one more premolar from today


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Authors have been credited  for the individual posts where they are.
Photos: Courtesy of Sashi Nallapati- www.rxroots.com

From: Sashi Nallapati
To: ROOTS
Sent: 16 May 2007 6:51
Subject: [roots] one more premolar from today

Tooth 20 was referred for endodontic retreatment.
patient has increased discomfort to chewing and also spontaneous pain.
Dx: Acute apical periodontitis with atleast 2 root canals  untreated.

end of visit 1 all canals were cleaned and shaped to length. 2 buccal canals (MB,ML) and 1 Lingual
canal were identified and treated. MB canal was the hardest of all to treat as the original treatment has
ledged the canal space making negotiationg to length difficult. second visit the canals were obturated and
I placed cavit /IRM as interim restoration. patient is returning for retreat in 19 and the final restoration
will be done at that time.

I have treated quite a few 3 canal lower bis and this is byfar the easiest. i separated a lentulo in it while
applying caoh, but was able to get it out with out sweat.

relevant facts

Upto 40% of lower bicuspids have more than 1 canal. even more so in black population.
only 5% of all lower bicuspids have 3 canals and thats the highest number reported in the literature.
these cases are fun to treat if one uses magnification and special microendodontic instruments.
otherwise its very stressful to treat these teeth.
when 3 canals exist, more often than not there are 2 canals to the buccal and 1 to the lingual. occasionally
they could lie in a  Letter 'C" shape.
its important to recognise the anatomy from straight and angled radiographs. case selection is key in these
cases if you want to avoid misadventures. hope you find this case interesting.- Dr. Sashi Nallapati




What "special microendodontic instruments" are you using to help you in cases like this ?
Excellent case as always, - Thomas

Thomas, micrscope, small mirrors, discovery burs used in a precise manner to obtain straight line (atleast close)
access, ultrasonics to blend the canal orifices into the walls to create an even taper. nothing special from other
cases, but more of a stringent application. - Sashi

what is the difference between Meuller bur and Discovery bur?
what level of magnification do you normally work at when you found the 3 orifice of each canal?
how did you bypass the ledged canal?
what is your irrigation of choice to reach these deep trifurcated areas?
EDTA to remove the smear layer? or NaOCl to disinfect and get rid of debris?

You are the undisputed king of these multi canal premolars, not to mention the only one who has continuously
posted even during residency.....

sashi, how many upper and lower bicuspids have you personally done with 3 or more canals?
does this support what the literature points out about its prevalence? - Ahmad

Munce burs v. Mueller burs   Munce has diff't sizes, depth markings, non-flexible.- KendelG
Awesome photos Sashi.- KendelG

Your comments please