a root canal after devitalization with pressure anaesthesia.
Zinc Chloride is a caustic and anti-putrescent. It is very
poisonous. Is very useful for stimulating indolent sockets that
show little inclination to heal some time after the extraction of
teeth. Syringe the socket or dry it out, then introduce a tiny
piece of crystal or pass a silver or platinum ball-ended probe
with a little zinc chloride on it. It is very hygroscopic, and there
is usually some liquid in the bottle. On account of its stimulating
properties on septic tissues zinc chloride aural drops (guttae zinci
chloridi [aural]) is a useful form for pyorrhoea pockets:
Zinc chloride . . . . . . . . 4 grains.
Glycerine . . . . . . . . . . 2 drachms.
Alcohol . . . . . . . . . . . . I ounce.
Must be used with caution (Martindale and Westcott).
Copper Sulphate is a very poisonous chemical, but is a potent
germicide and astringent. Dose, i grain. It is used in pyor-
rhoea by powdering the crystals and packing them down into
the pockets, but caution is necessary as to the amount used,
and too large an area must not be attempted. It is soluble in
water I in 3^, glycerine I in 2, insoluble in alcohol.
Bifluoride of Ammonia. This preparation has been investi- S
gated by Dr. Joseph Head, M.D., D.D.S., Philadelphia, U.S.A., \S
as a specific for pyorrhoea and a solvent of tartar deposits
on the roots of the teeth. It is well worthy of attention (see
Dental Cosmos, 1912, p. 41).
1 86 OPERATIVE DENTAL SURGERY
Aromatic Sulphuric Acid. The United States Pharmacopoeia
preparation is very useful for hyperaemic gums that occur around
the necks of teeth and where crowns are present. It has been
used as a caustic, styptic, and antiseptic.
Trichlor acetic Acid. This is a chemical substance prepared
either by the chlorination of acetic acid or by the action of
acetic acid on chloral hydrate. It "is in the form of deliquescent
crystals, melting at 55, very soluble in water, alcohol, and
ether. It is a quickly acting escharotic. The application of
a 50 per cent, solution produces a dry adhering eschar which is
quickly thrown off. There is said to be no secondary inflam-
mation. For use as an astringent lotion or gargle i to 5 per
cent, in water may be used, or I in I of glycerine for local
application. Tobacco stains on the teeth can be removed by
its cautious use, 25 per cent, or less. In the early stages of
pyorrhoea, after swabbing out the pockets with 10 or 20 volumes
strength peroxide of hydrogen, it is a practical remedy and well
worth trying as it has a powerful astringent and drying action as
well as being escharotic. It appears to drive the blood out of
swollen hypertrophied gum. This property of drying may be
tried when superficial bleeding occurs when filling a cavity near
the cervical edge or when putting a crown on.
Its action in pyorrhoea pockets is probably dual killing the
infective organisms and dissolving the calcium carbonate of the
tartar. It should be tried before sound teeth are sacrificed.
(See Martindale and Westcott's Extra Pharmacopoeia, " Acida
Chloracetica.") The writer has given some attention to this
drug and finds that it is well worthy of a prominent place in the
Hypochlorites of Calcium and Soda have been brought, during
the last few years, into extensive surgical use with remarkable
success. They contain hypochlorous acid, which is stated to be
the most powerful antiseptic known. " Eusol," Dakin's solu-
tions, chloramine " T " and di-chloramine " T" are well-known
preparations which come under this heading.
Phenol Sulphonic Acid is .particularly useful where a powerful
stimulating antiseptic is needed, such as in fistulous tracts,
bone absorption around the apices of teeth as found in chronic
abscesses, pyorrhoea pockets, and as a preliminary treatment
in the removal of calcareous deposits about the teeth. The
detachment of bone sequestra in necrosis is enhanced by its
DENTAL MATERIA MEDIC A AND THERAPEUTICS 187
early application. It may be used as a substitute for Dr.
Callahan's 50 per cent, sulphuric acid for the enlargement of
root canals. It is applied in pure form or 50 per cent, solution
with an iridio-platinum loop or a broach of the same metal
wrapped with fibres of asbestos wool (see article in Dr. Prinz's
Martindale mentions a 3 per cent, solution as being useful in
gingivitis and pyorrhoea. It reduces swelling, arrests flow of
pus, and the gums return to their natural shape. As this
medicament is such a useful remedy in septic cases we will quote
Dr. Buckley's description of it in full from the Dental Cosmos,
1910, p. 434:
" In complicated abscesses, good results may be obtained by
forcing phenol-sulphonic acid in contact with the bone or forcing
it through the tooth and sinus, adding as much water as you have
of both constituents, and thus using it in a 50 per cent, strength.
