tion in the manufacture, as soon as a demand for
them is secured. It is not very creditable to those
who prepare materials for the dentist to use in
plastic fillings, that so many of the preparations fail
to keep up the character in which they are first
presented to the profession, after they have become
sufiiciently well known to create a brisk demand for
them. Of course this is because the early experi-
ments were made by some one person, who takes
care that everything he uses shall be of the best
quality ; the ingredients are accurately weighed, and
his manipulation is as nearly as possible perfect.
But when quantities are required, he must have
assistance in the work, and then materials are not
selected with so much care, and the exact propor-
tions are not maintained. It ought to be possible
for the dentist to trust his manufacturer as the
physician does his chemist ; and I hope this hint
will be one step towards a better state of things.
Many preparations of alloys for amalgam have
been tried, but I confess I have never had much
experience with any one that took a descriptive name
from any of the precious metals. If a dentist does
his duty to his patient, he takes care to select, for
filling teeth, the material that he thinks best suited
176 DENTAL PRACTICE.
to the case, and if asked to do so, frankly explains
the nature of his selection, and the reasons for
using it. There is no necessity for him to disguise
the fact that he is using amalgam, by calling it
a gold or a platinum alloy. Silver and tin are, and
must be, the metals chiefly used in all amalgams,
and, if other metals are used, it is only in very
minute quantities, which cannot affect the intrinsic
value of the alloy to any appreciable extent, and are
introduced to prevent shrinkage or discolouration.
It is, therefore, a mere pretence, unworthy of a pro-
fessional man, to call these fillings by any other
than the accepted name in the profession.
The cavity must, of course, be in every sense as
carefully excavated as it would be for a gold filling.
There must not be any fragile walls left to break
down after the filling is inserted. It is better to cut
away all such walls to a point where their strength
can be trusted, and then, if necessary, this can be
further protected by building up the filling to some-
thing near the original form of the tooth, covering
the edges of enamel, and so reducing the danger
of fracture to a minimum. Undercutting to any
extent is always a mistake, and leaving wide over-
hanging edges of enamel is worse still. In the
latter case the excavation may be faulty, and though
it is right sometimes to leave a part of the decalci-
fied dentine over the nerve, it can never be right to
leave any at the lateral edges of the cavity when
making a permanent filling. It can never be a cer-
tainty that the filling material can be packed into
AMALGAM. 177
deep cuttings, or under wide overhanging edges,
while, if it is not, a weak point is left in the work,
and as the strength of a cable depends upon its
weakest link, so the value of a filling, as a preser-
vative from decay, must depend upon its weakest
point.
It is important in mixing an amalgam for use,
that the quantity of mercury should be as small as
will suffice to make a cohesive mass of the filling.
For this purpose, if for no other, it is desirable that
the bottle containing the supply of mercury should
have a very small aperture to allow the mercury to
be added in minute globules, and that the alloy
should be finely granulated. The mixing should
be done in the palm of the hand, unless the hands
are moist from perspiration, when a small mortar is
better. A thin ivory spatula is the only instrument
necessary when the hand can be used, and I think
the danger of mercurial poisoning by using the
hand for this purpose is a remote contingency,
worthy to be classed with the invasion of England
by way of the Channel tunnel.
In packing an amalgam small round points are
by far the best, and they should be used with a
gentle tapping pressure to secure the filling of every
minute irregularity in the form of the cavity, and
the complete union of the particles. When the
cavity is full and the contour built up to the desired
extent, an ordinary burnisher may be used for
smoothing the surface. A bit of amadou, twisted
up tightly and held in the plugging pliers, serves to
M
178 DENTAL PRACTICE.
remove all loose particles, and then it may be left
to harden, before receiving the final polish.
Dr. 0. C. Allen once paid a deserved tribute to
the value of amalgam as a stopping for teeth, at a
time, too, when it was not so appreciated as it is
now, by saying, — ' ' If my life and fortune depended
upon the saving of a tooth without regard to its
appearance, I would fill it with amalgam."
I make the following extract from a letter I have
received from Dr. Foster Flagg since writing this
article. Knowing of his long course of thoroughly
practical experiments in the nature and working of
various combinations of metals for amalgams to be
used in filling teeth, I wrote to him for further
information as to the value of the precious metals
in these alloys.
