Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

D1 Pres/Res I > Quiz 2 > Flashcards

Quiz 2 Flashcards

1
Q

What are caries?

A

infectious microbial disease that results in localized destruction of calcified structures of teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the three primary etiologic factors of caries?

A
  1. Agent
    1. Acid producing bacteria - pH 5.5
  2. Environment
    1. Carbohydrate rich diet
  3. Host
    1. Susceptible tooth structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Besides Agent, Environment and host etiological factors for caries. What are other additional etiologic factors?

A
  • Time:
    • Demineralization (and subsequent cavitation) and remineralization
    • can be stopped or reversed
  • Fluoride:
    • In solution - can facilitate the arrest of lesion or aid in remineralization (“repair”
  • Saliva:
    • Protective mechanism
      • Promote bacterial clearance
      • Direct antimicrobial activity
      • Capacity as a buffer
      • Remineralization
    • Saliva can dramatically alter the oral ecosystem
    • Lower salivary quality and or quantity (xerostomia=dry mouth) typically have increased caries rate
  • Social and demographic factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain the salivary protective mechanisms against caries

A

Protective mechanism

  • Promote bacterial clearance
  • Direct antimicrobial activity
  • Capacity as a buffer
  • Remineralization

Saliva can dramatically alter the oral ecosystem

Lower salivary quality and or quantity (xerostomia=dry mouth) typically have increased caries rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the primary organism in caries initiation for enamel lesions and operates in concert with Actinomyces to initiate root surface lesions

**Also this organism is still regarded as the primary organism in root caries initiation

A

Streptococcus Mutans

Because they produce substances with which they can readily adhere to the tooth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What organism flourishes in a carious environment and contributes to caries progression

A

Lactobacillus Acidophilus

Because they are good acid producers and are acid loving

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the common sites of origin for caries?

A
  1. Pit and Fissure enamel surfaces
    1. Most likely to exhibit signs caries due to surface irregularities
      1. Area can harbor plaque
  2. Smooth enamel surfaces
    1. Proximal surfaces have a higher incidence than other smooth surfaces
      1. Nonself-cleaning areas
  3. Root surfaces
    1. Most susceptible surface to the carious process
    2. Typically requires recession of gingival tissue (surface exposure)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the common methods for overall Caries detection?

A

Teeth must (should) be both clean and dry for clinical detection

(Remove saliva and improved visibility of incipient lesion)

Radiographs: Proximal, Occlusal and Secondary/recurrent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the best ways for pit and fissure lesion caries detection?

A

visual inspection (best method)

BW radiographs

Tactile examination (explorer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the best ways for Proximal surface lesion caries detection?

A

Bw radiograph (most accurate in posterior teeth)

Anterior teeth (periapical radiograph, fiber optic transilumination)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the best ways forSmooth surface lesion caries detection?

A

Generally can be visually inspected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are other detection methods for caries other than visual inspection, radiographs and exploring?

A

Optical

Using a light to determine tooth structure destruction

Can get “false positives” due to stain or calculus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Who was the father of modern dentistry that developed a caries classification system based on anatomical areas involved and associated type of treatment that we still use today?

A

G.V. Black

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What classification regards caries that affects the pit and fissure, on occlusal, buccal, and lingual surfaces of posterior teeth and lingual of anterior teeth?

A

Class I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the classification regarding caries that affect proximal surfaces of molars and premolars (posterior only)

A

Class II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the classification regarding caries that affect proximal surfaces of central incisors, lateral incisors and cuspids not involving the incisal edge

A

Class III

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the classification regarding caries that affects the proximal including incisal edge of anterior teeth

A

Class IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the classification regarding caries that affect gingival 1/3 of facial or lingual surfaces of anterior and posterior teeth

A

Class V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the classification regarding caries that affect cusp tips of molars, premolars and cuspids (posterior or anterior canines)

A

Class VI

Infrequent, but do see it sometimes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the classification system regarding the number of surfaces involved?

A

simple = 1 surface

Compound = 2 surfaces

Complex = > 3 surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the type of surfaces involved classification system

A

smooth surface = sides of teeth

Pit and fissure = occlusal surfaced, grooves and pits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the definition of tooth preparation

A

The mechanical alteration of a tooth to receive a restorative material which will return the tooth to proper form, function, and esthetics

Achieving proper outline form for any tooth preparation significantly increases restoration longevity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the types of walls in cavity preparation and where are they located

A
  1. external = outer tooth surface
  2. internal = inside cavity prep
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What a mesial, buccal, distal or lingual wall is missing what replaces it?

A

When a mesial, buccal, distal or lingual wall is missing, a gingival wall (floor or seat) replaces it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

When would the terminology “FLOOR OR SEAT” be used in a cavity preparation

A

In a horizontal plane

Pulpal (floor) - class I usually

gingival - class II, III, IV, V only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What type of class preparation is the following?

