General Operative Info Flashcards
What is not true about enamel?
a. Enamel rods are largest at the DEJ and smallest at the external tooth surface
b. Enamel solubility increases closer to the DEJ
c. Enamel tufts are hypomineralized
d. Enamel has high strength but is very brittle
e. All of the above are true
a. Enamel rods are largest at the DEJ and smallest at the external tooth surface
What is a smear layer?
a. The surface of enamel when it is cut
b. The initial layer of liner placed to reduce tooth sensitivity
c. The surface of dentin when it is cut
d. A defect caused by amelogenesis imperfecta
e. A distinct layer found in the DEJ
c. The surface of dentin when it is cut
Which structure does this define: gray in color, shiny, semi-translucent?
a. Dentin
b. Pulp
c. Cementum
d. Alveolar bone
e. None of the above
e. None of the above (it is enamel)
Tooth preparations work to repair damage while preserving tooth vitality. They are also designed to prevent tooth fracture.
a. Both statements are false
b. The first statement is true, the second statement is false
c. The first statement is false, the second statement is true
d. Both statements are true
d. Both statements are true
- Below what distance is it acceptable to connect two separate preparations together?
a. 0 mm - never connect preparations
b. 0.5 mm
c. 0.75 mm
d. 1 mm
e. 2 mm
b. 0.5 mm
- _______ caries are characterized as slow-growing and dark in color.
a. Root
b. Chronic
c. Acute
d. Smooth surface
e. Incipient
b. Chronic
- A Class II preparation (MO) on number 30 would be classified as a(n):
a. Simple preparation
b. Elongated preparation
c. Compound preparation
d. Extensive preparation
e. Complex preparation
c. Compound preparation
The _________ is parallel to the long axis of the tooth, while the _________ is perpendicular to the long axis of the tooth.
a. Axial wall, pulpal floor
b. Gingival floor, pulpal floor
c. Axial wall, lingual wall
d. Gingival wall, axial wall
e. Buccal wall, lingual wall
a. Axial wall, pulpal floor
True/False: the axiopulpal line angle, found in Class II preparations, is an internal line angle.
a. True
b. False
b. False
A Class V preparation is a smooth surface preparation on the gingival third of a buccal surface. A buccal pit is an example of a Class V preparation.
a. Both statements are true.
b. Both statements are false.
c. The first statement is true, the second statement is false.
d. The first statement is false, the second statement is true.
c. The first statement is true, the second statement is false.
What is not important when forming an amalgam preparation?
a. Having a smooth and flowing outline
b. Conserving cusps and ridges to maintain resistance
c. Creating converging walls to maintain retention
d. Placing the restoration in a location that is easily accessible
e. All of the above are important in forming a preparation
e. All of the above are important in forming a preparation
What features of an amalgam preparation will prevent rotation of the restoration?
a. Preserving marginal ridges
b. Sharp line angles
c. A flat pulpal floor
d. Smooth and flowing outline
e. Easy access to the preparation
c. A flat pulpal floor
What is true regarding enameloplasty?
a. No more than 1⁄2 of enamel thickness should be removed
b. Carbide burs are primarily used
c. Deep pits are destroyed to prevent decay
d. It causes pain to the patient, so anesthetics are used
e. None of the above are true
c. Deep pits are destroyed to prevent decay
In a buccal pit preparation, which wall/portion is not
converging?
a. Gingival wall
b. Axial wall
c. Mesial wall
d. Distal wall
e. Apex
e. Apex
When is an amalgam restoration contraindicated?
a. A patient with heavy occlusal wear
b. A patient who has never had caries, yet present with a small pit/fissure lesion
c. A patient with a Class V preparation on her mandibular second molar
d. A patient who has a large lesion on a tooth that might need to be removed
e. Amalgam can be used on any of these patients
b. A patient who has never had caries, yet present with a small pit/fissure lesion
True/False: if a Class V preparation needs to go interproximally, enamel should beremoved with a round bur, then undermined enamel should be removed with a gingival margin trimmer.
a. True
b. False
a. True
In a Class I preparation, diverging walls should be at an angulation of 5-8 ̊. When a wall is not diverging, it should be parallel to the long axis of the tooth.
a. Both statements are true
b. The first statement is true, the second statement is false
c. Both statements are false
d. The first statement is false, the second statement is true
c. Both statements are false
Why is sharpening instruments important for tooth preparations?
