Deep Caries Removal Considerations Flashcards
The dentino-enamel junction (DEJ) is an extremely
— part of the tooth. This is where enamel and
dentin meet.
sensitive
Hydrodynamic theory of pain transmission
- dentinal tubules are filled with odontoblastic processes
- wrapped in afferent nerves and dentinal fluid
- When enamel or cementum is removed during cavity preparation, the external seal of dentin is lost
- This allows small fluid movements in the tubules
- This movement causes distortions in the afferent nerve endings, hence, pain
most accepted theory of pain transmission
Hydrodynamic theory of pain transmission
Hydrostatic pressure changes within the tubules caused by external stimuli can cause
pain to the pulp through fluid movement within the tubules
examples of external stimuli: (5)
temperature change, high speed handpiece, air drying, osmotic changes from various chemicals, caries
— MUST BE TREATED WITH GREAT CARE DURING RESTORATIVE PROCEDURES
DENTIN
Air-water spray should be used
whenever
cutting with high-
speed handpieces
Air-water spray should be used
whenever cutting with high-
speed handpieces
•avoids (2)
heat build up and the
destruction of the odontoblastic
processes in the dentin (dead
tracts)
Dentin should not be
— by air blasts
•this could cause
dehydrated
aspiration of
odontoblasts into tubules
Caries control restorations are performed, as part of a larger caries control plan, when one or more of these conditions exist: (4)
- Caries is extensive enough that pulpal complications are likely to occur soon.
- It is desirable to quickly eliminate large carious lesions that are a source for caries infection in the patient’s mouth.
- Time does not permit definitive restoration of one or many large lesions.
- The prognosis for the pulp is questionable, and definitive restoration should be deferred until the pulp’s condition can be better assessed.
Caries control restorations refer to a situation when one tooth, or multiple
teeth at the same appointment, are treated quickly by: (3)
- Removing the infected dentin
- Medicating the pulp, if necessary
- Restoring the defects with a temporary material. If a
temporary material is used, undermined enamel can be left to
better retain the temporary.
INFECTED (2)
- Microorganisms are present
* Soft, leathery
AFFECTED (1)
• Dry, powdery
It’s not always possible to tell with 100% certainty where
affected dentin ends and infected dentin begins
The Indirect Pulp Cap
Used when a
deep carious lesion occurs and there is no clinical
or radiographic evidence of irreversible pulp damage (such as a
history of spontaneous pain, heat sensitivity relieved by cold,
or a P. A. lesion)
Tooth should be asymptomatic, or—at most—have symptoms
consistent with reversible pulpitis, such as
moderate cold
sensitivity, with pain subsiding within about 15 seconds.
Remember, caries is usually — than it appears to be on
X-ray.
deeper
THE OBJECT OF AN INDIRECT PULP CAP IS TO
AVOID A DIRECT
PULP EXPOSURE.
There are two approaches that might be termed “indirect pulp cap”:
The Two-Appointment Approach: (7)
•All caries are removed from all areas EXCEPT the deepest, nearest pulp
•Leave the last bit of infected dentin to avoid exposing pulp
•Cover remaining infected dentin with calcium hydroxide (Dycal or Life) then
glass ionomer (Vitrbond)
•Place a temporary restoration
• IRM
•It may be acceptable to leave some undermined enamel temporarily to help
hold in the temporary restoration
•Allow 6-12 weeks to allow the body to form reparative dentin in the site of the near exposure
• desired result= dentin bridge formation
•At the end of the twelve weeks:
• confirm that the patient is asymptomatic and that the tooth is vital
The Two-Appointment Approach:
Traditional approach: (3)
- Remove the temporary restoration, the glass ionomer, and the CaOH
- Carefully remove the remaining infected dentin (soft, leathery caries)
- Leave the affected dentin (dry, powdery caries).
Leave the affected dentin (dry, powdery caries). (2)
• A #4 round bur on the slow speed just above stall speed, with a light, shaving touch is the best choice for this function. It is
better than a spoon excavator, since the larger bur will put less force per unit area than the hand instrument would do, therefore
making it less likely that one would break through into the pulp.