A

Class I preparation

pit/fissure prep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What type of class preparation is this cavity restoration?

A

Class V

gingival 1/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Explain the types of external walls in a cavity preparation

A

Buccal

Distal

Mesial

Lingual

***Gingival* (if one of the above walls is missing - same as the floor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Explain the types of internal walls in a cavity preparation

A

Axial - parallels long axis, vertical plane of tooth adjacent to pulp

Pulpal - perpendicular to the long axis of the tooth closest to the pulp in horizontal plane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the junction of two walls called?

A

Line angle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the junction of three walls called?

A

point angle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the junction of a cavity wall and the external tooth surface called?

A

Margin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the angle of the tooth structure formed by the junction of a prepared wall and the external surface of the tooth called (alternate name)

A

cavosurface angle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the process of placing the cavity margins (cavosurface) in the position on a tooth they will occupy in the completed preparation

A

Outline form

Should be visualized before any tooth reduction occurs

“measure twice, cut once”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the major factors that influence outline form

A
  1. Location of the carious lesion
  2. Size of the carious lesion
    1. Primary determinant = lateral spread to dentin layer occurs very quickly
  3. Tooth anatomy
    1. ex. pit, fissures, developmental defects, decalcified areas
  4. Type of restorative material
  5. Esthetics
  6. Positioning of adjacent structures (teeth, gingiva)
  7. Functional requirements
  8. Retentive factors (ex. dovetails)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the name for the shape and placement of the preparation walls that best enable both the restoration and the tooth to withstand, without fracture, masticatory forces delivered principally in the long axis of the tooth

A

RESISTANCE FORM

Helps maintain function and to last

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the descriptions that relate to resistance form of a cavity preparation

A
  1. Flat floors/walls that are perpendicular to masticatory forces
    1. Pulpal and/or gingival floors
  2. Restriction of preparation extension to allow strong cuspal or marginal ridges
    1. Ex. conservation of unaffected tooth structure
  3. Inclusion of weakened tooth structure in the preparation design to prevent tooth fracture
    1. ex. capping a compromised cusp
  4. Proper consideration of restorative materials
    1. Ex. amalgam should have 90 deg cavosurface angles, rounded internal line angles, adequate pulpal depth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the terminology for the shape or form of the preparation that resists displacement or removal of the restoration form tipping/lifting forces

A

Retention form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the main features of retention form that help strengthen the design

A
  1. Dovetails
    1. Proper positioning maintains width and strength of marginal ridges
  2. Convergent walls
  3. Grooves
  4. Pins (only used in preparations that are larger than idea)
  5. Frictional resistance of walls (nearly parallel, vertical or minimally tapered)
  6. Acid etch with bonding system
  7. Mutually divergent rounded areas (composite resin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Explain the idea of Dovetails retention form

A

Proper positioning maintains width and strength of marginal ridges

Provides retention to the restoration

(little C shape up thingy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Explain the idea of convergent walls in retention form

A

occlusal convergence = “convergence”

Whereas you go from pulpal floor to cavosurface margin, walls become closer together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What type of cavity preparation is this?

A

Class II

Proximal surfaces preparation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Explain grooves retention form technique

A
44
Q

Explain the terminology for the shape or form of the preparation that provides for adequate observation, accessibility, and ease of operation in preparing and restoring the tooth

A

Convenience form

45
Q

What are the factors that influence convenience form?

A

Factors that influence:

  1. Extension of the preparation
  2. Changing the direction of approach
  3. Changing the instrumentation utilized

Inadequate convenience form prevents properly instrumentation

** want to be as conservative as possible

46
Q

What is the terminology for the excavation of any infectious structure still remaining after the basic cavity design has been completed

A

Removal of remaining carious dentin

47
Q

What is it called when dentin penetration by carious process 0.5 mm or less?

A

incipient lesion

48
Q

What is it called when >0.5 mm of dentin penetration by the carious process

A

extensive lesion

49
Q

Explain the “ideal preparation”

A

Depth is 0.5 mm inside the DEJ after sets I, II, and III have been completed

  • With inception lesion, Black’s step IV does not apply
  • With Extensive lesions where steps I, II, and III have been performed to 0.5 mm inside the DEJ and caries remains in the deeper aspects of the tooth
50
Q

What is the step/terminology that involves smoothing and refining the walls of the cavity preparation as well as the cavosurface angle?

A

V. Finishing enamel walls

51
Q

What is the purpose of finishing preparation walls?

