Check Page Ranking

Home
Dental tourism
Conferences
New additions
Dental books
FREE journals
Bad breath
Kids caries
Smoking effects
Patient info
Dental Videos
Latest news
ROOTS cases
Wisdom tooth
Diabetes
Drugs of choice

Endo tips    Better Endo    Endo abstracts    Endo discussions

  Troughing advice needed


The opinions within this web page are not ours. Authors have been credited
for the individual posts where they are. - www.rxroots.com Images courtesy: Doug R
From: GURPREET SINGH
Sent: Friday, December 30, 2005 7:24 AM
To: ROOTS
Subject: [roots] troughing advice needed

Please guide me about troughing between mesials of lower molars and mb 
and palatal to find mb1 as since last month I have found  mb1 in almost 
every upper  first molar  but getting to prepare them needed troughing 
so i was only able to prepare 10% less canals than the # I found as 
I could not get the file past the opening of the canal and  files #8 n 10  
tips used to bend like question mark ? - Dr.Gurpreet Singh

Satelec P5 ultrasonic unit, a BUC 1 tip, rubber dam, microscope..follow 
the white lines in the pulpal floor.. 98-99% of it is SEEING!!!!!.......

What you are basically asking is equivalent to the question :  can someone 
help me get this key I have here in to the lock of that door over there 
while I have my eyes closed

The simple answer to the question is : open your eyes

Plain and simple there is nothing to be taught other than the value of 
light and magnification - Craig

First, realize that while upwards of 90% of maxillary first molars have a 
second canal in the MB root, only about 10% of mandibular first molars do. 
In neither location can they always be negotiated. The maxillary molar is 
common, however, so let's consider that one.

As John West is fond of saying, negotiating the MB2 is "not a big job, 
it's a smart job." The problem is that the MB2 is very curved at the coronal 
limit of the canal. The shelf of dentin that grows over and obscures the 
(minute) orifice has the effect of moving the canal entrance distal to the 
true path. When you insert your file, it immediatedly runs into a wall of 
dentin on the mesial side of the canal, and the extremely narrow confines 
of these typically very small canals will not allow the file to
negotiate the abrupt curvature. Excessive vertical work merely crumples 
the file tip and risks ledging. Therefore, access must be created.



You do this by working the tip of the file to the point where resistance 
is met, and then pulling it to the mesial to file away the overhanging 
dentin. When your file first engages, you will note that the it
"points" almost straight to the mesial, with the handle at a radical 
distal angle (see illustration). Realize, there may only be 2 or three 
flutes of the file that are engaged.As you do this you will observe
that the MB2 orifice moves far to the mesial from where it began. later
you will gain experience and become quite artful in your troughing so as 
to make for the mesial extent of the canal more directly. I often alternate 
ultrasonics with a small round bur (eg, LN burs); the sonics strip away 
the overhang while the round bur polishes the dentin, making the orifice 
highly visible in the scope.When you have accessed sufficiently, you will 
note that the file begins to drop vertically as you work it; this will
coincide with in creasingly vertical file orientation. You will, of course, 
use up a number of small files, less with experience. You want to avoid a 
lot of work with the tip early on, as the possibility of ledging
the mesial wall is quite high at first; you should be "taking what the 
canal will give" and using the side flutes to remove what Ruddle calls 
the triangle of dentin that
obscures the true path.

It will become easier, with experience. But it never becomes EASY. 
Good luck and good hunting! ......DougR

G'day Doug,

Thank you for taking the time to distil your thoughts regarding Gurpreet's 
question on this subject - I thought it was so clearly explained it didn't 
take a second reading.

Would you mind posting your thoughts on what should be going through our 
minds when "chasing the white line" during a search for missing orifices?  
I'm prompted to ask for two reasons:

I've had a few iatrogenic perforations in 2005 during this phase of 
endodontic treatment despite exploration with ultrasonic tips at 10+  
x's magnification, and

I enjoyed the clarity of your explanation for Gurpreet's question.