"Your ideas of the 'chief positions of silver
and tin, as components of alloys for amalgams for
filling teeth, correspond with the conclusions I have
reached in experiments. I also am ' on the record '
in reference to platinum as a valueless metal, and
one which is only useful for its name ! I, therefore,
regard its employment as fraudulent, and its accep-
tance as discreditable to the intelligence of the den-
tal profession. . Gold and copper and zinc I view
differently. Each of these metals shows proof of
its presence, by giving increased value to amalgams,
as shown by appropriate testings. But in the
so-called ' gold and platinum ' alloys there is
very seldom enough gold to give any appreciable
increased value to the amalgam, if judged by its
AMALGAM. 179
ivorhing characteristics. At least five per cent, of
gold is needed, and it is not proven that much more
is not beneficial — especially as regards maintenance
of colour— though of this I am, as yet, sceptical.
The experiments of the ' New Departure Corps '
gave decided value to copper, also to zinc as a pre-
vention to shrinkage." The letter closes with a few
sentences expressing his regret for his inability to
write more at present upon subjects which have
recently so severely taxed his strength, and his
intense interest in the queries propounded.
180
CHAPTEK VII.
Pivoting.
A GREAT deal has been written in the last few years
about restoring the crowns of broken down teeth by
various processes of pivoting, but some of the
methods described have been such as to deter the
great majority of operators from attempting them,
because of the difficulties that must occur in the
manipulation, and the amount of labour involved.
To those who prefer to spend their time over some
of these laborious processes, I have not a word to
say. They will find their satisfaction in having
performed a very beautiful operation, at the cost of
hours of toil, with utter weariness at the finish, and
the consciousness that only the professional training
of a dentist will ever enable any one to appreciate
the work. But to those who will be satisfied with
an operation which will look as well to any ordinary
observer, be as comfortable to the patient, and
certainly last as long as any one of the more com-
plicated and difficult operations, I have a few
suggestions to make for improvements on the old
processes, without materially increasing the labour,
and without claiming originality, except in the
manipulation, and perhaps — for I do not remember
PIVOTING. 181
that I have ever seen it suggested, except in a paper
of my own — the idea of interposing a gutta-percha
filling between the cervical end of the root and the
artificial crown, thus preventing decay at this vital
point in all pivoting operations.
We will suppose that we are operating on any
one of the six upper front teeth, and that the pulp
is already devitalized. We first cut away the
remaining fragments of the crown, using the engine
as much as possible for this purpose, and the
excising forceps as little as possible, for the jar
from the latter is very irritating to the peridental
membrane, which, perhaps, is ripe for the develop-
ment of alveolar abscess from very slight causes.
A thick-edged corundum wheel, and a round or
oval file, will enable the operator to shape the
end of the root so as to correspond to the
margin of the gum, and be just slightly hidden
by it, so that when the tooth is fixed in position
the joint will be covered by the
gum. Fig. 79. We then, with fine
hooked or barbed instruments,
scrape away all putrescent matter
from the pulp canal, taking care Figure 79.-showmg
that we do not push any of this the root prepared for
, , , , 1,1 taking the impres-
poisonous substance through the sion.
apical foramen, and also taking
care to keep the instrument wet with carbolic
acid, washing it in the acid every time we with-
draw it from the root. We then, with a small
drill that will follow the canal, open and straighten
182 DENTAL PRACTICE.
the latter, lubricating with carbolic acid. We
then use a larger and still larger drill, until
the hole is large enough to admit the gold wire
which is prepared for the English tube tooth,
as this is of a proper size, and being already
straightened, it saves trouble. The pulp canal
should all the time be kept wet with carbolic acid,
and the wire should slip easily in and out of the
hole, but not too loosely, and the hole should be
at least three-eighths of an inch in depth. The
purpose of the gradually-increasing size of the
drill is to enable us to feel the way, and avoid per-
foration of the sides of the root. We then flatten
the end of a piece of the wire to a chisel edge, and
barb the sides of the flattened portion thus, Fig. 80,
cutting this so that, when the wire is in the hole,
the barbed end will be a trifle shorter than the teeth
on either side, so that in taking the impression the
tray will not press on the wire. We now place the
wire in position thus, Fig. 81, and take an impres-
Figure 80. — Showing form Figure 81. — Showing wire in position for
of wire. taking impression.
sion, which shall bring the wire away with it, with-
out altering its direction in the least ; the barbing
of the sides of the wire being to assist its with-
drawal. The impression need not cover more than
PIVOTING. 183
one tooth on either side of the root we are treating ;
and indeed is better so, as the wire is then more
readily withdrawn without altering its direction.
When the model is cast, all that we want is a
distinct representation of the root, with the wire in
position, showing the exact direction of the hole in
the root, and the form of the teeth on each side of
it. Before dismissing the patient from this first
sitting, we select a flat tooth of suitable form and
colour, and take care that the root canal is open to
and through the apical foramen. We dry the canal
with a twist of bibulous paper, and apply a dressing
of carbolic acid, which we cover with cotton and
gum sandarac. If the tooth is broken down below
the surface of the gum, and the latter growing over
it, we may so pack the cotton and gum sandarac as
to press the gum away, and in this case we must
defer taking the impression until the end of the
root is uncovered, and its surface cleaned and pro-
perly shaped. It is important that the wire should
be of the right size and length, because if it is too
small it tips in the hole, and thus gives a false
direction, which only becomes apparent after the
tooth is fitted and soldered, unless we keep the
patient waiting while the laboratory work is being
done, and try the tooth in before it is soldered,
which may sometimes be desirable, but it is not
necessary, if sufficient care is taken. If the wire is
too short, or not roughened at the sides, or if it fits
the hole too tightly, it will not come away with the
impression. The best way is to have a drill of
184 DENTAL PRACTICE.
exactly the right size, and keep it for this purpose
only, as the wire is procurable from any dental
depot in Great Britain, and is always of the same
size. If more than one tooth is to be fitted in this
way, an impression must be taken for each tooth, as
the pulp canals would never be so nearly parallel
that two or more wires could be withdrawn in the
same impression. Having made the plaster cast,
we find the wire standing exactly as it was in the
mouth, and with the teeth on either side indicating
exactly how the new crown must be placed. Ee-
moving the wire from the cast, we now bend and
shape a piece of gold plate to fit the surface of the
root, and drill a hole through it to correspond exactly
with the hole in the root. Then putting the wire
through it and fastening with wax, we withdraw wire
and plate together, and bed them in a wet mixture
of plaster and sand to keep them in position until
they are soldered. After this we cut off the wire
from the concave side of the plate, and bevel the
edges of the latter. The wire and plate should now
exactly fit the hole in the root and the surface of it.
We may now proceed to put a backing on the tooth,
and grind it to fit the anterior edge of the root.
When this is satisfactorily done, we place the tooth
in position on the model, fasten it with wax, and
withdrawing all together, bed them in wet plaster
and sand for soldering. The plate and backing of
the tooth should be of eighteen or twenty carat
gold, the finer the better, and the solder should be
as fine as it can be to run. In selecting a tooth,
PIVOTING. 185
colour, form, and suitableness in every respect
should be studied, in order to avoid the very
un-rtrf-ificial appearance that neglect of any one of
these points would give the finished work ; for art,
in these cases at least, is imitation of nature, and
not an attempt to improve upon it. The tooth
being soldered to the plate, we may smooth and
polish the lingual surface, thus completing the
laboratory work, Fig. 82. We are now ready to
try the tooth in the mouth, and see if it is
satisfactory in every respect : form, position, colour,
if the bite is right, and if the tooth fits so that
the joint will not show. Fig. 83. If in all
Figure 82.— Showing tooth ready Figure 83.— Showing tooth in
for fixing. ' position.
