US 2253132 A
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Description (OCR text may contain errors)
Aug. 19, 1941. T, LSON 2,253,132
DENTAL INSTRI'JMENT Filed May 31, 1940 INVENTOR. 7'077'f/V 8.!74130/9 BY fizz/ Tm I ATTORNEYS.
Patented Aug. 19, 1941 UNITED STATES PATENT OFFICE DENTAL INSTRUMENT Totten S. Malson, Cleveland Heights, Ohio Application May 31, 1940, Serial No. 337,991
4 Claims. N 01. 3243) This invention relates broadly to dental instruments and more specificallyto improvements in forceps for taking plastic impressions of teeth or a portion of a tooth. One of the objects of the invention is to provide a dental instrument having a pair of arms pivotally connected together with a looking attachment formed on one end thereof for imparting a spring pressure upon the material retained between the opposed ends of the arms.
Another object of the invention is to provide a dental instrument consisting of a pair of arms pivotally connected together and having an end portion thereof curved to form fingertip con-.
trol handles with the curved portion of one of the arms extending across the other arm for the reception of a locking nut and washer.
Another object of the invention is to provide a pair of dental forceps having an end portion thereof curved downwardly to facilitate their reentrance in a patients mouth and engagement with a tooth along the medial axis thereof the end portions of the forceps being formed with recesses in their opposed faces for the retention of a plastic matrix material.
Another object of the invention is to provide an instrument which is designed to facilitate the manipulation and adjustment by one hand and the fingers thereof, the Weight of the instrument being proportioned so that the dentist may recognize the tensive effort of application during the use thereof.
Another object of the invention is to construct an instrument which is economic of manufacture, durable, and which may be sterilized without separation of the component parts thereof.
Other objects and advantages more or less ancillary to the foregoing and the manner in which all the various objects are realized will appear in the following description, which considered in connection with the accompanying drawing, sets forth the preferred embodiment of the invention.
Referring to the drawing wherein the preferred embodiment of the invention is illustrated:
Fig. 1 is a perspective view of a pair of dental forceps as viewed from the top thereof;
Fig. 2 is a perspective view of the opposite side of the dental forceps illustrated in Fig. 1 and showing the downwardly curved end portion and the cups for the retention of a plastic material;
Fig. 3 is a plan view of the instrument including in dotted lines the outline of a tooth retained between the plastic matrix material seated in the cups in the end portions of the forceps;
Fig. 4 is a side elevational view of the forceps shown in Fig. 1; and
Fig. 5 is a sectional view through a portion of the instrument, the section being taken on a plane indicated by line 5-5 in Fig. 1.
Referring to Figs. 1 and 2, the improved dental forceps embody a pair of arms l0 and H which are pivotally connected together, intermediate their ends by a rivet l2. The end portions [5 and I6 of the arms contiguous the pivotal connection are curved downwardly to accommodate their entry into the mouth of a patient and their engagement with a toothwithout obscuring the View of the dentist. Formed in the opposing faces of the end portions I5 and Hi there are recesses or cups I1 and I8 adapted to retain a plastic material therein while an impression of a tooth or a missing portion thereof is made.
The opposed end portions of the arms II] and I I are curved outwardly and inwardly to pro. vide handles 20 and 2| which permit the operator to employ a finger tip grip or control. The free end of the arm I 0 is curved inwardly and extended across the central portion [9 of both of the arms and is threaded for the reception of a flat surface 24 which forms withthe side of the arms a ledge for the engagement of the locking washer 22. i V
As shown in Fig. 5, the washer 22 is swiveled upon the nut 23 and is provided with a plurality of grooves or indentures in one end thereof. The grooved end of the washer is adapted to engage the ledge defined by the flat surface on the arm II when it is restrained from rotative movement as the nut is adjusted to effect the compressive engagement of the end portions of the arms or jaws l5 and it upon the tooth.
The improved dental forceps disclosed herein may beemployed as a matrix for either a synthetic filling or a direct inlay. In the use of the forceps as a matrix for a synthetic filling a plastic compound is heated and then molded into a wedge or cone form in the cups I! and I8, after which the material is allowed to cool. The surface of the patients tooth or teeth in the area of the cavity are lubricated after which the tips of the plastic material within the cups are surface heated prior to the forceps being clamped over the tooth containing the cavity. The nut the outline of the tooth.
