US2107181A - Denture - Google Patents

Description

Feb. 1,1938; w. R. A. GUYTON DENTURE File'd April 4, 1935 2 Sheets-Sheet l INVENTOR.

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Feb. 1, 1938. v w. R. A. GUYTON 2,107,181

DENTURE I Filed. April 4, 1935 2 Sheets-Sheet 2 M ATTORNEY.

Patented Feb. 1, 1938 UNITED STATES PATENT OFFICE 5 Claims.

dinarily formed of plastic material such as plaster of Paris or artificial stone and the like. These models serve as the foundation upon which the dentures are constructed.

The patients bite is then taken to determine .the occlusion of the teeth and position of the patients jaws with respect thereto. The models are assembled with the bite and then mounted on an articulator which reproduces the movements of the patients jaw. A wax set-up or a trial plate is then built on the models in the articulator.

These set-ups are generally formed by using a shellac base plate as a reenforcing foundation for the trial wax plate. The teeth are then positioned on the shellac base plate and held in place by Wax. After the teeth are set to the bite, wax is then added to strengthen the trial plate and to produce a facial contour similar to that of the patients gums.

The trial plate is then removed and fitted into the patients mouth. Generally the position of some of the teeth in the wax plate have to be reset to compensate for slight inaccuracies in obtaining the patients originalbite.

This trial wax plate or set-up is easily distorted by temperature changes such as occur when it is inserted into the patients mouth for trial. In general practice this wax plate is not permitted to remain in the patients mouth for over two minutes at a time, as it is likely to become permanently distorted, rendering it valueless. Great care of these trial plates must be taken during the summer months or they will become distorted due to the hot temperatures. Again, precaution must be taken in handling and packing them for shipment through the mails. Further precaution is taken by placing a label thereon as a Warning that the contents are wax and must not be subjected to extreme heat or cold.

Under ordinary conditions these trial iwax plates become materially distorted and at least fifty percent of them must be reset or completely changed before making the denture therefrom. The time and material required for remodeling these trial plates materially increases the cost of manufacture of the finished denture.

When the wax plate is satisfactory and the finished denture is ready to be made therefrom, the plastic model of the patients mouth with the wax set-up are placed in the lower section of a flask. A separating medium is then placed on the plastic material of the lower flask and the upper flask section is positioned thereon. Plastic material is then molded around the set-up enveloping the teeth and the wax.

After the plastic material has solidified, thereby holding the teeth in their proper positions, the flask is placed in boiling water which softens the wax. The flask is then opened and the wax removed therefrom.

Denture base material such as rubber, phenol resin or material having a cellulose base is placed in the cavity formerly occupied by the wax. The flask is then subjected to heat and pressure for vulcanizing or otherwise forming the finished denture.

After cooling the denture is removed from the plastic material of the flask and finished for. use.

To strengthen a partial horseshoe plate or denture whose base material is rubber, reenforcing members such as goldoid wire, mesh or filigree have been used. These members were wrapped in the soft rubber and placed in the cavity of the flask from which the wax was removed. Additional rubber was then added and the denture completed by vulcanizing. However, there is no provision for holding such members in their proper position while the rubber is being pressed therein. This results in the exposure of the members in the finished denture. In finishing the denture a material portion of the members often had to be removed to produce a smoothly finished surface, thereby weakening or destroying the reenforcing properties of the members.

Again, the exposed portion of these reenforcing members will become corroded because of the acids of the mouth. For these reasons such reenforcement has not met with success.

Such reenforcing members could not be used with resin or cellulose denture bases as there was no known method of supporting them in the flask cavity.

The principal object of my invention is to provide a reenforcing member for use in a set-up to prevent its distortion and which member may be properly held in position during the process of manufacturing the finished denture from the set-up and which provides reenforcement for the same. r

'I attain'this object by the provision of reenforcing members provided with removable anchor means, which members are built into the wax set-ups or trial plates in their proper predetermined position with respect to the artificial teeth and the surfaces representing the gums thereof.

Such reenforcing members prevent material distortion of the set-up when handled or fitted in the patients mouth. During this operation the anchor means are removed, permitting the of the flask in the usual manner and when removed therefrom the anchor means are withdrawn and the holes are filled up.

Again it will be noted that in my invention it is possible to have the wax model reenforced before, during and after the fitting operation, thus preventing injury to the same from handling or transportation. Again, the reenforcing foundation or shellac base plate may be omitted from the set-up, as the reenforcing members adequate- 1y fulfil their function.

