Comprehensive Exam Material Flashcards
When do we use an S curve?
In class II prep
Purpose of an S curve:
- keeps the narrow isthmus away from the axiopulpal line angle
- allows the preparation to break buccal contact
- creates a smooth and rounded outline
- allows the buccal wall to be 90 degrees to the cavosurface margin
Exposes the ends of enamel rods for a strong bond and gives a better seal
gingival bevel
Why do we place a gingival bevel?
exposes ends of enamel rods for stronger bond and better seal
Where do we place a gingival bevel?
at axiopulpal line angle
When we place the gingival bevel at the axiopulpal line angle, this allows for:
increased resistance to fracture of isthmus of restoration
What is the most common cause of fracture at the isthmus of a class II?
Lack of gingival bevel
When and why would we extend margins of the box portion of preparation?
Sharp axiopulpal line angle (this is why we bevel it)
Appropriate exit angles of buccal, lingual, and gingival walls of amalgam:
90 degrees on all
Appropriate exit angles of buccal, lingual, and gingival walls of composite:
buccal & lingual- flare greater than 90 degrees
gingival- 90 degrees
when would you not need to place a gingival bevel?
once you get into deeper preparations when enamel is extremely thin or you’re into dentin or cementum (bc no enamel rods are present here)
Where do you place retention grooves in a box?
-buccal-axial line angle and lingual-axial line angle
- just inside the DEJ, entirely in dentin
When placing a retention groove into a box, the groove does not go into the:
gingival floor
Label this photo:
A: gingival-axial line angle
B: buccal-gingival line angle
C: buccal-gingival axial point angle
D: buccal axial line angle (w/optional retention groove)
E: axiopulpal line angle
F: lingual-axial line angle (w/optional retention groove)
G: lingual-gingival axial point angle
H: lingual-gingival line angle
List the advantages of composite resin: (6)
- esthetics
- conservation of tooth structure
- bonding
- no metal
- can be economical (vs. crown/ inlays/onlays)
- prep more forgiving (restoration is NOT!!!)
Why is it advantageous that composite resin involves bonding? (2)
- reduced micro leakage and recurrent decay
- increased retention
Why is it advantageous that composite resin does not incorporate metal? (3)
- no mercury discussion
- no corrosion
- no galvanic shock
List order of expense from least to greatest:
- crown & inlays/onlay
- amalgam
- composites
- amalgam
- composites
- crowns & inlays/onlays
What are the disadvantages of composite resin restorations? (9)
- low modulus of elasticity
- porous
- more technique sensitive placement
- more time-consuming placement
- microleakage
- pullback- can create voids
- expensive compared to amalgam
- can’t place in bulk
- can’t support occlusion
What do we mean by “composite cannot support occlusion”
must have tooth supported occlusion on marginal ridges and cusp tips)
What is the purpose of using a wedge in a class II preparation?
closes the margin at the gingival of the box and prevents overhang
When using a tofflemire retainer band the narrower opening faces:
gingivally
What way should the opening slits of the tofflemire face?
gingival
Why should the opening slits of the tofflemire face gingivally?
so when you release the tofflemire it comes off of the tooth towards the occlusal surface
How to troubleshoot errors in proximal box restorations: (2)
- choose correct wedge (size/shape) and properly seat it
- Properly condensing amalgam
Properly condensing amalgam prevents:
voids into point angles
Choosing the correct size and shape of wedge, as well as correct placement of wedges ensures:
good contour of gingival margin
This instrument should be used in a proximal box restoration to press and wiggle into internal line angles (BG and LG), against margin areas, and contact areas of the band.
Hollenback condenser
What instrument should be used for the pre-carve burnishing in an amalgam proximal box restoration?
side of hollenback condenser or large ball burnisher
What instrument should be used in a proximal box restoration for defining occlusal embrasure by using at a 45 degree angle
explorer
An explorer can be used to define the occlusal embrasure of a proximal box restoration by holding at:
45 degree angle
What instrument is used for forming grooves and carving the marginal ridge in a proximal box amalgam restoration?
