endo sheet # 2 (of Dr Jamal 3a8rabawe) - SAJA AL-AJARAMAH

بسم الله الرحمن الرحيم

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http://www.freefileconvert.com/converted/4d17485802c98/Filling_the_root_canal_with.doc
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Filling the root canal with
the lateral condensation technique

the doc started the lec by asking, what is the purpose of filling the root canal ?
1-To eliminate the space that has been left after we removed the pulp tissue.
2-To prevent reinfection .
3-To prevent percolation .

*The technique we r using for filling the root canal system during our lab work is the lateral condensation technique- ( there is another technique for clinical use which is vertical condensation technique )-that we r going to go through it .
** we have to meet 5 mechanical objectives of cleaning and shaping before we do the filling if there is any defect in one of these objectives then the filling will be defect ,therefore don’t proceed to fill the root canal if u have anything wrong with the cleaning and shaping or if u have a doubt that ur cleaning and shaping is not enough yet ,and these objectives are :
1-To develop a continuously tapering cone
2-Make the canal narrower apically with the narrowest cross-sectional diameter at the terminus
3-Have the conical cross-section meet the concept of flow; continuously tapering cone that the cone is smaller in the apical area and get bigger and bigger and bigger to the orifice of the canal ,stepwise thing ,.
4-Keep the apical foramen in its original position ; we don’t do any perforation
5-Keep the apical foramen as small as practical,not as small as possible coz we can reach to the size (15) but we don’t need such a size ,we need size (30) when we do lateral condensation coz there is no cone provides a good apical seal below the size of (30) and when we do vertical condensation we can go up to the size (25).

*How do we do the lateral condensation technique ?
The procedure as we actually do in the lab:
1-Spreader size determination :
2-Master cone size determination:
3-Drying the canal
4-Mixing the sealer and place it into the canal, then placement of the master cone then the accessory cones into the canal.

1-Spreader size determination :
We have two kinds of spreaders ;
A-handle spreader ; it has a hand and a shank,the part of spreader goes into the canal is from the tip of the spreader to a certain length of the spreader's shank determined by the canal's length .
B-finger spreader ; it looks like a file but it's smooth , has no cutting edges and no cerations unlike files and it is also tapered .
It's Mandatory to fit the spreader ;we have to pick up the spreader according to the last file size used, one size smaller,ex: if the size of the last file is 40 we use a spreader of the size of 35 .

*The spreader has to fit 1mm short of the working length of the canal ,if it goes 2mm or 3mm short it's not good .
*The rubber stop; we put it on the spreader shaft or on the finger spreader in order to measure the spreader's length and it's end on the incisal edge of anterior teeth or the occlusal surface of posterior teeth .
**Then put the appropriate spreader aside for immediate use .
2-Master cone size determination:

-we clean and shape the canal to the size 35 then the master cone has to be one size smaller that would be 30 ,whatever the last file used size is pick a master cone one size smaller, why? Because the standardization of manufacturing the instruments are different than the standardization of manufacturing the gutta percha cones ; from experience if the master cone and the master file of the same size it doesn’t go to the full working length it goes shorter so we use a one size smaller gutta percha cone .
-it should fit snugly and resist removal ,we call it tug pack ; it means it resists removal of the gutta percha ,the gutta percha is well packed in the apical area so if we hold the tooth upside down the gutta percha master cone shouldn’t not fall out from its place bcz it's packed in the apical area not in the coronal area .
**radiograph must be taken to determine that the length is ok and the master cone is within the limit .
-we only need (3-4)mm from the apical third tug pack not the whole length of the canal , we don’t want to have a space between the master cone and the tooth wall in the apical area but we want this space in both the middle and the coronal thirds of the tooth and the master cone no tug pack in these areas .
-we use a pliers to bend the master cone in order to know the length it must reach
This might give u a false feeling of the tug pack in the middle third and actually there is no tug pack there is a space, that might be bcz of a defect in the cleaning and shaping.
*if the master cone is protruding out of the canal it isn’t good it should fit the canal working length so we have to take the cone out of the canal and put it in the trash and pick up a bigger cone than this one ,we don’t cut the cone with scissor to fit the canal bcz 1- the gutta percha cones which we use in the lateral condensation technique r manufactured according to the standardization 30 , 35.
2-and if u look at the cone u will notice that the cone almost parallel it's not as tapered as other gutta perch cones which we call them conventional gutta percha cones which come as different sizes ( fine,medium,large) so cutting the cone wont provide u a solution the same size is being left after the cutting .
***so if the master cone is protruded from the apical foramen a larger size should be fitted .
***if the master cone is (2-3)mm short we get another one and we measure it and we fit it ,another radiograph should be taken to define the fit of the cone into the working length .

