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practice, for instance, where a lateral was missing, to destroy the pulp of a perfectly sound adjoining canine, cut off the crown, and mount two teeth on its root; and, perhaps, also, cut a cavity in the central to give the fixture additional firmness, as I am told is being done, I am pleased to add,-by dentists who advertise extensively, for I cannot conceive that a real dentist would ever commit so great an outrage?

We may often to advantage make one root support two or even three teeth where the conditions are favorable, as I have done several times; but when we make an appliance that is rigidly fixed to two or more roots or teeth, is not the risk of failure largely increased? We all know how uncertain a pulpless tooth is. Is it not a great risk to rigidly fasten several of them together with an apparatus that is not readily removed? What will be the probable result if any of them become inflamed, as they are so liable to do? And again, the advocates of bridge-work, as it is called, urge the attaching of eight or ten teeth, or even an entire denture, to four roots. What will be the probable effect on the four roots thus made to do the work of two or three times their number? It seems to be one of those things in which it will be well to advance slowly. It may be practicable. I saw two such arrangements in the same mouth, constructed in Paris about 1856. On each jaw were about ten teeth, mounted on a heavy half-round gold wire, and rigidly fixed to about four roots. The roots had been plugged with wood, and gold pivots soldered to the fixture driven into it. In each jaw were several natural teeth, but the denture had no connection with them. Nearly all the roots of the missing teeth were in; they had been filed down, and the wire rested upon them. I understood from the patient that she suffered very much for several weeks after they were inserted. When I first saw the case, it had been in place about twenty years, had never been removed, and had given entire satisfaction. It was lost some five years afterwards from recession of the gums loosening the roots. In that case, there is no doubt the patient had a far more comfortable and satisfactory denture than plates would have been; but, I must add, the odor from the roots and the accumulation of food the patient was unable to remove was very, very vile.

Bridge-work is not to be utterly discouraged; in skillful and discreet hands its capabilities are great, and so long as it is confined to roots or teeth of little value, it can be made to relieve the patient of the inconvenience of a plate,—at least for a time, -make a more

serviceable denture while it lasts, and if it does hasten the loss of the roots, it leaves the mouth in no worse condition for a plate than it found it. When we see how much has been done to make pivotteeth more permanent and cleanly, who can say what persistent effort may not do in that direction in the future?

Dr. STOCKTON: I hope very much that the other Sections connected with this Association will be able to promulgate knowledge among the members of the profession and the world at large, so that very soon there will be no occasion for a Section on Artificial Dentistry. It is difficult now to discern just where the line between operative and mechanical dentistry should be drawn.

Take, for instance, such operations as Dr. Bonwill performs, which seem to be entirely in the province of operative dentistry, and, on the other hand, such operations as are performed by Dr. Matteson and Dr. Richmond and others, which seem to belong almost exclusively to the mechanical department. Hence it is a very difficult thing to decide what belongs to one department and what to the other. There is one fact brought to notice by Dr. Trueman, which, it seems to me, should receive the condemnation of this intelligent body, and of all other enlightened dentists. It is this: I understand the practice to be, when the loss of one or more teeth has been sustained, to advocate that an adjoining tooth, sound and useful, shall be sacrificed-cut off—and upon its root the two or more teeth be placed, in order to avoid the use of a plate. A very intelligent gentleman made the remark, which seems to me almost justified, that anyone who would be guilty of such a practice as that deserved to be horsewhipped.

My attention has been called to a new mode of holding in the mouth an entire upper denture. It is to do away with the central suction cavity, and to secure it upon the alveolar ridge. I present the plate for your inspection. The inventor tells me he has tried it in a number of cases, and there is no difficulty except for a short time, a day or two,-when he has an entire adaptation of the plate to the mouth. I am inclined to think very favorably of this. I remember the case of a prominent preacher who had to have a set of teeth made about every six months, and he said to me that he was afraid he would have to give up preaching. The plates got loose. I made him a plate without any suction cavity, and from that time to this I have never had to change it. I believe a perfect adaptation of the plate to the mouth is a great deal better than depending upon a little place in the centre to retain it.

Dr. BÖDECKER: About six or seven months ago, at a meeting of the New Jersey Central Dental Association, Dr. Timme, of Hoboken, exhibited a hydraulic press, invented by Dr. Robert Telschow, of Berlin. It appeared to me that this was an exceedingly good idea, and I determined that the first opportunity I had I would use this method. Dr. Timme has lately struck off two gold plates for me with the press. The particulars of this process are as follows:

The plaster impression is taken, and into this a compound of sulphur and plumbago (Spence's metal) is poured, which melts very quickly, and very quickly hardens. This is removed from the plaster impression, and a gold plate is pressed over this with the fingers as well as it can be done; or, a zinc die is made, and over this the gold plate is roughly hammered, as the Spence metal will stand any amount of pressure but no hammering. The gold plate and a piece of rubber which holds it in its place are put into the hydraulic press. The press will force it home with greater accuracy than I have ever seen accomplished by any other process. The pressure is about eight hundred atmospheres to the square inch. I have seen a good many plates fitted in the mouth, but I have never seen any that fitted so perfectly as those made by the hydraulic press.

