Specification of John Macintosh : setting artificial teeth.

  • MacIntosh, John.
Date:
1860
Catalogue details

Licence: Public Domain Mark

Credit: Specification of John Macintosh : setting artificial teeth. Source: Wellcome Collection.

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    Macintosh's Improvements in Setting Artificial Teeth. these forms are placed in a metal box, such as is used in the vulcanite process, which is well understood by dentists, and they are secured the one in the top and the other in the bottom of the box by running them in with plaster. The collodion to be employed may be prepared in the ordinary manner; and I 5 prefer in order to increase its toughness to mix with it a small quantity of short cotton fibre, and I evaporate the solvent until the collodion is brought to a plastic and putty like state. If it be desired to obtain a hard setting, I add to the collodion and thoroughly incorporate with it powdered gum copal, in quantity varying according to the hardness desired; if great hardness is 10 required I employ as much as 20 per cent. The collodion whilst still warm I carefully press into the mould around the teeth, as in filling a mould with the compound of india-rubber and sulphur in making teeth of vulcanite, as is well understood; I then place the two parts of the mould together, and force them together by means of the screw with which the box containing them is 15 fitted; thus the collodion between the two parts of the mould is forced into every crevice of it; and in order that the collodion may remain thoroughly plastic the mould is kept heated to about 200° Fahrenheit; when the two parts of the mould are pressed close together, the mould is allowed to cool, and when cold, the teeth with the setting, which is then complete, are removed. 20 If it is necessary in order to render the fit of the setting more complete, parts of it may afterwards be pared away as has before been practised when settings of other material have been employed. In order that the teeth may be securely held by the setting, they may be notched or under-cut in a similar manner to the teeth now employed for setting in vulcanite; and I prefer to 25 form the teeth with a hole or passage up the centre of each, which at the base is opened out as wide as the tooth will admit of without becoming unduly weakened. These holes or passages I fill with collodion, singly or in the process of filling the mould, so that when the setting is finished each tooth will have a stem of collodion forming part of the setting passing up its centre, and 30 the teeth thus become firmly held, or they may be attached to the setting by pins, as is well understood. I color the collodion to make it resemble the natural gum by means of alkanet root, the whole of the collodion may be thus colored while in a liquid state ; or the setting, when finished, may have a coating of colored collodion applied to its surface. If it be desired to obtain 35 a plate or thin flexible setting, I proceed in a similar manner to that already described, but I produce the two forms of which the mould consists in a readily fusible metal (a mixture of tin and lead answers well) in place of in plaster as before described; but in this case, after producing the wax model the teeth are not left in it whilst the plaster cast is taken, but are first carefully