made by rolling the gold between the thumb and fingers, can be wedged between the buccal and lingual walls and malleted or pressed against the cervical wall. Repeat until the cavity is about two-thirds full, when the cohesive gold may be incorporated with the non-cohesive and the operation completed with cohesive gold. Of course it is necessary to anchor the cohesive gold in the grooves and against the walls of the cavity. It is all-important to use a good flat burnisher between the teeth, and condense the noncohesive gold thoroughly against the edges.

In the majority of distal cavities in bicuspids and molars a matrix works nicely.

Hard cylinders are not suitable for matrix work. The pellets or rolls can be placed into the cavity with ease by standing them upon end, pressing laterally, and forcing the last pieces into the center, condensing cervically and matrixally-if I may be permitted to coin the word. In approximo-occlusal cavities where the anchorage is slight, the buccal or lingual wall broken, necessitating the contouring of the tooth, possibly non-cohesive pellets, might be used in some cases to start the filling. Such a case, as a rule, requires an entire cohesive filling with gold anchored in grooves.

The judgment of the operator must decide when a certain procedure is best. Specific rules are hard to formulate, but general rules may be observed, as suggested in the foregoing, taking into consideration the quality of the teeth to be operated upon. The same general rules may be applied to the filling of approximal cavities in the anterior teeth.

DO WE USE THE ALL-GOLD SHELL CROWN TOO MUCH?

BY F. A. BALLACHEY, D.D.S., BUFFALO, N. Y.

(Read before the thirty-fourth annual union convention of the Seventh and Eighth District Dental Societies of the State of New

York, Buffalo, October 28, 1902.)

It is our privilege from time to time to meet together for the interchanging of ideas and opinions on matters relating to the profession which we follow, and by hearing new things and discussing old ones we get the corners rubbed off of our own way of doing things, and learn not to be too "cast-iron" in any method of practice. If each of us de

livered himself of just one idea at a dental convention, he would get in return the ideas of all the other members, and would therefore be very much the gainer. It is with this thought in mind that I have come before you at this time with but a single idea. It cannot be a new one, for it must surely have voiced itself deep in the heart of everyone present, but I think it will not be amiss to bring it to the light of criticism and discussion and let the cleansing rays of publicity play upon it for a few minutes. You have a suggestion of what it is in the title, "Do We Use the AllGold Shell Crown Too Much?"

The method of saving teeth when nothing but the roots are left, by means of a gold crown, was first suggested by Dr. Beers, who settled in California about 1849. He had his invention patented in 1873, after he had been using it for some years. He died in the following year, so that the matter was not brought before the profession as much as it might have been, until a few years later. This invention was a wonderful stride forward, because the preservation and restoration to usefulness of teeth which had nothing left except the roots must have seemed before that an utter impossibility. But if there were great possibilities for good in the new invention there were also great possibilities for evil, and many good teeth were needlessly covered up by gold caps.

SOME EXTREME CASES.

When I was a student, a few years ago, a friend of mine was having some work done at a dentist's, and one evening it chanced that I was called upon to stop the aching of one of her teeth. It was an upper second bicuspid and had a good large cavity in it. The buccal and lingual sides were both good, but (would you believe it?) that tooth had been flattened off preparatory to crowning. The pulp had not been devitalized, though probably it was the intention of the operator to devitalize it before crowning. But think of the case: A beautiful pearly tooth disfigured in that manner, in order to be covered up by an all-gold shell. Of course the tooth should have been filled and not crowned.

Last spring a patient whom I was treating had had several gold caps on the lower teeth. One of these had been removed some time subsequent to the crowning operation.

The tooth thus exposed was almost intact, and the patient informed me that other crowns covered teeth fully as good. The crowning in this case had been done as a cure for pyorrhea alveolaris, and the dentist who did the work had informed the patient that she would have no more trouble with those teeth in any way. If the patient remains under my care, I think it probable that some more of those shell crowns will follow the fate which the first one met.

It not infrequently happens that we have to remove cap crowns for the purpose of treating chronic alveolar abscesses, and where I have had to do this it almost invariably exposes a tooth which could have been and should have been saved by filling. I removed one only a short time ago and do not intend to put it on again, partly because it doesn't fit anyhow, and partly because I can make the tooth useful and comfortable by filling it. I believe it would be safe to say that hundreds-yes, thousands,-of teeth have been needlessly covered with shell crowns since the introduction of this system; and not only that, but that they have been actually ruined by crowning, whereas they should have been preserved in wholesomeness and beauty by filling. I am not referring now to the all-gold cap on anterior teeth -there is no shadow of excuse for that under any consideration—but am speaking of the posterior teeth, the molars and possibly second bicuspeds, which are presented having from one-quarter to two-thirds of their substance lost by caries. And remember I am not running down the system, but am deprecating the abuse of the system. The all-gold shell crown is a good thing; it is a grand thing to be able to make an old root almost as good as it ever was; but to take a tooth which might be filled and cover it up in such a way is an abuse. It should not be done.

I assert, then, that we have used and still do use the allgold shell too much. A tooth which it is possible to fill should not be crowned. I will give two reasons for this statement, though of course there are many others. First: Nearly all the crowns cause a little irritation to the gingivæ. Second: Crowning is a last resort. If you fill a tooth and the filling breaks out, then you can crown it, but you will have the satisfaction of knowing that you didn't crown it until you had to. Besides that, it is wonderful

how these large fillings will stay in and do good service for years.

THE COMMERCIAL FACTOR.

It is my private opinion that commercialism has been a large factor in bringing about the too frequent use of shell crowns. It is so much easier to cement on a gold cap and pocket a comfortable fee than to toil over a large and difficult filling for a less remuneration. The individual con

science of the operator must settle this question in all cases, but, gentlemen, let us remember that there is a higher aim in the practice of a profession than the amount of wealth to be accumulated, and a better reward than the almighty dollar.

There you have my idea, and if the telling of it is resultant in the saving of one tooth from an unnecessary gold cap it will not have been in vain.-Cosmos.

PLASTER OF PARIS.

Of all of the materials which the development of dental practice has called into requisition it is probably safe to assert that none has filled so important a place as plaster of Paris. Ample scope is furnished to the speculative mind in the endeavor to realize the tremendous extent to which dental art is built upon a foundation involving the use of this indispensable material. Doubtless other methods would have been devised to accomplish similar ends had plaster never been discovered, yet so intimately is its use bound up in the majority of our procedures that the dentistry of to-day would have been unknown, and the whole practice of our art would have been fundamentally different in the absence of this material. Dental and oral prosthesis, orthodontia, and much of purely operative dentistry would have been restricted in their growth, and many ordinary operations would have been impossible, had we been deprived of the useful aid of plaster of Paris.

So familiar are its qualities, and so accustomed are we to the feeling and belief that we know all about it, that the suggestion that much is yet to be learned about it may seem somewhat overdrawn; nevertheless we are convinced that there is a large field for investigation in connection with this material, not merely as an interesting

subject of research, but because certain data with regard to its physical characteristics and behavior are urgently needed, and indeed must become matter of common knowledge before precise and accurate work can be uniformly accomplished with it.

The general use of plaster as an impression material and its universal use in the making of casts of the jaws upon which to construct artificial dentures have brought out the fact that the material is subject to great variations in form and in texture during and after the process of setting, and that these variations exert a strong modifying influence upon the adaptation of the dental mechanism which has been constructed upon it, in so far as perfection of fit is concerned. Its expansion, its warpage, and its varying density are all factors which must be severally reckoned with if the finished mechanism made upon it is to be accurately adapted and comfortably fitted to the mouth for which it was intended. We know in general certain things about the behavior of plaster, and we have certain general notions as to the causes of its varying qualities, and something as to the methods of controlling these variations. We know, for example, that there is hard and soft plaster, fine and coarse, quick setting and slowsetting; that the setting may be hastened by the addition of potassium sulphate or common salt, and that alum increases the hardness of the casting. We know also that plaster expands in setting, that the rate of expansion is different for different grades, and that the rate is modified by the temperature of the water used in the mixing and by the degree of temperature at which the crude gypsum was dehydrated. These data are, however, little more than generalities, and are therefore merely indications of what should be more precisely worked out and recorded. The work already done in a scientific way in connection with this subject has been meager, but little as it has been, it is extremely valuable, for the reason that each item of definite information brought out with regard to this material is another practical step toward precise, accurate work in dental prosthesis.

Our attention has been recently directed to this subject because of recent discussions as to the causes of ill-fitting dentures, particularly in upper cases of the Gothic or high