To better anchor the reenforcing bars first in the wax set-up and later in the finished denture, the surfaces or edges of the bars are roughened by sand-blasting.

Another object which I have in view is the more efficient and rigid anchoring of the artificial teeth in the plate.

These teeth are subject, when in use, to very considerable grinding and biting pressure and tend to pivot on their necks in the denture base. i 'To counteract these forces I position the reenforcing members adjacent and substantially parallel with the necks of the'teeth on the inner and outer sides thereof.

I thus form not only a reliable and improved reenforcement of the denture base but hold the teeth absolutely rigid, enabling them to successfully resist the forces referred to.

Referring to the accompanying drawings wherein I have illustrated a practical embodiment of the principles of my invention,+

'Fig. 1 is a perspective view of a model of a patients gum ridge. i

7' Fig. 2 is a perspective view of a trial wax plate partially constructed on the'model, to illustrate the application of the reenforcing bars thereto. Fig.3 is a front elevation of a set of partially finished trial wax plates mounted on their respective models which in turn are supported from an articulator. V

Fig. 4 is a perspective view of a completed trial Wax plate with some of the anchor members removed from the reenforcing bars.

Fig. 5 is a plan view of a trial wax plate .mounted on its model'in'a flask section showing the anchor members in place.

Fig. 6 is a plan view of a flask section with thev teeth of a set-up embedded therein and their bases extending into the mold cavity and also showing the reenforcing bars held in position by the anchor members.

Fig. 7 is a sectional view taken along the line of Fig. 6.

Fig. 8 is a sectional view taken along the line 83 of Fig. 5.

Fig. 9 is a front elevation of .a'reenforcing bar.

Fig. 10 is a perspective view of alabial reenforcing bar shaped to fit the exterior of an upper or lower denture, as illustrated in Figs. 5 to 8.

Fig. 11 is a perspective view of a lingual reenforcing bar shaped to fit the interior of an upper or lower denture, as illustrated in Figs. 5 to 8 and Fig. 14.

Fig. 12 is an enlarged sectional view of a reenforcing bar showing a threaded anchor member screwed therein.

Fig. 13 is an enlarged sectional view of a reenforcing bar havinga tapered anchor member secured therein;

Fig. 14. is a plan view of a finished partial plate illustrating the application of a lingual reenforcing member, as shown in Fig. 11.

Referring to the drawings and more particu-' larly to Figs. 1 to 4, I represents a model formed of plastic material, such as plaster of Paris or artificial stone and the like. This model is cast from an impression taken from the upper gum' ridge of'the patients mouth and represents the contour of the upper side of a denture to be made.

Great care must betaken in obtaining an accu-'' rate impression and a" model whose contours are a replica of the patients mouth or the denture made therefrom will be unsatisfactory.

2 represents the patients labial gum is cast. The base '3 is provided with the beveled line which determines the peripheral flange of the denture.

shoulder 4 separating thejrnodel from the base. and following the general contour of the labial gum line2. T V 1 The base of the model maybe secured to an articulator or within a molding flask or otherwise employed during the process of making dentures without endangeringthe model. The base 3 is also constructed from a. substantial amount of plastic material so as to provide protectionfrom fractures resulting from sudden changes in temperature,

After'th'e model has been completed and the artificial teeth for the denture have been chosen, the wax 5 is applied to the surface of themodel completely covering the same. This wax coating acts as the wax base of the trial plate. It may the contour of the patients mouth and the relative positions of the artificial teeth 6 witl'ithe vary in thickness on themodel, depending upon a patients bite. The teeth are roughly set around the model ridge and tacked in place by melting wax and permitting it to flow around the necks thereof. 1

During this procedure the teeth are positioned on the models in an articulator which is arranged to duplicate the position and movement of the patients jaws. The patients bite is then employed in the articulator to determine the occlusion of theteeth. Thus the teeth. may be properly set in the wax base and held more firmly byplacing additional wax around the necks thereof.

and 8 represent the labial and lingual reenforcing bars. The labial reenforcing bar 1 is shown in Figs. 9 and 10. This bar is formed to provide clearanceat 9-for the frenum which connects the front. lips to the'human gums at the center of the mouth. The sides of the labial bar are formed'as at H] .to provide clearance for'the buccinator muscles which connect the cheeks of a human being to the gums. The peripheral flange of the denture must necessarily follow the irregular contour of the patients mouth, as shown in Figs. 1 to 4 so that the denture will properly fit therein without interference with these human muscle organs. The labial reenfcrcing bars 9 are shaped so that they may be applied to any denture and provide ample clearance for this purpose.

