American dental journal. [Vol. 7, no. 6]

OUR FOREIGN DEPARTMENT 3

355

He contends that there should be an interproximal space of onesixteenth of an inch on each side at the gum line.
By this method this can usually be secured with ease and certainty
and with but little discomfort to the patient.
THE EFFECT OF ABRASIVE SOAPS ON METAL PLATES
BY MR. WILLIAM FISK, OF WATFORD.
(Ash Quarterly Circular, London, January, 1908.)
Two ladies, sisters, were supplied with partial upper and lower
gold artificial dentures, and were instructed to clean the clasps with
any kind of soap-not excluding "Monkey Brand"-by putting a little
cotton wool on the end of a match, rubbing it on the soap and applying it to the inside and outside of the clasps.
The lower partial dentures were made of two gold plates, Nos.
5 and 6, 18-karat, soldered together. Some three or four months
later one was brought back with a tiny hole in it, caused, as was
erroneously thought at the time, through the plate having been overpolished in the workroom. It was accordingly repaired.
After one set had been worn eighteen months the lady brought
it back and complained of the condition of the plates. On examination it was found that there were holes in them, and the lady
volunteered the statement that she had used "Monkey Brand" soap
every day for cleaning them. Cotton-wool had been wound round a
piece of wood, rubbed on "Monkey Brand" soap, and the plates
polished with it.
Her sister, whose dentures had been in wear for about twelve
months, had done the same. On examining this second set there
was also evidence of abrasion.
I have sent the plates for inspection to Messrs. Ash, Son & Co.,
with these particulars.
It is only of recent years that abrasive soaps have come extensively into use, and this word of information may be of some service
to some dentists who may be blamed for bad work, when the defect
may be due to the powerful abrasive quality of the soap which is
employed for cleaning the metal plates.