Knowing that the value of these artificial substitutes for the natural teeth is entirely dependent upon the conservation of the teeth or roots upon which they are mounted, and believing that the methods of treating these roots whksh have been worked out in connection with the system known as crown and bridge-work are superior to those practiced by the majority of the profession, I am disposed to devote considerable space to this part of my subject. Before describing the several modifications of bridge-work illustrated in this article, I desire to call attention to a few of the cases which I have treated, and which are more or less radical departures from those ordinarily met with.

Case I. This case was reported in the Independent Practitioner for April, 1884, from which I quote as follows: "Mrs. S. had been wearing a pivot-tooth on the root of the upper right central for several years, and as it required frequent resetting she desired to have it replaced by a more permanent operation. On removing the crown the root was found in a bad condition. Decay had penetrated the side of the/ root, leaving quite a large opening into the pericementum. An enlarged foraminal opening led to a cavity at the end of the root, from which an offensive pus was discharged. But the root was very firm, and promised to give a secure foundation for a crown if it could be brought into a healthy condition. A little cowardice prompted me to attempt the treatment through the root, but after a week's effort my ambition in that direction was satisfied, and I resorted to a method which has proved eminently successful in several cases of this character. The end of a soft, smooth broach was bent so as to form a little hook. This was passed up the enlarged pulp-canal until the hook slipped over the end of the root. The broach was then seized with pliers at a point exactly opposite the external end of the root and drawn out, and the length carefully measured.

"A point of orange-wood was carefully shaped to fit the pulpcanal, a notch cut on one side, showing the exact length of the root inside, and after dipping in a solution composed of equal parts of carbolic acid, chloral hydrate, and gum camphor, it was driven into the canal until the notch appeared precisely opposite the end of the root. I know of no other method by which an enlarged pulp-canal can be so perfectly filled, with a certainty that the filling-material has gone exactly to the end of the root and no further.

impossible to follow it its entire length, the canal can probably be most perfectly and safely closed by filling the root canal, as far as it has been opened, with a solution of gutta-percha in chloroform, to which have been added a few drops of a solution of iodoform in eucalyptus oil. After carefully pumping this solution into the canals, insert a wood point previously prepared and drive it gently to place.

"The wood point was twisted off at a point about half the length of the root, where it had been weakened by passing a knife around it, cutting partly through. Heavy gold foil was placed over the opening in the side of the root, and the large funnel-shaped opening filled with amalgam. An external opening was made opposite the end of the root, and the diseased bone and end of the root cut away with rose-burs. A cotton tent was kept in for two days. On the third day a crown was placed on the root, and in ten days the external opening healed and all irritation had passed away."

Case II. Mr. W. had a central incisor broken near the margin of the gum by a base-ball. The pulp was removed and the canal filled with gutta-percha. Inflammation followed and an abscess threatened, which was prevented by removing the filling. When he came to me the canal had been open for more than a year, and from it there had been more or less constant discharge. On examination I found it filled with black and very offensive matter, which had stained the dentine to a considerable depth. After syringing with warm water, I enlarged the canal materially and passed directly through the end of the root with a rose-bur. I enlarged the cavity which I found at the end of the root until I had produced quite a copious flow of blood through the canal. After the bleeding had ceased a broach wound with cotton was dipped in chloride of zinc, 20 per cent, solution, and passed up through the root. After this treatment the canal was simply dressed with Listerine for ten days, the dressing being changed every day. At the end of that time, there being no discharge (in fact, I could not discover at any time after the operation that there was any discharge of pus), the root was filled precisely as described in the preceding case, and a Eichmond crown mounted

upon it.

I believe the most rational treatment for that persistent pathological condition which remains around the roots of teeth which have been the seat of alveolar abscess may be summarized in a single short sentence. If the source of the primary irritation remains, remove it; cleanse the root thoroughly and fill it; then reduce the territory of perverted physiological action to the condition of a simple wound, and treat it as such. If the case is one of long standing, I enlarge the external opening and enter the cavity at the end of the root with a large rose-bur, cutting out the walls of the cavity and trimming the end of the root. Syringe out with warm water; inject a ten per cent, solution of chloride of zinc, and insert a cotton tent for a few days. Dress the wound-for this is what you now have-daily, syringing with peroxide of hydrogen, followed by Listerine. I believe this simple treatment will cure the most persistent cases of abscess, or, more properly speaking, alveolar ulcers, in from

Fig. 1.

ten days to two weeks. The medication of these ulcerated tracts for many weeks and sometimes months is neither humane nor scientific treatment.

