Page 241 - My FlipBook

PREPARATORY TO FILLING 225
a canal wants reaminsj^ out, so the difficulties of
doing it are increased, and even when reaming
is resorted to, it is safer to first have the root
as sterilised as possible, in order to prevent trouble
in the event of any dentine that is removed by the
reamer being forced through the apex. It is con-
sidered important for all instruments used for root
treatment to be surgically clean, but to carefully
sterilise an instrument, and then immediately foul
it by inserting it into a septic root, seems to be
taking an unnecessary precaution. Clean cases
demand surgically clean instruments. For dirty
cases one need not be so extremely particular.
The Evans root drier is, however, always
aseptic, owing to the heat to which it is subjected.
It is generally considered unnecessary to do any-
thing more than superficially sterilise a root canal,
if a live pulp, or one that has been destroyed by
arsenic, has been removed. The dentine, however,
contains a certain amount of organic, and conse-
quently decomposable matter, and unless an attempt
is made to sterilise the dentine in these cases, it is
certain that every possible precaution has not been
taken.
The Dressing Method.—This name has been given
to repeated applications of germicides to root canals
before filling them. In this case the canals are