4/18: Deep Caries Removal Considerations Flashcards
What is a sensitive part of the tooth?
The dentino-enamel junction (DEJ)
Where do enamel and dentin meet?
At the dentino-enamel junction
What is the most accepted theory of pain transmission?
Hydrodynamic theory of pain transmission
What are dentinal tubules filled with?
Odontoblastic processes
What are odontoblastic processes wrapped in?
Afferent nerves and dentinal fluid
What happens when enamel or cementum are removed during cavity preparation?
The external seal of dentin is lost
What happens when enamel or cementum are removed during cavity prep?
Small fluid movements in the tubules
Movement causes distortions in the afferent nerve endings, hence, pain
What do hydrostatic pressure changes within the tubules caused by external stimuli cause?
Pain to the pulp through fluid movements within the tubules
What are examples of external stimuli?
temperature change, high speed handpiece, air drying,
osmotic changes from various chemicals, caries
What must be treated with great care during restorative procedures?
Dentin
What must be used whenever cutting high speed handpieces?
Air water sprat
What does air water spray avoid?
Heat build up and the destruction of the odontoblastic processes in the dentin (dead tracts)
What should not be dehydrated by air blasts?
Dentin
- this could cause 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:
- 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.
- 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.
THESE ARE NOT DONE OFTEN AT UMKC
What is infected dentin?
Microorganisms are present
Soft, leathery
What is affected dentin?
Dry, powdery
Its not always possible to tell with 100% certainty where __________________________________________________________
Affected dentin ends and infected dentin begins
When is an 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)
What are the qualifications of a tooth for an indirect pulp cap?
- Be completely asymptomatic
- Show signs of reversible pulpitis
Ex: moderate cold sensitivity, with pain subsiding within about 15 seconds
What should you remember when looking at caries on a radiograph?
Usually deeper than it appears on a radiograph
What is the object of an indirect pulp cap?
Avoid a direct pulp exposure
Is this a candidate for a pulp cap?
Upper arrow: may be candidate
Lower arrow: certainly not a candidate for indirect cap - probably already a direct exposure
What are the two approaches that might be termed “indirect pulp cap”?
Two appt approach:
One appt approach
What pulp capping approach do we use at UMKC?
One appointment approach
What happens during the first appointment of the two-appt approach?
- 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
How long should you wait to allow the body to form reparative dentin in the site near exposure?
6-12 weeks
What is the desired result after waiting 6-12 weeks?
Dentin bridge formation
What happens at the end of 12 weeks in the two appt approach?
Confirm that the patient is asymptomatic and the tooth is vital
What is the traditional approach of the indirect pulp cap?
- 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)
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.
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 appt
What is the theory behind the cavity being well sealed?
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 will be arrested and the pulp will remain in good health
What is the single appt 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
Where can the dentin be left in the single appt approach?
*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
What should you do in the single appt approach to avoid pulp exposure?
May be permissible to leave a small amount of affected 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
What is no longer an option for pulp exposure?
Indirect pulp cap
When are direct pulp caps used?
When a small pulpal exposure occurs during cavity prep
What do you do during a direct pulp cap?
*A thin layer of calcium hydroxide is placed over the
exposed pulp
* 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.
When is a direct pulp cap most successful?
- When exposure is mechanical rather than carious
- 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 - young patient
What is the exposure site size when the patient is young?
0.5mm
What is becoming more recommended at UMKC?
Direct pulp cap
What should you do on boards if there is need for a direct pulp cap?
Do NOT leave affected dentin, direct pulp cap is indicated
Whats this?
A Large Amalgam with a Liner of Calcium Hydroxide over the
Pulp Horns and a Base of Glass Ionomer
Who are pulp caps most 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
Where do direct pulp caps work better at?
the tips of pulp horns than they do on an exposure on the side of a pulp chamber (as from a class V lesion)
What can mild to moderate spontaneous pain for three days after a direct pulp cap indicate?
not indicate the need for endodontics, but after that, spontaneous pain is more
ominous.
Some cold sensitivity may linger for several weeks.
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
What can a broken or leaky restoration cause?
Failure because bacteria will leak into the pulp and kill it
Why must all restorations adequately seal the cavity?
To avoid microleakage, bacterial penetration, and recurrent decay
Describe a pulp cavitys contour
A miniature of the external surface of the tooth
When does the size of a pulp cavity decrease?
With age
- younger children have larger pulps than older adults and younger pulps are more reparative than older pulps
What is the defensive function of the pulp related to?
Its response to irritation by mechanical, thermal, chemical, or bacterial stimuli
What does the deposition of reparative dentin by the replacement odontoblasts lining the pulp cavity act as?
a protective barrier against caries and various other irritating factors
Describe the formation of reparative dentin
a continuous but slow process, taking 100 days to form a reparative dentin layer 0.12 mm thick
What happens to the pulp in cases of severe irritation?
the pulp responds by an inflammatory reaction similar to any other soft tissue injury
What happens in some cases of inflammation of the pulp?
