Basic Root Canal Procedure Steps Flashcards
What three things are done prior to the basic root canal procedure steps?
- diagnosis
- case assessment
- anesthesia
What are the basic root canal procedure steps?
- Initial Radiographs
- Estimation of Working Length
- Rubber Dam Isolation
- Access Opening
- Working Length Determination (via radiographs)
- Cleaning and Shaping of the Canal(s) - either Step Back or Crown Down techinque
- Master Cone Selection
- Obturation (check with radiograph)
- Restoration (temporary or final)
- Final Radiograph (“finish film”)
What is the reference point on your “start films”?
the incisal or coronal-most point on the radiograph (the reference point)
How do you determine your estimated working length?
- measure from the incisal or coronal-most point on the radiographs (the reference point) to the apex of the root (or roots)
- subtract 1mm from the measurement.
What is required throughout the entire procedure (even during radiographs)?
rubber dam isolation
What is one of the hardest and most critical steps of root canal therapy?
achieving a good access opening
What do you use to measure the depth of your chamber or canal?
radiograph
Make sure you remove the ___ of the chamber (___ is yellow or brown color). The chamber floor is ___ and ___.
roof; dentin; gray; grooved
T/F. It is ok to touch the bur to the chamber floor.
False
How do you identify the canal orifice(s)?
with your endodontic explorer
Starting with a #___ file and ___ (EndoGel, Glyde, etc.), ___ the file to your estimated working length in a ___-winding motion.
10; lubrication; wiggle; watch
How do you help establish patency during the working length determination step?
with the #10 file, wiggle 1mm beyond the estimated working length
Once you have wiggled with the #10 file to the estimated working length, what should be done?
place a #15 file into the canal and wiggle it to the estimated working length. Leave the file in place and take a radiograph
How do you record your final working length?
Measure with your ruler on the radiograph and adjust your rubber stopper depending on whether the file appears short, long, or just right.
What must always be used to prepare the canal(s)?
lubrication and irrigation
Clinically, you will irrigate with ___ ___. When working with extracted teeth you will irrigate with ___.
sodium hypochlorite; water
T/F. Prepare the canal(s) moving through the file sequence from large to small. It may be necessary to force the file to length.
False, Prepare the canal(s) moving through the file sequence from SMALL to LARGE. NEVER force the file to length.
What should be done between each file used?
- recapitulate (gain patency) with a #10 file (1mm beyond your working length)
- continue to irrigate after every couple of files
What Gates Gliddens do you use? Should you force them?
#2, 3, and 5 NO
How far down do Gates Glidden files go? What is their purpose?
only part way down the canal (#2 farther than #3, #5 staying at the orifice)
to help create a straight line to the apex and help you to place bigger files to the working length
What should be down between using each Gates Glidden?
irrigate
You will keep preparing the canal(s) until when?
you have reached an appropriate FINAL APICAL SIZE. This is the biggest size you prepared at the apex.
continue to prepare the canals with larger files #20, #25, #30, etc… Remember to keep recapitulating and irrigating!
What is expected at the final apical size?
a minimum of #30 and is estimated by going TWO file sizes larger than the first file size that binds after using your Gates Gliddens.
Why do you perform the step back procedure?
now that you have opened up the coronal portion with Gates Gliddens and the apical portion with files, you need to combine the two in the middle portion of the canal.
How do you perform the step back procedure?
Select the next file size larger than your final apical file, set the stopper 1mm shorter than your working length, and prepare the canal with this file. Repeat this with the next three files sizes each 1mm shorter than the previous file length.
What should be done between every 1-2 step back files?
irrigate and recapitulate
When are you done cleaning and shaping? What should be done next?
once you have finished stepping back
check for a apical stop and take a radiograph with the file that matches your final apical size (size at the apex, at the step back sizes) at your final working length
How do you check the apical stop?
place your final file in the canal and apply gentle pressure apically on the file. If the file pushes beyond your final working length, you DO NOT have an apical stop. Prepare the canal at least 1 file size larger and repeat the apical stop check.
T/F. If you use a rotary file you ALWAYS use a combination of hand files AND rotary files.
True.
What is the conceptual difference between using rotary files versus only hand-filling?
when cleaning and shaping with hand files you use a step back procedure to enlarge the canal, while with rotary files you use a crown-down technique.
In other words, you are working down to the apex from the crown (“crown-down”) versus stepping back to teh crown from the apex (“step back”).
Explain the crown-down technique.
starts with the largest files at the coronal portion of the root, and goes through the file sequence with progressively smaller files until you reach your working length.