A
  • To effect a good marginal seal between the restorative material and the tooth
  • To affect a good marginal junction
    • Less noticeable to the patient
    • Facilitate cleaning (less plaque retentive)
  • To provide maximum strength to restorative material and tooth at the margin
52
Q

What are the factors to consider during wall finishing

A
  • Direction fo enamel rods
  • Dentinal support for enamel rods
  • Restorative material to be used
  • Location of preparation margins on tooth
53
Q

Explain the location of the enamel rods in the fissured surfaces (ie. occlusal)

A
  • Rods converge from DEJ to surface in areas of pits and groves
  • Rods diverge from DEJ to surfaces in areas of cusps and ridges
54
Q

Explain the location of the enamel rods on smooth surfaces (proximal, facial, and lingual surfaces)

A
  • Roughly perpendicular to long axis of the tooth in the middle 1/3
  • Incline occlusally in the occlusal 1/3
  • Incline gingivally in the gingival 1/3
55
Q

Explain the idea of finishing enamel walls - enamel support

A
  • Rods that form the cavosurface have their inner ends resting on sound dentin.
    • Full-length rods from DEJ to cavosurface are preferred
  • Full-length rods receive support form:
    • DEJ
    • By shorter rods that were cut, yet whose inner ends are resting on dentin
56
Q

Which of the following is the correct method of finishing enamel walls and which one is not

A
57
Q

Explain the final step in cavity preparation

A

VI. Cleansing and preparation

  • Removing all debris from the cavity prepartion
  • Followed by drying and inspecting for any remaining weakened structure (both carious dentin and unsupported enamel
58
Q

What is force and how is it defined?

A

Force = generated by one body pushing or pulling on another

  • Defined by:
    • Point of application
    • Magnitude
    • Direction of application
59
Q

Explain the details of occlusal forces as well as the loads during chewing

A

Biting force decreases from the molar region to the incisors

Normal chewing => usually < 10 N

Axial and horizontal loads are produced during chewing Axial > horizontal

60
Q

Explain the details of a stress-strain curve

A

Stress (force/area)

Change in length

***NOTE: INDEPENDENT OF GEOMETRY***

Stress = newton/meter ^2 = Pa

61
Q

Explain the types of stress that can occur

A
  • Axial (tensile) = elongation
  • Axial (compression) = shrinkage
  • Shear = opposing shear forces over plane
  • Twisting moment = torsion
  • Bending moment = bending
62
Q

Explain where stresses are experienced in the mouth, for example in a bridge

A
63
Q

Explain the details of strain

A

Change in length per unit length of body when subjected to a stress

64
Q

Explain the details of a stress-strain curve

A

Elastic = bounces back (straight line)

Plastic = permentent deformation

65
Q

Explain the concept of the elastic limit in a stress-strain curve

What is another name for this?

A

Maximum stress that a material will withstand without permanent deformation (looks specifically at the material to determine change)

PROPORTIONAL LIMIT (looks at the graph to determine change)

66
Q

Explain the concept of yield strength (such as a 0.2% offset)

A

The stress value at which a material exhibits a specified permanent strain

67
Q

Explain the concept of ultimate tensile strength

A

The maximum stress that a material can withstand before failure in tension

(strongest = cobalt-chrome alloys

Weakest = porcelains (strong in compression though)

68
Q

Explain fracture strength

A

the stress at which a material fractures

Not necessarily equal to ultimate strength

69
Q

Explain the elastic modulus of a material

A

Represents the stiffness within the elastic range

E = stress/strain

More verticle = stiffer (cobalt - chrome partial denture)

More horizontal = more flexible (silicone rubber = impression material)

70
Q

What are examples of brittle dental materials (in general)

A

Amalgam

Composites

Cements

Ceramics

71
Q

What is the ability of a material to be plastically deformed?

A

Ductility

Gold = more ductile

Lead = more brittle

72
Q

What is it when there is closing the metal margin of a metal crown

Recovery of elastic strain but not of plastic strain

A

Burnishing

**always have elastic deformation then go over to plastic to permanently deform

73
Q

What is the term describing the resistance of a material to permanent deformation

Important in orthodontic wire

A

Resiliency

Area under the straight portion of the curve

Maybe thought of as energy absorbed per volume of material

74
Q

What is the term for the resistance of a material to fracture?

A

toughness

area under entire curve

Also thought of as energy absorbed per volume of material

75
Q

Describe the following curves

A
76
Q

Describe the following curves

A
77
Q

What is the term for the maximum stress that a material can withstand before failure in compression?

A

Ultimate compressive strength

Amalgam = high compressive strength (posterior use)

Glass Ionomer (Fuji II - temporary fillings) = Low compressive strength, fill closer to gum line

78
Q

What is the impact strength

A

The energy required to fracture a material under an impact force

Popular for comparison of denture base material

**Charpy Impact Tester

79
Q

What test is used for testing brittle materials to obtain a tensile strength. AKA indirect tensile test

A

Diametral compression test

Not valid if the material deforms significantly before failure

80
Q

What is shear strength?

A

The maximum stress that a material can withstand before failure in shear mode.