** so the root canal requires several radiographs in its different stages :
1-preoperative radiograph
2- then working length radiograph
3- then cone fit radiograph
4- then filling radiograph
*it needs from 4-5 radiographs that of course if we don’t face problems , some times we need 8-10 radiographs so don’t feel upset we will get used to t 

After the master cone pass the trial test it should be removed with cotton pliers that scar the master cone to the appropriate length at the external reference point ( the incisal edge ) ,the scar and the incisal edge have to be coincided ,if the scar area is higher than the incisal edge that means the cone is short and if the scar area is going inside that means that the cone is long .
Another way to determine the length is the rubber stop but we cannt use here coz we are dealing with rubber made gutta perch cones unlike metal they will bend so it wont be useful to use rubber stop.

** Now we put the master cone aside after taking an x-ray.

3-Drying the canal with absorbent paper point , use many paper points as needed put them inside the canal and take them out keep doing until the canal is dry .
*how do we know if the canal is dry or not ?
- when u almost feel that the paper point u took out of the canal is not moist , move t on the rubber dam and as u know the rubber dam covered by a powder so if the paper is moist it will streak the dam so the canal isn’t dry yet ,we have to use more paper points ,and if doesn’t streak the dam that means the canal is dry . this is a clinical technique coz in the lab we don’t use rubber dam .

4-Mixing the sealer and place it into the canal, then placement of the master cone then the accessory cones.

*How do we mix the sealer ?
-we mix it on a glass slab and a spatula , we mix the sealer according to the manufacturer or according to the Doc demonstration .
-The sealer must be creamy in consistency but quite heavy
-Should string out ;at least an inch when the spatula left from the mix we don’t want it to be thin ,thin is not good , the sealer should be mixed as mentioned b4.

*After mixing the sealer we have to make placement of the sealer into the canal , we have two ways :
1-Using lentula spirals
We put the sealer on the lentula spirals and we put it in the canal and then we twist it clockwise.
2- we can put the sealer on the file , put it in the canal and twist it counter clockwise; COUNTER CLOCKWISE it will leave the sealer in the canal , if we twist it CLOCKWISE it will take out the sealer from the canal,, the way we do cleaning and shaping we twist the file 180 degrees clockwise ( clockwise = take out ,counter clockwise =leave inside ) ,,unlike lentula spirals which we put the sealer in the canal by clockwise movement that how it designed .


