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
Whether Doing an Indirect or Direct Pulp Cap, Temporary or “Permanent”
Restoration,
SEAL THE CAVITY
A broken or leaky restoration =
failure because bacteria will leak into the pulp and kill it.
ALL Restorations must adequately seal the cavity to avoid (3)
microleakage, bacterial penetration, and—of course—recurrent decay.
Defensive function of the pulp
•Related to its response to irritation by (4)
mechanical, thermal, chemical, or bacterial stimuli
The deposition of reparative dentin by the replacement odontoblasts lining the pulp cavity acts as a protective barrier against
caries and various other irritating factors
Formation of reparative dentin is a continuous but slow process, taking 100 days to form a reparative dentin layer — thick
0.12 mm
In cases of severe irritation, the pulp responds by an inflammatory reaction similar to any other soft tissue injury.
However, the inflammation may become irreversible and can result in the
death of the pulp because the confined, rigid structure of the dentin limits the inflammatory response and the ability of the pulp to recover.
Size of Pulp Cavity
Decreases in size with age
Younger children have — pulps than older adults and younger pulps are
more — than older pulps.
larger
reparative
Pulp cavity
Its contour is a miniature of
the
external surface of the
tooth.
Many teeth have pulpal sensitivity due to (2)
caries or following cavity
preparation and restoration
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 continuously
present or applied repeatedly
This causes an increased (2) and
— of the pulp
blood flow and volume (hyperemia)
inflammation
As long as an irritant, such as touching an ice stick to the tooth causes pain
that lingers no more than 10 to 15 seconds after removal, it’s called
reversible pulpitis and can be treated with a restoration
When pain is either spontaneous, or–if elicited by an irritant–lingers more
than 15 seconds, infection of the pulp often has occurred and resolution by
operative dentistry treatment is usually not possible; root canal therapy is
advised for this condition termed
irreversible pulpitis.
When this irreversible pulpitis is untreated, — follows
pulpal necrosis
Pulpal Necrosis (3)
- spontaneous, continuous, throbbing pain or pain elicited by heat that can be relieved by cold, and then, later, with no response to any stimulus
- As inflammation and infection move beyond the root apex, the tooth may become sensitive to percussion
- Root canal therapy is needed
A primary objective during operative procedures must be the
preservation of the health of the pulp.
All — must be removed, except in the event of an indirect pulp cap, that we already discussed.
caries
Avoid — the dentin—as, for instance, by using a high speedhandpiece without water coolant. All restorations must be well sealed
overheating
All restorations must be well —
sealed
Maxillary Sinusitis
Usually manifests as cold sensitivity, and sometimes spontaneous pain, in the maxillary
posterior teeth. Often hard to isolate to a single tooth.
Cracked Tooth
Usually manifests as cold sensitivity, or a sudden—usually unreproducible—pain when
chewing. An instrument called a Tooth Sleuth can often elicit the pain when placed
between the teeth in the central groove areas or at the tips of individual cusps.
Cracks can sometimes progress into the pulp chamber and cause pulp necrosis, or cusps
may eventually fracture off. Cracks can sometimes be seen externally with a fiber optic
light, or it may be necessary to remove restorations to see them.
These teeth require crowning.
Occlusal trauma
fremitis
Usually manifests as cold sensitivity, or pain in chewing.
Slight tooth movements when
the teeth are clenched and then moved from side to side may be seen, but not always.
This is called fremitis. Pain can often be relieved by occlusal adjustments. .
Cementum (3)
Is slightly softer than dentin and consists of about 45% to 50% inorganic material by weight. Covers the apical root.
It is permeable to a variety of materials.
Light yellow and slightly lighter in color than dentin, it has the highest fluoride content of all the mineralized tissue.
In about 10% of teeth, enamel and cementum do not meet, and this can result in
a sensitive area.
Abrasion, erosion, caries, scaling, and the procedures of finishing and polishing may result in
removing from the dentin its cementum covering, which can cause the dentin to be sensitive.
This must be distinguished from caries and often tooth sensitivity is caused by
exposed dentin
What to do about root sensitivity:
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Both abrasion lesions and erosion lesions on the root can be hypersensitive because of the exposed
dentin. Sometimes, due to the amount of lost tooth structure, it is necessary to restore the root surface
with amalgam or composite material. If you rely on resin bonding alone to retain a composite restoration,
remember that the restoration lifespan may not be long. It may be necessary to prepare the tooth
structure to
gain mechanical retention and do a restoration that will last over time.