a. Sharp instruments require more pressure to use
b. Dull instruments have less control
c. Sharp instruments cause less pain
d. A and B
e. B and C
e. B and C
A specific hatchet has the following Instrument formula: 12 - 75 - 10 - 60. The cutting
edge is ____ wide and the blade angulation is ___ of 360 ̊, in relation to the long axis of
the handle.
a. 12 mm, 75%
b. 1.2 mm, 60%
c. 12 mm, 10%
d. 1 mm, 60%
e. 1 mm, 75%
b. 1.2 mm, 60%
The cutting edge of a cutting instrument is similar to the face of a non-cutting instrument, just as the
blade of a cutting instrument is similar to the ______ of a non-cutting instrument.
a. Nib
b. Blade
c. Shank
d. Handle
e. Edge
a. Nib
What is true regarding sterilization of instruments?
a. The only time an instrument needs to be sterilized when sharpened is immediately before sharpening
b. Chemiclave systems require proper ventilation
c. Autoclaves use dry heat to rid instruments of microbes
d. A and B
e. All of the above
b. Chemiclave systems require proper ventilation
What is the most common type of caries?
a. Smooth surface
b. Root
c. Recurrent
d. Pit/Fissure
e. Incipient
d. Pit/Fissure
Class I lesions are best detected by ________. Class II lesions are best detected by ________.
a. Periapical radiographs, bitewing radiographs
b. Visual-tactile examination, periapical radiographs
c. Bitewing radiographs for both
d. Visual-tactile examination, bitewing radiographs
e. Visual-tactile examination for both
d. Visual-tactile examination, bitewing radiographs
When present, which type of lesion is the best indicator of a person with a high caries rate?
a. Class I
b. Class II
c. Class IV
d. Class V
e. Class VI
d. Class V
What is the role of saliva in caries prevention?
a. Uses CaOH as a buffer to raise pH
b. Strengthens enamel rods
c. Creates a barrier over pits and fissures, preventing the collection of sugars
d. Flushes out bacteria and food debris from the oral cavity
e. None of the above
d. Flushes out bacteria and food debris from the oral cavity
Which oral bacteria is cariogenic, but usually inhibits the growth of S. mutans?
a. Streptococcus mitis
b. Streptococcus sanguis
c. Lactobacillus acidophilus
d. Bacteroides melaninogenicus
e. Streptococcus inhibans
a. Streptococcus mitis
High amounts of _______ in pits and fissures cause caries in 6 to 24 months.
a. Carbohydrates
b. Sealants
c. S. mutans
d. Amalgam
e. Saliva
c. S. mutans
Both enamel and dentin will demineralize at a pH of 5.4. After each exposure to carbs, the pH can remain low for up to one hour.
a. Both statements are true
b. The first statement is true, the second statement is false
c. Both statements are false
d. The first statement is false, the second statement is true
a. Both statements are true
What is true about both liners and bases?
a. They stimulate reparative dentin
b. They can only be placed in the center of preparations
c. They can release fluoride
d. They seal dentin tubules
e. They are used in preparations of any depth
b. They can only be placed in the center of preparations
The axial wall of a Class II preparation should be:
a. Concave and parallel to the long axis of the tooth
b. Concave and perpendicular to the long axis of the tooth
c. Flat and parallel to the long axis of the tooth
d. Convex and perpendicular to the long axis of the tooth
e. Convex and parallel to the long axis of the tooth
e. Convex and parallel to the long axis of the tooth
What is the purpose of the Reverse S-curve in a Class II preparation?
a. Keeps the narrow isthmus away from the axiopulpal line angle
b. Allows the preparation to break buccal contact
c. Creates a smooth and rounded outline
d. Allows the buccal wall to be 90 ̊ to the cavosurface margin
e. All of the above
e. All of the above
Which of the following is not true regarding dental biomaterials?
a. Drugs used in dental procedures are not considered biomaterials
b. An allergic reaction falls under a biological response to a biomaterial c. Physical properties depend on the size and shape of the material
d. Biomaterials are classified by their biological, surface, physical, and mechanical properties
e. All of the above are true
c. Physical properties depend on the size and shape of the material
The greatest strength of dental materials is usually _______ strength, while the weakest strength is ________ strength.