Wonderful effort; this is what Roots is about - a colleague calls for 
help and an hour later there is knowledgeable advice to be considered.  
- Michael Moran

G'day Mike, Remember, "access outline for the first molar 
(upper or lower, by the way) should approach the height of contour of 
the MB cusp." What is not obvious, however, is that the orifice to the 
MB2 in upper molars is often located MESIAL to the orifice of the MB. 
This effectively places the "true orifice", i.e., the one that will let 
you into the canal proper, UNDER the mesial marginal ridge.

Initial troughing vertically means that you are essentially troughing 
the floor of the pulp directly overthe furcation (a-a' in the diagram). 
If you use a light touch initially and clear away the overhanging dentin
toward the MMR, and if you alternate ultrasonics with light polishing 
with a round bur, the white line will show up and THIS you can be a bit 
more aggressive in pursing vertically. It is very helpful to occasionally
"true-up" the mesial wall adjacent to your access trough (safe-end diamond) 
as more light will be refracted on the work (hat tip to Ruddle). 
This approach has the added advantage of not weakening the MB root by
excessively thinning the furcation at the junction of the MB root to
the furcation.

After a while, differences in the color of the dentin will tip you early 
as to where you are within the pulp floor. If, for example, explorer 
pressure on the dentin leads to visible blanching of the underlying
dentin color--you're getting a might thin partner!



Avoid using a lot of explorer pressure in hunting for the canal orifice 
for at least 2 reasons. One, explorer gouges will appear just like a real 
canal and can fool you into chasing your own, personal orifice to your 
man-made communication with the periodontium.

Second, the tip of the explorer will often raise a scallop of dentin 
(Like a wood shaving curling ahead of a wood chisel) which obscures the 
entrance to what may indeed be the true canal, preventing ingress of
the far more delicate tip of a #6,8, or 10 file. Do your exploring with 
the file itself. Good hunting - DougR

Doug, Great information- the diagram really helped me "get it"
- Arturo R. Garcia, DMD

Abhishek Mahajan 6:24pm Aug 5, 2013, in World Dental Association Facebook group

Excellent link!

You do this by working the tip of the file to the point where resistance 
is met, and then pulling it to the mesial to file away the overhanging dentin. 
When your file first engages, you will note that the it "points" almost straight 
to the mesial, with the handle at a radical distal angle (see illustration).
Realize, there may only be 2 or three flutes of the file that are engaged.
As you do this you will observe that the MB2 orifice moves far to the mesial 
from where it began. later you will gain experience and become quite artful in 
your troughing so as to make for the mesial extent of the canal more directly.
I often alternate ultrasonics with a small round bur (eg, LN burs); the sonics 
strip away the overhang while the round bur polishes the dentin, making the 
orifice highly visible in the scope.When you have accessed sufficiently, 
you will note that the file begins to drop vertically as you work it; this will
coincide with in creasingly vertical file orientation. You will, of course, 
use up a number of small files, less with experience. You want to avoid a lot 
of work with the tip early on, as the possibility of ledging
the mesial wall is quite high at first; you should be "taking what the canal 
will give" and using the side flutes to remove what Ruddle calls the triangle 
of dentin that obscures the true path.
Searching for MB2
Implants #18, #19
Nice retrofil
Molars with lesions
Tooth #4
Apex locators
Large Apex
Access pictures
Lower incisor retreatment
Horror case
porcelain onlay
Conservative access
Peri radicular healing
Beautiful cases
Resilon cases
Unusual Apex
Noemi cases
2 upper molars
2 Anterior teeth
Tooth #35
Anecrotic molar
Direct capping
Molar cracks
Obstructed buccals
File broken in tooth
Separated instrument
Delta
Dental Products
Dental videos
2 year trauma
Other case by Dr Glenn
dens update
Palatal root exits
Color map 3
Middle mesial
Continuous pain
Anterior MTA
Previous trauma
Ideal case
Dens Evaginitis