Week 14- Deep Caries Removal Considerations Flashcards
what is the most accepted theory of pain transmission
hydrodynamic theory of pain transmission
describe the hydrodynamic theory of pain transmission
-dentinal tubules are filled with odontoblastic processes and wrapped in afferent nerves and dentinal fluid
- when enamel or cementum is removed during cavity prep, the external seal of dentin is lost which allows small fluid movement in the tubules causing distortion in the afferent nerve endings and pain
what are examples of external stimuli that can cause pain in dentin tubules
-temperature change
- high speed handpiece
- air drying
- osmotic changes from various chemicals
- caries
why should air water spray be used
avoids heat build up and the destruction of the odontoblastic processes in the dentin (dead tracts)
why should dentin not be dehydrated by air blasts
it could cause aspiration of odontoblasts into tubules
what is the difference between infected vs affected dentin
- infected: microorganisms are present. soft and leathery
- affected: dry and powdery
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 history of spontaneous pain, heat sensitivity relieved by cold
in the indirect pulp cap teeth should either:
-be completely asymptomatic
-show signs of reversible pulpitis
caries is usually _____ than it appears to be on a radiograph
deeper
what is the object of an indirect pulp cap
to avoid a direct pulp exposure
what are the two approaches that might be termed indirect pulp cap
-the two appointment approach
- the single appointment approach
what happens in the first and second appointment in the two appointment approach for indirect pulp cap
- first appointment: all caries 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 then glass ionomer
- place a temporary restoration (IRM)
- may be acceptable to leave some undermined enamel temporarily to help hold in the temporary restoration
- second appointment: allow 6-12 weeks to allow the body to form reparative dentin in the site of the near exposure. desired result is dentin bridge formation
- at the end of 12 weeks confirm that the patient is asymptomatic and that the tooth is vital
- traditional approach: remove the temporary restoration, glass ionomer and the CaOH. carefully remove the remaining infected dentin . leave the affected dentin
what is the best way to leave affected dentin and why
-a #4 round bur on the slow speed just above stall speed with a light shaving touch. better than a spoon excavator because the larger bur will put less force per unit area than the hand instruments would do making it less likely that one would break into the pulp
- place a new liner of dycal covered by vitrebond. remove all undermined enamel, modify prep to retain restoration and restore with permanent material
research has suggested that if the cavity has been well sealed during the 12 week interval _____
and if the patient is asyptomatic and the tooth tests vital the tooth may not need to be reentered
describe the single appointment approach to the indirect pulp cap
- remove infected dentin, remove affected dentin from any areas where a pulp exposure is not likely to occur. DEJ must be caries free
- leave the affected dentin only in the deepest area where the possibility of a direct pulp exposure is a concern
- to avoid pulp exposure it may be permissible to leave a small amount of affected dentin in deep areas. Place CaOH over deepest area close to the pulp, place glass ionomer over the CaOH, fluoride release from the vitrebond allowing the possibility of remineralization of the affected dentin as long as the restoration is well sealed
- place permanent restoration
when is a direct pulp cap used
when a small pulpal exposure occurs during a cavity preparation
describe 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
- stimulates the pulp to form secondary odontoblasts which can produce dentin bridge on exposure site
when is a direct pulp cap most successful
when the exposure is mechanical rather than carious
- when pt 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
- if there has been little or no mechanical damage to the pulp tissue
what is on boards about the direct pulp cap
do not leave affected dentin-> direct pulp cap is indicated
how should you confirm direct pulp cap is successful
-months later at recall appointments with a radiograph and some form of pulp testing- electric pulp test, cold test
why are pulp caps more effective on young patients
they have 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 pulp caps work better
at the tips of pulp horns than they do on an exposure on the side of a pulp chamber
how long should mild to moderate spontaneous pain after direct pulp cap last without endodontic indication
as much as 3 days
how long might cold sensitivity linger after direct pulp capping
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 with direct pulp exposures
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____
microleakge, bacterial penetration and recurrent decay
size of the pulp cavity ____ in size with age
decreases
younger children have ____ pulps than older adults and younger pulps are ____ reparative than older pulps
larger; more
what is the defensive function of the pulp related to
its response to irritation by mechanical thermal chemical or bacterial stimuli
what deposits reparative dentin
the replacement odontoblasts lining the pulp cavity acts as a protective barrier against caries and various other irritating factors
describe how long the formation of reparative dentin takes
it is a continuous but slow process, taking 100 days to form a reparative dentin layer 0.12 mm thick
in cases of severe irritation of the pulp,
the pulp responds by an inflammatory reaction similar to any other soft tissue injury
describe the inflammation of pulp
can be 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
describe reversible pulpitis
many teeth have pulpal sensitivity due to caries or following cavity preparation and restoration
- small 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 blood flow and volume (hyperemia) and inflammation of the pulp
- as long as the irritant, such as touching an ice stick to the tooth causes pain that lingers no more than 10-15 seconds after removal its reversible pulpitis
what can reversible pulpitis 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 has occurred and resolution by operative dentistry treatment is usually not possible; root canal therapy is advised for this condition termed irreversible pulpitis
what is pulpal necrosis
when irreversible pulpitis is untreated pulpal necrosis follows
- 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 root apex the tooth may become sensitive to percussion
what therapy is needed in pulpal necrosis
root canal therapy
what does maxillary sinusitis manifest as
- cold sensitivity and spontaneous pain in maxillary posterior teeth
- hard to isolate single tooth
what does a cracked tooth manifest as
-cold sensitivity or a sudden unreproducible pain when chewing
-tooth sleuth- if hurts when biting its a PDL issue, if hurts when opening this indicated theres a crack
what does occlusal trauma manifest as and what can it be relieved by
- cold sensitivty 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- fremitis
- pain can be relieved by occlusal adjustments
cementum is slightly ____ than dentin and consists of about ___% inorganic material by weight
softer; 45-50%
what does cementum cover
the apical root
what part of the tooth has the highest fluoride content
cementum
what color is cementum
light yellow and slightly lighter in color than dentin
in about ___ of teeth enamel and cementum do not meet resulting in ____
10%; a sensitive area
what might result in removing the cementum from the dentin
abrasion, erosion, caries, sclaing, and the procedures of finishing and polishing
what is tooth sensitivity often caused by
exposed dentin
why can abrasion and erosion lesions on the root be hypersensitivity
because of the exposed dentin
why might it be necessary to restore the root surface with amalgam or composite
due to the amount of tooth structure. you cant rely on resin bonding alone to retain a composite resoration, the lifespan of the restoration may not be long
what is gluma
topical desensitizer
what could you do about root sensitivity
-restore if enough tooth loss
-gluma
-fluoride
-sensodyne toothpaste
what does overtontouring result in
flabby,red-colored chronically inflamed gingiva and increased plaqque retnetion
what does undercontouring result in
trauma in gingival tissues
which is worse: overcontouring or undercontouring
overcontouring
what tissue is important to preserve during the restorative process
attached keratinized tissue
