From: Benjamin Schein
To: ROOTS
Sent: Wednesday, October 05, 2005 10:48 AM
Subject: [roots] To culture or not to culture Revisited.

With cultures we only identify or isolate the free-floating planktonic bacteria, but not many of those stuck
together. Cultures are slightly  valuable because the less planktonic free floating bacteria we detect means  the
more  biofilm we did remove mechanically..   Endodontic biofilms are a three dimensional connection of various
species of bacteria that live in "stuck together" extracellular matrix made of polysaccharides.
Imagine the JELL-O moldsa made with pieces of fruit, such as peaches. The gelatin is analogous to the polysaccharide
matrix and the peach pieces are analogous to the bacteria. Much like it is difficult to isolate the peaches in the
gelatin mold, bacteria in a biofilm are less susceptible to be isolated. Additionally, channels within the
polysaccharide matrix allow the flow of nutrients and communication chemicals, making these films difficult to
overcome.

Since most antimicrobials bind to protein, biofilms are surrounded by a carbohydrate-rich sugar matrix devoid of
protein, which offers them a level of protection against antimicrobials, calcium hydroxide, sodium hypochlorite and
chlorhexidine included.. So, the basics of root canal system  preparation are  cleansing and debriding. (or cleaning
and shaping). Currently, the only successful way of dealing with endodontic  bacterial biofilms is excising them from
the root canal systems and trying to close the systems to entomb the bacterial biofilm remaining. The calcium
hydroxide magic, in my opinion,  is not its antibacterial action but the fact that it produces an environment where
the remaining biofilm we always leave does not get new nutrients and it prevents host cells to get to them and
release their enzymes in a frustrated kind of phagocytosis. PMN's for example hate an alkaline environment.   It's
much easier to remove as much as possible of the biofilms and close the environment  than it is to treat it with
chemicals of all sorts. If you do not feel you have done or can do a good job in one visit by all means do it in two
and three and yes use calcium hydroxide as a biofilm retarding material and  (PMN"S exploding)  in the areas you did
not clean until next vist when you can clean them better.

It is ENDO 101. - Benjamin Schein

How about the evidence that CHX eliminates Biofilm?. GOMES, LIMA, NOIRI
IEJ SEPT 2001
JOE OCT 2001
J PERIOD NOV 2003

Specially from this guy Noiri who has published both on the J Periodont and the JOE, we all know his work. I do agree
on DNA having an impact on new knowledge on microbiology, I am also not going to say anymore that DNA can live inside
phagocytes because it will be quickly degraded, but the fact that DNA can be detected from very little bacterial
cells in number which maybe were not in enough numbers to cause disease remains a controversy, also, DNA may be
degraded after being bound to dentine, the question is how long after?, Nobody knows exactly even to this point,  so,
are we still getting some false positives with this tests, I think so.. I believe we should be looking for something
to remove biofilm and still, try to achieve as good as a disinfection protocol as we can, if someone can do it on one
appointment, good for them!. - Jorge

Endo 102.....debride and disinfect the root canal system and you will achieve a high degree of success.
Everyone is jumping on the biofilm wagon as if this has not been known.  Yet...we still save teeth with endo, no?
Just ask the Swedes  ;-))
I will not say Seltzer and Bender, but Moller, Sundqvist, Fabricius, Sjogren, Siqueira, etc., etc.- Fred


Bandwagon?......

That was precisely the title of my talk in the AAE 1976 "Endodontists shuld jump into the bacterial plaque bandwagon"
30 long years ago.

We certainly save them. No doubt we debride and disinfect the canals. We are lucky also that we can eliminate the
space where biofilm can regrow and reorganize because we almost remove the ecosystem or habitat with GP and/or
resilon plus a film ;-) of sealer we just cover the remaining bio film if any with a ZN)@_EUGENOL FILM OR RESIN FILMS
we substitute the biological film with a chemical film.The "mono -blockers"  like you feel that they leave no
space...guttaperchers like me feel we remove the space  good enough to allow healing.;-) - Ben

You were ahead of your time...as usual. - Fred