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Introduction To Endodontics

Mona Marashdeh

Tasneem & Hana'a

Sun. 10-2-2013

Introduction To Endodontics

Endodontic Instruments

Endodontics is the specialty of dentistry that manages the

prevention, diagnosis, and treatment of the dental pulp and the

periradicular tissues that surround the root of the tooth.

"Endo" is the Greek word ="inside” "odont" is Greek ="tooth".

Endodontic treatment =treats the inside of the tooth.

*The pulp is located Inside the tooth, under enamel and dentin.

*The pulp Extends from the crown of the tooth to the tip of the

roots where it connects to the tissues surrounding the root.

*It Contains blood vessels, nerves and connective tissue .

* The pulp Creates the surrounding hard tissues of the tooth during

development .

* The pulp is important during a tooth’s growth and development.

* Once a tooth is fully mature it can survive without the pulp, because the

tooth continues to be nourished by the tissues surrounding it.(Mean when the

tooth is fully mature ,no problem to do root canal, it can survive without the

pulp bcz of reason mentioned above)

*The objectives of Endodontic Treatment :

-To relief the pain (to make the patient symptom free).

- To render the affected tooth biologically acceptable and functioning without

a diagnosable pathosis

- Removal of pulp from root(s) of tooth

- Disinfections of root and surrounding bone

- The Root canal treatment is an attempt to retain a tooth which may

otherwise require extraction.

** The Indicationes For Endodontic Therapy :

1. Teeth with pulpal and /or priapical pathosis

2. Teeth with no pulpal or periapical pathosis may need endodontic

treatment due to:

The need for post and core construction to rebuild the missing coronal

portion of the tooth

Traumatic pulp exposure due to dental work or accidental fracture.

Esthetic requirement

*** Contraindications for Endodontic Therapy : 1-Teeth with insufficient periodontal support. (If the teeth is periodontal

invoved with bone loss ,the extraction is better than Root Canal treatment.

2-Teeth with vertical root fracture.(Also for extraction)

3-Non restorable teeth which can not properly function after endodontic

treatment.

4-Non strategic teeth which can not serve in occlusion or as abutments

after endodontic treatment.

- Phases of Endodontics treatment : Diagnostic phase : you have to make agood diagnosis to know if the

tooth need root canal treatment or not ,then

Preparatory phase include access cavity,cleaning and shaking then

Obturation phase

In this phase you have to diagnose the condition of tooth and

determined the plan of treatment

You have to do radiography exam,clinical examination to

make agood diagnosis so we need akit for examination for

endodontic.

The kit of examination include :

(1) a front surface mouth mirror

(2) a periodontal probe

(3) an explorer

(4) spoon excavator

(5) the Glick No. 1 instrument

(6) cotton forceps

*Endodontic Explorer ,it is different from that we used in CONS Lab.

* Explorers are double-ended instruments with long tapered tines at either

a right or an obtuse angle.

* This design facilitates the location of canal orifices

* They are very stiff and should not be inserted into canals or used for

condensing gutta-percha

*Don’t heat it.

We use Explorer for diagnosis to locate the canal only .

The same to what we use in the CONS Lab .

The excavator is used to remove caries, deep temporary

cement,

or coronal pulp tissue.

The endodontic excavator has a right or left orientation

Also you shouldn’t heat the exvator to cut the gutta percha

,only we heat the plugger .

*Not nessary but it is good to have it .

* 2 tips:

One tip (Plugger for cutting and condensation of gutta percha and

the paddle tip looks like plastic instrument for putting the

temporary filling.

_The second phase of the endodontic after you did agood

diagnosis and the tooth need root canal treatment is the

- We do the treatment ,open the access cavity and we do the cleaning and

shaping.

- (In this lecture we not go to talk about the steps of shaping and cleaning ).

- During this phase the condition of the tooth is determined and the plan of

treatment is developed.

- Instruments used for access and cleaning and shaping include :

(1)hand pieces (slow and high speed)

High speed to enter through the enamel and slow speed through the dentine.

(2) burs (slow and high speed burs )

(3)rubber dam ,after we open the access cavity of tooth ,we put the rubber

dam ,sometimes if the access is simple we can put the rubber dam before the

access but usually we open the access and before instrumination we have to

put the rubber dam .

(4)We need a special syringe called Luer-Lok syringe with a 27-gauge

needle to do irrigation .

(5) We need locking cotton pliers

(6) rotary instruments (Gates-Glidden drills)

(7) a plastic instrument (Glick No. 1) for temporary placement

(8) broaches and files

(9) a lentulo spiral drill

(10)Endodontic ruler or a millimeter ruler to measure the length of the file.

*This is the rubber dam ,we use it to isolate the tooth from the saliva ,you

cant root canal without putting rubber dam .