a. Tensile, shear
b. Compressive, tensile
c. Shear, torsion
d. Compressive, flexural
e. Flexural, tensile
b. Compressive, tensile
Does premature occlusal contact increase or decrease stress on the tooth, and why?
a. Increase, because the bite force will be greater during premature contact
b. Decrease, because the bite force does not change during premature contact
c. Increase, because the surface area contacted is smaller
d. Decrease, because the surface area contacted is smaller
e. Premature occlusal contact has no effect on stress
c. Increase, because the surface area contacted is smaller
What type of stress is measured using a 3-point test?
a. Compressive
b. Tensile
c. Torsion
d. Flexural
e. Shear
d. Flexural
True/False: energy absorbed during elastic strain only is resilience, while energy absorbed during plastic strain only is toughness.
a. True
b. False
b. False
Which added element helps prevent expansion of amalgam?
a. Zinc
b. Silver
c. Tin
d. Copper
e. Palladium
a. Zinc
The order of needed compression force for amalgams, from highest to lowest, is:
a. Lathe > admixed > spherical
b. Spherical > admixed > lathe
c. Lathe > spherical admixed
d. Spherical > lathe > admixed
e. Admixed > lathe > spherical
a. Lathe > admixed > spherical
Which compound, when present in amalgam, causes weakness and corrosion?
a. Gamma (Ag3Sn)
b. Gamma-1 (Ag2Hg3)
c. Gamma-2 (Sn7Hg)
d. Eta (Cu6Sn5)
e. AgCu
c. Gamma-2 (Sn7Hg)
Which of the following will increase the strength of amalgam?
a. Mercury content above 55%
b. Trituration for 1 minute
c. High copper content
d. Waiting 10 minutes between trituration and condensation to mature the amalgam
e. Leaving residual mercury in the restoration
c. High copper content
Which of the following describes amalgam restorations compared to composite restorations?
a. Less recurrent decay
b. Moisture sensitive
c. Lasts for a longer time
d. A and C
e. All of the above
d. A and C
True/False: tarnishing and corrosion of amalgam changes the amount of material in a preparation
a. True
b. False
a. True
What is not a cause of bulk fracture in an amalgam restoration?
a. Improper trituration
b. Premature occlusal contact
c. Improper handling/condensation
d. Fatigue of the material
e. All of the above cause bulk fracture
e. All of the above cause bulk fracture
Color of enamel is a ________ property
physical
What is conservative dentistry?
dentists formally practiced “extension for prevention” but now we use better preventative measures to conserve tooth structure
What is the definition of convergence?
the angle between two opposing axial walls of a preparation and equals the sum of the taper of two opposing axial walls
- Walls slant toward each other
- Especially important with amalgam
What is the dovetail definition?
A cavity whose shape is flared, created to provide a retentive lock for a direct or indirect restoration
- Prevents tipping and proximal displacement
What is the class II outline form?
axial wall depth 0.2-0.8mm into dentin
Tooth preparation terminology: how many walls is compound?
compound = two surfaces
Two surfaces affected on a Maxillary Molar, with the occlusal surface and lingual pit affected. What is this considered a class?
Class 1?
What layer do you place the retention groove?
Retention grooves placed in dentin, just inside the DEJ
What bur does a rounded line angle?
56 or 169
What Burr does the internal line angle?
245
What is a liner made of?
Calcium hydroxide
What is the AP line angle?
beveled and 90 degrees
Flexure strength: responds to ______ force
bending
Does a liner contribute to fluoride (something like that)?
No
What does a liner do?
Stimulates reparative dentin formation
Example of a condensing instrument
amalgam condensers are NOT CUTTING INSTRUMENTS
What bur would you use to do a AP line angle? And what does this contribute to?
beveled using 56 or 169
- resistance
Can amalgam withstand high tensile stress?
No
What is the orange part of the prep?
axial wall
What is the arrow pointing to?
gingival floor/wall
What does alp stand for?
axiopulpal line angle
Unsupported enamel should be removed from the preparation because they are…
brittle and fracture easily
When is reparative/tertiary dentin formed?
in response to a moderate irritant
Where is a class V amalgam placed?
restores caries on gingival 1/3rd of the buccal and lingual surfaces of teeth
What is the definition of biomaterials?
any substance (other than a drug) exposed to patients that is used to treat, augment, or replace any tissue, organ, or function of the body
a. All dental materials exposed to patients are biomaterials
Why do you have to do a box on a class II amalgam prep?