" There is a little trick of pharmacy associated with this
remedy. If water is added to phenol sulphonic acid, it will
precipitate the phenol. If, however, the phenol is heated, and
while it is hot an equal amount of sulphuric acid is gradually
added, and then, while the mixture is still hot, an amount of
water equal to the mixture, phenol-sulphonic acid 50 per cent,
strength is obtained, which can be diluted to any strength and
used wherever indicated. Sometimes this solution is applied to
pyorrhoea pockets. I do not like to use acids in treating pyor-
rhoea because a hypersensitiveness of the teeth is produced by
their use. It is seldom necessary to use acids in treating
pyorrhoea, but sometimes the pus persists in forming in a pocket
even after the roughened portion of the bone and all of the
destroyed pericemental membrane seems to have been thoroughly
removed mechanically or surgically. This flow of pus is some-
times stopped by injecting (or swabbing) phenol sulphonic acid
into the pocket. In that case a 15 per cent, solution suffices,
but unless the precaution of heating the remedy in making it
has been taken, the solution cannot be diluted without preci-
pitating the phenol."
Menthol occurs as needle-shaped crystals, which are deposited
on cooling peppermint oil. It is used for various purposes, but
is somewhat refractory for use in solutions. It is practically
insoluble in water, insoluble in glycerine, soluble 5 in I of absolute
1 88 OPERATIVE DENTAL SURGERY
Creosote is a mixture of phenols, guaiacol, and cresol. It has
an unpleasant, persistent odour. It was widely used many years
ago, but its use has been largely replaced by more suitable
preparations. If employed at all it must be beech wood creosote,
and should not be confounded with coal-tar creosote, which is
very poisonous. It is still used, however, by many operators
with much success as a medicament for root treatment. It
is one of the most powerful deodorizers, anti-putrescents, and
antiseptics. Being a caustic it must not be used in full
strength. For root treatment mix i drachm of beech wood
creosote with 7 drachms of glycerine, specific gravity 1250
(see chapter on Root Treatment and Filling).
Nitrate of Stiver is a powerful caustic and astringent. It is
used in dentistry as an application for arresting dental caries
and erosions on the surface of the teeth. It is very useful for this
purpose as these surfaces are usually very painful for shaping
into cavities for filling. It is also a powerful coagulator of
albumen, deeply penetrating and rapid in its action. It turns
everything it touches black. It is very poisonous; the average
dose is I grain. The compound formed by the nitrate with the
organic constituents of the tooth is insoluble, with the exception
of the presence of a few substances. The nitrate can also be
absorbed by the affected dentine and stimulates the subjacent
dentine to more healthy action. (See article on Silver Nitrate
in Dr. Prinz's " Dental Materia Medica and Therapeutics ").
Dr. Howe's method of root treatment with silver nitrate is
well worthy of attention.
Growths in the mouth, such as small tumours, polypi, or
hypertrophied gum, are readily destroyed by applying the crystal
or a concentrated solution. As it is so poisonous it must be
used with great caution. The safest way of applying it is by
taking a silver wire, heating it, and plunging it on to a crystal,
forming a bead, or if a solution is used, take a tiny square of
amadou held in the tweezers. The stains of silver nitrate are
removed by a solution of sodium hyposulphite or ammonium
We have devoted a chapter to the consideration of drugs
used in dental surgery, in order that our readers may become
conversant with their nature. Practitioners are apt to regard
drugs as being incidental to the various methods of operating,
whereas they are factors in themselves and well worthy of
DENTAL MATERIA MEDIC A AND THERAPEUTICS 189
consideration and investigation as to their merits, potency, and
action. It is only by personal observation, therapeutically, that
one can know them authoritatively.
Dr. Buckley has said: " It is strange how some practitioners
expect to find one drug or remedy which can be used in every
case all through their practice."
We have pointed out that the employment of drugs for cura-
tive or remedial purposes depends on the conception of two
subjects which are intimately bound up with each other, Materia
Medica and Therapeutics. To put it in another way, it consists
of the drug and the organism. The practitioner has at his
command an armamentarium which is quite as potent and
reliable as the instruments which he uses. It remains, therefore,
to learn how to use and manipulate it in order to fully utilize
the whole of his equipment.
