P2-ENDO LEC-CHAPTER 8

ethyl chloride (-41 celcius)

dichlorodifluoromethane/DMD (-50 celcius)

frozen CO2 (-78.5 celcius)

what are the temperatures of:

a. ethyl chloride

b. dichlorodifluoromethane/DMD

c. frozen CO2

frozen CO2

which method of cold test will cause pitting on porcelain restorations?

buccal surface

what surface is cold testing applied on?

cold stimuli goes into a gas phase, which allows testing to be specific for one tooth at a time

advantage of frozen CO2 and refrigerant spray?

ice cold water

what method of cold test can be used regardless of restoration type, is inexpensive, and applied for a maximum of 15s?

A-delta fibers

which nerve fibers are stimulated with cold test?

C fibers

what nerve fibers are stimulated with heat test?

65 celcius then can be heated up to 200 celcius

at what temperature does gutta-percha melt?

non-vital pulp

what is the diagnosis if pain caused by cold stimulus is relieved by heat?

bipolar

it is presumably the more accurate mode of an EPT because its current is in the coronal pulp

1. adequate stimulus

2. appropriate application

3. careful interpretation of results

what are the requirements for an EPT?

summation effect

​

response threshold reached when a number of nerve terminals are activated

incisors - incisal edge

posteriors - middle third

the most desirable area of assessment using EPT in (a) incisor teeth and (b) posterior teeth?

tip of the mesiobuccal cusp

the optimum site for tester electrode placement on molars is on the?

incisors - lowest

premolars - slightly greater

molars - greatest

what is the response threshold (lowest-greatest) among healthy incisors, premolars, and molars?

crown surface temperature

cholesteric liquid crystals is used to measure crown surface temperature

This pulp vitality technique is based on the hypothesis that vital teeth are warmer and will rewarm quicker after cooling than nonvital teeth.

and what is used to measure?

Transmitted light photoplethysmography (TLP)

is a noninvasive technique used to monitor pulpal blood flow, and has lesser signal contamination than LDF

xenon-133 radioisotopes

what radioisotope can be used to differentiate between vital and pulpless teeth on the basis of blood supply?

Magnification is defined as viewing an object at a greater size; differentiation refers to making an object distinct or specialized.

differentiate magnification and differentiation

vertical root fracture

what is the probable diagnosis if there is an abrupt and isolated deep, narrow pocket when probing?

tooth slooth

has proved very useful for the differential diagnosis of various stages of incomplete crown fractures and allows chewing force to be applied selective one cusp at a time

Methylene blue dye, india ink or iodine tincture

have been very effective dyes used to diagnose the presence of crown or root fractures.

for vital tooth - bitewing

for periapical disease - periapical radiograph

what radiographs are indicated for (a) vital tooth and (b) suspected periapical disease?

condensing apical periodontitis

is a near-pathognomonic sign for long standing pulpitis

ultrasound

introduction of this real-time imaging technique made it able to distinguish between granulomas and cysts

K-type files (ANSI No. 28)

Hedstrom files (ANSI No. 58)

Barded broaches and rasps (ANSI No. 63)

Condensers, pluggers, and spreaders (ANSI No. 71)

Gutta-percha (ANSI No. 78)

Sealers (ANSI No. 57)

Ansi No. of:

1. k-type files

2. hedstrom files

3. barbed broaches

4. condensers, pluggers, and spreaders

5. gutta-percha

6. sealers

ISO No. 3630-1

- K files (ANSI No. 28)

- H files (ANSI No. 58)

- barbed broaches, rasp (ANSI No. 63)

ISO No. 3630-3

- condensers, pluggers, spreaders (ANSI No. 63)

what are the ISO standard of endodontic instruments, and what are their ANSI No.?

(1) to provide a biologic environment (infection control) conducive to healing and (2) to develop a canal shape receptive to obturation

The two primary goals of root canal instrumentation are

Files

manually operated instruments that enlarge canals with reciprocal insertion and withdrawal motion

Reamers

manual instruments that cut and enlarge canals with rotational motions

1. canal transportation

2. break the file from excessive torsion

what are the errors that will occur if a clinician is unaware of the tip design of a particular endodontic instrument?

if the canal is SMALLER than the instrument tip, then use a MORE cutting efficient tip

if the canal is LARGER than the instrument tip, then use a LESS cutting efficient tip

inverse relationship!

what is a good beginner's rule regarding the relationship between canal size and instrument tip to help prevent canal transportation?

number of sides and spirals

3 sided with few spirals - reaming

3/4 sided with more spirals - filing

what determines whether the instrument is best suited for filing or reaming?

nickel titanium (NiTi)

this material has increased flexibility than stainless steel hence it is used in manufacturing root canal instruments

Group I - Manually operated instruments (K-type and H-type instruments)

Group II - Low speed instruments (Gates-glidden, peeso reamers)

Group III - High speed NiTi instruments

Group IV - Self-adjusting file.

Group V - Engine-driven reciprocating instruments

Group VI - Ultrasonic instruments

what are the groups of endodontic instruments used for root canal cleaning and shaping?

barbed broaches and rasps

this instrument is mostly used to engage and remove soft tissue from the canal. it is also an excellent tool for removing cotton or paper points that have accidentally become lodged in the root canal.

K-file

penetrating and enlarging root canals.

"transportation"

refers to the excessive loss of dentin from the outer wall of a curved canal in the apical segment and can lead to perforation of the RCS

reaming

which has lesser transportation, reaming or filing?

counterclockwise direction

what direction will cause failure of a K-file to occur, clockwise or counterclockwise?