Used frequently in bond strength testing

  • Porcelain/metal interface
  • Interface between tooth and orthodontic brackets, composed resins and adhesives
81
Q

What is the test commonly used for testing adhesives?

A

Microtensile bond strength

Alternative to shear bond test

Very small sample testing

82
Q

Explain the concept of bending and the types of bending

A

-> compression <-

Neutral axis

<- Tensile ->

Pure bending = direct (perpendicular force)

Transverse bending = force directly from top

83
Q

Explain the concept of bending moment

A

Bending Moment = Force x Length = F x L = FL

**DEPENDANT ON SHAPE!!**

Not divided by L/Lo

84
Q

Explain Flexural strength

A

Also called transverse strength

3 point bending test

Dental relevance:

  • Denture base materials
  • Long bridge spans
85
Q

Describe the process of torsion

A

Twisting

Maximum shear stress on the outside

Torsional moment = shear force x radius

**Not normalized for area

  • Dental application
    • Endodontic files
    • Reamers
86
Q

What is a progressive fracture under repeated loading

A

Fatigue

Failure occurs below the single load strength (static)

Failure typically due to crack propagation

S/N Plot show stress vs. cycles to failure

87
Q

What are the factors affecting fatigue?

A
  • Environmental agents
  • Surface features
    • Smooth (higher failure stress) vs. rough
  • Material history
88
Q

What is a measure of a material’s resistance to brittle fracture when a crack is present?

A

Fracture Toughness (Kic)

Useful for brittle material because failure is frequently flaw dependent (crack propagation)

Metals = highest Kic

GI cements = low Kic

89
Q

What is the definition of viscoelasticity

A

Having appreciable and conjoint viscous and elastic properties

Behavior is intermediate between that of elastic solid and a viscous liquid

**Silly Puddy**

Important in impression material and other polymer-based materials (dependant on time)

90
Q

What is a time-dependent plastic strain of a material under a static load or constant stress (even if below elastic limit)

A

CREEP

Occurs in materials at temperatures above 1/2 melting temperature

91
Q

What is the reduction in stress in a material subjected to constant strain?

A

Stress relaxation

Useful in evaluating orthodontic modules or chains

92
Q

What is the resistance to permanent surface indentation?

What are the tests for this, name and describe

A

Hardness

Dental Importance:

  • Some (not direct) relation to wear
  • Affects ability to finish or polish a material
  • Gives indication to resistance to in-service scratches (decreasing fatigue strength)

Tests:

  • Brinell
    • Metals Only. Micro test = ball indenter
  • Rockwell
    • Metals and plastics. Ball or cone indenter. find depth
  • Vickers
    • Metals and plastics. Micro test. Pyramid indenter
  • Knoop
    • Variety of materials. Rhombic-based pyramid diamond
  • Barcol
    • Dental materials app. measuring resin composites
  • Shore
    • Used for rubber (denture liners and mouth protectors)
93
Q

What is a loss of material resulting from removal and relocation of material through the contract of two or more materials?

A

Wear

Grinding teeth

94
Q

What is it when two body surfaces rub together called

A

Abrasive wear

Two-body

Harder surface = indents

Softer material = cut away

Tooth/tooth contact

95
Q

What is it when two body surfaces rub together and there is another object between them called

A

Abrasive wear

Three-body

Food or toothpaste between teeth

96
Q

What is it when wear coupled with a chemical attack called?

A

CORROSIVE WEAR

  • Issue especially in posterior restorations
    • Hydrolytic breakdown of the resin
    • Breakdown of the resin/filler interface
    • Erosion of the surface from acids
97
Q

Explain the study of the flow of matter

A

Rheology

Viscosity: Fluid’s resistance to flow

Units: poise = pascal x second

High viscosity = flows slowly

98
Q

For liquids that do not set, how does their viscosity relate?

A

Viscosity decreases with increasing temperature and is independent of time

99
Q

For liquids that do set, how does their viscosity relate?

A

Viscosity increases with increasing temperature and also increases with time

100
Q

Explain viscosity on a shear stress vs. shear strain rate graph

A

Slope = visocisity

101
Q

Explain a Newtonian fluid viscosity curve

A

constant straight line

water

some dental cement and impression materials

102
Q

Explain a plastic fluid viscosity curve

A

No flow until a certain shear stress is reached (ex. tooth paste)

103
Q

Explain a pseudoplastic fluid viscosity curve

A

Decreasing viscosity as shear rate increases

104
Q

Explain a Dilatant fluid viscosity curve

A

Viscosity increases with shear rate

Corn starch and water

105
Q

Explain a Thixotropic fluid viscosity curve

A
  1. time dependence decrease in viscosity
  2. Yield point similar to plastic
  3. Not reversible shear stress/strain rate

Example = ketchup bottle

D1 Pres/Res I (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions