Brainscape's Knowledge GenomeTM

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


See full index

Endotontics > Hand filing, working length, and apex locators > Flashcards

Hand filing, working length, and apex locators Flashcards

1
Q

6 steps of endodontic infection (etiology)

A

BACTERIA

  1. pulpal injury
  2. irreversible inflammation
  3. ischemia
  4. infarction
  5. necrosis
  6. periradicular extension of disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

primary etiology of endo disease and who determined it? what year?

A

BACTERIA

1965 by Kakehashi

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

two major types of infections in endodontic lesions?

A
  1. Intraradicular infection

2. Extraradicular infections

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

Intraradicular infection

A

contained within the root canal system

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

Extraradicular infections

A

typically forms in response to an intrara-dicular infection lie apical abscess in response to necrosing pulp

can be independent of intra-radicular infection and thus may persist when host defense is unable to clear infection (chronic periapical inflammation)

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

what is considered to be the number one failure of a root canal procedure?

A

coronal leakage

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

what causes coronal leakage?

A
  1. delay in restoration after RTC
  2. temporary coronal filling compromised
  3. fracture to canal system exposed prior to final restoration
  4. final restoration lacks ideal marginal integrity or deteriorates
  5. recurrent caries present at restoration margins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

predictability of successful endodontics is compromised of what three factors?

A
  1. knowledge
  2. skill
  3. desire
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

primary objectives of cleaning and shaping (4)

A
  1. remove infected soft and hard tissue
  2. give disinfecting irrigants access to the apical canal space
  3. create space for the delivery of medicament’s and subsequent obturation
  4. retain the integrity of radicular structures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

in ideal shaping you develop?

A

develop a CONTINUOUSLY SHAPED CONICAL FORM from apical to coronal with apical preparation AS SMALL AS PRACTICAL and in its ORIGINAL SPATIAL POSITION

  • removal of a uniform layer of dentin in all dimensions and all regions of the canal is desirable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

shaping facilitates?

A

CLEANING

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

minimal apical size in shaping? what does this allow for?

A

30/0.06

or maybe 5 and 0.04

*exchanging of irrigants is enabled when open it up

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

shaping criteria and requirements?

when can you be considered done shaping?

A
  1. enlargement
  2. taper (0.06 taper for warm vertical compaction)

shaping can be considered complete when a non-standardized medium or fine-medium gutta-percha cone can be fitted to the working length

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

Schilder’s 5 BIOLOGICAL objectives

A
  1. confine instrumentation to the root canal
  2. beware of forcing necrotic material beyond the foramen
  3. remove all tissue debris from the root canal system
  4. complete cleaning and shaping of canals in one visit
  5. create sufficient space during canal enlargement for intra-canal medication and for potential exudates reception
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Schilder’s Five MECHANICAL objectives

A
  1. develop a continously tapering cone / canal
  2. decreasing cross sectional diameters at every point apically and increasing at each point as the access cavity is approached (canal more narrow apically)
  3. maintain the original ‘flow’ of the canal (prepare in a multitude of planes)
  4. do NOT transport the foramen
  5. keep the apical opening as small as PRACTICAL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the ISO?

A

International Standards Organization

- standardized specifications to improve instrument quality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

two primary goals of root canal instrumentation

A
  1. provide a biological environment (infection control) conducive to healing
  2. develop a canal shape receptive to obturation (filling material)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how do files work? shape vs a reamer?

A

enlarge canals with reciprocal insertion and withdrawal motions

3-4 sides with more spirals

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

how do reamers work?

shape vs a file?

A

cut and enlarge with rotational movements

3 sides with less spirals

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

barbed broaches and rasps function?

how are they made?

A

used to extirpate pulp and enlarge canals

does no cut/ machine dentin

good for removing cotton pellet in chamber or canal

made by hacking a round, tapered wire with a blade to achieve projecting barbs to cut/snag tissue

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

k-type instruments are either?

A

hand files or reamers

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

How do k-type instruments work?

