A NEW OR IMPROVED COMPOUND FOR FILLING DECAYED TEETH AND OTHER PURPOSES FOR DENTISTS' USE
Year: 1878

page_text: LETTERS PATENT to Thomas Fletcher, of Warrington, in the County of
Lancaster, for the Invention of "A NEW OR IMPROVED COMPOUND FOR FILLING
DECAYED TEETH AND OTHER PURPOSES FOR DENTISTS' USE."
Sealed the 10th December 1878, and dated the 30th July 1878.
PROVISIONAL SPECIFICATION left by the said Thomas Fletcher at the Office
of the Commissioners of Patents on the 30th July 1878.
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THOMAS FLETCHER, of Warrington, in the County of Lancaster. "A NEW OR
IMPROVED COMPOUND FOR FILLING DECAYED TEETH AND OTHER PURPOSES FOR
DENTISTS' USE."
I use phosphate or pyrophosphate of alumina, either alone or combined with other
materials, as a compound for filling teeth, substitute for continuous gum, repairing
teeth broken out, of rubber and other similar purposes for dentists.
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The process I prefer is to dissolve phosphate or pyrophosphate of alumina in
phosphoric or pyrophosphoric acid, to form a pasty mass. This mass, when ulti-
mately mixed with hydrate. of alumina, heavy oxide of zinc or magnesia, basic
silicate of zinc, or other materials of a similar nature with which it has the power
of combining in the same manner, has the property of setting into an extremely
hard mass, similar in appearance to unglazed porcelain, and which offers a singularly
great resistance to the action of the fluids of the mouth. It can be made of any
colour required by adding colouring matters during the mixing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Fletcher in the Great Seal Patent Office on the 30th January
1879.
THOMAS FLETCHER, of Warrington, in the County of Lancaster. "A NEW OR
IMPROVED COMPOUND FOR FILLING DECAYED TEETH AND OTHER PURPOSES FOR
DENTISTS' USE."
I use phosphate or pyrophosphate of alumina, or magnesia, or pyrophosphate of
lime, either alone or combined with other materials, as a compound for filling decayed
teeth, as a substitute for continuous gum, for repairing teeth broken out, of rubber,
and for other similar purposes for dentists.
The process I prefer is to dissolve the phosphate or pyrophosphate in phosphoric
or pyrophosphoric acid, to form a pasty mass, and which may be effected as follows:
-I mix and heat together 1 part pyrophosphate of alumina, pyrophosphate of
magnesia, or pyrophosphate of lime, 4 parts of glacial phosphoric acid, and 1 parts
of water, although other proportions might be employed.
Instead of using phosphoric acid, it may be partly or entirely replaced by pyro-
phosphoric acid. This mass, when intimately mixed with bydrate of alumina (the
heavy oxide of zinc, which must be of the very hard dense form well known to and
used by dentists for similar purposes), or other materials of a similar nature (for
instance, lime) with which it has the power of combining in the same manner, has
the property of setting into an extremely hard mass, similar in appearance to
unglazed porcelain, and which offers a singularly great resistance to the action of
the fluids of the mouth. It can be made of any color required by adding coloring
matter during the mixing.
Having thus particularly described and ascertained the nature of this my said
Invention, together with the best methods with which I am acquainted for carrying
the same into practical effect, I wish it to be distinctly understood that I do not
confine myself to the precise details and relative proportions herein-before described,
as the same may be considerably varied without departing from the Invention, but
what I claim is, the use of phosphate or pyrophosphate of alumina, or magnesia, or
pyrophosphate of lime, separately or together in a compound, as and for the purposes
herein-before described.
In witness whereof, I, the said Thomas Fletcher, have hereunto set my hand
and seal, this 27th day of January, in the year of our Lord One thousand
eight hundred and seventy-nine.
THOMAS FLETCHER. (L.S.)