Tin and Gold - Part 3
Large fillings in the morsal surfaces may be cut down with suitable corundum points or wheels. These instruments cut much more rapidly than the finishing-burs, and if kept wet with a stream of water from the syringe cause but little heating of the tooth. The bottom image shows a few of the various forms of these points and wheels. The best cutting and also the-most durable corundum points and wheels are those made of fine corundum and vulcanized rubber.
In the use of corundum points for dressing down the surfaces of fillings there is danger, from the rapidity with which they cut, of grinding the edges of the cavity and thus producing a thin and weakened margin.
A final finish maybe given to the surface of the filling by smoothing with
Arkansas or Hindostan stones of similar shapes and polishing with pumice or the burnisher.
Labial and buccal surface fillings are most readily finished with the corundum points, followed by the Arkansas stones and wood points carrying moistened pumice. The beauty of fillings lies in their perfect margins and natural contour. Any overlap ping of the gold gives the appearance of aragged edge, while any degree of deviation from the normal convexity of the surface detracts from their beauty of outline.
The Soft rubber polishing-cups, corrugated inside. final polishing may be done with felt or leather polishing-wheels or soft rubber polishing-cups. The latter are especially valuable in finishing bucco-cervical fillings in bicuspids and labio cervical fillings in the six anterior teeth.
They, are shown in top image. If a dead or satin finish is desired,- and this is best for the anterior portion of the mouth, because it is less conspicuous, - pumice moistened with water or glycerol will be found most satisfactory for this purpose, but if a brilliant finish is required, the pumice should be followed with precipitated chalk, oxide of tin, or rouge.
This is an instructive summary of the qualifications and the duties of the present day Dental Assistant -- The Diplomat standing between the dentist and lost income. | read more |