IMPROVEMENTS IN PREPARATIONS OR COMPOUNDS FOR PREVENTING PAIN IN DENTAL OPERATIONS
Year: 1880

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN PREPARATIONS OR COMPOUNDS FOR PREVENTING PAIN IN
DENTAL OPERATIONS." A communication from abroad by Herbert Enos
Dennett, of Boston, Massachusetts, United States of America, Dentist.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 29th September 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. " IMPROVEMENTS IN PREPARATIONS OR
COMPOUNDS FOR PREVENTING PAIN IN DENTAL OPERATIONS." [A communication
from abroad by Herbert Enos Dennett, of Boston, Massachusetts, United States of
America, Dentist.]
My Invention relates to that class of dental compounds or preparations which
are employed to prevent pain in filling the teeth, or during the process of exca-
vating or preparing the cavities to receive the filling, and consists in a novel
combination of ingredients, as hereinafter set forth, by which a more effective
article of this character is produced than is now in ordinary use.
As the structure or anatomy of the teeth is well understood by all practical
dentists a brief description of the same is all that is deemed necessary in order to
shew the nature of my improvement.
A tooth consists of three principal parts, viz., the enamel or outer coating, the
dentine or body, and the pulp or centre. Connected with the pulp and extending
throughout the body is a series of minute and extremely sensitive nerves, which
when exposed to the air or brought into contact with foreign substances cause more
or less pain. Hence when decay takes place, and it becomes necessary to fill the
cavity produced thereby, the pain caused by the instruments being brought into
contact with the exposed nerves in excavating the cavity is sometimes very intense,
and frequently interferes materially with the work of the dentist.
To obviate this has long been the study of the profession, use having been made
of a great variety of articles designed to produce deadening or anodyne effects on
ID 131

page_text: the nerves of the tooth, such as oil of cloves, creosote, camphor, spirits of nitric
ether, borax, carbolic acid, laudanum, chloroform, alum, myrrh, tinctures of iron,
chloral, morphia, carbonate of potassa, sulphate of zinc, chlorate of potassa, and
the like, and also compounds embodying more or less of these ingredients. Caustic,
preparations of arsenic, burnt alum, zinc, potash, acid, and the like, have also been
employed to kill or destroy the nerves; but aside from the poisonous nature of
some of the last named articles, and the great danger incurred in their use, it is
now considered by nearly all scientific dentists very objectionable to destroy the
nerves of the tooth when possible to avoid it.
In excavating and filling teeth an article designed to produce insensibility to
pain by direct application to the cavity should, in order to accomplish the desired
results, possess qualifications which do not pertain exclusively to any of the sub-
stances named, or to analogous substances or their compounds. At least three
elements acting wholly or in a measure independently of each other, and producing
somewhat different results, are essential in a compound or preparation of this
character, and a fourth may sometimes be employed with advantage as auxiliary
to the others, to wit, firstly, a desiccant; secondly, an obtundent; thirdly, an
astringent; and, fourthly, an anodyne. These elements should also have certain
peculiarities of their own, viz., the desiccant should possess few or no astringent
properties, and should not act as a caustic or escharotic; it should also be of such
a nature as to readily penetrate the tubes or ducts of the dentine and absorb the
fluids contained therein. The obtundent should be strictly what its name indicates,
deadening sensibility by coating and sheathing the exposed nerves, producing at
the same time a soothing demulcent effect. The astringent should be purely of an
astringent nature, without caustic properties, and the anodyne one that will have
a prolonged action, or not be readily evaporated or dissipated in use. It is also
equally important that none of these elements should either by themselves or
when combined operate to injuriously affect the teeth or health.
My improved compound is believed to possess in a marked degree all of the
essential features mentioned, and is prepared as follows:-
The
I take of glycerine, one fluid ounce; tannic acid, two drams; chloral, four grains.
I mix thoroughly by rubbing up all of the ingredients in a mortar or other
suitable vessel, after which they must be strained or filtered until clear.
glycerine should be of the very best quality, free from water, lime, butyric acid,
chlorine, chloride of calcium, lead, sulphuric acid, sugar, and all other adulterations
or impurities. The tannic acid should also be pure and of full strength, the white
being best, as it usually contains less gallic acid than the yellow.
