DENTISTRY, the art of the dentist, or that of treating disease in the teeth (dental surgery), and of replacing these organs when lost (mechanical dentistry).
1. Dental Surge?. y. —The disorders to which the teeth are liable are those arising from defective development, such as imperfections in form or structure, irregularity of posi tion, etc.; these, again, constituting diseases more properly so called, such as caries or dental decay, necrosis or death of a tooth, inflammation or neuralgia of the soft' tissues connected with them, such as the gum, the central pulp or nerve, etc.; lastly, those arising from accident of various kinds, such as blows, falls, and the like.
The treatment of all these different affections is generally of a local kind; or, in other words, confined to the spot in which the disease manifests itself. But dental diseases themselves are not always of a purely local nature; and it maybe generally stated that wherever a tooth becomes diseased without any well-marked or ostensible cause, such a tooth has been originally defective or weak. It has been, in fact, imperfectly de veloped, and this imperfection is due to constitutional causes, or such as affect the gen eral health of the individual. In this way, a very slight cause is sufficient to ease in, and lead to the destruction of, such a tooth. Disease impairs what of such little vitality it already possesses; it become less and less able to resist the action even influences as it is naturally exposed to in the mouth—chemical decomposition is set up, and the substance of the tooth is broken down, and decays—literally, rots away. This, in most cases, constitutes the pathology of dental caries; but there seems no doubt that in other instances caries, like any other morbid action in the bodily tissues, may commence in teeth previously quite healthy.
The object of the dentist, in these circumstances, is two-fold: he either attempts to arrest the decay, and repair its ravages; or he removes the diseased tooth altogether. These operations, along with supplying artificial teeth when the natural ones are lost, constitute, with those for the treatment of various minor affections, the main offices of dentistry.
Premising that all operations in dentistry require to be modified according to differ ent cases,'we shall shortly describe the various manipulations required in their per formance.
Scaling.—This is a little operation, by which the accumulation of a substance termed " tartar " is removed from the teeth. Tartar is a deposit from the saliva, and lodges in greatest quantity most commonly behind the lower front teeth. it accumulates it is generally accompanied by absorption of the gums, whereby the necks of the teeth are exposed, and they become loosened, and fall out. Its removal is effected by little hoe-shaped steel instruments. bent in a manner to reach more easily those situations in which the tartar is found. Their mode of use is by inserting the point of any one of them under the free edge of the miss of tartar, at the gum, and lifting it away from the backs of the teeth CO which it is' dherent. The teeth are then freed from any par ticks still sticking about them, and their surface smoothed by being rubbed with pum ice powder or chalk.
liegulating.—The teeth of the second, or permanent or adult set, are very liable to be crowded and misplaced, one overlapping the other, or those of the upper jaw falling behind those of the lower when the mouth is closed, thus producing the prominent con dition of the under-jaw denominated " under-hung." To remedy these defects, a variety of means have been adopted by dentists; the principle upon which all of them act, however, being that of pressing the displaced tooth or teeth into the natural posi tion. This, of course, requires that room or space should exist for them to be thus adjusted; and where this is not the case, the usual procedure is to remove one or more of the back-teeth, or any others which it is less desirable to preserve. Some consider able time is necessary to complete the regulation of misplaced teeth; and even after they have assumed their proper position, they require to be carefully maintained there, other wise a tendency to resume their former irregularity soon manifests itself.