** Now we have to pick up the premeasured master cone put sealer on it
Then we put the coated master cone in the canal and move it slowly to the full length of the canal it will displace cement coronally as it slowly move into position ( the canal full of sealer and the master cone coated with sealer so there will be excess amount that will go out and that is ok coz it makes space for master cone )
** Then the premeasured spreader introduced into the canal along side the master cone also along side the canal and with rotary vertical motion slowly moved apically to full length as marked on the shaft with the rubber stop ,the spreader enters to within 1 mm short the working length as the rubber stop indicates , after that the spreading process starts ,if we r using handle spreader we move it left ,right ,left, right without pulling the spreader out of the canal if u do so the gutta percha will get out of the canal just make the spreading movement (reciprocating motion) and the spreader will get out of the canal eventually don’t pull it out of the canal ,, now if we r using finger spreader as it enters the canal move it against the wall , against the gutta percha , against the wall , against the gutta percha and so on till it get out of the canal we can exert a little pulling force to help it to get out of the canal but not much coz doing so will take the gutta percha out of the canal too .why do we do spreading (reciprocating motion)? to provide space for accessory cones for more gutta percha cones.
we hold the accessory cone with cotton pliers then get t coated with sealer then place it into the canal more spreading creating more space for more accessory cones, as the process proceeding there will be shortening of the length that the spreader can reach within the canal till the spreader can no longer enter through the orifice at that point the filling is done so the spreader is removed by the reciprocating motion mentioned b4 , then we cut the gutta percha cone at the level of the orifice or beyond the cervical line , the cutting done by heating an instrument or we use a heated spoon excavator after we cut the gutta percha from the pulp chamber the gutta percha which is softened by the effect of heat can be packed with amalgam condenser at the orifice or below it by 1-2 mm but not above the orifice bcz if we have gutta percha and sealer at the pulp chamber this will coz discoloration to the tooth later on in the patient's life after that we should take a radiograph to see the filling.
**The doc show us a radiograph taken by kit called " RIN kit "
** So called according to the scientist RIN ,which is used to take a parallel radiograph .

*in the clinic we put cotton and a temporary filling then remove the rubber dam in order to make radiograph to show the filing .
*Remember to remove the rubber dam b4 taking the x-ray.
-voids within the radiograph indicate a bad filling " failure ".

Now the doc showed us radiographs:
-in the first one there is a periapical lesion from endo –root canal treatment- the scientific name is " chronic apical periodontitis "
-in the 2nd one there is also a lesion from endodontic origin but it's not periapical lesion coz it reaches the furcation area ,then the doc showed a 3rd pic to the same tooth after doing endodontic treatment ,there is no lesion anymore it healed.
-in the 4th radiograph there was an over-filled canal and the doc said that over-filling to 1mm is accepted but not more .
How to deal with such an over-filled canal?
Shall we repeat it ? we cannt take the gutta percha out of the canal so we have to do sth called surgical root canal treatment in which we do a flap in the gum then left the gum and take the gutta percha out by surgical means .

-the 5th one showed two molars (6 and 7 ) , the doc asked which one is better treated ?? the answer was the (6) molar coz it resemble the five mechanical objectives of cleaning and shaping , the (7) also resembles them but we can notice that the mesial canals are almost straight and we don’t want straight lines we want cleaning and shaping according to the curves of the canal .
-another (6,7) molars , the better treated is also the 6th, the 7th showed short filling and skinny canals indicated bad cleaning and shaping .

** question by a student , why do we put cotton under the temporary filling ?
-coz if we put the temporary filling on the wall of the tooth in the nxt visit we have to drill the wall of the tooth therefore we remove unnecessarily from the tooth structure so keeping a space between the filling and the tooth wall will conserve the tooth structure all we have to do now is using low or high speed round bur to remove the temporary filling .

* If one follow the lateral condensation technique of gutta percha number of questions arise :
1-What kind of spreader should be use ?
The handle spreader is made of anneal and that finger spreader is not that make it (finger spreader) more flexible in a way enable to enter the canal and follow the curvatures of it .
That make finger spreader better to use but that doesn’t mean that handle spreader is not good to use.
2-How much force should be exerted with the spreader ?
One kg of pressure is ok ,, 3 kg may coz damage root fracture))
3-Can root fracture occur ?
Yes.

Sry 4 being late t has been such a long sheet , hope t provides u with the needed information .
Good luck
SAJA AL-AJARAMAH

this is another link 4 this sheet
as the one above is corrupted...

http://www.mediafire.com/?r5w6s632oo6y541

((it was posted on fb by zaid)).. thx 4 him