• Place a new liner of Dycal covered by Vitrebond. Remove all undermined enamel, modify the prep. to properly retain the
restoration, and restore with your selected permanent material.
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Research has suggested that if the cavity has been well sealed during the twelve-week interval, and that if the patient is asymptomatic and the tooth tests vital,
the tooth may not need to be reentered.
◦ This avoids risking a pulp exposure at the second appointment.
The theory is that the food supply to the bacteria is cut off by the well sealed restoration and that the bacteria will
die or become dormant.
Caries progression, these researchers believe, will be arrested, and the pulp will remain in good health.
This is an evolving area of thought in dentistry, and you will encounter different opinions & a degree of confusion on this issue, even among dental school professors. Some of the confusion arises from the fact that it is impossible to determine clinically exactly where infected dentin stops and affected dentin begins. Most agree that leaving some infected dentin deep in the preparation when necessary is O.K. However, there is disagreement about how much is O.K.
The Indirect Pulp Cap:
The Single-Appointment Approach:
•Remove infected (soft, leathery) dentin. Remove affected dentin (dry, powdery caries) from
any areas where a pulp exposure is not likely to occur
• The DEJ must be completely caries-free
•Leave the affected dentin only in the deepest area where the possibility of a direct pulp
exposure is a concern.
• You want to remove ALL affected dentin, if at all possible
•TO AVOID PULP EXPOSURE, it may be permissible to leave a small amount of infected dentin in
deep areas
• Place CaOH (Dycal or Life) over the deepest area close to the pulp
• Place glass ionomer (Vitrebond) over the CaOH
• There is fluoride release from the Vitrebond allowing possibility of remineralization of the affected
dentin as long as restoration is well-sealed
•Remove all undermined enamel and place the permanent restoration
• If time does not permit placing the “permanent” restoration (if, for instance, you are
trying to do temporary, caries control restorations in several teeth at the same
appointment), place a temporary restoration.
• Schedule next appointment to complete the definitive restoration
• Do not remove the Vitrebond or Dycal—why risk a pulp exposure?
•If crown is indicated, it is prudent to wait several months before beginning
treatment.
• Confirm that tooth is asymptomatic and vital before beginning crown prep
Direct pulp cap
•Used when
a small pulpal exposure occurs during
cavity preparation.
Direct pulp cap
A thin layer of calcium hydroxide is placed over the
exposed pulp (2)
•A layer of glass ionomer is placed over the CaOH
•stimulate the pulp to form secondary odontoblasts,
which can produce a dentin bridge across the
exposure site.
It is most successful when the exposure is — rather than carious
mechanical
It is most successful when the exposure is
mechanical rather than carious (4)
◦ when the patient is young, in exposure sites less
than 0.5 mm,
◦ if bleeding at the site is easily controlled and
there is no pus or serous exudate
◦ if the area has not been contaminated by saliva,
and
◦ if there has been little or no mechanical damage to
the pulp tissue.
Endodontists aren’t fond of direct pulp caps
since
CaOH may cause the canals to calcify
over time.
Direct pulp cap may not be successful
• Confirm vitality months later/at recall appointments with a
radiograph and some form of pulp testing (electric pulp test, cold test)
Pulp caps are more effective on
young patients with large pulp chambers and open root canals that provide better circulation to the area where we are trying to induce dentin bridge formation
Direct pulp caps work better at the — than they do on —
tips of pulp horns an exposure on the side of a pulp chamber (as from a class V lesion)
Mild to moderate spontaneous pain for as much as — days after the procedure may not indicate the need for endodontics, but after that, spontaneous pain is more ominous. Some cold sensitivity may linger for several weeks.
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If the tooth will require a crown to adequately restore it, DO NOT RELY ON A
DIRECT PULP CAP . Complete root canal therapy before crowning teeth that have had direct exposures