7. Treatment III Flashcards
We will go into more detail on how to get the initial working length. The first time as you see the figure, on the molars all the cusp tips are gone and it is kind of flat. The reference point needs to be flat and more stable thats why this example is pretty good. So you place a #15K file in the root canal and you keep moving the file apically.
The working length radiograph should show the file is about short of the apex. Here it is a radiographic apex it is not a anatomic apex. Its the ____ surface of the root tip.
As we know the anatomic apex/apical constriction is placed between ____ mm short of this radiograph apex. The file is supposed to stop ____mm short of this apex. If there are two canals in one root, like the upper premolar and the multi rooted morals, you have to place two diff type of files. There are two diff ones, the K file and H file. You need to do this to tell the difference radiographically which root is buccal and which is lingual. With 4 canals it is extremely difficul
external
0.5 to 2.0
1
Sometimes the easiest tooth like the lower incisors look very straight but you see there is a slight double curvature. We may not be able to see that clinically, but you always have to think about it and anticipate it. One way to determine this anatomy, when you place #10 or #____ stainless steel file and take it out the file will represent the curvature of the root canal. Don’t forget to see the files after you place them in the canal.
15
How to Read Radiographs SLOB Rule (Same Lingual Opposite Buccal) for Posterior Teeth
- In 1909, Clark reported a radiographic procedure for the localization of impacted teeth.
- The Buccal Object Rule is a method for determining the relative location of objects hidden in the oral region.
- The rule is: When two different radiographs are made of a pair of objects, the image of the ____ object moves, relative to the image of the lingual object, in the same direction that the ____ beam is directed.
- The initial concepts of the procedure were reported in 1952 & 1953 [Richards AG] & since that time the procedure has been developed to its present state of refinement & usefulness.
buccal
X-ray
How to read radiographs
Basically we take two shots. We being with a standard PA which is angled like #1 which is a straight line. Then we slightly ____ move for the second shot. You can go medially or distally doesn’t matter. When you slightly move the angle now you apply the SLOB technique, same lingual opposite buccal.
Also using the two different ____ types in conjunction with SLOB technique makes determining what you are looking at even more easier. especially to determine and distinguish the lengths of the apex (this is not exactly what she said but i summarized and put it in a coherent thought). Whenever you are working with multiple canals in the root like upper and lower molars and upper pre molars you have to apply this rule.
horizontally
file
In radiographic methods to détermine the working length can have alto of errors. One could be when taking the x-ray, the patient biting down could move the file deeper.
When you place a file and the canal is much bigger the file can move in it and not be stable. If you don’t notice that minor error you repeat taking x-rays and induce radiation dosage to the patient and waste time. That is why we need to use ____ to get accurate working lengths. Talks about old techniques like paper points and multiple X-rays and says how she doesn’t want them in the lecture.
apex locators
Later it was noticed that electric resistance were different between the instrument in the canal and the electric load was applied to the oral mucosa. It was applied at the mucosa b/c we obviously can’t directly apply anything at the ____ surrounding the root tip clinically. He decided to put clips on the oral mucosa to make a connection. GOES BACK TO PREVIOUS SLIDE
COMES BACK to this slide: So basically he found the oral mucosa’s and the periodontium’s electrical resistance are the ____. When you hit the PDL ligament through the apical foramen and when they meet the same resistance with the oral mucosa they said you have reached the PDL which is the apical foramen and that gives you the numbers which is the ____.
PDL
same
working length
This is the best updated device, the Root ZX. It has a ratio measurement method behind it. When your file is in the canal but the canal surface is pretty wide and the files are not engaged anywhere so you can get an off reading. This is the machine we will use in clinic, when you see the blue bar that verifies that you are in the root canal dentin. When you move the file more of those bars start showing up as you get closer to the apex.
At the last ____mm of the root apex you are gonna get a more delicate reading from the machine b/c the files and the periodontium reading is more engaged so they give you a more delicate reading of where is the anatomical apex/apical foramen. The machine has a scale number 3,2,1 but these numbers are not actual distance from the apex foramen. When you have a 3,2 reading you are just verified you are in the root canal ____.
2
dentin
When you reach 1 that means you must be within ____mm of the apex. Sometimes you can breach your file through the apical foramen. To prevent this you can stop in the ____ zone and then you measure the length of the file. You then take an x-ray. The x- ray can show that the file is still very far or close to the radiographic apex. Based on this information now you can finalize what is you’re working length. if you get into the ____ zone on the machine, you have gone through the apical foramen and you have touched the PDL.
