of _______ health is needed before a definitive retoration
Ideal; large; pulpal
161
Amalgam is used as a __________ for badly broken down teeth that need extra ________ and __________ forms in anticipation of crown placement
Foundation/core; retention; resistance
162
Amalgam has ______ mechanical properties such as ________ ________, ________, and _________ __________.
High; compressive strength; rigidity; wear resistance
163
Amalgam has packable insertion to provide ________ proximal contact and intimate cavity adaptation
Positive
164
Amalgam is carvable with _______ instruments after insertion to provide optimal _______, __________, and _________.
Hand; contour; surface; occlusion
165
Amalgam has _____ ______ properties over time.
Self sealing
166
Purpose of reverse S curve
Preserve the cusp and and triangular ridge; forms a 90 degree cavosurface margin that creates a place of limited undermined enamel
167
Where are Class II carious lesions found in relation to contact point?
Located just apical to contact point
168
What is the purpose and functions of matrix bands?
For class II, matrix band replaces the missing proximal wall
169
Why does the wedge slightly separate teeth?
To compensate for the thickness of the matrix band
170
What does the wedge protect?
Gingival tissue/rubber dam during prep
171
What does the wedge seal?
Seals matrix against gingival floor to avoid overhang of amalgam
172
What does the outer nut of the Tofflemire matrix retainer do?
Locks matrix band into retainer
173
What does the inner nut of the Tofflemire matrix retainer do?
Adjusts size of matrix band
174
What does the slotted guide of the Tofflemire matrix retainer do?
Holds the matrix band in place
175
The Tofflemire matrix retainer should be _______ to the arch
parallel
176
What is self assessment?
Learning process
More than recalling info
Assists in making individuals more aware/responsible of their own learning
177
When does self assessment occur?
178
What is the sequence of use when polishing amalgam restorations?
1.Brownie polisher = achieves smooth surface (pre-polish)
2. Greenie polisher = creates lustrous polish
3. Supergreenie polisher = creates high polish
179
What does finishing a restoration mean?
Process of removing surface defects/scratches created during contouring process through use of cutting or grinding instruments (or both)
180
What does polishing a restoration mean?
Most refined of the finishing processes; removes finest surface particle
Production of shiny mirror like surface, which reflects light similar to enamel
181
How do you cause mercury to rise to the surface of an amalgam restoration?
During polishing, heat is created
Heat brings mercury to the surface of the restoration, which results in a dull, cloudy surface, and a surface that is more susceptible to corrosion
182
How long should you wait before finishing and polishing amalgam restorations?
At least 24 hours after it has been placed and carved
183
What is required for the development of caries?
Primary modifying factors (like tooth anatomy, saliva, pH) + secondary modifying factors (education, socio-economic status, age) + host + cariogenic biofilm + time + fermentable carbohydrates = caries
184
What bacteria is responsible for caries formation?
Streptococcus mutans