H files

instrument has spiral edges arranged to allow cutting only during a pulling stroke

more positive rake angle, better cutting and has a blade for cutting rather than scraping

advantage of H-type over K-type instruments regarding their rake angles

pulled and rotated clockwise

what motion is used for H-files?

multiaxis grinding

computer-assisted machining that allows development of H-type instruments with very complex forms

tip design

it has an effect on file control, efficiency and outcome in the shaping of root canal systems

pyramid

the tip design of a K-file

1. guide the file through the canal

2. enlarge the canal

what are the two functions of the instrument tip?

loading plateau

a characteristic of NiTi as an exotic metal where the initial stress applied remains essentially the same as application of additional stress reaches a specific level

martensitic crystalline, results in superelasticity (can return to original shape after being deformed)

external stresses transforms austenitic crystalline form of NiTi into what?

and this unique crystalline structure results into what ability of NiTi?

Peeso reamer

used for post space preparation

taper

usually is expressed as the amount the file diameter increases each millimeter along its working surface from the tip toward the file handle

flute

groove of the working surface used to collect soft tissue and dentin chips removed from the wall of the canal

cutting/leading edge

it is the surface with the greatest diameter that follows the groove and is the blade of the file

land/marginal width

a surface projects axially from the central axis as far as the cutting edge between flutes

Relief

surfaces of the file against the canal wall that are reduced to lessen frictional resistance

helix angle

angle formed by the cutting/leading edge and the long axis of the file

Helix angle

this determines which file technique to use

rake angle

angle formed by the cutting/leading edge and the radius of the file

positive rake angle, it results in a cutting action

what is the rake angle if the angle formed between the leading edge and surface to be cut is obtuse?

and what action is the result?

negative rake angle, it results in a scraping action

what is the rake angle if the angle formed between the leading edge and surface to be cut is acute?

and what action is the result?

effective rake angle

is considered as the cutting angle and is measured when the angle between the leading edge and radius of the file is section perpendicular to the cutting edge

true

true/false

If the flutes of the file are symmetric, the rake and cutting angle are essentially the same

pitch

is the distance between a point on the leading edge and the corresponding point on the adjacent leading edge

more spirals and greater helix angle

what does a smaller pitch indicate about the spirals of the file?

gates-glidden bur

used for enlarging the root canal orifice, is side cutting and self centering

outward brushing

what is the motion used for a gates-glidden drill

machined

manufacturing method of K-reamers

grounded

manufacturing method of K-files

K-file: square

K-reamer: triangle

H-file: rounded/teardrop

cross-sectional forms of K-file, K-reamers, and H-file

White

Yellow

Red

Blue

Green

Black

What is the sequence of the color coding for files?

Lentulo spiral

obturating material for bringing sealants into the canal

Plugger​

Used for the vertical compaction of gutta-percha, but it should not be done directly over the apex and at the middle third of the root instead

sodium hypochlorite

gold standard for irrigation, and is able to dissolve soft tissue and has antimicrobial activity as well

Chlorhexidine

- if high concentration, it is bactericidal

- if low concentration, it is bacteriostatic

what irrigant has a broad antibiotic effect, but is not able to dissolve either organic or inorganic tissue, such as pulp tissue or dentin shavings?

substantivity

refers to the ability of CHX to bind to dental hard tissues and oral soft tissues and then be slowly released over time

EDTA (ethylenediamine tetra-acetic acid)

it is an irrigant that has no antibacterial action but it can dissolve inorganic canals and effective for calcified canals

it can chelate and remove the mineralized portion of the smear layer

parachloroaniline (PCA)

what is formed if NaOCl and CHX are mixed?

25-30mm

so end using a red file

average root canal diameter?

16mm

regardless of the file used, at what measurement does the cutting edge end at?

#6 pink, #8 gray, #10 violet

what are the patency files?

#12 orange

what is the canal probe?

canal orifice opener - SX

shaping files - S1, S2

finishing files - F1, F2,....F5

for pro-tapered files, what is the canal orifice opener, shaping file, and finishing file?

velocity - 300rpm

torque - 3.0Ncm

what is the velocity and torque for pro-tapered files?

K files - increase canal size

H files - bulk removal of dentin

at the coronal part of the canal

reamers - for reaming

differentiate the use of reamers, K- and H-files

k files - more flutes, less aggressive

reamers - less flutes, more aggressive, more flexible

h files - less torsional resistance, more aggressive than K-files, difficult to bend

differentiate the characteristics (flutes, aggressiveness, etc) between K files, H files, and reamers

Giromatic handpiece

an endodontic handpiece with 3000 quarter turn reciprocsting movements per minute

apexum

device for periapical debridement that widens the apical foramen by sliding a #30 file 1mm beyond the foramen

electronic apex locator

considered an accurate tool to measure working length

spreader

Tapered, pointed instrument intended to displace guttapercha laterally for insertion of additional accessory guttapercha cones

Plugger

used for vertical compaction of gutta percha

heat carriers

Used to transfer heat to the gutta percha in the root canal, allowing apical and lateral displacement of the gutta percha

size and length of irrigation needle

it is of utmost important for effectiveness of proper root canal irrigation

Iodine Potassium Iodide

it is used as alternative if patient is allergic to NaOCl

chlorine

responsible for the antibacterial and dissolving action of sodium hypochlorite

2%

what is the concentration used for chlorhexidine?

MTAD

first irrigant that is capable of both the removal of smear layer and disinfection of the root canal system

MTAD: doxycycline + tween

Tetraclean: doxycycline + polypropylene glycol

differentiate MTAD and tetraclean

doxycycline

provides the antibacterial effect of MTAD

low surface tension

for an effective irrigant, should it have high or low surface tension?

formaldehyde

Used in endo therapy despite its high toxicity, mutagenic and carcinogenic potential, is volatile and releases antimicrobial vapors when applied to a cotton pellet for pulp chamber disinfection