Another approach, if the tooth does not require a restoration to protect if from further damage, is to treat
the exposed dentin with —, which we discussed previously as a dentinal tubule sealant.
Isolate with cotton and dry the tooth. Use a small applicator and rub onto the root surface for about 30
seconds. Gluma is somewhat caustic to soft tissue. Minimize soft tissue contact with Gluma. If it works,
desensitization may last for 2 or 3 months.
Gluma Desensitizer
The apical root can resorb due to
orthodontic movement.
overcontoured tooth
Overcontouring is the worst. It results in flabby, red-colored, chronically inflamed gingiva and increased plaque retention
undercontoured tooth
Undercontour results in trauma to the gingival tissues.
The facial and lingual surfaces possess convexity that protects and allows
stimulation to gingival
tissues during mastication.
Normal tooth contours deflect food only to the extent that the passing food stimulates the
gingival by gentle massage rather than by irritating it. If the curvatures are too great, the
tissues usually receive inadequate stimulation, and a potential plaque trap is created.
Should leave enough room for —
gingiva
Improper contacts can result in (4)
food impaction, producing periodontal disease, carious lesions, and possible movement of the teeth.
Proximal Contact and Marginal Ridge Heights
Located in the — central incisors.
incisal third of the Max and Mand
Proceeding posteriorly, the contact is at the
junction of the occlusal and middle thirds which creates a larger occlusal embrasure.
Marginal ridges should be the same height to prevent
food impaction.
Proximal contacts are slightly – to
the center of the proximal surface
faciolingually.
facial
Clinically, the level of the gingival attachment and the gingival sulcus is an important factor in restorative dentistry. The soft tissue health must be maintained by the teeth having correct form and position. If not,
apical recession of the gingivae and possible abrasion and erosion of the roots can occur.
The margin of the cavity preparation should, ideally, not be positioned subgingivally (at levels between the marginal crest of the free gingival and the base of the sulcus) unless dictated by (3)
caries, previous restoration, or esthetics.
It is extremely important to not destroy
attached keratinized tissue in the restorative process. This must be preserved.
Palodent is more useful with
small composite preparations
like this one than with amalgam.
Grasp the Palodent ring with a rubber dam clamp forcep, and
place it with its tines in the facial and lingual embrasures. The
theory is that this clamping action will cause a
slight
separation of the teeth, and assist in getting a better contact
on the restoration.
A BIG DRAWBACK OF THE ORIGINAL
PALODENT IS THAT IT DOESN’T ALLOW
WEDGING.
ALL SECTIONAL MATRICES REQUIRE A RUBBER DAM FOR SAFETY,
IN CASE A RING BREAKS OR FLIES OFF.
Another SECTIONAL MATRIX system, Palodent Plus has –
choices of band and two choices of ring clamp.
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THE AUTOMATRIX SYSTEM–LIMITATIONS (2)
1. Must be held in place by your non- dominant hand when there are no undercuts on the side walls of the tooth (as when tooth has been prepared for a crown). 2. Doesn’t work well when tooth defects go far apically.
THE COPPER BAND
Simple copper cylinders, available in a variety of diameters, can be shaped in the fingers to have a cross section that approximates the cervical outline of the neck of the tooth (rectangle, oval, trapezoid, parallelogram, etc.)
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THE COPPER BAND—REMOVAL AFTER PACKING AMALGAM
After packing amalgam, use a Hollenback carver, cleoid
discoid carver, and the explorer to carve occlusal and
axial walls to approximate crown preparation form. Let
the amalgam partially set. Use a 169 bur to make a
vertical slit through the copper band. Stabilize with
the finger of the non-dominant hand to prevent
resonance (as the bur cuts the metal) from fracturing
the amalgam. Peel the metal back , like opening a
gate. Refine the buildup further by carving. Place a
temporary crown and do the final refinement of the
crown preparation at the next appointment, after the
amalgam has set.
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THE COPPER BAND MATRIX—LIMITATIONS (3)
- Because of the stiffness and thickness of the copper band, it is useful primarily on teeth already prepared for crowns. True contact with neighboring teeth is nearly impossible to obtain with a copper band matrix.
- It must be stabilized with your non-dominant hand while packing amalgam, or when cutting the band for removal.
- Copper bands are subject to strain hardening if you “work” the metal very much. If this happens, hold the band with pliers over a flame until it glows red. Quench it in water. This process is called “stress relief annealing”. It will soften the metal again so the copper does not resist attempts to shape it.