(In the lab you will not put the rubber dam but you have to learn how to

put it ).

*This is the rubber dam kit and it concerned the rubber dam sheets (green

sheets).

*This is the Punchior ,we make the punchior inside the rubber sheets.And

this is the foreceps ,this is the frame ,it can be metal frame or plastic frame

.we can see also the Clamos in different sizes and shapes for different teeth

(Anterior or Posterior ,right or left ,and Molar or Premolar ).

*This is the rubber dam kit (Forceps, Punchior,Frame,Rubber dam sheets

and Clamps).

*This is the with different gauges.

*look to the tip ,this is safety tip ,the opening from the side not from the

tip,don’t allow the irrigants to go outside the apex .In the other side we use

standard syringe bcz we are not using the sodium hypochloride irrigants (this

is safety tip syringe).

* The nomenclature follows the recommendations of the

International Organization for Standardization (ISO):

1. Hand-operated include K-type reamers and files,

broaches, and Hedstrom-type files.

2. Engine-driven are hand types that have a latch that inserts

into a slow-speed handpiece. These include rotary (Gates-

Glidden and Peeso) engine-driven reamers and files and

reciprocating files or reamers.

3. Ultrasonic and sonic are diverse in design.

4. Nickel-titanium is a cross-over design and has been

adapted both for hand instruments and rotary applications

To debride a region of the canal space completely, the

instrument must contact and plane all walls.

Despite continual improvements in design and physical

properties, there are still no instruments that totally clean and

shape all root canal spaces.

Stainless steel instruments are relatively inflexible, which

renders them not particularly adaptable to canal curvatures.

(Mean if you have acurve canal it is difficult to use the

stainless steel file)

Nickel-titanium instruments are more flexible and adapt more

readily to fine, curved canals but have no advantage over

stainless steel files in irregular canal spaces.(Mean the canal

not round ,(it is Oval ) ,no one file can clean the canal walls

,you have to cross the file against all wall bcz the shape of

the canal is oval .

A hand-operated reamer or file begins as a round wire that is modified

to form a tapered instrument with cutting edges.

The instrument is used with a twisting (reaming ,rotation ) or pulling

(filing , push out side ) motion in an attempt to produce clean, smooth,

symmetrical canal walls.

*Several cross-sectional shapes of files are commercially available

The FIRST File is flex and we not use it .

The SECOND File is that we are using .

The cross section is square in small files and rhomboid with

large files .

The fourth File is the H-File

* Two techniques for manufacturing these instruments have been

developed:

1- Machined

2- Ground Twisted

Machined: - One technique involves machining (grinding) the instrument directly on a

lathe(They don’t do twistint to file ,the wire was square ,they do

grinding).

- H-File (Hedstrom file is machined ,we will not use it ).

- All the nickel-titanium instruments are machined.

- Sometimes K-type files which is ground twisted ,they do machined to

them and the properties of them become different .

- This change from the grinding and twisting manufacturing process results

in different physical and working properties from the original K-type file

- The machined file has less rotational resistance to breakage than a

ground-twisted file of the same size.(Mean when we used the machined

file for twisting ,it can break )

- H-Files ,we cant use it for reaming or twisting ,they are used only for

filling(pulling) motion,they are liable to fracture for that H-files not use

for treatment ,they are only used for retreatment bcz the cutting edges

sharpe ,so it is useful to remove thr gutta percha in retreatment ,but in

treatment we use the K-files bcz they are flexible ,we can do reaming and

filling .

- H- file only used for filling (pulling)motion.

The Ground twisted (The second way of manufacturing)

Another technique consists of first grinding, then twisting.

Raw wire is ground into tapered geometric blanks: square,

triangular, and rhomboid with different cross section

according to the type of the file, as we said the small K-files

are square cross section ,and the large K-files are rhomboid

(They do grinding accordint to the shape then twisting)

The blanks are then twisted counterclockwise to produce

helical cutting edges. These are K-type files and reamers(the

number of flutes in the files are more than in the rreamers

and the number of twisting for files more than reamers).

K-files have more twists per millimeter than the K- reamers.

Both have a pyramidal tip (75 ± 15 degrees) that is produced

by grinding after twisting.

A- Wire after grinding

B- File (more flutes per millimeter )

C- Reamers(Fewer flutes)

1- start with length ,we have 3 lengths (21,25,31 mm),the shorter the

easier to use ,21mm is the easier to ues but the 25 mm the most use

bcz it is ideal for most length ot teeth.

(31 mm most of time will be short )

2- The next is the sizing

* Dimensions of K-type files and reamers are designated according to

the diameters of the instrument at specified positions along its length

*On 3mm from the tips ,all the files have same sizes .

*Files divided to distance (working distance).

*Working length usually 60 mm not less.