Dr. PRIEST: The method of pressing plates into form has been advocated before this Association at a previous meeting. I think a better way is to cut the plate near the centre of the anterior portion, allowing it to lap as it is bent into shape, first forming it in the palatal arch (after cutting), which will allow the metal to move laterally; and with a die made by pouring lead into the arch of the zinc die, making what is often called a frog, then placing tough paper or thin cloth at each side of the plate, it can be easily and quickly driven, and made to approximate the form of the palatal arch, when the remaining portion can be readily shaped over the alveolar ridge, the lap reduced to the proper width, the edges beveled, and, after it is quite well fitted, soldered. If done nicely, and with fine solder, it will be hardly thicker than the plate; and, if properly finished, will not melt or flow during any subsequent heating. I consider it necessary in forming all "suction" plates to make two sets of dies (and sometimes the third), to produce a perfectly formed plate.

Dr. MATTESON: The improvement in the crown which I have to offer to the profession will necessitate a somewhat lengthy description, and as I have no notes here you will excuse me if I do not make it as clear as I would otherwise.

[Dr. Matteson intended to have had cuts to illustrate his remarks, but they did not arrive until too late. He has since furnished them, and his remarks are made to refer to them.-CHN. PUB. COM.]

The crown is formed with a shell (Fig. 3) which covers the lingual surface, extending around the sides and cutting edges and with a narrow band (e Fig. 1) embracing the circumference of the root in front at the gum, and into the opening thus left, is fitted a porcelain front (Fig. 5), presenting very much the appearance of the Richmond crown. The shell is made of gold and platinum plate,-gold on one side and platinum on the other, of about No. 33, standard gauge.

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The porcelain front is a plain plate- or rubber-tooth, with a dovetailed slot, which is cut with a corundum wheel and disk, running lengthwise of the tooth. The root is prepared to receive the crown by enlarging the canal two-thirds of its length, so as to receive a platinum wire screw, No. 16 to 18, wire gauge, the screw taking firm hold when inserted. The outer one-third of the pulp-canal is further enlarged with a cone-shaped bur with its base toward the apex, and the end of the root countersunk.

A platinum ring (Fig. 4) is fitted to the inner circumference of the shell, so that when in position the ring rests on the end of the root and about midway of the width of the band in front, in which position the ring is soldered. The porcelain front is then fitted into the opening in front, and the screw is inserted and cut the required length; the screw should extend about two-thirds of the length of the crown. The root is filled around the screw, and the end of the root is covered with amalgam or cement, the crown adjusted, and the packing of the filling continued through the opening in the front, covering the ring in the shell,-if amalgam is used about one-half of the shell should be filled,-leaving sufficient room to insert the front.

Into the dovetailed slot and in the front and remaining portion of the shell is inserted sufficient cement to complete the filling, when the front is inserted, the excess escaping around the edges, which are burnished around the front.

The appliances for making these shells are in the form of dies and counter-dies, which are interchangeable in forceps made for this purpose. Each set comprises dies and counter-dies for the six superior front teeth, two lower cuspids, and one lower incisor. The inner surfaces of the lower incisors of the two sides are so nearly alike that but one die and counter-die are needed for both.

Dr. KINGSLEY: I observe among those present some gentlemen who have heard me speak fully upon my present subject-" Articulation and the Mechanism of Speech "-years since, and I have to ask their indulgence for some things I shall say which to them may appear ancient history. To such I would say that there is really nothing new in what I shall present, for the years that have passed have only served to prove by repeated demonstration that the opinions I then advanced were true.

I have devoted more than a quarter of a century to the study of the subject, have performed many experiments to improve the speech of those afflicted with cleft palate and have probably seen a larger number of such cases than any other person.

The physiological and philosophical origin of articulate speech lies in the vibration of the vocal chords, which creates vibrations or waves in the passing current of air, and such waves reaching the ears of the hearer produce the effect we call sound. Sound and voice may here be used as interchangeable terms. The sound produced by the vocal chords may be one in tone, note, and key, but in passing through and out of the mouth it becomes changed by the alterations in the form and size of the buccal cavity. The one note produced when

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