Lec 10-11 Flashcards
(30 cards)
objectives for access
-gain visualization
-room for instruments
-obturation
-maintain strength of tooth
-preserve incisal edge, marginal ridge
proper outline form for max anteriors
max CI: triangular with base towards incisal edge
max LI: same, narrower and less flared
max canine: more oval shaped
pulp is usually located in center mass of root form
TRUE
proper outline from for mandibular anteriors
very narrow M-D and have 2 canals 40% of time, easily perforated
-triangular to oval but narrow
-canines are oval
should look for canals with the bur
FALSE
use endo explorer
mark bur at what depth for reaching the pulp?
7 mm depth should reach the pulp
if you are lost during access
stop and take radiograph and ask for help
if your access is not proper form, too much removed, what could happen?
the tooth is weakened and more complications can occur like fractures
max central access
-triangle shaped
-incisal edge and marginal ridges intact
-3 mm of tooth structure on all sides of access
max lateral access
-use 2 round
-triangle shaped
-watch incisal compromise bc smaller
max canine access
-use 2 or 4 round
-oval shaped
-single canal usually
-huge chamber
mand incisor access
-use 2 round
-very small and narrow
-easily perforated
-2 canals 40-44% of the time
-mostly type II canals
-if fast break seen, then multiple canals
mand canine access
-oval shaped
Weines classification for premolar access
type I: one canal
type II: 2 canals join at apex
type III: 2 canals that don’t join
type IV: one canal divides into 2
type 2 and 4 most difficult
max 1st premolar access
-2 canals 85% B-L
-thin oval access
-use 2 round bur. no wider than #4 bur
-most common error is not totally unroofed
what is the color of the roof and floor of the pulp chamber
roof is more clear/yellow
floor is darker colored
max 2nd premolar access
-one canal usually
-use 2 round
-thin oval access
-4 round width
-if canal not in center, then 2 canals probs (23%)
what does it mean if you see a fast break in the root and a fuzzy canal, or 4 PDLS seen on a radiograph of mandibular 2nd premolar?
means that there are 2 canals (rare)
mandibular premolar access
-thin oval access
-usually 1 root and 1 canal
-color of pulp chamber floor is darker than the roof
what is the law of centrality?
pulp chamber is located in center of tooth
what is the law of concentricity?
the pulp chamber walls are concentric to the external surface
what is the law of the CEJ?
the CEJ is the most consistent landmark for locating the pulp chamber
what is the worst access error?
perforation
mand 1st molar access
and mand 2nd molar access
-3 or 4 canals
-trapezoidal shape, wider base on mesial
-may be 2nd distal canal (DL) that is often missed (30%)
-single distal canal will be in center of access shape