*We have 2 points :

-D zero :diameter at the tip

-D 16 :diameter at the end of the working part of file .

*Dzero starts from file number 6 ,8,10(very small files ),we use them

only in narrow canals.We start usually from file number 15 .File number

15 the diameter at the tip is 0.15,after the file number 15 we have file

number 20 the size of tip is 0.2 ,after file 20 we have 25 the tip siza is

0.25 ,the ten file is number 60 increase by 0.05,the larger files from 60

to 140 increase by 0.1 not by 0.05 (Mean after file 60 we have file 70

,80,90 ……).

-From file 15 to 60 increase by 0.05

- The file diameter increases at a rate of 0.02 mm per running millimeter

of length like file number 20 D zero =0.2,D1 after millimeter =0.22(bcz

the taper increase 0.02 ) ,D2 =0.24(.2+.02+.02) ……………. Until D16

-K-files tapers FOR THEM =.02

-We can know tip sizes from file number like file #15 .15

millimeters

File #20 .2 mm

-Taper for every millimeter increase .02

-If we start with file #20 the tip is .2 after I millimeter ,the D2 =.22(add

.02) until we reach D16

-Other files (rotation files or manual files like nickel-titanium have

different tapers not .02 but they are .04 and .06 .

-When we do instrumentation in new files (nickel-titanium),we have

alarger tapers than manual files we used in lab.

TIP DESIGN :

o Originally, the tip angle of K-type files and reamers

was approximately 75 degrees plus or minus 15

degrees.

usually the tip here is cutting tip, but there is a

modification on K-type which is sometimes make the tip

of it safety tip (non- cutting) And this decrease the

procedural error like :

Canal transporation and perporation that happened because

of cutting tip

-This design was intended to provide cutting efficiency

without an excessively sharp transition angle.

-Newer designs have different tip angles and designs in an

attempt to minimize canal alterations.

-Some machined K-files incorporate a so-called

nonaggressive tip or noncutting tip to provide less dentin

cutting by reducing the sharp tip

transition angle.

So the modification and angles of some files becomes from 75 smaller or

larger . but the standered 75 plus minus 15 and the tip in stainless steel

file that we are using are cutting tip.

Torsional Limits

-Torsional limit is the amount of rotational torque that can be

applied to a “locked” instrument to the point of breakage

(separation) so the file is bind in the canal and we applied

twisting motion the point of breakage called "torsional

limit".

Smaller steel hand-preparation instruments (less than size

20) can withstand more rotations without breaking than

larger (greater than size 40) instruments .

So we have to be carful when using large file.

-Machined K-type files (like H-file):

have different physical and working properties

than ground-twisted files. Machined files

are weaker, demonstrating less plastic

deformation before failure occurs.

Therefore this tendency toward less visible deformation

before separation equires more caution with the use of

machined files to avoid instrument failure.

COLOR CODING :

Each color in this coding have a specific size .

In the first we start with

This sequence will not repeated :

Pink 6 (we will

not use it )

Gray

8

Purple

10

so when using a machined file you have to throw it befor see

the marks of deformation BUT in the twisted file you can see

the plastic deformation then throw it (you inspected you see roll

up of the file you don't use it)

This sequence will be repeated with different size :

You have to memorize this

e.g : when you see a white file you should know that this is num (15)

if it's large so the num (45)

BROACHES : Barbed broaches are stainless steel instruments with plastic

handles. The tapered-wire broach is barbed by scoring and prying a

tag of metal away from the long axis of the wire.

Barbs entangle and remove canal contents. This instrument should be neither bound in the canal nor aggressively

forced around a canal curvature because it can be easily break .the

barbs to engage the canal wall, preventing the broach from being

removed intact or fracturing.

We use it to exacerbate the pulp tissue in vital teeth we don't use it

in necrotic teeth.

(we usually start with it in

Ant. Teeth )

Yellow

20

Red

25

Blue

30

Green

35

Black

40

White

45

Yellow

50

Red

55

Blue

60

Green

70

Black

80

LENTULE SPIRAL DRILLS :

-Lentulo spiral drills are twisted wire instruments used in the slow-

speed handpiece .

1. They have been used to spin pastes, sealer, cements, or calcium

hydroxide into the canal.

2. They must be used with care to avoid “throwing” quantities of

unset material out of the apex.

3. The drill must be rotated so that it will not “screw” itself into

the canal; it may lock and separate.

ENGINE-DRIVEN Instrument :

Some preparation techniques require slow-speed rotary instruments to

facilitate preparation, primarily in establishing straight-line access, the

most common are :

1. Gates-Glidden drills

2. Peeso reamers ( we will not use it in the lab )

This table (slide 34) shoe the different size of Gates-Glidden and Peeso

reamers .