Hollenback carver
What instrument should be used to redefine the occlusal embrasure?
explorer
In a class II restoration what instrument should be used to-
A: carve excess off the buccal and lingual walls of box
B: break corner off of marginal ridge
C: carve embrasures
hollenback carver
In a class II restoration what instrument should be used to-
A: carve away gingival margin excess
B: instruments drawn laterally or occlusally
hollenback carver held obliquely OR wiland carver OR 34-35 jaquette scaler
In a class II restoration what instrument should be used when amalgam is partially set and need to adjust occlusion:
discoid carver
In a class II restoration what instrument should be used to redefine groove anatomy after doing final occlusal adjustment?
hollenback carver or cleoid carver
In a class II restoration what instrument should be used to smooth surfaces and bottom of grooves?
beavertail burnisher
Bond agent that does NOT require a separate etch step?
self etch
Requires etch, rinse, then bond agent:
total etch
When you only etch the enamel, avoiding dentin, (20-30s)
selective etch
A selective etch as opposed to a complete etch may:
reduce sensitivity
What should be avoided when doing a selective etch?
dentin
How long should the etch stay on in a selective etch?
20-30s
Etch placed all over the enamel and dentin:
complete etch
Describe the process of a complete etch:
- etch is placed over the enamel first for 20-30s
- etch is placed on the dentin for 15-20s
How should composite resin be placed?
incrementally not exceeding 2mm at a time (NO BULK FILL)
uncured layer of composite in which oxygen interferes with polymerization:
oxygen inhibited layer
When is the oxygen inhibited layer removed?
removed with finishing and polishing
The oxygen inhibited layer is a ____ thick layer which on the outside allows addition and wetting of subsequent layers of ____.
15 microns thick; composite
The oxygen inhibited layer just cured is ____ % ____ to co-polymerize with the new material
50% unreacted methacrylate groups
In an older restoration (no unreacted methacrylate groups), the repair strength =
50% original restoration (roughen with diamond)
Excavators and chisels are considered ____ instruments
cutting
Amalgam condensers, mirrors, probes, and explorers are considered ____ instruments
non-cutting
on the end of a non-cutting instrument, what is present?
face and nib
on the end of a cutting instrument, what is present?
Blade with cutting edge
Which instruments are best for different stages of carving anatomy:
- plastic instrument
- hollenback carver
- optrasculpt
instrument used to place and smooth composite on occlusal surface
plastic instrument
instrument used to carve anatomy, primarily used for amalgam
hollenback carver
instrument used to develop anatomy in composite resin prior to light curing:
optrasculpt
After light curing, what should be used to develop anatomy?
carbide burs (for finishing)
What is a “swivel”?
allows ergonomic manipulation of handpiece between dental unit
Where is the motor located in a handpiece?
motor located in actual handpiece
What is the purpose of water when drilling with a handpiece:
- cools are of contact between bur and tooth structure to prevent pulpal irritation
- avoids heat build up and destruction of odontoblastic processes in the dentin (dead tracts)
heat build up causing destruction of odontoblastic processes in the dentin leads to:
dead tracts
- uses steam under pressure
- 250 degrees F, 15 PSI, 20 min
- shelves for cassettes
autoclave
- oven-type sterilizer
- 320 degrees F, 60-120 mins
dry heat
- chemical vapor pressure
- use chemical solution in pressurized chamber
- 270 degrees F, 20-40 PSI, 20 min
- proper ventilation must be installed
chemiclave
- several hours BELOW 100 degrees Celcius
- proper ventilation must be installed
Ethylene oxide
Temp, pressure, and time requirements for autoclave sterilization:
250 degrees F, 15 PSI, 20 min
Temp and time requirement for dry heat sterilization:
320 degrees F for 60-120 min
Temp, pressure, and time requirements for chemiclave sterilization:
270 degrees F, 20-40 PSI, 20 min
Temp and time requirement for ethylene oxide sterilization:
several hours below 100 degrees C
the STATIC relationship between incising and masticating surface of the maxillary and mandibular teeth or tooth analogues
occlusion
the STATIC AND DYNAMIC contact relationship between occlusal surfaces of teeth during during function:
articulation
Occlusion can be described as a ____ relationship.
static
Articulation can be described as a ____ relationship.
static and dynamic
forces are directed over the long axes of teeth:
axial loading
In axial loading, forces are directed:
over the long axes of teeth
Type of contacts:
when each functional cusp occlusion in a fossa of the opposing tooth:
cup-fossa contacts
Type of contacts:
commonly used for single restorations
cusp-marginal ridge contacts
Type of contacts:
majority of natural dentitions have this:
cusp-marginal ridge contacts
Type of contacts:
Not seen a lot in nature:
cusp-fossa contacts
Type of contacts:
used when restoring both opposing quadrants
cusp-fossa
Type of contacts:
tooth to tooth arrangement
cusp-fossa contacts
Type of contacts:
each functional cusp contacts the MR of opposing pair of teeth or fossae of opposing teeth
cusp-marginal ridge contacts
Type of contacts:
a one tooth to two teeth arrangement:
cusp-marginal ridge contacts
- each function cusp occludes in a fossa of the opposing tooth
- tooth to tooth arrangement
- used when restoring both opposing qaudrants
- not seen a lot in nature
Cusp-fossa contacts
-each functional cusp contact the MR of the opposing pair of teeth or fossae of opposing teeth
- a one tooth to two teeth arrangement
- majority of natural dentitions have this
- commonly used for single restorations
Cusp-marginal ridge contacts
When comparing cusp-fossae contacts to cusp-marginal ridge contacts, which one is superior?