Dr. Prinz's " Dental Materia Medica and Therapeutics."
Dr. Buckley's " Dental Materia Medica."
Martindale and Westcott's Extra Pharmacopoeia.
LOCAL AN/ESTHESIA OR ANALGESIA
THE use of local anaesthesia is considered a great boon both to
the patient and the dental operator, as it can be employed at
any time with ready convenience. In general surgery it has
been brought to a high scientific level with methods of block
anaesthesia for the facial regions and upper limbs; also spinal
analgesia for operative measures on the abdomen and lower limbs.
In spinal analgesia an injection of a local anaesthetic is made
in the lumbar region under supreme aseptic conditions. The
cerebro-spinal fluid which occupies the spinal canal is drained off
and the anaesthetic is again injected with a large quantity of
a weak solution. The cerebro-spinal fluid is constantly being
secreted, and when the anaesthetic has been absorbed, the canal
becomes normal. The certainty of anaesthesia is a constant
factor and precludes any doubt as to the patient being com-
pletely insensitive to pain. The cerebro-spinal nerves running
off from each side of the spinal cord are affected as the anaesthetic
solution rises, until the surgeon is satisfied that it has reached
the region he desires. If continued it rises until it reaches the
ventricles of the brain and universal analgesia supervenes, which
in some cases extends to the mouth and the nose.
Block anaesthesia secures a similar guarantee of painlessness
by the anaesthetization of the nerve-trunk which controls the
zone of operation.
In dental operating the production of local anaesthesia is
quite an insignificant matter compared with block and spinal
analgesia, yet we are faced with conditions that are not so
scientifically definite. We are called upon to extract a tooth
in the routine of a busy practice. The operation must be done
quickly. There is always present the uncertainty of the extrac-
tion of a tooth being entirely painless. Fortunately the majority
of cases are painless. The point which we wish to emphasize
is that the scientific accuracy accompanying major operations,
LOCAL ANESTHESIA OR ANALGESIA 191
anatomically and physiologically renders such procedures an
For dental operating the profession has universally decided,
so far, that the analgesic effect shall take place in the direct
region of the tooth structures. For the extraction of teeth the
anaesthetic solution has to be injected into the gums, and reliance
has to be placed on the anaesthetic, and great pressure, in order
to reach the structures beneath the bone. The nerve filaments
do not come into direct contact with the anaesthetic; it has to
reach them rather than their being the centre of the anaesthetic
zone (see Fig. 45). The success of this method is dependent,
therefore, on the skill of the operator to take full advantage of
the little things which are present to get the anaesthetic to the
periodontal membrane which surrounds the root of the tooth to
be operated upon either for extraction or cavity preparation.
The drugs employed for local anaesthesia in dentistry are
usually cocaine hydrochloride, beta-eucaine hydrochloride, and
Cocaine is an alkaloid of the coca plant. An alkaloid is the
active principle of a drug. Alkaloids occur in many plants and
some in animal tissues. They form salts with acids, such as
hydrochlorides, lactates, nitrates, etc. They are generally
crystalline bodies, and act powerfully on the animal system, and
are used in ..aredicine as morphine, strychnine, etc. They are
usually violent poisons.
Cocaine as a local anaesthetic has been in use for many years,
and went through an experimental period when practitioners
naturally took full advantage of its powerful anaesthetic property.
But it was found also, in the large doses employed, that it had
alarming systemic effects, and several deaths were reported.
However, its use is now better understood, and in dentistry it
may be employed in \ to I per cent, solutions with comparative
safety if suitable judgment and precautions are taken. There
is no doubt that the purity of the alkaloid is the first considera-
tion. There are two varieties of plants that produce the coca
drug: one is grown in Northern Peru, and the other in Bolivia,
which is considered better for medicinal purposes. The prepara-
tion of the alkaloid by reliable manufacturers is another factor.
The unfavourable symptoms which gave cocaine a setback
through its incautious use gave chemists an impetus to investigate
the subject, which resulted in eucaine and novocain being pro-
OPERATIVE DENTAL SURGERY
FIG. 43. DIFFICULT EXTRACTIONS BY VARIOUS OPERATORS WITH LOCAL
LOCAL ANAESTHESIA OR ANALGESIA 193
duced as synthetic alkaloids for substitution of cocaine. Novo-
cain has given great satisfaction on account of its efficiency and
greater safety; authorities agree that it is six or seven times less
toxic than cocaine.
