US 2171695 A
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Description (OCR text may contain errors)
Sept. 5, 1939. HARPER I 2,171,695
METHOD AND APPARATUS FOR PROCURING IMPRESSIONS OF THE SURFACES OF' THE ANTERIOR TEETH FOR DENTAL WORK Filed Feb. 8, 1939 'IIIIIIIIIIIIIIIIIM v W Q/MHW Patented Sept. 5, 1939 UNITED STATES PATENT OFFICE Robert N. Harper, Danville, Va.
Application February 8, 1939, Serial No. 255,348
This invention relates to a method and apparatus for procuring impressions of the surfaces of the anterior teeth for dental work and has for one of its objects to provide a tray that is adjustable and is shaped to hold material for taking impressions of the labial and incisal surfaces of the upper and the lower anterior teeth together with part of the incisal-lingual surfaces of the uppers simultaneously with any degree of overjet.
A further object of this invention is to provide a tray that is adjustable to all types of occlusion and is adapted to secure upper and lower impressions at the same time, usually in centric relation.
A further object is to secure in a single impression accurate and detailed outlines of the teeth from which a model is made, that is convenient to file for use as guides in arranging the 0 artificial replacing of teeth in prosthodontia, as records in orthodontia and periodontia as well as definte means of identification. It also provides a means of obtaining accurate impressions of any labial cavities that may appear for inlay 5 replacements.
With these and other objects in view the invention consists of a novel method and features of construction as will be more fully described and pointed out in the appended claims.
) Figure 1 is a plan view of the tray.
Figure 2 is a side elevation of the tray.
Figure 3 is a sectional view on the line 3-3 of Figure 1, illustrating, in section, the impression material.
5 Figure 4 is a section on the line 44 of Figure 1.
Figure 5 is a front elevation of the model.
Figure 6 is a sectional view of the model.
Referring now to the several figures of the drawing, the tray comprises an upper section I0 provided with a curved plate II at its forward end, and a lower section l2 provided with a curved plate I3 at its forward end. The two sections l0 and i2 of the tray are adjustably coni nected together by the Winged nut l5 and bolt I! that passes through the opening [6 in the upper section and slot M in the lower section. By
manipulating the winged nut the sections I I and I2 may be clamped in adjusted position. The I sections are also provided with cooperating guide pins l8 and guides l9 to keep the sections l0 and I2 in alinement with each other.
As shown in Figure 2 the curved plates I I and I3 overlap and form a substantial surface for i supporting the impression material 2|. The rear or plane portions of sections IE! and I2 serve as handles with which the tray may be manipulated in pressing impression material evenly against the labial surfaces 22 of the anterior teeth, for obtaining a mold for a model 20 showing the rela- 5 tive position of the upper and lower anterior teeth. By this method the overjet and overbite may be registered on a single model, that is practicable for filing for future use and reference. The accurate model obtained by this method '10 avoids the necessity of an articulator. The taking of the single simple impression upon the upper and lower teeth is not as annoying or objectionable to patients as the bite procedure heretofore in use.
In protrusive cases, where the teeth of the lower jaw protrude anterior to the upper teeth, the tray is inverted and an accurate unitary impression can be obtained in that way, showing the relative position of the upper and lower anterior teeth.
The method of the invention as practiced with the apparatus illustrated is as follows:
The sections l0 and I2 are adjusted so as to position the curved plate H from the curved plate l3 a distance substantially equal to the distance that the upper anterior teeth of the patient extend beyond or anterior to the lower teeth, A unitary mass of impression material 2| is then placed upon the pair of concave surfaces of the curved plates H and 13. The impression material 2| carried by the curved plates of the tray is then firmly pressed upon the labial side of the anterior teeth in the upper and the lower jaw by a single impression of the tray. When so impressed the material spreads over the labial side of the anterior teeth and also flows to cover the incisal surfaces of the teeth and to some extent the lingual surfaces particularly of the upper teeth due to the overbite.
After the impression has been taken, the formed material or mold is carefully taken from the teeth and is filled with a suitable plastic or molding composition such as plaster of Paris to form the record or model 26 whereby a correct reproduction of the teeth and interdentulous spaces is obtained. The amount of overjet or overbite, or the amount of retrusion or protrusion can be measured from the model with accuracy and the model can be retained as a permanent record.
It will be understood that various changes may be made in details within the scope of the appended claims without departing from the spirit of this invention.
Having described the invention, I claim:
1. An impression tray for dental work comprising a pair of superposed supporting sections, means for adjustably securing said sections together, a curved plate formed upon one edge of each section said curved plates being mounted in spaced apart concentric relation to each other one of said plates extending above and below its supporting section, said plates together forming an open concave receptacle for supporting a unitary mass of impression material in position to be molded against the labial side of the anterior teeth of the upper and lower jaws in occlusion.
2. An impression tray for dental work comprising a pair of overlap-ping curved plates concentric with respect to each other, and means for supporting said plates, said plates forming an open concave surface for sustaining a unitary mass of impression material upon said surface whereby the said material may be simultaneous- 1y molded against the labial sides of the anterior upper and lower teeth in occlusion.
3. An impression tray for dental work comprising an upper section having an upstanding curved plate projecting from said. section, a low' er section having a curved plate projecting therefrom and overlapping the curved plate on the upper section, said sections being adjustably mounted upon each other and having means to secure said sections in adjusted position, said curved plates being shaped and adapted to carry a unitary mass of plastic impression material to be impressed upon the labial side of the upper and lower anterior teeth simultaneously by means of said curved plates.
4. The method of forming a unitary model having impressed thereon a replica of the labial side of the upper and lower anterior teeth in occlusion, which comprises forming a mold by moving and pressing a unitary mass of impression material laterally against the labial sides of the anterior upper and lower teeth, removing the mold from the teeth, filling the mold with casting material for forming the model and then removing the mold from the model.
5. The method of forming a unitary model having formed thereon a replica of the labial side of the upper and lower anterior teeth in occlusion, which comprises forming a mold by moving and pressing a unitary mass of impression material laterally against the labial sides of the anterior upper and lower teeth, flowing the material over the incisal surface of the lower teeth and over the incisal-lingual surfaces of the upper teeth, removing the mold from the teeth, filling the mold with casting material for forming the model and then removing the mold from the model.
ROBT. N. HARPER.