one is not proven better than the other
This occlusal relation ship allows for some cusps to occlude onto MRs and others to occlude into fossae:
cusp-marginal ridge occlusal relationship
This occlusal relationship allows ONLY for each cusp to occlude into one fossae:
cusp-fossa relationship
key aspects of nutritional counseling for patients with HIGH caries rates:
- identify sources
- reduce frequency and ingestions
describe silver diamine fluoride:
- silver in color and used to arrest caries
- primarily used on children who will lose the primary teeth
- used on occlusal caries that may be hard to get to
- very dark color
- not aesthetically pleasing
Fluoride toothpaste should be given to patients with:
root caries
Enamel with fluoride pH=
4.5
Clinical presentation:
- no clinically detectable lesion
- dental hard tissue appears normal in color, translucency and gloss
Clinical presentation:
Sound tooth structure radiographically can be labeled as:
E0 or R0 (no radiolucency)
Clinical presentation:
- earliest clinical detectable lesion compatible with mild demineralization
- lesion limited to enamel or to shallow demineralization of cementum/dentin
- mildest forms are detected only after drying
- when established and active lesions may be white or brown
- enamel has lost its normal gloss
initial
If caries are classified as initial, they are visually:
noncavitated
initial caries radiographically may be labeled as:
E1, E2, or D1 (radiolucency may extend into the DEJ or outer 1/3 of the dentin)
Clinical presentation:
- visible signs of enamel breakdown
- signs the dentin is moderately demineralized
moderate
moderate caries may also be classified as:
established, early caveated, shallow cavitation or microcavitiation
radiographically, moderate caries will be labeled as:
D2 (radiolucency extends into middle one-third of dentin)
Clinical presentation:
- enamel is fully cavitated
- dentin is exposed
- dentin lesion is deeply/severely demineralized
advanced
advice caries may also be classified as:
speed/disseminated, late cavitated, deep cavitation
radiographically advanced caries will be labeled:
D3 (radiolucency extends into the inner 1/3 of the dentin)
No radiolucency:
E0 or R0
Radiolucency may extend to the DEJ or outer 1/3 of the dentin:
E1, E2, D1
radiographs are not reliable for:
mild occlusal lesions
Radiolucency extends into the middle 1/3 of the dentin:
D2
Radiolucency extends into the inner 1/3 of dentin:
D3
What is the brand name for resin infiltration:
ICON
Resin infiltration is treatment for:
- initial (incipient) caries
- mild fluorosis
- white and brown spot lesions
- class II
Resin infiltration (ICON) can penetrate into:
outer third of dentin (d1)
resin infiltration (ICON) can be described as
microinvasive
What resin infiltration is used in our clinic?
icon
List steps prior to applying resin infiltration (ICON)
- clean tooth well (pumice)
- dry working field (rubber dam)
- etch for at least 30 sec 1-3x; rinse and dry well
Icon etch is:
15% hydrochloric acid gel
Icon etch acts as a:
“chemical drill”
Finishing and polishing a composite restoration:
The occlusal surface is shaped with a ____ or ____ finishing bur or similarly shaped finishing ____.
round or oval carbide; finishing diamond
What additional instrument is needed to attach a finishing disc to the handpiece?
SOFLEX mandrel
Cause of dentinal sensitivity:
hydrodynamic theory of pain transmission
Hydrodynamic theory of pain transmission:
dentinal tubules are filled with ___ and wrapped in ____ and ____
odontoblastic processes; afferent nerves; dentinal fluid
Hydrodynamic theory of pain transmission:
when enamel or cementum is removed during cavity preparation, the ____ of dentin is lost, which allows ___ in the tubules. This movement causes distortions in the afferent nerve endings, hence pain.
external seal; small fluid movement
Hydrodynamic theory of pain transmission:
_____ changes within the tubules caused by ____ can cause pain to the pulp through the fluid movement within the tubules
hydrostatic pressure; external stimuli
What are examples of external stimuli that can cause changes in hydrostatic pressure leading to pain?