The proportions given in the above formula may be varied as desired without
departing from the spirit of my Invention, although I prefer in all cases to use a
saturated solution of tannin and glycerine, the relative proportions of the last-
named ingredients in such a solution being substantially as stated, or about four
parts of glycerine to one of tannin. The amount of ordinary chloral required for
one and one-fourth ounces of the compound is one grain; but I sometimes omit
the anodyne entirely, and at others increase this quantity to five grains or more,
or use butyl chloral instead where a stronger anodyne is indicated. Acetate of
morphia and some other anodynes may be substituted for the chloral, or used in
varying proportions therewith, but simple chloral is deemed preferable. I also
sometimes employ camphor in place of chloral, as well as in combination with the
same and the other ingredients, the camphor and chloral being used in nearly equal
quantities. The tannic acid may also be substituted by sulphate of zinc, sulphate
of cadmium, and various other astringents, but the tannin is far superior in every
respect to any similar article with which I am familiar, being very powerful and
entirely harmless.
As glycerine possesses remarkable capillary or penetrative powers, and has an
intense affinity for water, its peculiar value as a desiccant in this connection will
be readily appreciated. It rapidly penetrates the dentine, 'absorbing the contents
of the tubes or ducts, and also all moisture from the cavity, at the same time

page_text: serving as a perfect obtundent by sheathing or coating the exposed nerves, thus
combining in itself two very essential features or elements of my Invention, to wit,
an obtundent and a desiccant. The glycerine also acts as a vehicle by means of
wbich the astringent and anodyne are brought more speedily and effectually into
contact with the sensitive portions of the tooth than is possible by any other agent
with which I am familiar.
Other oils or oily compounds may be used in place of the glycerine, but are far
less effectual in nearly every respect; for instance, the hydro-carbon oils, both light
and heavy, either alone or in combination with oils of a different nature, while
possessing some of the characteristics of glycerine, do not produce equally satis-
factory results.
In using the hydro-carbon oils I prefer the heavy grades, and have found the
following formula the best, viz. :-
(1.) Heavy hydro-carbon oil, one ounce; camphor, sixty grains.
(2.) Heavy hydrocarbon oil, one ounce; camphor, eighty grains; chloral, eighty
grains.
I also use the following, viz. —
Chloral, one part; absolute alcohol, one part.
These proportions may be varied somewhat.
The method of using my improved compound will readily suggest itself to any
dentist without explicit instructions in that respect. It may be conveyed to the
cavity as often as required before and during the operation of excavating by means
of a small piece of cotton saturated in the solution, and held in any proper imple-
ment, or it may be applied in any other manner most convenient, using about one
drop at each application. When prepared in accordance with the formula the
compound is too strong for use in making the first applications to the tooth, and
should be diluted with distilled water until reduced to the proper strength to be
borne by the patient, the undiluted compound being used for the later and final
applications.
It will be obvious that the compound may be employed to prevent pain not only
in preparing the cavities and filling the same, but in numerous other operations on
the teeth; also that on account of its transparency it will not interfere with a
free inspection of the work being done, a very essential feature in an article of
this character.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the
28th March 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN PREPARATIONS OR
COMPOUNDS FOR PREVENTING PAIN IN DENTAL OPERATIONS." A communication
from abroad by Herbert Enos Dennett, of Boston, Massachusetts, United States of
America, Dentist.
My Invention relates to that class of dental compounds or preparations which
are employed to prevent pain in filling the teeth, or during the process of
excavating or preparing the cavities to receive the filling, and consists in a novel
combination of ingredients, as hereinafter set forth, by which a more effective
article or preparation of this character is produced than is now in ordinary use.
As the structure or anatomy of the teeth is well understood by all practical
dentists, a brief description of the same is all that is deemed necessary in order
.to shew the nature of my improvements.
A tooth consists of three principal parts, namely, the enamel or outer coating,
the dentine or body, and the pulp or centre. Connected with the pulp and
extending throughout the body is a series of minute and extremely sensitive
nerves, which when exposed to the air or brought into contact with foreign
substances cause more or less pain; hence when decay takes place, and it becomes
necessary to fill the cavity produced thereby, the pain caused by the instruments
being brought into contact with the exposed nerves in excavating the cavity is
sometimes very intense, and frequently interferes materially with the work of the
dentist.
To obviate this pain and facilitate the operations upon a tooth has long been the
study of the profession, use having been made of a great variety of articles designed
to produce deadening or anodyne effects on the nerves of the tooth, such as oil of
cloves, creosote, camphor, spirits of nitric ether, borax, carbolic acid, laudanum,
chloroform, alum, inyrrh, tinctures of iron, chloral, morphia, carbonate of potassa,
sulphate of zinc, chlorate of potassa, and the like, and also compounds embodying
more or less of these ingredients. Caustic preparations of arsenic, burnt alum, zinc,
potash acid, and the like have also been employed to kill or destroy the nerves;
but aside from the poisonous nature of some of the last-named articles, and the
great danger incurred in their use, it is now considered by nearly all scientific
dentists very objectionable to destroy the nerves of the tooth when it is possible to
avoid it.