While I have thus written encouragingly of the practice of retaining pulpless teeth in the jaws, I would always encourage the removal of healthy pulps, except when absolutely necessary. But the operator should not hesitate to do this when convinced that the patient will be greatly benefited by the insertion of a piece of work which necessitates the removal of a healthy pulp. However, the constant modifications and improvements in the methods of constructing the

work is making the removal of pulps more and more unnecessary.

We will now proceed to consider the principal object of this paper, which is the illustration and description of some of these improvements.

Fig. 1 shows a piece of work made for a ease of quite frequent occurrence. It represents the restoration of the inferior bicuspids and first molar of the right side. A gold crown is made for the second molar, and then the three intervening teeth or " dummies" are made as described in my former paper. For the support of the anterior end of the bridge the method hitherto practiced has been to excise the crown of the cuspid and fit a porcelain crown with gold backing to the root, and to this the anterior end of the bridge is soldered.

Fig. 2 illustrates a device Fig. 2. which obviates the necessity

for removing the cuspid crown. A gold band is fitted around the cuspid. At the front, shown at a, Fig. 2, this band is allowed to pass a little beneath the margin of the gum so as to make the smallest possible exhibition of gold. On the lingual aspect of the tooth this band is allowed to be nearly the length of the crown. It will be seen that when this band is fitted as perfectly as possible there must necessarily be quite a vacancy between the upper part of the lingual surface of the tooth and the band. It is important that thisportion of the band fit the tooth perfectly, and an accurate adaptation is obtained as follows: A piece of pure gold, rolled to 35 American gauge, is fitted over that portion of the lingual surface of the tooth which it is desired to cover, d, in Fig. 2, shows the shape that this little pure-gold plate usually assumes. It can easily be fitted perfectly by the use of a burnisher, and then, with the band in position, a drop of melted resin wax is flowed into the space between the pure gold and the band. It is now removed from the tooth, invested, and, after melting out the wax, solder is flowed into the vacancy, filling completely the space occupied by the wax. The top of the lingual portion will now be thicker than is necessary, but can be easily ground ^IG' or filed down to the proper thickness. We now have a band which fits all portions of the tooth perfectly. The anterior end of the bridge is soldered to this band, and after the work is properly finished it is cemented in place in the usual manner, b and c, Fig. 2, show side and lingual views of this band after the fitting is completed.

Figs. 3, 4, and 5 illustrate a method of inserting extensive pieces of bridge-work in cases where there are no natural teeth or roots for , supporting one end of the bridge. The work from which these drawings were made was constructed by Dr. H. A. Parr, of New York, By this method bridges may be inserted in cases where all of the teeth on one side of the mouth have been lost, or where all of the teeth anterior to the molars on both sides are wanting. Crowns are first fitted to the teeth which remain. These crowns being in position, an impression is taken. From this a cast is obtained with the crowns in their proper positions. A second impression is also taken of that portion of the mouth where there is no natural support for the bridge. From this impression metallic dies and counter-dies are obtained, from which is « struck" a small gold plate about three-fourths of an inch in length and width, the size of the plate varying according to position and other conditions. After this little plate or -saddle" has been perfectly fitted, it is waxed in the proper position on the

Fig. 4.

Fig. 5.

model, with the crowns. The intervening teeth are now placed in position, and the work invested and soldered. I have had no practical experience with this method, but Dr. Parr informs me that he has inserted several cases which are ,being worn with perfect satisfaction. To provide for the possibility of shrinkage or absorption at the point where the plate or saddle rests, I would suggest that it

be not soldered to the bridge, but attached by means of an adjustable screw.

Fig. 6 illustrates another device for obviating the necessity for removing the crowns of natural teeth in preparing the mouth for bridge-work. Crowns are fitted in the mouth to the points of attachment in the usual manner. An impression is taken, bringing the crowns away in their proper positions. From this the cast or model is obtained. Heavy bands of half-round gold or platinum bars are now fitted around the necks of the natural teeth on their lingual surfaces. These bands being waxed in position, serve to connect the different parts of the bridge, uniting them in one piece without the loss of any of the natural crowns. I have found this a highly satisfactory method of inserting Fig. 6. extensive pieces of the work.

Fig. 7 shows the mouth as presented for which the piece shown in Fig. 6 was constructed. Fig. 8 shows the piece in position.

Fig. 9 illustrates a case which is a type of a class of frequent occurrence. Alternate molars and bicuspids in the upper and lower jaws are lost until the occlusion is somewhat changed, and the force of mastication is gradually brought upon the front teeth. Kapid wearing of these teeth results. These cases are among the most difficult that the operator is called upon to treat by the ordinary methods. In the case herewith illustrated the lower bicuspids with a molar on one side were in good condition, but the loss of the upper bicuspids and molars made them useless. As usually happens, the upper incisors had suffered most. The lower incisors were restored by capping them with cohesive foil. The bridge shown at