Page 546 - My FlipBook

544 DISCOLORED TEETH AND THEIR TREATMENT.

which jxTinaiuMit clo.sure of the apical ioraincn of the root may l)c safclv
pci'foi'incd.
The rubber dam should be adjusted with especial care and (»nly
include the tooth to be bleached. If two adjoining teeth are to be
bleached* they may both be isolated by the dam, but in no case should
one or more adjacent normal teeth be included with the tooth to be
bleached. AVhilc the inclusion of teeth adjacent to the one which is the
subject of any ordinary dental operation is in nearly all cases desirable^
there are good reasons why such a plan should not be pursued in the
bleaching procedure. The chemicals used for the purpose may possibly
have some disintegrating or solvent action u})on the enamel structure,
and such action, should it occur, should be confined strictly to the tooth
undery-oiny; treatment and held within the limits of safety bv close
observation and appropriate treatment, which conditions cannot be as
thoroughly controlled and the process as satisfactorily managed when
several teeth are included within the territory of operation.
Furthermore, as nearly all of the bleaching agents used or those
which are employed as adjuvants in the process have a more or less
irritative or escharotic effect U])on the soft tissues of the mouth, extra
precautions must be taken, in adjusting the dam, against leakage at its
attachment to the cervix of the tooth. As the chances of leakage are
greatly niulti})lied when several holes are punched in the dam for ad-
justment to as many teeth, it is for this reason also that no other than
the tooth to be treated should have the dam adjusted to it.
Su]iposing the tooth to be an u])per incisor, the dam should be
slipped over it and the margin of rubber encircling the cervix should
be gently carried under the free margin of the gum either by means of a
small flat burnisher of suitable angle and curvature, or by means of a
waxed floss-silk thread. One or two turns of a ligature should then be
thrown around the cervix below the dam to hold it securely in place.
The dam may be fixed with greater security, especially as against any
accidental traction made u])on it during the operation, by fastening it
with a liMture made as follows and thrown around its cervix :
A piece of waxed ligature silk about eighteen inches in length has
a large knot tied at about its middle portion by making six or eight
turns of the thread loosely around the end of the index finger of the
left hand. Upon withdrawing the finger a series of loops are had
through which one of the free ends of the thread is now passed, as
in making the first half of a flat knot, as illustrated in Fig. 480.
By drawing upon the free ends of the thread until all of the loops
are closed upon themselves, a hard knot of more or less spheroidal
shape is formed about midway between the ends of the ligature. The
ligature so prepared is placed around the tooth in such a manner that