International Tooth-Crown Company v. Gaylord

This was a bill in equity for the infringement of two letters patent, granted May 22, 1883, to Cassius M. Richmond, viz., No. 277,941, for an artificial denture, and No. 277,943, for a process for preparing roots of teeth for the reception of artificial dentures.

The main contest took place over No. 277,941, which covered a device intended to replace the loss or destruction of that part of the natural tooth which projects into the month externally to the gum, the device being an artificial crown, to be placed upon and supported by the natural stump or root of the partially destroyed tooth. The manner in which this is done was stated in the specification substantially as follows: The top of the tooth is cut off, and a hole drilled in the root. The end of the tooth being then properly prepared, a ferrule is made of such a size and shape as to exactly fit the base of the root. An artificial porcelain or other crown of suitable color, size, and shape is then selected to be applied to the root. Upon the beack of this crown is placed a platinum or gold plate, which has holes through it to allow the passage of pins, which are firmly imbedded in the procelain. The root and crown having been so prepared, the crown is placed in position and attached to the ferrule by wax, which holds the crown sufficiently firm in position to allow of the removal of the ferrule. Thereafter a suitable pin is imbedded in the wax, which is designed to enter the hole which has been drilled in the root. The crown thus prepared is then invested or protected by a suitable covering of marble dust or plaster, leaving the wax exposed. This investiture holds the parts firmly in the position they are to occupy when placed in the mouth. The wax is then melted from behind the crown, and replaced by a suitable gold solder, which is blown in by blow-pipe, and fused around the pin. This solder unites with the pin, the ferrule, and plate, making a solid backing to the crown, and firmly holding all the parts together The prepared crown is then slipped upon the prepared root and cemented thereto. The ferrule, when in position, should project under the free margin of the gum sufficiently to prevent the root from decay, and is likewise concealed from view by the gum.

Following this description, the patentee proceeded to state that 'when this denture is applied to a root the end of the root is entirely protected from the injurious action of the fluids of the mouth and is hermetically sealed, being covered by a closed cap. This inclosing cap is of the greatest importance, because otherwise decay must necessarily take place by reaosn of the action of the fluids of the mouth on the exposed dentine, and the denture would become useless. By this arrangement, therefore, both and end of the root and so much of the same as might otherwise be exposed to the fluids of the mouth are hermetically sealed, and the root is thus protected from the injurious effect which would otherwise result from the action of the fluids. It is obvious, likewise, that by this arrangement the end of the root may retain its natural configuration, and its substance is not destroyed by cutting away or shaping the same at the sides, which is very injurious, and tends greatly to the destruction of the root. * * * The caps hereinbefore described are so constructed, as set forth, as to cover and inclose the prepared end of the root, wholly excluding the juices of the mouth therefrom, and preventing the decay that would otherwise result.'

Infringement was alleged and admitted of all the claims of the patent, which read as follows:

(1) The combination of a prepared root, having its natural terminal controur near the margin of the gum, with an inclosing cap attached thereto for supporting an artificial denture substantially as described.

(2) Combination of a prepared root, having its natural terminal contour near the margin of the gum, with an inclosing cap attached thereto, and with as artificial porcelain or other crown supported by said cap, substantially as described.

(3) The combination of a prepared root, having its natural terminal contour near the margin of the gum, with an inclosing cap attached thereto, the said cap being attached to the root by a pin or suitable attaching contrivance passing upward and into a suitable cavity in the root, substantially as described.

(4) The combination of a tooth-crown, a metallic backing soldered to said crown, and a pin firmly soldered to said artificial backing and secured to and passing through a ferrule adapted to surround the root, substantially as described.

Two other claims are practically repetitions of the above.

The principal defense to this patent was that of abandonment, and upon this ground the bill was dismissed by the circuit court, whose opinion regarding the validity of this patent is contained in another case involving the same facts, reported as Tooth-Crown Co. v. Richmond, 24 Blatchf. 223, 30 Fed. Rep. 775.

Patent No. 277,943 was for a method of preparing the roots for the application of the cap covered by the prior patent, which consisted in grooving the same by opposite grooves, suddenly removing the crown from the root by a suitable forceps or other contrivance, and then immediately expelling the nerve from its cavity by driving a suitable shaped piece of wood into the nerve cavity, in removing the same and cleansing the cavity, and in immediately plugging or filling the upper part of the nerve cavity by driving in another piece of wood.

The defense to this patent, viz., want of novelty, was sustained by the court below, and the bill dismissed.

E. N. Dickerson, for appellant.

John K. Beach and ''Chas. K. Offield'', for appellees.

Mr. Justice BROWN, after stating the facts as above, delivered the opinion of the court.