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42 Cards in this Set
- Front
- Back
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Files in UBC cassette
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6-20 steel K-files
debride all canals to working length 15-25 : FlexSSK K-files non-active tip and more flexible working part to minimize the risk of ledging and transportation |
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Types of Filing Motions
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reaming
turn and pull watch winding watch winding and pull peripheral filing |
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Reaming
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Reaming is a clockwise or right hand rotation of the preparation instrument
instrument separation may be elevated with this motion |
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turn and pull
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The turn and pull motion is a one quarter turn right with a straight outward pull
The size of the arrow indicates the magnitude of force There is more force on the outward pull |
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watch winding
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Watch winding involves a gentle right and left rocking motion with a light inward pressure
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watch winding and pull
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This motion is like the previous watch winding but indicates a pull with the withdraw of the instrument
The force begins when rotation is cease and the instrument is pulled out |
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peripheral filing
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Peripheral filing is done at the final preparation stage to ensure the taper of the root canal as well as the uniform and flow
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balanced force technique
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one fourth - one half turn clockwise
one fourth - one half turn counter clockwise (while maintaining pressure) after 2-4 turn if not yet reach WL, rotate out of the canal by 1-2 noncutting clockwise rotation combined with pulling. final clockwise cleaning rotation: 2-3 full circles at WL |
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Hedstroem files
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for push and pull motion
not to be used with rotation and allowed to bind to dentin should be one size smaller than the size of canal at WL, for polishing use |
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FLEXNTK Files:
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comes in size 15-60
UBC use 30 and on check for asymmetry |
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UBC file cassettes
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6-10 K-files
15-25 flexSSK k-files (non-active tips) 30-60 FlexNTK files (active tip) |
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sealer
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ROTH
zinc-oxide and eugenol Thermaseal (AH+) : epoxy resin based |
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Maxillary central incisor
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round
99% one canal but review for variation: invagination, gemination |
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Maxillary lateral incisor
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usually one canal and one root
round dilacerate distally (palatally or labially) dens invaginatus common lingual radicular groove: provides a pathway for salivary leakage to the root apex |
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Maxillary canine
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one canal and one root
dilacerates distally longest and strongest root oval |
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Max first premolar
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two roots two canals usually
root tips fine - may result in perforation in a straight canal if a large apical open size is attempted one canal (10-20%), three canals (1%) |
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Max 2nd premolar
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single root
can have two canals join ( class II or class III) |
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Max first molar
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canals:
4 80% 3 5 palatal, distobuccal, mesiobuccal often fail because missed one fo the mesiobuccal (which should be straight...1-3mm lingual to MB1) palatal root often curved buccally at the apex |
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Max second molar
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most variation
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Mand central incisor
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1-80%
2-41.4% flattened canal missed often lingual canal |
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Mand Lateral incisor
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1-2mm longer root than incisor
distal dilaceration |
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Mand canine
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oval
2 canals in one root - 20% root tip curve distally/labially sometimes, but most often straight root |
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Mand first premolar
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1-70%,
2-30% |
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Mand 2nd premolar
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one canal, sometimes have lingual canal
molarization more frequent than first premolar, but still rare |
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Mand first molar
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4 - 60%
3 - 39% 5 - 1% distal root - often 2 canals mesial root - usually 2 canals, sometimes three, rarely 1 |
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Mand 2nd molar
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3 - 60%
4 - 40% likely to have fuse or C shape susceptible to vertical root fractures |
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Max adn mand third molars
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large variation
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What are 2 reasons why there would be a variation in the WL?
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1. Root resorption,--WL may be 1.5 to 2.0 mm short of radiographic apex
2. Increased cementum deposition—in elderly pts, causes WL to be 1-2mm short of the apex |
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debridement
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instrumentation and irrigation
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instrumentation
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planning all walls to loosen debris
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Irrigation
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flushing debris from root canal
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Minimum MAF file
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30
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Minimum PWL film file
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15 (in order to see on radiograph)
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Coronal half preparation
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1. Take a #35 file and place it passively into the root canal
2. If it advances ½ way up the root canal w/o interference, give it a quarter or half turn and remove it from the canal or 3. Take a #2 Gates Glidden burr and place it spinning into the canal to the distance the #35 file was placed 4. Irrigate 5. Repeat with #3 and #4 bur |
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step back and recapitulation
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1. Used a file 1 size larger than the MAF and instrument it ½ mm short of the WL
a. Place instrument to length, b. give ¼ turn in clockwise direction c. remove and clean debris d. reinsert to length, & file peripherally e. irrigate with @ least 1 ml irrigant 2. Return to the MAF file and instrument back to WL to loosen debris @ apex 3. Repeat step ** with the next larger file until a total of 3-5 successive files are used, each instrumented 1/2mm shorter than the preceding file - if MAF can't go in, use a size 10 file to clean the debris |
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crown down technique
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min PWL file #20
SX : proceed - resistance - withdraw 0.5mm - proceed - resistance - withdraw 40 profile vortex - proceed - resistance - withdraw 0.5mm - advance 1mm - withdraw (repeat with all size file:) 40 (1/2 - 2/3 WL 35 (2/3 - 3/4 WL) 30 (3/4 - 4/5 WL) 25 (4/5 - full WL) 20 FULL instrumentation of WL to at least size 30 |
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Hybrid technique
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crown down and step-back
if size 35 or 40 vortex goes full WL, use step back to prepare apical third. |
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Criteria for determining end point to CLEANING
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1. glassy, smooth walls
2. clean dentin shavings 3. clean irrigating solution |
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criteria for determining end point to SHAPING
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1. apical matrix: at least 3 sizes greater than the first one to bind at WL
2. flare is sufficient to allow penetration of the D11 and D11T to within 1-2mm of WL alongside the master cone seated to WL. |
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common irrigant
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sodium hypochlorite *.5-5.25%
KILLS MICROORGANISM, DISSOLVE NECROTIC TISSUE chlorhexidine glucontate: does not dissolve tissue EDTA 17%:remove smear layer MTAD: tetracyline, citric acid, detergent: remove smear layer, antibacterial sodium hypochlorite: irrigate, EDTA: final rinse to remove smear layer |
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What are 4 indications for obturation?
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• patient is asumptomatic
• tooth is not tender to percussion • pre-existing fistula has sealed • canal can be dried (i.e., no fluid in the canal) |
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material cautions:
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RC prep not to be used in calcified canal until it has be negotiated to at least the middle root third
EDTA not to be used when a ledge happens |