temp change, high speed handpiece, air drying, osmotic changes from various chemicals, caries
Used when a deep carious lesion occurs and there is no clinical or radiographic evidence of irreversible pulp damage:
indirect pulp cap
Evidence of pulp damage that is likely irreversible:
- history of spontaneous pain
- heat sensitivity receive by cold
- P.A. lesion
For an indirect pulp cap, the tooth should be:
- completely asymptomatic
- show signs of reversible pulpitis
If a patient is experiencing moderate cold sensitivity with pain subsiding within about 15 seconds, this is evidence of ____, and we would use a ____.
reversible pulpitis; INDIRECT pulp cap
caries are usually ____ than they appear on the radiograph
deeper
The objective of an INDIRECT pulp cap is to:
avoid a direct pulp exposure
What are the two approaches that might be termed “indirect pulp cap” the:
- two-appointment approach
- single appointment approach
Describe the sequence of steps at the first appointment in the two-appointment approach of an indirect pulp cap:
- All caries removed from all areas except the deepest, nearest pulp
- Leave last bit of infected dentin to avoid pulp exposure
- Cover remaining infected dentin with calcium hydroxide (Life or Dycal) and then glass ionomer (Vitrebond)
- Place a temporary restoration (IRM)
- It may be acceptable to leave some undermined enamel (temporarily) to help hold in the temporary restoration
Describe the sequence of steps at the second appointment in the two-appointment approach of an indirect pulp cap:
- Remove temporary restoration, glass ionomer, & calcium hydroxide
- Carefully remove infected dentin (soft, leathery caries)
- Leave the affected dentin (dry, powdery caries)
How long should you allow in between the first and second appointment in the two appointment approach to indirect pulp capping:
allows 6-12 weeks
Why should you allow 6-12 weeks between the first and second appointment in the two appointment approach to indirect pulp capping?
Allows the body to form reparative dentin in the site near exposure
The desired result in the 6-12 week period in two appointment approach =
dentin bridge formation
In two appointment approach to indirect pulp capping, at the end of the 12 weeks, confirm that the patient is ____ and that the tooth is ___
asymptomatic; vital
In the two-appointment approach, research has suggested that if the cavity has been well-sealed during the 12 week interval, and that if the patient is asymptomatic and the tooth tests vital, the tooth may:
not need to be re-entered
What is the benefit of not re-entering the tooth if the criteria is met?
avoids risking a pup exposure
What is the theory behind the two-appointment approach to indirect pulp capping?
food supply to the bacteria is cut off by the well sealed restoration so they will die or become dormant
Where does confusion arise with the 2-appointment approach to indirect pulp capping?
clinically impossible to determine infected dentin from affected dentin
When are direct pulp caps used?
when small pulpal exposure occurs during cavity prep
For a direct pulp cap, a thin layer of ____ (____) is floated over the exposed pulp.
calcium hydroxide (Dycal)
For a direct pulp cap, a thin layer of calcium hydroxide (Dycal) is floated over the exposed pulp and then a layer of ____ is placed over the calcium hydroxide. This may help stimulate the pulp to form ____ which can produce a ____ across the exposure site.
glass ionomer (vitrebond); secondary odontoblasts; dentin bridge
A direct pulp cap is most successful when the exposure is ___ rather than ____.
mechanical; carious
A direct pulp cap is most successful the the pit is ____ and the exposure site is less than ____.
young; less than 0.5mm
A direct pulp cap is most successful if bleeding at the site is ___ and there is no ____ or ___.
controlled; no pus or serous exudate
A direct pulp cap is most successful if the area has not been:
contaminated by saliva
A direct pulp cap is most successful if there have been little or no ____ to the ____
mechanical damage to the pulp tissue
In a direct pulp cap, ____ may cause canals to calcify over time
calcium hydroxide (CaOH)
When should you NOT rely on a direct pulp cap?
If the tooth requires crown to adequately restore
Direct pulp caps occur better at the _____ than they do on an exposure on the ____ (as from a class V lesion)
tips of pulp horns; side of a pulp chamber
Direct pulp caps are more effective on ____ patients with ___ pulp chambers and ____ root canals that provide better ____ to the area where we are trying induce dentin bridge formation.
young patients; large pulp chambers; open root canals; circulation
If the tooth will require to adequately restore it, then you should:
NOT RELY ON A DIRECT PULP CAP
A pulp tissue’s reaction to stimuli is related to its response to irritation by:
- mechanical stimuli
- thermal stimuli
- chemical stimuli
- bacterial stimuli
The deposition of reparative dentin by secondary odontoblasts lining the pulp cavity acts as a ____ against ____ and various other irritating factors.
protective barrier; caries
Describe the formation of reparative dentin:
continuous and slow proces
Describe the timeline of formation of reparative dentin:
It takes 100 days to form a reparative dentin layer of 0.12 mm thick
In cases of severe irritation, the pulp responses by an ____ similar to any other soft tissue injury. However, the inflammation may become ___ and can result in ___.
inflammatory reaction; irreversible; death of the pulp
Death of the pulp due to an inflammatory reaction can occur because of the ___, ____ structure of the dentin, limiting the inflammatory response and the ability of the pulp to ____.
confined, rigid structure; recover
Many teeth have pulpal sensitivity due to caries or following cavity preparation and restoration.
