Lecture 2: Cleaning & Shaping Flashcards
Determine what type of canal is seen below:
Type I
Determine what type of canal is seen below:
Type II
Determine what type of canal is seen below:
Type III
Determine what type of canal is seen below:
Type IV
What are the five principles to shaping?
- a CONSTANTLY TAPERING FUNNEL from crown to WL
- CURVES OF CANAL RESPECTED without transportation
- Retention of the APICAL CONSTRICTION
- ENLARGEMENT OF THE CANAL SYSTEM to create clean white fillings
- ADEQUATE DEEP SPACE for proper obturation
List the nine steps following proper access:
- scouting (#10 hand file)
- patency (#10 hand file)
- working length (#15 hand file) TIGHT file
- glide path (#15 hand file) LOOSE file
—ONLY HAND FILES TO THIS POINT—-
- shaping of coronal 1/3 of canal (wave one gold)
- shaping of middle 1/3 of canal (wave one gold)
- perfecting straight-line-acess to mid-root (.25/.12)
- shaping of apical 1/3 of canal (wave one gold)
- final shaping objective (vortex blue)
When using hand files after the shaping of the apical 1/3 of canal, this process is called:
SSB (serial step back)
What file is used for scouting?
10
What file is used to find patency?
10
What motion is used during scouting?
watch winding
The gentle, right & left rocking motion, which causes the instrument to cut while a light and inward pressure (straight arrow) keeps the file engaged and progressing towards the apex:
watch winding
The canal is _____ when a #10 file goes slightly beyond the apex and 0.5mm into the PDL
Patency
When watch-winding, how many degrees each way?
30 degrees
The canal is _____ when a #10 file goes slightly beyond the canal exit (0.5mm) = long = into the PDL
Patent
The ______ will help us located the canal exit clinically
apex locator
Patency is maintained by:
recapitulation
Patency is maintained by recapitulation which is:
irrigated and resisting patency after wave one with the #10 file
When trying to obtain patency, if there is TIGHT resistance to apical advancement, you probably have:
small canal
When trying to obtain patency, if there is LOOSE resistance to apical advancement, you probably have:
canal curvature
All shaping is done at:
WL
What is the reference point for anteriors?
incisal edge
What is the reference point for posteriors?
Cusp for which canal is named
On the apex locator what denotes patency?
single red line
How do you tell if two canals converge or are simply two canals in close proximity?
The 2 file technique
What is being described below?
- establish working length of “each canal” separately
- attempt to place 2 files to WL in each canal at the same time
- If both go to working length this means you have two canals
- If one goes to WL and the other is short, reverse the placement sequence and if one is still short this means you have a converging class II canals
2 file technique (to determine if there are two canals in close proximity or if canals converge)
To determine if there are two canals in close proximity or if canals converge:
If both files go to working length:
2 canals
To determine if there are two canals in close proximity or if canals converge:
Only one canal goes to WL:
canals converge to single apical exit
You should create a smooth glide path only after:
WL is confirms with #15 hand file
List the purposes of creating a smooth glide path: (3)
- smooth curves and make sure no canal obstructions
- create space for rotary instruments
- to relive stress on tip of rotary file (minimize fracture risk)
The glide path is created using:
Hand files (pre-curved to match or slightly exceed the curvature of the canal); watch-winding entry & pull strokes
What motion do we use when using waveone gold to shape the canals?
Light “pecking” motion
When do we perfect the straight-line access to mid-root?
following second 1/3 shaping with wave one
What do we use to perfect straight-line access to mid-root?
.25/.12 Vortex orfice opener
What files are used for the final shaping and smoothing of the canal?
Vortex blue files
Radiographs will generally show ____ & ____ curves
mesial & distal
____ & ____ curves will usually NOT be seen on the radiograph
facial & lingual
A bulls eye indicates:
root tip severely turns to facial or lingual
What can happen when we place a straight hand file in a curved canal?
Ledges & blockages
A ledge can be the first step to _____ or ____
blockage or transportation (outside wall)
____ of apex occurs within the root. This may also be called:
tranportation; zip
If a zip occurs through the apex to the exterior of the root, we have an:
apical strip perforation
Occurs when files used are either too large or too aggressively used for a small and thin walled canal:
strip perforation
Strip perforations commonly occur on the distal or mesial root of ____ and MF of _____ & _____
lower molars; upper molars; 2-canal premolars