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
Why do many teeth have pulpal sensitivity?
Due to caries or following cavity preparation and restoration
What are symptoms of reversible pulpitis?
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
What do twinges of pain due to reversible pulpitis cause?
An increased blood flow and volume (hyperemia) and inflammation of the pulp
What is reversible pulpitis?
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
What is irreversible pulpitis?
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
What is treatment for irreversible pulpitis?
root canal therapy
What is pulpal necrosis?
When irreversible pulpitis is left untreated
What is symptoms of pulpal necrosis?
spontaneous, continuous, throbbing pain or pain elicited by heat that can be relieved by cold, and then, later, with no response to any stimulus
What happens in pulpal necrosis as inflammation and infection move beyond the root apex?
The tooth becomes sensitive to percussion
What is treatment for pulpal necrosis?
Root canal therapy
What is the primary objective during operative procedures?
the preservation of the health of
the pulp
All caries must be removed EXCEPT in the event of a?
Indirect pulp cap
What should you avoid during operative procedures?
Overheating the dentin- for instance, by using a high speed handpiece without water coolant
All restorations must be well _______
Sealed
What does maxillary sinusitis manifest as?
cold sensitivity, and sometimes spontaneous pain, in the maxillary
posterior teeth
Often hard to isolate to a single tooth.
What do cracked teeth manifest as?
Cold sensitivity, or a sudden unreproducible pain when chewing
What can a tooth sleuth do for a cracked tooth?
elicit the pain when placed
between the teeth in the central groove areas or at the tips of individual cusps
Where can cracks progress into?
The pulp chamber and cause pulp necrosis, or cusps may eventually fracture off
What can cracks sometimes be seen externally with?
a fiber optic light, or it may be necessary to remove restorations to see them
What is treatment for cracked teeth?
Crowning
What does occlusal trauma manifest as?
cold sensitivity, or pain in chewing
What may be seen (not always) in occlusal trauma?
Slight tooth movements when the teeth are clenched and then moved from side to side
What is fremitis?
Slight tooth movements when the teeth are clenched and then moved from side to side
How is pain relieved for occlusal trauma?
Occlusal adjustments
What tissue is softer than dentin?
Cementum
What does cementum consist of?
45-50% inorganic material by weight
What does cementum cover?
Apical root
What is cementum permeable to?
Variety of materials
What is the color of cementum?
Yellow and slightly lighter in color than dentin
What has the highest fluoride content of all mineralized tissue?
Cementum
What happens in 10% of teeth where enamel and cementum do not meet?
Sensitive area
What does abrasion, erosion, caries, scaling, and the procedures of finishing and polishing result in?
Removing from the dentin its cementum covering, which can cause the dentin to be sensitive
What is tooth sensitivity caused by?
Exposed dentin
What is this?
Abrasion lesion
What is the form of an abrasion lesion?
Angular in form
What is the form of an erosion lesion?
Rounded in form
Why can abrasive and erosive lesions cause hypersensitivity?
because of exposed dentin
What should you do about root sensitivity?
- Gluma
Topical desensitizer - Fluoride
Varnish or prescription Fluoride toothpaste - Toothpaste
Sensodyne, “sensitivity formula” in most brands
Potassium nitrate
Describe these
A = Overcontouring is the worst. It results in flabby, red-colored,
chronically inflamed gingiva and increased plaque retention.
B = Undercontour results in trauma to the gingival tissues.
C = just right
What do facial and lingual surface convexity do?
Protects and allows stimulation to gingival tissues during mastication
What do normal tooth contours do?
deflect food only to the extent that the passing food stimulates the
gingival by gentle massage rather than by irritating it
What happens if tooth curvature is too great?
the tissues usually receive inadequate stimulation, and a potential plaque trap is created
What do closed gingival embrasures impinge on?
Papilla
When embrasures are properly open, where is contact?
At junction of occlusal and middle third
What can improper contacts result in?
food impaction, producing periodontal disease, carious lesions, and possible movement of the teeth
Where are contacts in max and mand central incisors?
Incisal third
Where is contact as it proceeds posteriorly?
Junction of the occlusal and middle thirds which creates a larger occlusal embrasure
Where should marginal ridges be?
Same height to prevent food impact
Where are proximal contact?
Slightly facial to the center of the proximal surface faciolingually
What happens when there is open contact between a restoration?
What is an important factor in restorative dentistry?
Level of the gingival attachment and gingival sulcus
How is soft tissue health maintained?
By teeth having correct form and position, if not, apical recession of gingiva and possible abrasion and erosion of roots can occur
Where should the margin of the cavity prep ideally not be?
positioned subgingivally (at levels between the marginal crest of the free gingival and the base of the sulcus) unless dictated by caries, previous restoration, or esthetics
It is extremely important to not destroy _________________ tissue in the restorative process
Attached keratinized tissue
- this must be preserved
