Working Length Cleaning and Shaping Flashcards
When is the estimated working length measured?
before starting your access opening
If your working length is off by 3 mm or more, what should be done? less than 3mm?
take new radiograph
Okay to adjust and go
What are the two main objectives (regardless of technique used) to cleaning and shaping?
- clean (debride) the root canal system
2. shape and enlarge the canals in preparation for the obturating materials
T/F. The apex should be prepared slightly larger.
True, to size #20 hand file
What prevents losing the working length and prevents packing of debris (blocking out or ledgings/zipping)? What is done using small hand files 1mm beyond the working length?
patency
What is the irrigant of choice? Why?
Sodium hypochlorite (bleach)
It is tissue dissolving
What is the most important step in the root canal process?
Cleaning
What do Gates Glidden or rotary orifice openers remove to maintain straight line access?
Dentin overhangs
What does “blocking out” mean?
Packing debris and occluding canal
Patency should first be ___ then ___.
Established; maintained
What is the last Gates Glidden used? How far down does it go?
5
Goes into orifice but not deep within the canal
What is the minimum final size?
Minimum of #30
If you go two file sizes larger than the first file (20) that binds after using your Gates Glidden, what file do you use?
30, which is ideal
If first was 30, the two sizes larger would be 40
If the final file size is 50. What is the size of the 3rd step back file?
70
After size 60, count in increments of 10
How do you check for apical stop?
Place your final file in the canal and apply gentle pressure apically on the file.
