07- Cleaning and shaping the root canal Flashcards
biological aim of cleaning and shaping
- removal of pulp tissue or pulp tissue remnants
- removal of infected dentin
- disinfection to remove bacteria
minor constriction
- at cementodentinal junction
- narrowest site of the apical foramen
- 0.5-1.0 mm from major constriction
- “apical stop”
- point to which tissue is removed (amputated) and instruments shape
what is the point to which tissue is removed (amputate) within the canal?
the minor constriction
what type of files are the hand files?
K files
what does the “root zx”(EAL) identify?
it “announces” the minor constriction
crown down technique
-coronal 3rd, middle 3rd, apical 3rd
pathfinding or scouting canals
- used before rotaries to provide information about the canal system
- K-files only (size #6, 8, 10, 15, 20)
- stainless steel
- used to establish a working length and investigate apical foramen
what instruments would be used for pre-enlargement of the coronal third
- Gates-Gliddens
- -#1, 2, 3, 4, 5, 6
- operated in slow-speed or electric handpiece
- orifice shapers (operated in electric handpiece)
what irrigants are used?
- NaOCL (remove vital and necrotic tissue)
- EDTA (remove smear layer)
- Chlorhexidine (disinfect canal)
EDTA
remove smear layer on walls of the canal after preparation with instruments
the “radiographic apex” is what structure?
the major constriction
Objectives of Mechanical Shaping
- Leave as much radicular dentin as possible yet enlarge adequately to remove tissue & infected dentin
- Maintain original shape of the canals yet enlarge that shape uniformly from apex to coronal
- Shape canal to a size that can be easily obturated
“revolutionary” rotary instrument are made of what
Ni-TI (nickel titanium), it bends without permanent deformation
different tapers available when shaping the canal space to minor diameter
0.02, 0.04, 0.06
irrigants do what?
“clean and disinfect”
