Disc Review Flashcards
access cavity preparation: objectives
- to create a smooth, straight line path to the canal system up to the apex
- to remove caries and debris from the chamber
- to allow for complete irrigation and easing of shaping
- to establish maximum visibility to gain access up to the end of the canal (apical foramen)
key objectives in access preparation
- cleaning
- shaping
- obturation
best area to gain access to apical foramen
labial or incisal edge
why access prep is done in lingual area
esthetics
main cause of persistent infection
- inadequate access
- inadequate cleaning and shaping of canal
orifice of the chamber: location
- 1st law of orifice location
- 2nd law of orifice location
- 3rd law of orifice location
1st law of orifice location
the orifices of the root canals are always located at the junction of the walls and the floor
2nd law of orifice location
the orifices of the root canals are always located at the angles in the floor - wall junction
3rd law of orifice location
the orifices of the root canals are always located at the terminus of the root’s developmental fusion lines
orifice of the chamber: symmetry
- 1st law of symmetry
- 2nd law of symmetry
- 3rd law of symmetry
1st law of symmetry
(except for max. molars) canal orifices are equidistant from a line drawn in a M-D direction through the center of the pulp chamber floor
2nd law of symmetry
(except for max. molars) canal orifices lie on a line perpendicular to a line drawn in a M-D direction across the center of the pulp chamber floor
2 reasons why rubber dam placement can be painful
- improper selection of clamp
- incorrect placement technique
principles of isolation
- patient protection
- clinician’s protection
- surgically clean operating field
- retraction and protection of the soft tissue
- improved visibility
- increased efficiency
principles of isolation
- patient protection
- clinician’s protection
- surgically clean operating field
- retraction and protection of the soft tissue
- improved visibility
- increased efficiency
diagnostic tests
- thermal pulp testing (heat, cold)
- electric pulp testing (EPT)
- percussion
- palpation
- pocket probing
- tooth mobility test
responses to thermal tests
- no response
- false negative response
- within normal limits
- strong, momentary response
- moderate to strong response
thermal test: no response
non vital pulp
thermal test: false negative response
- excessive calcification
- immature apex
- recent trauma
- recent premedication
thermal test: within normal limits (mild to moderate transient response)
- degree of awareness
- slight pain that subsides within 1-2 secs after stimulus is removed
thermal test: strong, momentary response
- painful response that subsided within 1-2 secs after stimulus has been removed
- e.g. reversible pulpitis
thermal test: moderate to strong response
- painful response that lingers for several secs or longer after stimulus has been removed (more than 5 secs)
- e.g. irreversible pulpitis
disadvantage of EPT
- only info you can get is whether the tooth is vital or non-vital
- has to be used in adjunct with other diagnostic aids
responses to EPT
- positive response
- negative response
- false positive response
- false negative response
EPT: false positive response
- (+) response but tooth is non-vital
- patient anxiety
- wet tooth (to gingiva)
- metallic restorations (to adjacent tooth)
- liquefaction necrosis
EPT: false negative response
- (-) response but tooth is vital
- premedication (drugs/alcohol)
- immature teeth
- trauma
- poor contact w tooth
- inadequate conductor (toothpaste)
- partial necrosis with vital pulp remaining in apical portion of root
- atrophied pulp
- high pain thresholds
percussion: pain
- mild tenderness
- moderate pain
- severe pain
percussion: interpretation
shows if PDL is inflamed/periapical involvement
percussion: what is recorded
reaction and intensity of pain
palpation: pain
- mild tenderness
- moderate pain
- severe pain
palpation: interpretation
shows if periodontal inflammation has reached the periosteum
pocket probing: interpretation
shows attachment loss
pocket probing: importance
essential in distinguishing between disease of periodontal or pulpal origin
tooth mobility test: interpretation
shows integrity of attachment apparatus
pulpal diagnoses
- normal pulp
- reversible pulpitis
- symptomatic irreversible pulpitis
- asymptomatic irreversible pulpitis
- pulp necrosis
- previously treated
- previously initiated therapy
normal pulp
- symptoms: none
- pulp testing response: normal
- pain: felt only a few secs (1-2) after test
teeth to examine during diagnostic tests
- contralateral
- adjacent
- offending
reversible pulpitis
- symptoms: discomfort when cold or sweet stimulus is applied
- pulp testing response: 1-2 secs
- pain: short but not spontaneous
- radiograph: no significant radiographic change
- etiology: exposed dentin, caries, deep restoration
symptomatic irreversible pulpitis
- symptoms: painful tooth and inflamed pulp; influenced by postural change
- pulp testing response: sharp pain
- pain: 30 secs or more, unprovoked; spontaneous/referred
- radiograph: may or may not have radiographic changes
- etiology: deep caries, extensive restoration, fractures exposing pulpal tissues
asymptomatic irreversible pulpitis
- symptoms: none; usually very damaged teeth
- pulp testing response: normal
- pain: none
- etiology: trauma or deep caries followed by exposure
asymptomatic irreversible pulpitis: 3 conditions
- teeth is calcified
- internal resorption
- pulp polyp/chronic hyperplastic pulpitis
apical diagnoses
- normal apical tissues
- symptomatic apical periodontitis
- asymptomatic apical periodontitis
- chronic apical abscess
- acute apical abscess
- condensing osteitis
anatomical considerations before starting root canal preparation
- (canals) may divide, rejoin and possess lateral ramifications
- apical foramen lies several mm away from the end of the roots
- roots may posses an additional canal
- all canals are curved especially in the apical 3rd
- in flattened and curved roots, canal may lie closer to the bifurcation side of the root
features of an ideal preparation
- minimal enlargement of apical foramen
- creation of even, progressive taper from apical stop to stop pulp chamber following natural curvature of canal
- provision of apical stop at the end of the canal
- adequate cleaning of canal at optimum working length
most commonly used intracanal irrigant
sodium hypochlorite (5.2%)
criteria for obturation
- asymptomatic tooth
- intact seal (temporary filling)
- dryable canal
- no foul odor
- no sinus tract (gum boil, fistula) if previously present
- properly flared/shaped canal
- negative culture result