Cocaine, however, still has its advocates. The writer has had
opportunities of forming an opinion that it has a very wide use
in spite of those who find novocain safer. One half to f per cent,
of cocaine is used as a safe solution. The dose of the alkaloid
is J grain. One grain dissolved in 100 minims of water is I per
cent., so that J grain equals 25 minims of I per cent, solution
or 50 minims of | per cent, solution. Chloretone added to the
solution is claimed to preserve cocaine solution and to enhance
its anaesthetic effect. It is soluble I part in 200 of water.
Eucaine is not largely used in dentistry.
Adrenalinum or suprarenin is added to the anaesthetic solution
in order to localize its action to the region of the tooth to be
extracted and to retard its absorption. When this drug is
present the solution should be colourless and clear; if decom-
position has set in it will become pink, and finally brown; in
this condition it must be discarded. Many operators realize the
potency of this drug, and it is well to understand why we use
it, the dose we are administering, and the action it is producing
on the tissues. It is a powerful vaso-constrictor, and the strength
usually employed with cocaine is I in 50,000, but many men
prefer i in 100,000 because it is desirable to curtail the period
of its action. The reason for this is, that if vaso-constriction
continues, which causes a condition of stasis or arrested circula-
tion, the resistance of the blood cannot counteract septic
development if infection is present.
Novocain is a vaso-dilator and therefore requires a larger
proportion of adrenalin or suprarenin. Dental tablets E are
Novocain, 0-02 gramme, or approximately ^ grain.
Adrenalin, 0-0005 gramme, or about ^Vu grain.
One tablet is dissolved in I cubic centimetre of water or approxi-
mately 17 minims, which makes the proportion about I in 17,000.
The same percentage of novocain as tablet E is supplied in solu-
tion already prepared, and contains in addition, thymol T ^ grain,
approximately. The addition of thymol to novocain (and also
to cocaine) solution has been advocated as a useful and non-
194 OPERATIVE DENTAL SURGERY
toxic antiseptic, and assists the anaesthetic action. The strength
of i in 1,700 ensures its complete solution, as the solubility of
thymol is i in 1,500. If the thymol could be added to the
dental tablet E it would be appreciated by many operators.
Some men prefer to lessen the proportion of adrenalin; this
can be done by putting two tablets dental E with one tablet F
(without adrenalin) into 75 minims of sterilized water, which
makes a 2 per cent, solution or thereabout. The strength of
adrenalin would then be about i in 3,400. Another important
factor in the anaesthetic solution, whether it is cocaine or novo-
cain, is that it should be rendered isotonic by the addition of
sodium chloride, 15! grains to 4 ounces of sterile water.
Dr. Halliburton has described the importance of Ringer's
solution and the investigation of its constituents in the blood,
and also the cerebro-spinal fluid. Fischer's modification of
Ringer's solution is considered an improvement for dental
purposes and is supplied in tablets for preparing the solution
for novocain. It consists of the chlorides of sodium, potassium,
The object of using physiological or normal saline solution,
or Ringer's solution, is to render it isotonic. In this condition
it is non-irritant to the cells of the tissues. The anaesthetic
solution is carried into the cells by a principle called " osmosis."
This process is well understood by physiologists and chemists.
It consists of the passing of dissimilar chemical substances and
gases through a membranous diaphragm or membrane. There
are many instances of it in the animal body, and also plants,
whereby their functions are carried on.
