inferior bicuspid. The work was accomplished with every possible care and left no thought on my mind that the least trouble was to be apprehended, although everything was necessarily hurried through with the greatest rapidity; the young man immediately upon its completion, hastened to his home in New Jersey, I think, whence in a few days to return to college, but, alas! his college days were ended; from cold or other causes, the tooth became sore, an abscess suddenly formed, and the patient (if the account I afterwards received was correct), actually choked to death from swelling of the neck, the tooth having been allowed to remain in the mouth until very shortly before he breathed his last. A more minute account of the circumstances attending his death, I am unable to render, as what is here stated is all I ever received.

The question will instantly arise upon hearing this recital, as to how such catastrophe could occur if the pulp had been thoroughly removed, and the root perfectly filled. A number of possible conditions might be named, but that one probable in this case may perhaps be best illustrated by the following circumstance.

In the winter of 1856, while practicing in Pottsville, I attended to the teeth of a young man living four miles distant, for whom I removed the pulp and filled the roots of a very large inferior, first molar. The canals seemed to be unusually long, but sufficiently large in proportion, and easy of access to the accomplishment of all the work that seemed necessary with unusual case, and when completed, I felt as unsuspicious of future trouble as though it had been the most simple operation possible. A few nights later, however, I was awakened by a furious ringing of the door bell. Upon opening the door, which I did myself, there stood my young friend W., for such was his name, having ridden on horseback through a cold driving storm the four miles that lay between his office and mine, with, as the poet hath written: "a raging canal in his mouth." How furiously raging you may suspect from the anxiety mani

fested to rid himself of it by the four mile ride in the storm. It was of course, extracted as speedily as possible, but after such a tug as dentists rarely meet with; notwithstanding the length of the canal that had been filled, there lay beyond another division and lakelet, in shape like the leaf of the lemon trifolia; as long and as broad as a large grain of wheat flattened, thinner in the centre than laterally, between which and the former there was a contraction to almost nothing. This lakelet was filled with a highly inflamed and congested part of the nerve, which could not have been suspected, and therefore would not have been discovered by any operator.-Dental Office and Laboratory.

ARTICLE II.

PRINCIPLES AND METHODS OF FILLING
TEETH WITH GOLD.

BY A. G. BENNETT, D. D. S., PHILADELPHIA, PA.

To the question, "What is the most urgent need of dentistry to-day?" several answers may be given. Perhaps few will dispute the assertion that our great need is scientific knowledge- exact and exhaustive-of the structures and materials, the pathology and therapeutics, involved in saving teeth. No one doubts that "the need of the profession of the age is to know;" but that "our mechanical ability has outrun our scientific attainments," may be considered a debatable question. To what extent have we been able to utilize our knowledge of dental anatomy and physiology in saving teeth? It is true that our most successful operators have usually been, and are, the best educated; yet skill, after all, is the one thing needful to give

any meaning or value to knowledge in practical dentistry. Dr. Thompson claims that "it is most imperative and important that we better understand why we perform our operations; the how will follow of itself. Filling a hole in a tooth is an absurdly simple thing to do-a mere mechanical and artistic performance." The why we fill a tooth has never been considered much of a mystery. The tooth cannot resist decay nor restore the lost portion-in short, it cannot fill itself. Again, what is the value of "scientific reasoning," as opposed to experimentation? Is it not a fact that all theories and supposed principles are established or destroyed by experimentation and experience? Again, Dr. T. claims that we are not scientific, because the lost parts are not restored in natural substance. There may be such a thing as "striving after the unattainable."

As long as the operation of filling a tooth is slightly surgical and largely mechanical, so long there will exist a greater necessity for developing skill than for acquiring knowledge... How many educated dentists are guided in operating by the structure and functions of the dental tissues? The enamel-rods, the living fibres, the nutritive currents, receive little or no attention, or must yield to mechanical requirements.

When all is summed up, it must be admitted that, though one should have the learning, he must have the skill. It has been not unfrequently more than hinted that some operators who can talk fluently and write elegantly on saving teeth are unable to make even a presentable filling.

Filling a hole in a tooth may be an absurdly simple thing as regards mechanical principles, especially if the tooth is to be thrown into the operator's drawer; and simple enough, even when the tooth is exposed to the forces and fluids in the mouth, if the object be merely to insert the filling so that it will be retained till it decays out; but to insert a gold filling in such a manner that the tooth will resist, for say ten years, all chemical, thermal, and perhaps electrical, forces to which it may be exposed, is quite a different thing.

Our text-books on operative dentistry, though treating the subject of filling in detail, give space and importance to certain features of the subject out of proportion to their relative value. For instance, Taft dwells at great length on the preparation of cavities by classes and their modifications, and on the various forms of gold; yet gives comparatively little exact information and few definite directions on the most essential of all points-the adapting or packing of the gold against the walls and around the margins of the cavity. No one doubts or denies the fact that proper preparation of the cavity is the basis of a perfect filling; but, after all, the adaptation of the gold to the dentine and enamel surfaces is the essential requirement. This is trite enough to those who use gold successfully, but it has not received the general recognition which its importance demands. Adaptation is the vital point, for the obvious reason that defects, even the smallest in the cavity, can readily be seen, with or without a magnifier; and removed, while defects in packing the gold are more or less concealed from view, and generally cannot be corrected except by taking out all or a part of the filling.

Some one remarks that it is difficult, if not impossible, to adapt two hard substances such as dentine and extracohesive gold to each other so as to form a moisture-proof joint; hence the necessity of having as much softness in the gold as is consistent with the required cohesion, and hence the necessity of an even, smooth wall; for, since adaptation to such a wall is difficult, it is obvious that it is well-nigh impossible to adapt gold against rough, uneven surfaces. It is clearly impossible to force gold into the minute inequalities of dentine and enamel. In short, as some one has said, a filling should resemble a cork in a bottle rather than a ground-glass stopper.

Though the essentials of successful tooth-filling are more or less familiar to all, yet, as a basis for what is to follow, they will bear repetition. "It has been said," remarks Dr. Atkinson, "that almost anybody can make a

filling moisture-tight. Almost nobody does. If the cavity is properly prepared, you will have no difficulty." The expert few may have no difficulty, but the unskilled many, even with a perfectly prepared cavity, will often fail of

success.

To prevent breakage and leakage, and because a tooth is partly an animal tissue, and not wholly a mineral substance, the following are the essentials for cavity preparation:

A cavity should be so prepared and its border so beveled that when filled the tooth will offer the greatest resistance to mechanical and chemical forces.

2. Complex cavities should be so simplified and their parts made so accessible that the filling material can be readily and certainly adapted to their walls.

3. Approximate cavities, which extend to the excising edges or occluding surfaces of the teeth, should be so prepared and filled that the strength of the operation will be equally divided between the tooth and the filling.

4. The walls of a cavity should have no corners or acute angles, and should, when possible, form the segment of a circle; and the bevel of the enamel should, as far as may be, conform to the line of its cleavage.

5. Smooth, strong walls, secure anchorage, and perfect adaptation of the filling material to the tooth-bone, are the essentials of durability.

6. As regards the enamel, it is better to remove too much than too little; as respects the dentine, better to remove too little than too much; and as to the anchorage, it had better be too deep than too shallow.

7. Anchorage should be secured by so combining pits and grooves as to do the least injury to the dentine and give the greatest strength to the filling; and the enamel should, when possible, be supported by living dentine.

And, to sum up, smoothness of surface and softness of material insure closeness of adaptation.

A few words on the final preparation of approximal