A

Work by compression and release destruction of dentin in surrounding canal
- reaming motion has less transportation than filing motion

penetrating and enlarging canals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

which has more flutes per length unit a file or reamer?

A

FILE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how are k-files made?

A

stainless steel wire ground to tapered square or triangular cross-section and then twisted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

describe how to use a reamer and what is most useful for

A

used in a CLOCKWISE srew-in motion followed by a withdrawl stroke from the canal

used for shaping the CORONAL AND MIDDLE THIRDS of the canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

files are used for shaping what part?

A

the APICAL AND MIDDLE THIRDS of the canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

ISO files aka

A

K files

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what does ‘D0’ signify

A

the diameter at the TIP is measured in 1/100 of a millimeter which corresponds to the file sizr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

all ISO files have how many mm of cutting flutes on them? taper?

A

16 mm (same LENGTH of cutting flutes) with a 0.02 mm taper

30
Q 
in sizes #10-#60 what is the increase in diameter of the file at the tip when go up a size? 
#60-140?
A
  1. 05 mm between each larger file

0. 1mm between each larger file size

31
Q

standard file lengths

A

21
25
31

32
Q

Hedstromes (H-type) files are milled how? importance of that? use?

A

milled from a round steel wire with spirals milled into it

  • sharper edges
  • circumferential filing
  • used in retreival of gutta-percha and seperated instruments

spiral edges to allow CUTTING only during a PULLING stroke

  • has a positive rake angle
  • CUTTING NOT SCRAPING
  • SO SCRAPING PUSH PULL
33
Q

reamers and files have what type of rake angle?

A

negative

34
Q

File cross sections

A
  1. triangular
  2. square
  3. diamond
  4. teardrops
35
Q

which is smaller/ bigger? triangular or square k- file?

which is more flexible?

A

smaller k file is square

bigger k file is triangular

36
Q

in terms of tip cross section being triangular or square —

what has more cutting sides? which is more effective?

A

square has more sides but less efficient at cutting because angulation and space between where it would cut is less

37
Q

in terms of tip cross section being triangular or square —

what has more cutting sides? which is more effective?

A

square has more sides but less efficient at cutting because angulation and space between where it would cut is less

38
Q

two motions for hand files?

A

Reaming - rotation

push-pull - up down

39
Q

sizes of gates gliden 1, 2, 3, and 4?

A

50, 70, 90, 110

40
Q

describe gates glidden drills and their use

A
  • engine driven
  • latch attachment
  • flame shaped
  • used for opening orifices, gaining striaght line access and shaping the coronal third of canals
  • should be used by BRUSHING against walls which are AWAY FROM the furcation area
41
Q

What size file of gates gliden do you need if at WL with a size 40 file?

A

Atleast a #3 = 90

because size 40 file is .40 +. 02 x (.16) =.72

a number 2 gates wouldnt reach the working length

42
Q

composition of rotary instruments

A

NiTi

  • nickel titanium
  • 56% nicel and 44% titanium
43
Q

method of use for rotary

A

use at rpm between 150-600

generally in a CROWN DOWN tchniue

gentle pecking motion

flutes must be cleaned of dentinal mud between each insertion

44
Q

how do rotaries ‘vary’

A

they can be used by varying

  • tip size with same taper
  • taper with same tip size
  • vary both simultaneously
45
Q

you want irrigants to have wat type of surface tension?

A

LOW

46
Q

types of irrigants

A
  1. NaOCl ( 5.25 or half strength at 37 degrees celcius)
  2. H2O2 (hydrogen peroxide)
  3. saline
  4. chloroexidine
  5. Chelators (EDTA or Citric Acid)
47
Q

best irrigant? WHY?

A

CLOROX

  • Sodium hypochlorite
  • antibacterial and DISSOLVES ORGANIC DEBRIS
48
Q

medicaments used as chemical adjuncts in canal tx?

