S2 - Endo sim content Flashcards
What is the importance of accurate detection of foramen
helps determine how far instruments should advance within canal and at what point preparation and filling should stop (WL) -> at the apical constriction (narrowest diameter of canal)
Where does WL terminate
apical constriction (usually 0.5-1mm before apical foramen)
What is patency?
where the apical portion of the canal is maintained free of debris by recapitulation with a small file through the apical foramen
What are the measurements shown
- radiographic length
- patency length
- WL
Name some irrigants in RCT
- NaOCl
- CHX
- EDTA
Why is NAOCl the most common irrigant. What is a caution
antibacterial capacity
+ ability to dissolve necrotic tissue, vital pulp tissue and organic components of dentine and biofilms in fast manner
if used w/o caution, very destructive to IO soft tissues, the periradicular vasculature and cancellous bone where it can elicit severe inflammatory responses and degradation of organic components
Pro and con of CHX. Which strength is best? A caution
- antibacterial efficacy is concentration dependent (2% > 0.12%)
- lacks dissolution capacity of organic matters like NaOCl
- combination of NaOCl and CHX produces change of colour and toxic insoluble precipitate, formation of 4-chloroaniline, that may interfere w the seal of the root obturation
When is EDTA used and why? At which concentration and for how long?
once cleaning and shaping is complete, to chelate and remove mineralised portion of smear layer
17% for 3min in direct contact w RC wall
What is the taper of ISO files
0.02mm
ISO colours
8 - grey
10 - purple
15 - white
20 - yellow
25 - red
30 - blue
35 - green
40 - black
45 - white
Summarise the crown down technique (6)
Using K files
Scout the canal to RL using 15 or 10
- Coronal to middle 2/3: File RL-5mm using increasing files 5 sizes up from the first one that binds + Use Gates Glidden burs to open entrances/orifices for better access, do not force down or go further than RL-5mm
- Patency length: get a small file (6-15) down to PL.
- WL: 0.5-1mm less than PL, and enlarge canal to file size 2x larger than PL (first to bind)
- Step back: WL -1, -2 then -3mm w 3 increasing large files from the last step
- Recapitulate: to patency and irrigate w size 15 or 10 between steps
- Finish: using size 20 K and H files to WL
rmb: coronal and middle 1/3, PL, WL + 2, step back, recapitluate, finish
What is apical stop
apical end of RC preparation that prevents further advancement or progression of both endodontic instruments and obturation materials
What is radiographic length
tip or end of root determined radiographically, location can vary from anatomic apex due to root morphology and distortion of radiographic image
What is the crown down prep?
WHAT IS THE MAIN POINT?**
technique of canal prep involvig early flaring w instruments followed by incremental removal of canal debris and dentin from orifice to apical foramen, involves files w no apical pressure once binding occurs
emphasises cleanign and shaping of coronal portion of canal prior to apical portion (avoid transferring bacteria)
What is recapitulation
reintroduction of small files during canal preparation to keep apical area clean and patent