In general, the ___ files are used from larger to smaller and the files should be taken until slight ___ is felt. What should be done next?
rotary; slight
stop and move to the next smaller file
Why should you NOT force rotary files?
they can separate
What are the two parts to a rotary instrument?
taper and tip size
What is the rate of change of cross-sectional diameter, or the amount of size increase along each millimeter of its length (ie. 0.04, 0.06, etc)?
taper
bigger numbers meaning larger tapers
What is the diameter at the end of the file (also referred to as D0)?
tip size
How does file diameter increase?
in 0.05 increments up to size 60 files and then by 0.10 increments up to size 140
rotary file example. a 30/0.04 file has a tip size of 0.30 mm. At 1mm from the tip, the size (diameter) is 0.34 mm.
The smaller more curved canals should have ___ tapers while larger, straighter canals can be prepared with ___ tapers.
smaller; bigger
What is the smallest apical size generally accepted?
a size #30
What do the colors on the rotary files correspond to?
the colors on the hand files
For most systems, the number of stripes can be multiplies by ___ to get the taper.
2
What is the number listed first? second?
the size at the tip of the file
the taper of the file
How should you record the information?
length/final apical size/taper
T/F. Rotary files must be used with lubricant.
True. Running them in a dry canal increases the risk of file separation
What should the rotary speed be set to?
500RPM
Use the two ___ ___ in sequence (black, then red), first coating them with ___. Use an in-an-out “___” motion, applying ___ pressure as the instrument is rotating in the canal.
orifice openers; lubrication; pecking; GENTLE
Do not use excess pressure on rotary files as they will bind and separate in the canal
T/F. Orifice openers are longer than the preparation files.
False, they are shorter. You DO NOT take them to working length
During the crown-down procedure, how do you know you have the appropriate final apical size (size of the canal at the apex)?
minimum of #30
estimated by going two file sizes bigger than the first hand file that binds
What do you want the final size to at least be?
30/.04
T/F. The master cone should be the same apical size as your initial apical file.
False, The master cone should be the same apical size as your FINAL apical file.
T/F. Once you are confident that you have the correct size master cone, you do NOT need to take a radiograph of it in the canal.
True.
What do you do after you have the correct size master cone?
Remove the fitted cone and set it aside
Place sealer with your final file (in this case #30) by working the file counterclockwise to coat the canal walls
Place sealer on your master cone and seat it to the working length.
Once you have set the master cone to the working length should you take a radiograph?
NO
How do you condense the master cone against the wall of the canal?
with the D-11 spreader (D-3) for really long teeth
Where do you set the silicon stop?
to the working length. gently place it alongside the master cone as far as you can in the canal, using slight pressure
What is the purpose of the spreader?
to create space for the accessory gutta percha points
How do you remove the spreader? What is done after it is removed?
Do not pull
Try to move the spreader from side to side until it is gently loosened and removed
Place an accessory cone coated with sealer in the space made by the spreader
You are condensing the cones ___ taking a radiograph to see if you get movement of the ___ material.
before; obturation
When do you take a radiograph?
after a few accessory cones are placed
What do you do if the fill appears short?
Remove the filling materials and clean/prepare the canal with the master file and place cones. Take another radiograph
What do you do if the fill appears long?
measure the distance that you are long, remove the master cone (and accessories) from the canal and cut the amount off the end of the master cone. Then reseat the master cone and new accessories. Take another radiograph
When do you stop placing sealer-coated accessory cones?
until your spreader can no longer be inserted beyond the coronal third
sometimes you need to sear off the accessory cones that are in your way to be able to add more
In the clinic, when are post-operative instructions, medications, posting out, etc…. done?
after obturation
before post space preparation
Another name for post-space preparation
gutta percha clean-out
During post space preparation, subtract __-__ mm from your final working length or where the ___ ___ stops radiographically.
4-5; gutta percha
T/F. You must have at least 4mm of gutta percha in the canal to maintain an adequate apical seal.
True.
Why should the post length not be more than 18 mm (depending on the amount of coronal tooth structure remaining)?
You will not get your impression material and/or post to the full length of the prepared space.
Can a post go around a curve?
NO, so you must make your space only in the straight portion of the root
How are most post make for maxillary premolars/molars? mandibular molars?
lingual/palatal canals
distal canals
T/F. Post space can be made at the same appointment as root canal completion or at a future appointment.
True.
When making a “traditional” post space or space for a cast post and core, how is the gutta percha removed?
in a coronal fashion
you should NOT be cutting walls
follow canal architecture to prevent any undercuts
The #3 Gates Gliddens should go to your post preparation length then you should move to #___. Your final post preparation files should start with #___. You can stop at #___ if you have no undercuts and all of the material is removed.
4; 70; 90
Once your post preparation is adequate, what is done next?
take a radiograph WITHOUT the file in place to verify the length, size and absence of any filling material in the preparation space
T/F. You should irrigate the canal during a post space preparation.
False.
Para Post drills are ___-___ and will cut more easily through ___ than Gates Gliddens.
end-cutting; dentin
