piseases of the Pertnanent Teeth.—The diseases to which the per manent teeth are subject have been arranged as follows by :Mr. Tomes :— It will be unnecessary here to refer in detail to these disorders of the teeth and gums, as many of them are common to these tissues with other pasta of the body, and require the same general treatment. We shall therefore refer more particularly to those disordered conditions of the teeth and gums which produce the complaints known under the name of toothache and faceache, and the other more frequent disorders of these organs.
Dental Caries.—One of the most frequent causes of pain in the teeth is that destructive process known by the name of caries. Various views have been taken of the nature of this process; but Mr. Tomes defines it as " the death and subsequent progressive decomposition of a part or the whole of a tooth." The changes which indicate the occur rence of this condition are, first, a discoloration of the dental tissue, which is succeeded by softening and disintegration. The enamel first suffers, and then the dentine. The disease spreads in the direction of the dentinal tubes down to the pulp, forming a conical cavity with an oblique direction. It is not, however, infrequent to find the hole in the enamel less than that in the dentine, as the process of decay goes on much more rapidly in the latter than in the former.
This process of decay may or may not be atteuded with pain from the time of its first setting in. Eventually, however, the caries extends to the pulp cavity where the nerves are situated, and pain is the result. Even this is sometimes prevented by a kind of reparative process going on in the dentine, which forms the walls of the cavity, and which prevents the nerves from being affected.
If the caries extends, the pulp may become inflamed, and also the dental periosteum, which may be followed by alveolar abscess. Before inflammation of the pulp is established, the pain from the tooth becomes intolerable by irritation in the pulp. This state comes on gradually : first a little pain is felt when hot or cold or sweet or acid things are put into the mouth. This goes on increasing till inflamma tion is established in the pulp of the diseased tooth. This frequently leads to irritation in the pulp of the sound teeth, so that pain may be felt in several teeth by the unsoundness of one.
It is when the pulp becomes inflamed that the violent throbbing pain known as toothache comes on. In this state a destruction of the
pulp may take place and the pain cease, and the tooth retaining its vitality from its external periosteum alone may still be useful. This is, however, a very rare occurrence.
In the treatment of caries of the tooth, and its attendant irritation and inflammation of the pulp, it should be recollected that all external remedies are palliatives. A natural cure, which is very unlikely, may go on whilst a little relief is obtained by such applications as opium, ether, creasote, alum, chloroform, tannic acid, nitrate of silver. The multitude of remedies for toothache show how utterly intractable a disease it is, and how little amenable to anything like external treat ment. Nor will internal remedies affect the tooth, or in any manner arrest the caries which produces the pain.
If caries is observed in the early stages, before the pulp cavity is affected, then the diseased part may be scooped out, and the cavity plugged up in various ways. This, however, must be done early, in order to ensure success. It not unfrequently happens that where irritation of the pulp cavity has been set up plugging will relieve. Where irritation is set up in neighbouring teeth from inflamed pulp, then the removal of the offending tooth is immediately attended with relief to the others.
In the case of inflammation of the pulp, where the pain is severe, the tooth should be removed. The hazard of ulterior consequences to the alveolar process and the jaw should always prompt to the removal of the inflamed tooth.
The consequences of decay of the teeth are not at all confined to the simple pain called toothache. The inflammation may extend from the tooth to the gums, and from the gums to the surrounding structures, so that inflammation of the submaxillary glands takes place, and a of the whole face occurs. Such inflammation may be acute or chronic. When it is acute it may subside in a few days after the application of the ordinary remedies for an acute inflammatory con dition of the soft tissues. It may, however, be chronic, and attended with ulceration of the mucous membrane, which may extend to the throat. In these cases local remedies may relieve. The application of tannic acid, alum, or chlorate of potash will he of service, but the great remedy of all is the removal of the cause—the extraction of the decayed tooth or teeth.