-
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
-
-
What is the standard taper of most hand files?
- 0.02mm/mm taper
- The width change between Do and D16 is .32mm
- NiTi 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
- Rotary NiTi
- 4. Recapitulation
-
Why do we want to start our apical preparation with small files?
Smaller files used to gather initial length and maintain patency
-
-
What is a patency file?
- Maintains patency of the apex
- Removes debris from the apical area
- Pre-curved
-
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 outer wall (the safe side)
- The file is pressed away from the furca
- Prevents strip-perforation
- 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
- ex: safe side of disto-buccal canal is the disto-buccal side
-
What type of instruments do we use for coronal flare?
Gates-Glidden drills
-
Which technique do we use for the coronal flare?
The crown-down technique
-
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: anti-curvature shaping
- 3. Prep on upstroke only, 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 0.5mm to give .1 taper
- Sequential stops of 1.0mm give .05mm taper
-
What are GT NiTi hand files used for?
- Used for flaring
- Crown down: .10, .08, .06
- Used for checking flare
- Has a reverse thread
-
What are rotary NiTi instruments used for?
- Crown-down technique
- 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?
- Black- #40
- Green- #35
- Blue- #30
- Red- #25
-
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 canal1mm 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
- Less binding
- Less suck-down
- less breakage
-
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
- Use ss files to bypass any ledges
- Don't engage the entire length of the file
-
What is recapitulation?
- Debris removal
- smoothening walls
- 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?
- Strip perforation
- File separation
- Ledging, transportation, zipping, perforating
-
What does the spreader test check for?
- If there is adequate flare
- Adequate cleaning
- room for obturation
- Is it within 2-3mm of apex
|
|