The green zone is what you want to reach, being at a 3,2 you are still too ____. Good thing about this apex locater, the canal isn’t always dry, there could still be debris or vital tissue, or bleeding. You are gonna use irrigation, to keep the canal moisture. When you have a wide canal/an open apex, the accurate reading has now occurred. So you better find the one file that is gonna get more binded to the apex to give a more accurate reading.
So when you have a very ____ apex like in an immature tooth, the apex locator is not reliable. When the tooth is discharging pus and its very wet with ____ as well, you can’t get an accurate reading also. You don’t want the tooth to be overly wet, just slightly ____.
2
green
red
far
open
blood
irrigated
Hand files are still needed, we can’t do root canals without hand files b/c they give us ____ sensation. It helps us tell if the canal is calcified,
how narrow it is, so you’re still gonna use hand files especially #10 and #15.
tactile
NiTi Alloy Properties
- ____
- ____
The major rotary file properties are their elasticity and shape memory. When you pull them out of the canal, they don’t stay in the shape of the canal, they conform back to their original shape. Hand files although do present the shape of the canal. Thats the main different between stainless steel and NiTi files.
super elasticity
shape memory
This slide is a video: When they are cooled down and you change their shape it doesn’t go back to its original shape until its heated. So in the root canal, the file is under body temperature which isn’t super cool or super hot. Therefore it stays in its ____.
shape
This is the endodontic hand piece we provide to you in the clinic. You have a pen grip on it and the recommended speed is ____ RPM. When you place a file you need a finger grip.
Think of a root canal prep as a very small narrow cavity prep. You need a good ____ to control the high speed of the hand piece.
You start ____ the file outside the canal first and put it in as its rotating. You don’t put it in and then start rotating. Once the file starts rotating you never ____, you always move your hands up and down. Once the file engages any curvature the file will bend then break. So you have to constantly move the file to not allow the file to engage the canal surface to prevent breakage.
500
finger rest
rotating
stop
Infection control
- All our techniques are about how we are going to disinfect the canal and eliminate bacteria. Goal is to reduce the amount of bacteria to below the threshold of disease.
- We want to make the canal “sexy” and clean w/ 0 bacteria
- The files won’t kill all the bacterial. We need anCmicrobial ____ (liquid soluCon)
- Intra-canal medicaCon = medicaCon we place directly into the canal
- InfecCon control is difficult b/c we can only use symptoms to tell if we’ve eradicated enough bacteria (we can’t count the bacteria or anything like that)
- Don’t fill the canal unCl the bacteria has been removed
irrigation
ffects of Root Canal Preparation on Apical Geometr Assessed by Micro–Computed Tomography
“… all instrumentation techniques left ____% or more of the canals’ surface area unchanged.”
35
Irrigating Solutions
• Traditionally an irrigant is used to aid the instruments cutting efficiency and to facilitate the removal of cut dentin.
• HOWEVER, the most important quality of the irrigant is its ____ property.
- Remember: canal must always stay ____!
- Need to wash out canal whether it’s vital or necroCc. We will be using irrigaCng soluCons to do this. They improve mechanical funcCons as well as act as anCbioCcs
antimicrobial
wet
Desired Irrigant Actions • \_\_\_\_ antimicrobial spectrum • Dissolve necrotic tissue • Inactive \_\_\_\_ and mø by-products • Prevent and dissolve smear layer • Non-\_\_\_\_ or lead to anaphylactic reactions
- Some studies look at ____ amounts to quanCfy # of bacterial
- Just like in restoraCve, we need to remove the ____ layer. This allows irrigant to reach and kill bacteria in denCnal tubules
broad endotoxins allergic endotoxin smear
Irrigating Solutions
NaOCl (sodium hypochlorite) 0.5% - 6.0%
EDTA 17%
Chlorhexidine 0.12% - 2%
- These are the most important irrigaCng soluCons in our clinic
- ____ is the most important irrigaCng soluCon for us. The strength depends on the situaCon.
- Also we can use Chlorhexidine as mouthwash
NaOCl
Core Protocol - Vital and Necrotic Cases
- InstrumentaCon with a ____ and ____ is like a “boyfriend + girlfriend.” They are always together. You won’t use one without the other.
- Enter access cavity, irrigate with NaOCl (brush out debris), now you can use file with the improved visualizaCon
file
NaOCl
