Week 14- Deep Caries Removal Considerations Flashcards
(57 cards)
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