You have to know the size of Gates-Glidden frome number 1 to

6 (usually in the lab we use num. 2, 3 and 4)

1- Gates-Glidden Drills -Gates-Glidden drills are elliptically (flame) shaped burs with non

cutting tip (safety tip).

used to open the orifice of the canal.They also achieve straight-line

access to the canal (you have to be carful not to make oozing of the

canal) by removing the dentin shelf and rapidly flaring the coronal

and middle third of the canal. . designed to break high in the shank

region. This design allows easier removal of the broken instrument

from a tooth; fracture near the cutting head may block a canal.

-drills are available in 15- and 19-mm lengths . we use the shorter

which is 15 mm in the posterior teeth.

2- Peeso Reamers : They are basically similar to Gates-Glidden drills but have parallel

cutting sides rather than an elliptical shape and more aggressive so

we not use it .

have been suggested as a means of improving straight-line access.

Engine-Driven Nickel-Titanium Files :(rotary files)

Engine-driven nickel-titanium files allow greater control in small, curved

canals. These instruments do not have a cutting end and have less

tendency to transport the apical preparation. The files are available in a

variety of shapes and designs .

Now we will talk about INTRACANAL INSTRUMENT

of the previous instrument :

1. Broaches : use to make pulp exacerbation.

2. Reamers & Files : use it to enlarge the canal.

-we have Two types of motion which are:

A- Reaming motion : consists of rotating the instrument clockwise

and scribing an arc from one cutting edge to the next.

B- Filing motion : we insert the file passively then we make a quarter

turn reaming then pulling firmly against all walls to make

circumferential filing

As we said H-files we can use it only in filing motion we can't

reaming it cannot tolerate torsional force.

Avoidance of instrument separation :

Separation of hand files in the canal is prevented by regularly inspecting

the instrument for defects such as:

NOTE :(we said that when manufacturing of the files make it

twisting counter clockwise ).

1. unwinding of the flutes (twisting clockwise and opening of the

flutes).

2. roll-up of the flutes (excessive continued clockwise twisting after

unwinding)

3. tip distortion (the tip has been bent excessively)

4. corrosion

If an instrument exhibits any signs of wear, it should be

discarded and throw it immediately

Rotary Instruments It is nickel-titanium files and we said that is machined instrument so you

have to follow the recommendation of the manufacture .

The number of canals that can be prepared with a

nickeltitanium instrument varies from 4 to 16, depending on

the size and curvature of the canals and pressure used with

the files. When the canal is smaller and more curved, there

is more wear and tear on the instrument.

the final of the root canal is Obturation phase : we make a diagnosis , we judge that need root canal

treatment , make the abscess , cleaning and shaping

then we have to make the obturation .

During this phase the root canals are filled with an inert material to

achieve a hermetic seal as close as possible to the anatomic apex.

( the obturation that is acceptable should be short from radiographic

apex from 0.5 – 2 mm )

Instruments and materials used for obturation include:

1. Gutta percha

2. Paper points.used to dry the canal befor obturation.

3. Root canal sealer which binds Gutta percha together and adhere obturation to

dentine .

4. spreaders or pluggers to make condensation to Gutta percha

5. Glick No. 1 for heat transfer and temporary placement.

6. locking cotton pliers

7. 5/7 plugger or pluggers used for vertical condensation.

- Several filling techniques are available. The two most practiced

techniques are , lateral and vertical condensation.

This is the Gutta percha ( slide 43) with different sizes 15,20,25,. . . .

according to the size of the file . the largest the file called "Master

File" that we should used with it the "Master Cone".

During instrumentation befor we go to then larger file we do irrigation .

Lateral Condensation o The instruments used for lateral condensation are spreaders and small

pluggers

o Finger spreaders and pluggers have different tips.

o

Vertical Condensation o In this obturation technique the filling material is alternately softened

(with heat) and then vertically compacted with pluggers

So the modification and angles of some files becomes from 75 smaller or

larger . but the standered 75 plus mines 15 and the tip in stainless steel file

that we are using are cutting tip.

-STERILIZATION AND DISINFECTION :

Endodontic instruments are contaminated with blood, soft and hard tissue

remnants, and bacteria and bacterial byproducts.

Thus they must be cleaned often and disinfected during the procedure and then

sterilized. Also, because the instruments may be contaminated when new, they

must be sterilized before initial use.

Different sterilization techniques are available.

Small kits, such as those used for examination, may conveniently be bagged,

sterilized, and stored in the package until needed.

Larger kits for treatment may be more rapidly and easily handled in cassettes for

sterilization and storage.

THE END

Challenges are what make life interesting, and overcoming them is what makes life meaningful.

Forgive us for any mistake

Done by :

Tasneem Hamdan

Hana'a Ajour

CORRECTED