these points the work is satisfactory, it only
remains to fix the tooth in the root. "We first
shape a cavity in the cervical end of the root
of sufficient size and depth to ensure perman-
ence for a gutta-percha filling. The twentieth part
of an inch is deep enough, and superficially it
should be at least two-thirds of the surface of the
end of the root. We undercut all around with an
inverted cone-shaped drill attached to the engine ;
and with a strong thick-bladed knife we then barb
186 DENTAL PEACTICE.
the wire on four sides, so that it will require pres-
sure to push it into the hole, and so render with-
drawal difficult, if not impossible. If we have made
the hole larger than was necessary, a little fine
floss silk may be wound on the wire, but this must
be very smoothly and evenly done. Then warming
the tooth, we place a sufiicient quantity of gutta-
percha around the wire, on the convex side of the
plate, to fill the cavity we have shaped in the end of
the root, taking care to have enough, as any surplus
will be squeezed out. Now, if the root is clean and
free from disease, the terminal portion of the canal,
above the enlargement made with the drill, may be
filled by first packing a few fibres of cotton,
moistened with carbolic acid, up to the apex — being
careful not to go beyond, but this can be guarded
against by using a point that will not quite go
through the foramen — a few more fibres with a
little sandarac varnish, then more of the same, until
this part of the root is filled. A little very stiff
sandarac varnish is then placed in the enlarged
portion of the canal ; the tooth is again warmed in
the flame of the lamp, this time as hot as the
fingers can bear to hold it, so as to thoroughly
soften the gutta-percha; and while it is in this
heated condition we push it firmly up to its place,
using a piece of wood, notched at the end; so as to
guide the tooth while pressing it up — wood being
better than metal for this purpose, because it does
not chip the tooth. The surplus of gutta-percha is
now smoothed away with a warm burnisher, and
PIVOTING. 187
the work is complete. The whole time spent with
the patient in the chair need not exceed half-an-
honr ; and I am perfectly certain that, if the work is
well done, it will outlast any elahorate operation of
building up a back or lingual surface of gold foil
that can be made ; for the gutta-percha is, I repeat,
a perfect preservative from decay in positions where
it is not exposed to attrition, from which the plate
protects it ; while gold is never a safe protection
when packed under the gum.
I had a case some years ago where a tube had
been fixed in the root of a central incisor, and a
gold filling packed around it down to the surface of
the root, and then a tooth fitted with a wire secured
into the tube, very beautiful and highly-finished
work, done by a clever and celebrated man, but the
filling became loose in a few months, and as the
distance was too great for the lady to go back to
her own dentist, she came to me in great trouble
to see if I could do anything, however temporarily,
for her, until she could get home to have it properly
done. I could see that the filling was quite loose ;
indeed, it came away with the tube while I was
examining it, and without the application of any
force. The filling was easily removed from the
tube ; but the wire, to which the tooth was
attached, was firmly fixed in the tube. I therefore
dried the root carefully, filled it quickly with gutta-
percha, and while the latter was still soft, warmed
the tooth with the tube still in position, and pressed
the whole firmly up to its place, holding it there
188 DENTAL PRACTICE.
until it was cool. It looked all right, and felt firm
and strong, but the lady went away feeling very
doubtful about my rough and ready treatment.
She, however, remained abroad several years, and
called on me on her return, to say that the tooth, as
I had replaced it, had lasted more years than the
former operation had lasted months, and she did
not mean to have it disturbed.
The use of gum sandarac in solution for filling
roots is, I believe, an idea that has not been
suggested to the profession, but it is worth trying.
If well mingled with cotton fibre, it will make a
filling that will keep a cavity clean, and protect it
from decay for months. I recently removed a
dressing of this nature, that had been two years in
a tooth, owing to the sudden departure, and con-
tinued absence from home, of a patient for whom
my brother had been treating a dead tooth. To my
surprise, the surface of the cavity beneath the
dressing was as clean and dry as it would have been
with a proper filling in it. I think Dr. Foster
Flagg has mentioned a case where an arsenical
dressing of his remained covered up with cotton
and gum sandarac for an equal length of time.
The formula is — equal parts of gum sandarac and
gum benzoin dissolved in spirits of wine to the
consistence of stiff varnish .
