Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

endo II > lecture 2: cleaning and shaping > Flashcards

lecture 2: cleaning and shaping Flashcards

1
Q

the 9 step prep

A
  1. scouting
  2. patency
  3. working lengths
  4. glide path
  5. shaping of coronal 1/3 of canal
  6. shaping of middle 1/3 of canal
  7. perfecting straight-line-access to mid-root
  8. shaping of apical 1/3 of canal
  9. final shaping objective
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

step 1: scouting file

A
  • locate and negotiate canals

- once pulpal access is achieved you locate canals using endo explorer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what do you look for with the endo explorer

A

you look for a ‘stick’ in the canals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what file do you use for step one

A

scouting file #10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

if you don’t irrigate what will happen

A

if you don’t irrigate you will almost certainly block yourself out and never reach patency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is watch winding

A

a gentle right and lock rocking motion which causes the instrument to cut while inward pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

step 2: obtain patency

A

finding patency using the #10 file going slightly beyond the canal exit and use the apex locator.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how it patency maintained

A

by recapitulation (irrigating and revisiting patency occasionally with the patency file only)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

if you have a tight resistance to apical advancement then

A

you probably have a small canal which must be enlarged carefully to reach patency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

if you have a loose resistance to apical advancement then

A

you have encountered a canal curvature and you must ben the terminal flute of your file and search for the path to negotiate the curve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

during recapitulation what is very important:

A

you need to irrigate the canal and revisit patency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

step 3: working length

A

ALL shaping is done at WL which is 1mm short of the canal exit.

confirm with a #15 SS File

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

is WL critical to RCT success

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are your reference points

A

ant: incisal edges
post: cusp for which canal is named, flatten cusp when possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

step 4: create a smooth “glide path”

A
  • its created using hand files (pre-curved to match or slightly exceed the curvature of the canal)
  • enlarge the canal to a size #15
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

the purposes of creating a smooth glide path

A
  • to smooth curves and make sure there are no canal obstructions
  • to create space for rotary instruments to be used safely without excessive torque requirements
  • to relieve stress on tip of rotary file to minimize fracture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

step 5 to 8: shaping the canals by thirds

A
  • coronal, middle and apical

- use the machine driven file to begin canal shaping.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what lengths do wave one files come in

A

21, 25, and 31 mm.

select the appropriate length for your tooth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

you choose the size of wave one file to be used based on the

A

diameter of the canal you are treating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

a 10 K file was resistant to movement so you use

A

a wave one gold small file

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

if a 10 k-file moves to length easily, is loose or very loose, use

A

a wave one gold primary file

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

if a 20 hand file or larger goes to length, use

A

a wave one gold large file

23
Q

you will be shaping the canal 1/3 at a time:

A

you will shape around 3-5mm at a time for each section

24
Q

wave one gold reciprocal files sizes are

A

small: 0.2mm at tip
primary: .25mm at tip
large: .45mm at tip

25
Q

step 7: straight line access to mid root

A
  • use a .25/.12 vortex orifice opener
  • mill to the depth of mid root only.
  • any lateral motion should be away from furcal area
  • recapulate: irrigate
26
Q

step 8: shaping apical 1/3

A
  • confirm patency and WL

- then irrigate

27
Q

step 9: final shaping objective

A
  • pick MAF at the WL

- each canal is different and allows for a certain cleaning and shaping

28
Q

MAF =

A

master apical file

29
Q

MAF for small, medium and large roots

A

small: #30-35
medium: #40-45
large: #45-50

30
Q

final shaping objective

A
  • using vortex blue file keep moving and go completely to WL.
  • they should be flexed while rotating and being drawn out to increase the flare fo the canal in an appropriate direction .
31
Q

vortex blue files automatically give you a __ taper

A

0.06 taper

32
Q

how long should the vortex blue be there when taken to WL

A

no longer than 1 sec at WL or short of WL

33
Q

if you rotate the vortex blue file short of the WL what will it create

A

it will ALWAYS create a ledge

34
Q

primary etiologies of pulpa and periapical ds

A
  • caries or other injuries
  • infected dentin and soft tissue (pulp)
  • microorganisms and their toxins invade
  • substrate in canal system fuels micro-organisms
  • result is peri-radicular lesion
35
Q

primary objectives of rct

A
  • remove all caries
  • remove infected dentin and pulp
  • remove micro-organisms and toxins
  • remove substrate from the canal system
  • create a shape encouraging proper obturation
  • seal the root canal system and all portals
36
Q

what are the 5 shaping principles

A
  1. a constant tapering funnel from crown to WL
  2. curves of canal respected w/o transportation
  3. retention of the apical constriction
  4. enlargement of the canal system to create clean white fillings (adequate cleaning)
  5. adequate “deep space” for proper obturation
37
Q

what shapes do we want:

A
  • constantly tapering funnel
  • that is a better deep shape
  • and follows the natural shape of the canal
38
Q

shaping techniques

A

shaping: the files do the shaping
- removes of all caries and infected dentin
- allows convenience form for effective irrigation
- creates a resistance form to facilitate effective obturation
- conserve tooth and root structure to minimize VRF

39
Q

cleaning techniques

A
  • irrigation cleans
  • 8.3% NaOCl and 17% EDTA
  • it dilutes and neutralizes toxins
  • dissolves and removes substrates
  • flushes out debri
  • edta removes the smear layer
40
Q

what removes the smear layer

A

edta

41
Q

results of early RCT attempts by students

A
  • over-enlarging
  • strip-perf
  • transportation
  • inadequate flair
42
Q

WL key points

A
  • critical to success

- 1mm short of canal exit

43
Q

how is the WL measured

A

at a reproducible reference point

usually use the cusps for which the canal is named.

44
Q

if the WL is too short what will it result in

A

a blockage

45
Q

if the WL is too long what will it result in

A

a blow out

46
Q

finding the WL: ETL

A

estimated total length

if tooth in mount, ETL

use the apex locator in clinic

47
Q

what is a “serial step back”

A
  • aka SSB
  • a process to create an apical resistance form when rotary instruments are not available due to very large canal diameter
48
Q

is it difficult to blow out lots of sealer with a large apical foramen

A

NO, it is EASY

especially with hydraulic obturation

49
Q

when should SSB be used

A
  • when a canal requires enlargement larger than a size #.50, it will be necessary to employ SSB
  • when a blow out has been created and you need to create a new and larger apical control zone and taper to contain the GP within the root
50
Q

ACZ is

A

apical control zone

51
Q

how does SSB work

A
  • initial apical gauge = #50 file
  • take MAF to #60 hand file at ACZ to retain (GP)
  • SSB at 1mm to #70, #80, #90, #100, #110, creates a taper using essentially straight hand files
  • SSB creates a taper coronal to ACZ to facilitate obturation in the absence of appropriate tapered files
  • final apical gauging
  • now have a good shape for GP
52
Q

what is final apical gauging

A
  • using hand files for SSB

- it should show a #45 goes patent, after MAF, a #60 file binds to ACZ and a #70 binds 1mm short

53
Q

what type of shape will you end up with in a SSB

A
  • a “stepped” preparation

endo II (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions