Imagens das páginas
PDF
ePub

MONTHLY MEETING, TUESDAY, APRIL STA.

PĒTER MATTHEWS, ESQ., IN THE CHAIB. The Chairman having made some observations relative to the business of the evening, called upon Dr Purland for his report.

Dr Purland wished particularly to call the attention of the members to the recent re-interment of the remains of John Hunter in Westminster Abbey ; an event which must give the greatest satisfaction to every scientific man, but more particularly to Dentists ; for to John Hunter the Profession and the world were indebted for the first really scientific work on the teeth; it was he who had taken Dental Surgery out of the hands of Barber Surgeons, and it was he who had laid the foundation of all the subsequent laborious and scientific investigations which had taken place relative to our Profession; he might most justly be called the father of the Dental Profession. These being his own feelings, and little doubting but that the majority of the members of the College of Dentists entertained the same feelings, he thought that nothing could be more acceptable to them than something in the shape of a lasting memento of the great man to whom the Profession owed so much; he had therefore made up his mind to get a rubbing of the inscription plate on the coffin ; and although he had had considerable difficulty in carrying out his intention, he was most happy to say that he had succeeded; he had met with some dificulty in obtaining the opportunity, and also a little in getting as good a representation of the plate as could be desired, on account of the old plate having been refilled with wax previous to his getting to it; he had, however, got a very fair copy with the exception of the coat of arms at the top of the plate, for which he had substituted the portrait of Hunter, engraved by Sharp. He had had the whole framed and glazed, and had now much pleasure in presenting it to the College. (Cheers.]

He had also to report that he had received a copy of the DENTAL REVIEW for the current month, presented by the Proprietors.

Mr James Harley presented a specimen of mineral teeth made twenty-five years ago, also a specimen of coral applied as a base for ar, tificial teeth. He also exhibited an improved form of the key instrument.

Mr Spencer exhibited a new kind of dental saw, with a contrivance for reversing the cutting edge.

- Mr Matthews presented a model showing a change of locality in an upper canine and a first bicuspid tooth; the canine having taken the place of the bicuspid, while the bicuspid occupied that of the canine. Mr Matthews observed that we had had the disinterment and the reinterment of John Hunter, and we had had the indomitable courage of one of our members, to get a rubbing of the coffin plate of the great man; that member had had considerable difficulty in obtaining that valuable memento; and he (Mr Matthews) thought that the members present could not, and would not, do less than accord to Dr Purland their most cordial and unanimous thanks for the very handsome present he had made to the College.

A vote of thanks was unanimously given to Dr Purland.

Mr Matthews also begged, in the name of the members, to thank those gentlemen who had presented smaller things; and would remind them that small things led to greater, and that if all would contribute in only a small degree, we should have, in a comparatively short time, a large museum. He now called upon Dr Blandy, of the United States, to read his paper.

Dr Blandy then read the following paper on Cheoplasty :

THE BEST METHODS OF APPLYING ARTIFICIAL

SUBSTITUTES.

The subject of this paper is “ The Best Method of applying Artificial Substitutes in the Mouth, in connexion with a description of Cheo. plasty."

It has been selected as best suited to the understood condition of practice prevailing in this country, trusting to advance some ideas which may not be altogether new, yet may be serviceable in directing attention to some abuses of certain privileges of our art.

It is not only desirable that all teeth should be servicable as well as beautiful, but the means which are used to obtain these objects should be, at the same time, free from all injurious consequences.

A method which is liable to induce a new evil in its remedial capacity, is not one that the skilful operator can use, nor is it proper that a Profession should countenance a means by which applicants for relief for a certain disease are subjected to the liability of a second equally great. Still, as the loss of teeth is attended invariably by a greater or less injurious result to the general system, by imperfect mastication and consequent increase of labour of the gastric functions, it may possibly become at times advisable to accept of certain conditions in the use of plates for the mouth as the least of two evils. With this view, we condemn the use of clasps for the sustainment or even the contact with the natural organs of any substance used in the construction of artificial plates in all cases where a piece may be sustained by atmospheric pressure, and we are fully persuaded by much experience that the very great majority of pieces worn by clasps, could be as usefully worn without these appendages. We do not think it can be at this time ques. tioned that the use of clasps, is without exception attended by, the chemical or mechanical destruction of the teeth supporting them, a like consequence following the contact of plates with the necks or crowns of the natural organs. These injurious results are made evident in a greater or less time, according to the density of the teeth, the condition of the fluids of the mouth, the skill employed in forming the pieces, or the habits of the patients in wearing them, and by the ability of the

process used to obtain a positive accuracy of fit with a required immobility ; but that certain injury must follow, sooner or later, all mechanical contact in the mouth of the teeth with artificial pieces, we presume cannot, from the great accumulation of experience upon this subject, be brought in question. To avoid this at times we admit is sometimes impossible, perhaps one case in ten may be found too difficult to sustain without the assistance of clasps, and doubtless among those supported by atmospheric pressure, many may require great skill from the practitioner and patience from the wearer, but to compensate both there is always the certainty of an entire absence of all liability of injury resulting ; a sufficient cause to justify the attempt without clasps, and when found impossible, then resort to them only as a lesser evil than would be inflicted upon the patient by the non-mastication of food from the absence of a complete denture.

It is a most desirable object that the means used to obtain these clasped plates should be as near a perfect one as can be adopted, for the injurious consequences are not only mechanically but chemically induced, not only destructive to the individual teeth connected, by friction, but also destructive to them and to the parts with which they are most vitally connected by the inequality of pressure from these springs, and by improper leverages induced by rudely adapted plates and badly prepared springs, most frequently resulting from the unreliable method used in forming these pieces. A process which requires many attachments or connections is therefore necessarily a bad one, especially if from its frailty it is subject to much springing from applied pressure, because the attachments are alone called upon to do the whole work of supporting the piece, which in time must be followed by a loosening of the teeth thus unduly acted upon, as well as the great liability of chemical and frictional injury to the integral parts of each tooth thus assailed or made use of. Even admitting that such a piece when it rests in its position should be a good fit, still, if it is not strong and stiff enough to resist pressure without yielding, it is unquestionably more liable to produce injury than a piece which fitting perfectly, at the same time is motionless in its attachments from the necessary stiffness to resist pressure, for in the one you have only the fear of chemical injury in a much less degree from its equally good fit at rest or in use, which enables it to prevent introducing particles of food which by decompositon aid every destructive operation; in the other you have an increased liability from chemical causes with an added mechanical friction and undue leverage. Again, a process which requires a large amount of surface in connection with the teeth by clasps and by its. elasticity, is objectionable as greatly encumbering the mouth, in such a way as to present obstruction to the tongue by breaking the palate surface in such parts as to prevent the tongue from properly directing the volume of air it uses in producing especial articulate sounds, for although this is thought to be also effected by the use of atmospheric pieces, it is not so much so by an immense difference very perceptible in most cases even to the shrewd experimenter upon this point, and easily understood when it is considered that in the one you present a full and complete articulating surface, and in the other you break a perfect by an imperfect surface.

A plate that is worn and supported by a lateral pressure, is, from the before-mentioned reasons, one that must be attended by a much increased liability to effect injury, because it has contact not only by the clasps, but it is constantly exerting a power in opposition to the natural position of the teeth themselves, in all cases productive of more or less irritation to the mouth, at the same time as it incorporates much greater friction than a piece which simply becomes gently attached at the precise moment that it reaches its true position. It is therefore best in using clasp pieces to cover as little of the palate surface as possible, and avoid all unnecessary contact with the teeth, especially in connexion with the lateral pressure too generally applied in the use of elastic materials ; close observation will generally discover that such pieces are sustained as much by the binding of the artificial and natural teeth as by the clasps used in connexion with the general contact of the plate along its edges ; as a consequence the natural teeth are often found pressed out of their natural inclination and accompanied by local as well as general irritations, followed sooner or later by a loosening of such teeth in their sockets, and by gradual absorption of the soft integuments around them.

The practice of assisting the retention of a clasp piece by running small points of metal in between the necks of teeth, sometimes even passing in front, entirely exposed, is of course to be reprehended as productive of the worst evils ; besides being divested of all art, it becomes a mere mechanical fixture that any artizan would have been qualified to make, and properly debars our Profession of its claim to a curative usefulness.

Such pieces are actually destroying more teeth than they support artificial ones, and are always so imperfectly adapted as to invariably expose their artificial character upon first inspection.

To obviate these troubles there are certain imperative requirements ; first, a material which has little if any elasticity, lightness, strength,

and easy adaptability ; second, a plate fitting the gums perfectly at all parts of its surface, and having contact with the teeth only at such points intended to be clasped ; third, the clasps should but gently bind at the moment the plate meets the gum surface, 80 as to make a foundation capable from its accuracy of fit of supporting all pressure, the clasps only doing office in supporting the plate to that position, and not affording any support of pressure, because, if thus made, they are never required to sustain pressure, but if otherwise, they always do injury by friction and leverage, as well as the invariable injury of chemical action.

The objections to springs are somewhat less radical, because they seldom do an irreparable injury; they are simply in the great majority of cases a useless encumbrance, by impeding the action of mastication, by occasional irritations of the cheek, increasing the necessity of care in cleanliness, by giving additional trouble to the wearer and to the Dentist, and by causing at times unequal absorption of the hard and soft parts of the mouth.

These are but slight objections as compared to those attending the use of clasps, as they are not irremediable, but as they are not necessary difficulties consequent upon the wearing of full sets, trivial though they may be, it were best to avoid them.

Little is ventured in saying that in all cases full upper or lower sets, or both together, can be worn with entire usefulness without springs.

Such pieces require perfect adaptation, each portion of the upper surface should be in contact with the gums and palate, and the teeth made to antagonize in the most regular manner, and at the same moment of time, these simple precautions will be sufficient to ensure the full retention of all full sets without exception, totally avoiding the use of springs.

Of course at times there may be such an accumulation of obstacles as to justify their assistance, found as much perhaps in the prejudices and ignorance of people, as in the physical difficulties of structure in the case itself.

The principles are still the same in those worn with springs and those without, perfection in their fit and perfect antagonism of the teeth, without these cares are had in both, want of comfort and usefulness must be the result, more especially as to the fit, for if this is imperfect the use of such pieces will result in their constant motion, in the inferiority of articulation, and in the constitutional irri. tation following an unequal action of the absorbents of the mouth.

With these facts it becomes most desirable to use a method which

« AnteriorContinuar »