This would be an example of:
reversible pulpitis
A twinge of pain may be due to sugar, cold, or acid from caries first contacting dentin. Pain lasting a few seconds may be due to the irritant continuous present of applied repeatedly.
This would be an example of:
reversible pulpitis
reversible pulpitis causes an increased ___ and ____ (____) and inflammation of the pulp.
blood flow and volume (hyperemia)
As long as an irritant, such as touching an ice stick to the tooth causes pain that lingers no more than 10-15 seconds after removal, it’s called ____ can can be treated with a ____.
reversible pulpitis; restoration
When pain is either spontaneous, or – if elicited by an irritant– lingers more than 15 seconds, _____ has occurred and resolution by operative dentistry treatment is ____.
infection of the pulp; usually not possible
Treatment that is advised for irreversible pulpitis
root canal
results when irreversible pulpitis is left untreated:
pulpal necrosis
characterized by spontaneous, continuous, throbbing pain or pain elicited by heat that can be relived by cold, and then, later, with no response to any stimulus:
pulpal necrosis
As inflammation and infection move beyond the ____, the tooth may become ____.
root apex; sensitive to percussion
Alternative causes of dental pain that are NOT pulpal in origin: (3)
- maxillary sinusitis
- cracked tooth
- occlusal trauma
Usually manifests as cold sensitivity, and sometimes spontaneous pain, in the maxillary posterior teeth. Often hard to isolate to a single tooth.
maxillary sinusitis
Usually manifests as cold sensitivity, or a sudden –usually unreproducible– pain when chewing.
cracked tooth
Instrument that can often elicit the pain when placed between the teeth in the central groove areas or at the tips of individual cusps.
tooth sleuth
Cracks in a tooth can sometimes progress into the pulp chamber and cause:
pulp necrosis
Tooth cracks can sometimes be seen externally with a ____, or it may be necessary to remove restorations to see them.
fiber optic light
Treatment for cracked tooth:
crowning
Usually manifests as cold sensitivity, or pain with chewing. Slight tooth movements when the teeth are clenched then moved from side to side may be seen, but not always.
Occlusal trauma- fremitis
Occlusal trauma pains/fremitis can often be relieved by:
occlusal adjustments
neutral position for dentist includes:
describe head position:
head at 0-20 degree tilt; ears over sholders
neutral position for dentist includes:
Shoulders over _____, and ___ relaxed at sides
hips; elbows
neutral position for dentist includes:
forearms should be _____ or slightly ___
parallel to floor; upward
neutral position for dentist includes:
describe back position:
slight curve in lower back/lordosis
neutral position for dentist includes:
Hip angle ____, ideally ____ (hips higher than ____)
greater than 90 degrees; 105-125 degrees; knees
neutral position for dentist includes:
describe foot position
feet flat on floor in tripod position
CTD stands for:
cumulative trauma disorder
What is the main cause of MSD in dentistry?
cumulative trauma disorders
The primary cause of disability among dentists:
cumulative trauma disorder
In CTD, microtrauma occurs on the ___ level, with damage that ____
cellular level; accumulates
The greatest strength of dental material is usually _____, while the weakest strength is ____
compressive strength; tensile strength
To resist masticatory (chewing) stresses without fracture
resistance
- walls parallel or perpendicular to forces
- rounded line and point angles
- flat and smooth walls
- giving bulk to restoration
factors contributing to resistance
To retain the restoration securely during function:
retention
- wall convergence (undercut)
- taller wall
- dovetail
factors contributing to retention
Convergence of walls is especially important in:
amalgam
Taller walls will increase ____ (resists the pull of sticky food)
frictional retention
What is the purpose of a dovetail?
prevents tipping and proximal displacement
Form that allows you to access the defect:
convenience form
Allows you to see what you are doing (ideally with perfect ergonomics)
convenience form
The cavosurface is the junction of ____ cavity wall and the ___ surface of the tooth
prepared; external