After the plastic material has been chilled the forceps are released and lifted from the patients mouth and any irregularities appearing on the material, which may be caused by the cavity in the tooth, are then removed therefrom so that the matrix will conform to the contour of the tooth. The cavity in the tooth is then prepared and filled with a synthetic filling in the usual manner. When the filling is in place a Celluloid strip isplacecl thereover and the forceps with the matrix in the'end portions l5 and I6 are clamped upon the tooth by means of the nut 23. When the synthetic filling has set the forceps and Celluloid strip are removed. The use of the- Celluloid strip between the matrix and the filling provides for a polished finish onthe outer surface of the tooth and filling;
In obtaining a wax model for a direct inlay w the same procedure is followed as disclosed in connection with the synthetic filling, up to and including the preparation of the cavity. After the cavity is prepared the inlay wax is inserted therein and a thin strip of Celluloid is placed thereover. The forceps are then tightened -on the tooth by the nut 23 where they are retained until the wax-has set. a r a In the use of the. improved dental forceps in securing an impression of the form of a tooth or teeth for an indirect inlay a sphereof plastic matrix material is placed in each of the cups I1 and I8, after which the forceps are inserted Within the mouth of the patient and adjusted so that theplastic will encompass the tooth where, upon manipulation of the nut 23, it will be extruded to the contours and lineation of the objective mol-d. r
a When the nut 23 is tightened against the arm ll sufiicient spring pressure is initiated through the arms l0 and H and-through-the end portions and 16 to facilitate the support of the nstrument in self sustained position upon the tooth. It will be recognized that the impression obtained in the plastic material by means of the improved instrument will be free from air pockets, folds or deformation which would impair the accuracy thereof, since the matrix is formed under a sustained pressure and while the instru ment is supported in a fixed position.
Furthermore the matrix formed in the plastic material contained in the cups I1 and I8 will provide an accurate reproduction of the'contours of the teeth and/orportions thereof surrounding the cavity. Thus by first making an impression of the tooth then clamping the matrix over the filling theoriginal contour of the tooth will beaccurately reproduced in the filling.
It will'be further apparent that since the nut and Washer are disposed upon the threaded end of the arm [0 the dentist may effectuate adjustments with a finger of the hand employed in holding the forceps'and that the bent jaws of the instrument afford a wide latitude of adjustment and broader scope of vision.
, an end portion-of said arms having recesses in their opposing faces forming jaws, curved portions on the other end of said arms constituting finger engaging handles, the curved portion of one of said finger handles extending across said arms and constituting a spring, threads on the end of said portion and means mounted on the threaded end for adjusting said jaws and the pressure of said spring; a
2. A-dental tool embodying a-pair of crossed arms pivotally connectedto each other, opposed cups in an end of said arms for holding a plastic material, finger engaging handles on theother end of the arms, a portion of one of the handles extending across both of the arms and constituting -a spring, threads on the end thereof, a
locking washer and nut mounted on the threaded end and. adapted toengage one of said arms to restrict the pressure of the cupsupon the plastic material, 35A dental instrument embodying a pair of crossed arms pivotally connected toeach other, an end portion of said arms being curved downwardly and having recesses in their opposing faces, loops on the other end of said arms constituting finger grips, a flat surface on one of said'arm defining a ledge, the end of one of the loops extending across both of the arms, threads formed thereon, a nut, a washer swiveledl thereon, said nut threaded on said end, said washer having grooves in an end thereof for engaging said 'ledge to sustain a spring pressure through said arms which is initiated"v upon the tightening of the nut; r V
4; A dental tool embodying'a pairof crossed arms pivotallyconnected to each other adjacent one of their ends; downwardly curved portions in said arms contiguous their pivotal-connection, 'cups 'inthe opposed facesthereof for the support of a plastic material, a lineal extension on one 'of-said arms, a fiat surface on each of s aid arms, rings in the opposed end of said arms; said lineal extension projecting across said fiat surface of bothlia-rms, threads thereon and locking means mounted on said extension to impart a springpressure upon the plastic material between saidcupsg i i TOTTEN S. MALSONP