In view of the foregoing, experiments have been made to discover a substance,
preparation, or compound that would produce, when directly applied, such an effect
as to enable cavities to be properly excavated and filled witliout causing pain, or
killing or destroying the nerves of the teeth. These experiments have disclosed
the following facts having direct relation to the present Invention, namely:-
-
The body or dentine of the tooth is formed or built up of superposed layers
composed of infinitesimal cubes, between which layers and in immediate contact with
the nerves there is a series of exceedingly small flattened tubes or ducts, filled with
serum or a thin watery fluid, and extending through from the enamel to the pulp.
These ducts while in their normal state act as liquid telegraphs so to speak, to
convey along the line of the nerves the impulse or vibrations produced by the
dental instruments used in excavating or preparing the cavity, and filling the same,
thus greatly increasing the senitiveness of the nerves, and rendering the operation
much more painful.
By simply desiccating or drying the exposed surfaces in the cavity the pain may

page_text: be lessened; it may also be reduced by means of powerful astringents and caustics;
also by the direct application of substances possessing obtundent properties; and
by the use of anesthetics or anodynes. As a desiccant, hot air has been employed
with some success, being forced or injected into the cavity by means of a proper
pump or instrument designed for that purpose; but as hot air can be brought into
contact with the surface only, the relief afforded is not always certain and never
more than partial.
For the same reason several of the substances hereinbefore enumerated may be
properly termed surface desiccants, such, for instance, as burnt alum, carbonate of
potassa, and the like, whose action is mainly superficial, as they possess very slight
if any capillary or penetrative properties, their astringent or caustic action tending
to greatly limit their absorbent action when used as indicated, an objection
which applies with equal force to various other metallic and vegetable substances
possessing absorbent, or absorbent and astringent properties which have been tried
for the same purpose.
According to this Invention however, it has been found that in excavating and
filling teeth an article designed to produce insensibility to pain by direct application
to the cavity should, in order to accomplish the desired results, possess qualifications
which do not pertain exclusively to any of the substances named, or to analogous
substances, or their compounds. It has also been found that at least three elements
acting wholly or in a measure independently of each other, and producing some-
what different results are essential in a compound or preparation of this character,
and also that a fourth may sometimes be employed with advantage as auxiliary
to the others, to wit, firstly, a desiccant; secondly, an obtundent; thirdly, an
astringent; and, fourthly, an anodyne. These elements should also have certain
peculiarities of their own, namely, the desiccant should possess few or no astringent
properties, and should not act as a caustic or escharotic; it should also be of such a
nature as to readily penetrate the tubes or ducts of the dentine, and absorb the
fluids contained therein. The obtundent should act strictly as its name indicates,
deadening sensibility by coating and sheathing the exposed nerves, producing at
the same time a soothing demulcent effect. The astringent should be purely of an
astringent nature without caustic properties; and the anodyne one that will have a
It is also
prolonged action, or not be readily evaporated or dissipated in use.
equally important that none of these elements should, either by themselves or when
combined, operate to injuriously affect the teeth or health.
My improved compound is believed to possess in a marked degree all of the
essential features mentioned, and is prepared as follows, that is to say :-I take of
glycerine, one fluid ounce; tannic acid, two drams; and chloral, four grains. I mix
these ingredients thoroughly by rubbing up all of the same in a mortar or other
suitable vessel, afier which they must be strained or filtered until clear. The
glycerine should be of the very best quality, free from water, lime, butyric acid,
chlorine, chloride of calcium, lead, sulphuric acid, sugar, and all other adulterations
or impurities. The tannic acid should also be pure and of full strength, the white
being best, as it usually contains less gallic acid than the yellow.