If the anaesthetic solution is of less density than the blood it
will cause swelling of the cells and is said to be hypotonic ; if of
greater density it will cause shrinkage and is said to be hyper-
tonic. If it is isotonic, it is of the same specific gravity, or
freezing-point, as the blood, and will not irritate or disturb the
normal condition of the tissues, whereas hypotonic and hyper-
tonic solutions will cause disturbance and probably sloughing
The hypodermic instruments include a good syringe for the
injection, suitable hypodermic needles, a Dappen's glass for
holding the solution when in use, a test-tube for bringing the
solution to the boiling-point, especially with novocain, a holder
for the test-tube, a large glass-stoppered pot for holding the
LOCAL ANAESTHESIA OR ANALGESIA 195
syringe and needles when not in use, another one for holding
the anaesthetic bottle or tubes. These pots keep dust away
and preserve the instruments from air contamination. A well-
made electro-plated metal case will hold the instruments very
The main instrument is the hypodermic syringe. This should
be strong and withstand considerable handling both in use and
in constant cleaning, when it is liable to be dropped. An all
metal one answers this purpose better than a glass one. There
are glass compounds on the market for scientific purposes, such
as fused silica tubes and " Vitreosil " tubes, which would be
strong enough. They can be bought with closed ends. Such
a tube could be improvised, but as there is no practical advan-
tage in having a clear barrel it is better to avoid having the
necessary joints, which after a time get out of order. There
are many syringes on the market, the D. M. Co.'s " Washerless
Syringe " and the " Imperial " are popular. The former con-
sists of a hard rubber core at the end of the plunger, the latter
has washers or packing in the head of the barrel. In spite of
the number of syringes which have been put on the market to
appease the operator's annoyance, it appears from experience,
so far, that packing and washers are necessary. The point to
consider, then, is, how can we keep the working parts of the
syringe clean and the packing and washers in a desirable condi-
tion ? There is more in this point than the manufacturers seem
to appreciate. Many operators have a box containing syringes
that have been discarded, the metal parts are beautifully made,
but the joints and washers have rendered them useless. There are
two things to be learnt from this discarded box. One is that
the metal parts are as good as new in appearance, which proves
tha't the metal keeps in perfect order when kept quite dry and
away from the air. The second thing is that where washers
and packing have been, the metal is corroded and black. We
have discovered soon after use that washers and joints disturb
our peace of mind, not from an aseptic point of view, because
we have boiled or otherwise sterilized them, and this process only
aggravates the trouble, but because of corrosion at these parts.
A syringe comes to us well greased, and the first thing to do is
to clean it, but how are we to clean leather washers, or any kind
of washer, without impairing them ? Particles also break off
and clog up the nozzle. Rubber is equally unsatisfactory
OPERATIVE DENTAL SURGERY
because the corrosion disintegrates it quicker than other packing.
Rubber, however, can be boiled and cleaned by itself, which is
satisfactory, but it must not be left in contact with metal.
Salts of nickel and brass are very poisonous ; damp affects them
quite apart from being wet. If a syringe has been perfectly
cleaned and well dried, but the interior left wet, or even damp,
it will produce a blackish stain on clean cotton-wool or a napkin
within twenty- four hours, and if washers and packing are present
the staining will be greater. Therefore all washers or any part
of the syringe where the anaesthetic solution comes into contact,
and damp can get in or underneath, should be taken out at least
once a week. Some operators go some time, perhaps a month,
without requiring the use of a hypodermic syringe. Such is
FIG. 44. AUTHOR'S SUGGESTION FOR KEEPING A RUBBER PLUG
SEPARATE FROM THE METAL PlSTON WHEN NOT IN USE.
A. End of cork fitting in barrel; D, C, body of cork fitting in plunger;
E, hole of nozzle leading to needle; B, extending handle bar with
screw seating in plunger tube.
often the case in a busy conservative practice. When it is
required and the syringe shows evidence of oxidation around
the washers he discards it. In a busy practice in an industrial
centre where the syringe is in constant daily use it does not
matter so much, as it is being constantly cleansed by the solution
and the amount of oxidation would not appear so great. How-
ever, if we could keep the metal parts separate and adjust the
washer at the time of using only it would obviate the trouble.
The writer has improvised a syringe which consists of a strong,
open, tubular piston with the usual extending screw bar at one
end to hold a rubber cork which must not be too soft. The
tube must not be blocked in any way, as the cork plunger will
not stay in position. A vela rubber cork can easily be made by
forming one accurately in wax, then making a plaster mould
LOCAL ANESTHESIA OR ANALGESIA 197
from it, which gives a matrix in which wax forms can be
moulded and removed. In flasking, the cork should be com-
pletely covered excepting the end which goes into the piston.
A cork can easily be put into a flask when flasking a plate. If
they could be supplied by the dental manufacturers so much the
better. The hypodermic needles, being made of metal, come
under the above statement, so that after use they should be
cleansed from blood, well washed and dried by blowing hot air
through them, and carefully put away. There is no need to put
a wire through them.
Operators vary in their methods of injecting the anaesthetic