Card Set Information
What are the aims of cleaning and shaping?
Remove bacteria and debris to create healing environment
1. Smooth and continuous taper and flare
2. Small apical opening
3. Irrigation of the entire canal system
4. Facilitate obturation
What are the criteria for cleaning and shaping?
What are the goals of irrigation?
What is the function of sodium hypochlorite?
Sodium hypochlorite denatures and damages proteins (like collagen)
Why do you never want to wedge a needle into the canal and irrigate?
The irrigant would be forced out of the apex
Stainless steel files
What is the standard taper of most hand files?
The width change between Do and D16 is .32mm
files often have greater tapers up to .12mm/mm
What is recapitulation?
Checking to see if the master apical file goes to length
What is the step back method?
Work backward from the apex to get more taper
What is the UCLA treatment sequence?
1. Apical preparation
2. Coronal Flare
3. Overall flare
Step-back with hand files
Hand NiTi GT (greater taper) files
Why do we want to start our apical preparation with small files?
Smaller files used to
gather initial length
SS K files
What is a patency file?
Maintains patency of the apex
Removes debris from the apical area
How large are patency files usually?
#10 or #15/20 in big canals
How far do we insert the patency file?
All the way to the radiographic apex
Which files are considered the workhorse?
SS Flex-R- Files
What is the initial apical file?
The first file to feel snug at length
Usually sizes 15-40
When it's loose, change to the next file
What is the "quarter turn and pull" technique? What follows it?
A technique used to reach length
Followed by circumferential up-down filing
What is the master apical file?
The largest file brought to length
At least size 30
Used for cleaning and shaping
What is the anti-curvature technique?
The file is pressed against the
(the safe side)
The file is pressed away from the furca
Maintains natural curvature
Files are pre-curved
How are the safe sides of canals named?
The safe outer sides take the names of the canals
: safe side of disto-buccal canal is the disto-buccal side
What type of instruments do we use for coronal flare?
Which technique do we use for the coronal flare?
What are Gates-Glidden drills?
Used for coronal flares
Stainless steel and not flexible
Used at slow speed and high torque
How much should the canal be opened before using Gates-Glidden Drills?
at least #25
What are the steps for using a GG drill for coronal flare?
1. drop passively into an open canal
2. Prep on the safe side:
3. Prep on
never on downstroke
Which three techniques can be used to get an overall flare?
1. Step-back with hand files
2. Hand NiTi Greater Taper GT files
3. Rotary NiTi
Which files are used in a step-back technique?
Ordinary .02mm/mm taper files
How far should you go on the first step of the step-back technique?
The first step is 1mm to preserve the apical stop
Sequential stops are
to give .1 taper
Sequential stops of
give .05mm taper
What are GT NiTi hand files used for?
Used for flaring
: .10, .08, .06
Used for checking flare
Has a reverse thread
What are rotary NiTi instruments used for?
Must open canal up first with apical prep and coronal flaring
Don't bind file by using on-off technique
7 seconds maximum per canal
What are the color codings and tip sizes for Black, Green, Blue, and Red bands on NiTi 'Profile ISO" rotary instruments?
How can you tell taper on NiTi Profile iso Rotary instruments
2 rings and red stop= .04 taper
3 rings and green stop= .06 taper
What are some of the features of Rotary NiTi handpieces?
Very slow 300 rpm for NiTi files
Slow 800 rpm for GG's
Torque control and auto reverse functions
Apex locator option
Only use after mastering hand instruments
Good for easy canals only
X-Smart Endo Motor Set up features
How close to the apex do NiTi files go?
1mm shorter than MAF in a
dead straight canal
1mm shorter than MAF for a mid-root curve <30 degrees
1mm shorter than MAF for a coronal curve <30 degrees
2mm shorer than MAF for apical curve <30 degrees
Never further or a bigger size than the MAF
When will we not use the NiTi files at all?
Not used with sharp or >30 degree curves
Why alternate .06 and .04 taper files?
Limit file contact and engagement
When do we avoid rotary NiTi?
Sharp apical, mid-root, or coronal curvatures >30 degrees
Dividing or merging canals
Very wide or highly flared canals
Can rotary NiTi files be reused on patients?
No, one use only
Avoiding errors with rotary
Straight line access
Avoid difficult anatomy
to bypass any ledges
Don't engage the entire length of the file
What is recapitulation?
blend prep and parts together
ensure length is maintained
Canal preparation and features diagram
What are some common errors during root canal cleaning and shaping?
Ledging, transportation, zipping, perforating
What does the spreader test check for?
If there is adequate flare
room for obturation
Is it within 2-3mm of apex