The proportions given in the above formula may be varied as desired without
departing from the spirit of this Invention, although I prefer in all cases to use a
saturated solution of tannin and glycerine, the relative proportions of the last-
nained ingredients in such a solution being substantially as stated, or about four
parts of glycerine to one of tannin. The amount of ordinary chloral required for
one and one-fourth ounces of the compound is one grain; but I sometimes omit the
anodyne entirely, and at other times increase this quantity to five grains or
more, or use butyl chloral instead where a stronger anodyne is indicated.
of norpbia and some other anodynes may be substituted for the chloral or used in
varying proportions therewith, but simple chloral is deemed preferable. I also
sometimes employ camphor in place of chloral, as well as in combination with the
same and the other ingredients, the camphor and chloral being used in nearly equal
Acetate

page_text: quantities. The tannic acid may also be replaced by sulphate of zinc, sulphate of
cadmium, and various other astringents, but the tannin is far superior in every
respect to any similar article with which I am familiar, being very powerful and
entirely harmless.
As glycerine possesses remarkable capillary or penetrative powers, and has an
intense affinity for water, its peculiar value as a desiccant in this connection will be
readily appreciated. It rapidly penetrates the dentine, absorbing the contents of the
tubes or ducts, and also all moisture from the cavity, at the same time serving as a
perfect obtundent by sheathing or coating the exposed nerves, thus combining in
itself the very essential features or elements of my Invention, namely, an obtundent
and a desiccant. The glycerine also acts as a vehicle by means of which the
astringent and anodyne are brought more speedily and effectually into contact with
the sensitive portions of the tooth than is possible by any other agent with which I
am familiar.
Other oils or oily compounds may be used in place of the glycerine, but are far
less effectual in nearly every respect; for instance, the hydro-carbon oils, both light
and heavy, either alone or in combination with oils of a different nature, while
possessing some of the characteristics of glycerine, do not produce equally satisfactory
results. In using the hydro-carbon oils I prefer the heavy grades, and have found
the following formulas the best, viz. :-(1), heavy hydro-carbon oil, one ounce;
camphor, sixty grains; (2), heavy hydro-carbon oil, one ounce; camphor, eighty
grains; chloral, eighty grains.
I also use the following, namely, chloral, one part; absolute alcohol, one part.
These proportions may be varied somewhat.
The method of using my improved compound will readily suggest itself to any
dentist without explicit instructions in that respect. It may be conveyed to the
cavity as often as required, before and during the operation of excavating, by means
of a small piece of "spunk" or cotton saturated in the solution and held in any
proper implement ; or it may be applied in any other manner most convenient,
using about one drop at each application. When prepared in accordance with the
formula, the compound is too strong for use in making the first applications to the
tooth, and should be diluted with distilled water until reduced to the proper
strength to be borne by the patient, the undiluted compound being used for the
later and final applications.
It will be obvious that the compound may be employed to prevent pain not only
in preparing the cavities and filling the same, but in numerous other operations on
the teeth, also that on account of its transparency, it will not interfere with a free
inspection of the work being effected, a very essential feature in an article or
preparation of this character.
"
Having thus fully described the compound or preparation, which I term
"Näboli," as prepared according to this Invention, and as communicated to me by
my foreign correspondent, and the manner of performing the same, I wish it
understood that I claim in a dental preparation or compound for preventing pain
in operating upon the teeth,-
First. The combination of an astringent and an obtundent, substantially as and
for the purpose specified.
Second. The combination of a desiccant and an obtundent, substantially as and
for the purpose described.
Third. The combination of an astringent, a desiccant, and an obtundent, sub-
stantially as and for the purpose specified.
Fourth. The combination of an astringent, an obtundent, and an anodyne, sub-
stantially as and for the purpose specified.
Fifth. The combination of an astringent, an obtundent, a desiccant, and an
anodyne, substantially as and for the purpose specified.
Sixth. An obtundent and a desiccant embodied in one and the same ingredient,
in combination with an astringent, substantially as and for the purpose set forth.

page_text: Seventh. An obtundent and a desiccant embodied in one and the same ingredient,
in combination with an astringent and an anodyne, substantially as and for the
purpose specified.
Eighth. The combination of glycerine and tannic acid, substantially as and for
the purpose set forth.
Ninth. The combination of glycerine, tannic acid, and chloral, substantially as
and for the purpose specified.
Tenth. The combination of glycerine, tannic acid, chloral, and camphor, sub-
stantially as and for the purpose described.
Eleventh. The combination of heavy hydrocarbon oil and camphor, substantially
as and for the purpose specified.
Twelfth. The combination of heavy hydrocarbon oil, camphor, and chloral,
substantially as and for the purpose specified.
Thirteenth. The combination of absolute alcohol and chloral, substantially as and
for the purpose specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this
day of March, in the year of our Lord One
thousand eight hundred and eighty one.
W. ROB. LAKE. (L.S.)