Caries attach to the contact area (why you have to break contact)
How many isthmus does a class II prep have on a mandibular 1st molar?
3 isthmus
What is the purpose of the reverse S curve?
It allows the preparation to break contact on the buccal side of the box, but also allows the buccal wall to meet the tooth surface at a 90 degree cavo-surface angle
ADV of box prep…
preserves tooth structure
What is the best material/geometry for amalgam strength?
High Cu (copper) Spherical – least corrosion
What is the area under the full curve? What does it refer to?
Toughness – energy absorbed to cause fracture
a. Area under both the elastic and plastic portion of stress-strain diagram
Plastic strain definition
permanent distortion of a material by an applied force/load
Occlusal amalgam depth…
0.2mm inside DEJ; molars =2mm, premolars= 1.5-2mm
Path of entry on #28 (mandibular 1st premolar) is the exception why?
parallel to the long axis of the crown instead of the tooth
What are the disadvantages of amalgam?
eventually may “ditch” at the margins, collecting plaque there
What is the definition of secondary retention?
places via retention grooves and points for restoration materials to stick better
a. Places in dentin just outside DEJ
Bucco-lingual longitudinal section: walls at the terminal ends of the buccal and lingual grooves diverge ____ degrees
3 degrees
- walls in the isthmus areas converge 3 degrees on each side of the prep and isthmus width is 1mm
Retention form definition
refers to what holds a restoration in a tooth
Resistance form definition
elements in the design of a tooth preparation that will help both the restoration and the tooth from resisting fracturing
a. Rounding internal line angles on a prep makes the tooth less likely to fracture
A class I prep (pit and fissure) amalgam because it occurs…
in the occlusal 2/3rd of a molar tooth and restores a developmental pit
Galvanic corrosion vs. galvanic shock vs. crevice corrosion
a. Galvanic corrosion – dissimilar metal restorations contacting each other; amalgam; LOSES material
b. Galvanic shock – electrical potential between dissimilar metals; results in PAIN but resolves over time; TARNISH DEVELOPS
c. Crevice corrosion – occurs at margins of amalgam restoration; DECREASES MICROLEAKAGE
Tarnish vs. Corrosion:
a. Tarnish: formation of a surface layer; GAIN OF MATERIAL
b. Corrosion: deterioration of metal by reaction with the environment; LOSS OF MATERIAL
What are the Goals of ergonomics?
prevent work-related musculoskeletal disorders (MSDs)
What is the defintion of musculoskeletal disorders (MSDs)?
include a group of conditions that involve nerves, tendons, muscles, and supporting structures such as intervertebral disks
What is the main cause of MSDs?
Cumulative trauma disorders
What are the 3 p’s to fitness?
Posture, positioning, periodic stretching
Something about brain-derived neurotropic factor? I think it was a true/false question like “first part true, second part false” or something like that. I think it was the definition and cause or something.
?????
Clinical failures occur as a result of what?
Most often operator error – bulk fractures
Outline form definition
traditional teaching; states that the preparation must not terminate in the bottom of a fissured pit or groove
GV Black Prep Classification – Identifying Prep Classes
Class I
◦ Occlusal surface of posterior teeth
◦ May include lingual/buccal grooves and pits
Class II
◦ Proximal surfaces of premolars and molars
Class III
◦ Proximal surfaces of incisors and canines
Class IV
◦ (See Class III, add incisal edge)
Class V
◦ Gingival 1/3 of smooth surfaces
◦ Buccal, lingual
Class VI
◦ Incisal edge or cusp
Axiopulpal line angle on Class II is…. How many degrees? Rounded? Beveled?
Degrees - 45%
Rounded - Yep
Beveled - Yep, convex
Something about bulk amalgam fracture
High compressive strength and low tensile strength
Brittle in small bulk
i. Requires minimal thickness of material to avoid breaking
The final stress point, where a material will fracture, is known as
its:
a. Strength
b. Elastic modulus
c. Resilience
d. Toughness
e. Fracture point
a. Strength
The elastic limit delineates the transition from elastic strain to plastic strain. Brittleness a property caused by a lack of elastic deformation.
a. Both statements are true
b. The first statement is false, the second statement is true.
c. The first statement is true, the second statement is false.
d. Both statements are false
c. The first statement is true, the second statement is false.
