Since Dr. B. A. R. Ottolengui introduced the ether spray for obtunding
sensitive dentine there have been a number of such agents introduced
for the same purpose.
There has been considerable confusion regarding the action of volatile
agents for sensitive dentine. Dr. Ottolengui in previous paragraph
first used ether, supposing it to dehydrate further than alcohol or
hot air; but it does not, because it has no affinity for water and
because it produces cold, which opposes vaporation of the dentine's
moisture. Dr. Curtiss in using nitrous oxide is led to the belief that
it obtunds because it dehydrates. But that is a mistake, for the same
reason as for ether. When these agents obtund sensitive dentine, it is
because they reduce the temperature far below normal, and the crown
of the tooth being easily isolated, it is not difficult to reduce the
temperature so low as to render it entirely void of sensibility.
Chloride of methyl being an ether quite low in the series, volatilizes
at 74° Fahr. between ether and rhigolene, and is capable of reducing
the temperature to 40° below zero, if necessary. It volatilizes with
considerable rapidity with the warmth of the hand, and so does away
with any blast apparatus. Is not as inflammable as ether. Is not a
solvent of caoutchouc, and so it may be conducted through a rubber tube
to the tooth and its flow regulated by a thumb-screw. It volatilizes
quicker than ether, so that the surrounding parts are not saturated.
Its objections are that it is a general anæsthetic and at the present
time rather costly. It is all that Dr. Rhein claims for it, and is to
be preferred as a cold-producing agent for sensitive dentine.
But the more experience we have the better we can control our patients
by a sort of personal magnetism, and dehydration will answer our
purpose without resorting to such dangerous methods as the reduction of
temperature.
_Discussion_—DR. C. R. BUTLER:—General anæsthesia is probably
slightly produced, which accounts for part of the effect.
DR. J. R. CALLAHAN:—A sort of hypnotism is produced when obtunding is
suggested by the use of alcohol or hot chloroform. For the worst cases,
a little nitrous oxide is effective.
DR. OTTO ARNOLD:—If you will impress the patients that everything is
being done to ease the pain, you will succeed. The Niles apparatus,
which throws a jet of vaporing alcohol upon the dentine, is very
effective. A few inhalations of chloroform have a good effect.
DR. C. R. BUTLER:—Small amounts of chloroform are very dangerous. It
would be as safe as nitrous oxide if the people had as much confidence
in it.
DR. H. A. SMITH:—Doctors disagree as to that. Dr. Hamilton says "ether
may be used to the 'ether glow' without a particle of danger." Quacks
are often successful, because they give a full dose. The use of such
anæsthetics is dangerous, but quacks, like fools, rush in where wise
men fear to tread.
DR. P. S. BOLLINGER:—I have tried nearly all obtundents, but have
been most successful in working upon the imagination of the patient.
Purchase a firm hold on the instrument.
DR. C. R. BUTLER:—The fountain-pen answers beautifully as an
instrument for using volatile agents.
DR. J. TAFT:—The rubber cloth must be used. There should be
dehydration and reduction of temperature. Cold is so successful as an
obtundent, because it does not vary like other agents. A combination of
therapeutic agents might be used in the Niles atomizer.
Dr. C. R. Butler, Cleveland, O., Paper, "A Means of Holding the Rubber
Dam, While Operating Upon Labial Surface Cavities."
Many appliances for this purpose have been devised, but when applied
are often very painful and difficult to carry the rubber over.
In these very low cavities a hole is drilled below the margin of the
cavity far enough to allow it to be excavated and still leave enough
for strength, and into this hole a platina-iridinum or gold wire is
screwed, first dipping in phosphate cream. The cud is cut off within
an eighth of an inch of the cementum and the rubber carried over the
projecting point, by which it is afterwards held. Sometimes two such
pins will be found necessary.
In performing this part of the work never cut a thread in the cementum.
If the shouldered spear-pointed drill is nicely gauged to the wire,
like the S. S. White retaining screw-set, the wire will cut its own way
in.
When the filling proper is completed, dress off the wire pins as though
they were fillings.
_Discussion_—DR. J. T. TAFT:—The Palmer clamps have been a source
of pleasure in my hands. They fit each tooth so nicely that great
stiffness is not required.
DR. H. A. SMITH:—If a chisel is rested against the cementum and
lightly tapped, the assistant can easily hold it. Bleeding gums cause
much time to be lost.
DR. F. SAGE:—Sharpen the large end of a steel pen and drive it in the
cementum. This has the general form of the festoon of the gum.
DR. M. H. FLETCHER:—Spunk and dry plaster of paris used when the
rubber leaks, takes up moisture and sets, adhering to the teeth and
rubber.
DR. CHAS. MILES:—Thrust a heated instrument through the rubber and it
will adhere.
DR. J. R. CALLAHAN:—The How clamp is a good appliance for this class
of cavities.
DR. C. A. BUTLER closed by saying there was no cut in the cementum by
using the screws. They are dressed like gold fillings.