A

Calcium Hydroxide
Ca(OH)2 — most common and placed when one visit RCT is not indicated

  • antibacterial
  • high pH
49
Q

dentin softening agents?

A

remove metal ions

examples are 17% EDTA or 10% Citric Acid

50
Q

use of lubricant in RCT?

A

provide less friction for passage of files

EDTA + Glycerin (Endo-gel, RC Prep)

51
Q

definition of working length?

RT vs AT?

A

Distance from a coronal reference point to a point where canal preparation and obturation should terminate

RT - radiographic terminus vs
AT - actual terminus

  • ideally we want to fill up to the AT as RT could be off
52
Q

Patency definition

A

Openness of the apical foramen

the apex should remain unblocked using a small file throughout the procedure

53
Q

Definition of Recapitulation

A

Re-instrumentation of the canal with the same series of instruments previously used

54
Q

Crown-down technique

A

Instrumentation of the root canal system from the coronal aspect towards the apex

Larger instruments are used first

55
Q

Describe step-back technique

A

Instrumentation of the root canal system starting from the apex towards the crown

smaller instruments are taken to the working length then each larger instrument is subsequently worked to a shorter distance than the previously instrument

56
Q

definition of stress

A

the deforming force measured across a given area

57
Q

Stress concentration point definition

A

An abrupt change in the geometric shape of a file, such as a notc, which results in a higher stress level at that point along the surface of the file where the shape is more continuous

58
Q

strain definition

A

the amount of deformation the file undergoes

59
Q

Elastic limit definition

A

A set value representing the maximal strain that, when applied to a file, allows the file to return to its original dimensions.

after the strain is removed, the residual internal forces return to zero

60
Q

elastic deformation definition

A

the reversible deformation that does not exceed thee plastic limit

  • basically just before the point at which it would break
61
Q

definition of shape memory?

what type of instrument is this a characteristic of?

A

a condition that exisit when the elastic limit is substantially higher than is typical for conventional metals

  • it allows an instrument to regain its original form after being deformed
  • ROTARY HAVE MEMORY
62
Q

Plastic deformation definition

A

Permanent bond displacement, which occurs when the elastic limit is exceeded,

the file DOES NOT return to its original dimensions after strain is removed

63
Q

Plastic limit definition

A

the point at which a plastic deformed file breaks

64
Q

how to tell when K-file has had permanent deformation

A

When flutes wound more tightly or opened more widely

  • should discard immediately as they will fracture during clock-wise motion after plastic deformation
65
Q

describe body shape and pre-flaring

A

Confirmation of coronal patency and probing for curves, obstructions, and extra canals

advantages

  • volume of irrigants early on
  • prevents extrusion of necrotic debris beyond the apex
  • allows for better tactile sensation to detect apical constricture
66
Q

describe balanced force technique with file

A

Insert file and engage Clockwise into the dentin 1/4th turn

with continued pressure, go counter clockwise 1/2 turn to strip the dentin away (apply pressure apically)

do this 1-3 times before removing the file
remove clockwise

67
Q

describe apical shaping and its componetns

A

After WL and MAF have been determined
- ‘deep shape’ provides resistance form for obturation

want a ‘seat’ not stop and not too open

68
Q

what is master apical file and how do you determine?

A

apical gauging - determining actual size of apex and want to be at atleast a #30 with .0 taper with rotary or #35 with .04 taper

LARGEST BINDING FILE AT THE CORRECT WL

69
Q

keys to successful apical shaping

A
  1. recapitualtion
  2. copious irrigation
  3. maintaining patency
  4. Respecting the anatomical constricture
70
Q

CDJ definition

A

The region at which the dentin and cementum are united commonly
- itsposition can range from .5-3.0 mm from the anatomical apex

71
Q

apical zipping creates what shape at the apex

A

a tear drop shape and this is what happens when you over instrument the apical area

72
Q

definition of transportation

A

excessive loss of dentin from outer wall of a curved canal in the apical segment

  • use a precurve file to limit chance of occurring

Endotontics (21 decks)

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