Pivoting lower teeth is rarely a necessary opera-
tion. I have never tried it in the case of lower
incisors, and I doubt whether there would be
sufficient thickness of root to admit a strong pivot ;
PIVOTING. 189
but the operation can be very satisfactorily done
with the lower canines and bicuspids, and I have
often pivoted the upper bicuspids in the way I have
described for the incisors and canines. But it
sometimes happens that one cusp only of an upper
bicuspid breaks down, and then, if the remaining
cusp is strong, I think it worth while to preserve it,
and fit a new cusp of porcelain to replace that which
is lost, and fill the space intervening between the
natural and artificial cusps with amalgam. The
process differs from those cases where a crown is
replaced — or rather the labial cusp, with a gold
backing, is fixed to give the external appearance of
a crown — but only in some points that would
naturally suggest themselves to the operator. If
the remaining cusp is strong enough to allow a
reasonable hope that it will not break down when it
is used for mastication, we cut away the fragments
of the broken cusp down to and a little beneath
the gum margin, open the root in the manner
previously described — only, if it is a first bicuspid,
remembering the probability of a bifurcation of the
root, and the consequent increased risk of perfora-
tion of its side, and being content with an enlarge-
ment of the canal to the depth of a quarter of an
inch, because the filling will assist in retaining the
artificial cusp in position. If there is much over-
hanging surface of enamel on the remaining natural
cusp, it may not be best to cut it all away, but leave
all that is strong. If there is danger that the
impression may drag in removing it, fill up the
190
DENTAL PRACTICE.
under-cutting with some soft and easily removable
preparation of gutta-percha, as we should prepare a
model with wax, so that it may draw properly out
of the moulding sand. Fig. 84.
Then, placing the wire in position,
we take an impression, as in the
previous case, and fit the new
cusp without a plate to cover the ^^s""" 84.- showing
^ _ the root and remaining
surface of the root, soldering the cusp ready for taking tlie
wire directly to the backing of ™P^^^^i«°-
the tooth, or even to the platinum pins in the
tooth, and leaving the whole as rough as possible,
Fig. 85. We should take care that the roughness
does not anywhere extend quite to the mesial, or
distal, edge of the tooth, but make it a roughness
that will be grasped by, and assist in retaining, the
amalgam filling. Fig. 86 represents the artificial
Figure 85. — Showing the artificial
cusp with wire attached.
Figure 86. — Showing the cusp in
position.
cusp fitted to its place. Having now cleaned and
shaped the natural cusp to do its part in retaining
the filling, we barb the wire, and place the gutta-
percha and sandarac as before, and after the new
cusp is pressed up to its place, we fill up the
space between the two cusps with amalgam, taking
care first that the surface of the root is well
PIVOTING. 191
covered with the gutta-percha, and when the filHng
has had time to harden, smooth and poUsh as in the
case of an ordinary amalgam filling, Fig. 87. The
labial, or lingual, cusp may be fitted in this manner,
and make very serviceable work. With a first
bicuspid, when the pulp canal
indicates bifurcation of the root,
we must take care to select that
which seems the thicker and
stronger root, and then feel the
r. 11 -.1 ,1 1 -n rri Fifiure 87.— Showing the
way cai-efully with the drill. The ^^^^.^^.^^ completed.
patient will feel sensation before
there is actual perforation of the side of the root,
and the driU should be kept well lubricated, or
else the heating will cause sensation so similar to
that of perforation, that both patient and operator
may be deceived. I have had several cases where
the natural cusp has broken down after a time,
and the artificial one, with the filling, has remained
for years ; the only thing done to them being to
smooth off the sharp edges of the filling where
the natural cusp had broken away from it.
192 DENTAL PRACTICE.
CHAPTER VIII.
Gutta-Percha for Impressions.
In taking impressions for the work I have been
describing in the last chapter, as well as for many
other purposes where the dentist requires a good
plaster cast, it is very desirable to have an accurate
representation of the neighbouring teeth, as well as
of the root ; and to obtain this it is necessary to use
some unyielding, inelastic material for the impres-
sion, like plaster of Paris, which will set firmly
around the teeth, and must be broken in removing it
from the mouth, and then laboriously put together
again; or else a material which is sufficiently elastic
in its nature to allow of its being withdrawn from
around the necks of the teeth over the larger part of
the crown, and then quickly contract again to the
form it had assumed before it was withdrawn. Wax,