Young Bui
 |
 ’M
SURE that most of you have stumbled upon difficulties while doing root
canals. Some of the problems are easy to fix; others are not.
I will bring up several difficult situations and then explain how to resolve
them.
Diagnosis
A patient presents with generalized pain and cannot pinpoint a specific
tooth. There is no pain to percussion, chewing, or palpation.
The x-ray shows no indication of pathology on any of the teeth in the quadrant.
Rinsing with hot water increases the pain, but the patient still cannot
point to a specific tooth. In a case like this, you need to isolate
each individual tooth with a rubber dam and run hot water from an irrigating
syringe over the buccal side of the tooth. Do this for all the teeth
in the upper and lower quadrant to make sure that the pain is not radiating.
The culprit tooth will show itself as hot water is poured over it.
A patient experiencing acute pulpitis enters your
office and has to constantly drink cold water to calm down the pain.
Apply Endo Ice on a piece of cotton pellet. Wait for the pain to
come back and apply the pellet to each of the teeth in the quadrant until
the pain calms down. Wait for the pain to reappear and apply the
cold pellet to that tooth again to make sure that it is the cause of the
pain.
Proper Isolation
There are times when the coronal tooth structure has
decayed out and there is not enough tooth structure above the gingiva to
properly place the clamp on. The first step is to use a #8 slow-speed
round bur to remove all the remaining decay. Then prepare a mixture
of Ti-Core and inject it onto the tooth using a Centrix needle to rebuild
the coronal structure. Wait for it to set and then clamp it like
a normal tooth. You can also do this using Ketac cement. The
only drawback with Ketac is that it is weaker than Ti-Core so it can crack
under the force of a clamp over time.
If the tooth has decayed out underneath a crown,
make sure you remove all the decayed materials. Never start the root
canal process until all the decay has been removed. If there is a
leakage in the margin between the crown and the tooth, seal it up by injecting
Ketac cement into the crown. The Ketac cement will flow into the
margin area and seal it up temporarily so that you can do the root canal
without saliva contamination.
Access Preparation
Creating an access opening can be difficult in certain
situations. If you go down too deep in calcified cases on molars,
you can perforate the floor. By using the PulpOut™ bur you can prevent
this from happening. The stopper on the bur will prevent you from
hitting the chamber floor. The diamond shaping bur will help you
create a perfect straight-line access without scratching the floor.
Some pre-molars have large crowns and thin roots.
Others are angulated due to spacing. Do not place the rubber dam
on these teeth before access preparation. The dam can obstruct your
view or give you a false angulation of the root. You can perforate
out to the side if you are not careful.
Locating Canals
The first thing you want is to create an access opening large
enough to allow light to get in. Next, make sure that the chamber
is clean of all decay and calcified pulp stone. This will illuminate
the chamber, allowing you to better locate the canals. Remember to
smooth out the groove along the floor of the upper molars to locate the
MB2.
Weeping Canal
I’m sure that every one of you has encountered an infected
canal that refused to be dried. You cleaned it out well and medicated
it with Ca(OH)2 and hoped that it would dry up by the next visit.
When you opened it back up, the canal was as wet as on the previous visit.
You continued this process of cleaning and closing for a few visits without
results. The reason for this is that the apex has been widened due
to resorption from the infection. What you want to do is clean out
the canal really well to the anatomic apex by using the apex locator.
After that, mix a little MTA and plug it down the canal to the apex using
an extra coarse paper point. This will absorb the moisture and create
a tight plug at the apex. Now you have a dry canal to fill.
Removing Excess EZ-Fill®
Cement
After the canals have been filled, you find the chamber
filled with EZ-Fill cement. Removing this cement is easy by using
cotton pellet soaked with alcohol. The alcohol seems to remove the
cement very well and leave a clean chamber to be restored with composite
or amalgam.
Post Hole Preparation
Do not use force when creating a post space with a flexi
drill. Always use a gentle pecking motion so that you can feel the
resistance of the gutta percha. If you feel the drill against hard
surface, do not push any further. Move the drill in different angles
until you feel the gutta percha being removed.
When using a Flexi-Flange® countersink drill,
run it with water. It will cut a lot smoother than it will when running
dry.
I hope that these suggestions will be of help
to you when you encounter such problems. Feel free to visit the Endo
Forum if you have any other problems pertaining to endo that you need
answered.
April-June 2005
|
|
