A System of Detachable Facings.
W L Mason · PubMed · 1896
Mr. President and Gentlemen,-I present to you to-night, for your consideration, a system of detachable facings for crown-and bridge-work,--a system that does not in any way change the appearance of the perfectly-made crown or bridge of to-day.About sixteen years ago porcelain facings, soldered to gold bands, were put in general use, and closely after came the bridge work, very crude at that time, but advancing rapidly to the almost perfect construction of to-day.I could say perfect but for one fault, and that is the uncertainty of the condition of the por celains after soldering and cementing into position.I know that we have teeth to-day that stand the strain better in the process of forming them into crowns or into bridges, but they will never be made to expand or contract like metal.We may be very careful in heating an invested piece for soldering, and cool off properly, and try the piece in, and have no strain upon it, so we cement in position.As near as we can see we have a perf^t piece of bridge work.But, just as long as the piece is in service, the porcelains are apt to separate from their backings.I think it is a great necessity that we attend to the future conditions which arc apt to happen with a porcelain on crown or bridge.There is constant