ACCESS AND INSTRUMENTS FOR RCT IN POSTERIOR TEETH Flashcards
pre treatment assessment
clinical
- can you isolate with rubber dam
is the tooth restorable following endo tx
radiographic
- need PA and BW (to assess coronal status)
furcation radiolucencies indicate
poorer prognosis
clinical assessment
caries restorations status of remaining tooth structure mobilitu periodontal pocketing status of mucosa TTP colour change
parallax
can be used to determine the differce between canals which overly each other
SLOB - the x ray tube moves mesially so teh canal moves the same direction (lingual)
preliminary tx
ensure tooth adequately restored
restore caries and replace defective restorations
dismantle coronal restorations if appropriate
access cavity
no undercuts
smooth axial walls
all canal orificies visible
ideal access is a funnel to allow instruments straight entry into the canal orificies
common mistakes with acess caity
orientation and shape guaging
- oriention based on the pre op radiograph
anterior teeth need angle through long axis of tooth
upper 2nd pre molar shape
1RC
1 roots
oval
lower premolars
30% have two RC
oval shapeed
lingual can be missed due to access
wider mesiodistally
upper moalrs
can have 3/4 RC shape like a trapezium/triangular MB 2 RC possible palatal tends to be the biggest MB1/2, MP, DB
upper second molar shape
traignular on the mesial aspect
MB, MP, DB
lower first molar shape
more to the mesial trapezium shape wider at the mesial buccal is wider than the distal 3RC for 1st molar 3/4 for 2nd molar (larger canal indictates 2)