The lingual reenforcing bar 8 as shown in Fig. 11 is not required to have the clearances 9 and i provided for the labial bar. The lingual bar is shaped in the manner of a horseshoe and its sides are slanting like that of a frustuin of a cone. The labial and linqual bars are placed on the wax plate with their outer edges adjacent the necks of the teeth fi. Thus the tacking wax forms a space between the reenforcing bars and the teeth. These reenforcing members are preferably made of a chrome steel alloy which is known for its strength and comparatively light weight. They are made into comparatively narrow strips so as to provide for a degree of latitude in fitting the average patients denture. The bars are sandblasted to provide roughened surfaces that aid in bonding them to the denture base.

I I and l 2 represent the anchor members of the labial and lingual reenforcing bars '5 and 8 respectively. These members are preferably made of high grade steel so that they may be used repeatedly without loss due to wear. As shown in Fig. 12 these members may be constructed in the form of a T wherein the stem I3 is threaded as at it to fit the tapped hole I of the reenforcing bar. A limiting and tightening shoulder may be provided at the inner end of the thread but it is preferable to permit the threads of the. hole iii to cut into the stem 53 to provide a tight engagement therebetween as shown in Fig. 12. In Fig. 13 the head of the anchor member is formed by the eye 56 and the end of the anchor stem l? is provided with a tapered portion is arranged to fit the. tapered hole l 9 of the reenforcing bar. To secure good anchorage these tapers must be small. These two figures illustrate two forms of heads and two methods of securing the anchor members to the reenforcin bars and they illustrate a preferred form, but the invention is not intended to be limited thereto.

These anchor members may be securely inserted in the bars before they are. positioned around the teeth. The wax is then melted and formed around the teeth and the reenforcing bars. The wax is then shaped to properly fill the patients cheeks and fit the inside of the mouth.

Thus the trial plate or wax set-up is finished and ready to be tried in the. patients mouth to determine the correctness of the fitting and the position of the teeth. After it is lifted from the model it appears as in Fig. i and the anchor members are then removed therefrom, leaving small holes in the wax which are hardly noticeable.

By building the reenforcing members into the wax set-up I have dispensed with the necessity of using a shellac base plate. I have provided a stiff trial plate that will withstand considerable abuse without endangering the accuracy of the work. It has an increased mass and is not as susceptible to temperature changes.

After the set-up has been tried in the patients mouth and the proper adjustments have been made the anchor members are replaced in the re enforcing bars and it is placed on its model which is embedded in a flask section 28, as shown in Figs. 5 and 8. A separating medium is then placed on the exposed surface 2! of the plastic material, so that the flask sections may be easily separated.

A mating flask section 22 is placed on the section 2t and plastic material 23 is poured or otherwise formed around the wax set-up and the protruding heads of the anchor members. After the plastic material sets the flask portions may be parted and the wax melted out by boiling or any other suitable manner. There remains a cavity 2 1 in the plastic material 23 of the flask 22 and the necks of the teeth 6 with the reenforcing bars are shown rigidly positioned therein, as shown in Figs. 6 and 7. If by chance a reenforcing member was not properly installed in the wax set-up the correction can be made at this stage of the process without injury to the product.

It will be noted that the heads of the anchor members are firmly held Within the solidified plastic material and suspend the bars in their proper relation with respect to the teeth and. the surface of the cavity mold. The necks of the teeth, being thus disposed between two parallel bars and mechanically supported by the denture base material, are firmly set and are reenforced in a manner similar to the natural root of a tooth within the jaw of a human being.

The material which is to form the denture base, such as rubber, resin or the like is then placed in the cavity 24, the flask sections are again assembled under heat and pressure and the denture base is vulcanized or otherwise pressure formed therein. v

Upon removal of the plastic material from the teeth and the anchor heads of the flask section 22, the denture may be removed from the model. The anchor members may then be removed and the holes filled with plugs which may be vulcanized or cemented in place. The denture is then finished and polished to glossy gum like appearance, which completely obliterates the plugged holes.

The denture base having the bars is far stronger than the ordinary denture and is not apt to break as readily under severe pressures.

Referring to Fig. 5, 25 represents a reenforcing member designed to strengthen the back of the plate across the arch thereof. This member is added when the arch of the upper denture base must necessarily be very thin because of the construction of the roof of the patients mouth. A denture which would otherwise be very fragile can be easily made to withstand heavy pressures with the use of my invention.

It will be noted that by properly positioning these members within the set-up they never become exposed at the surfaces of the completed denture base because they are firmly held in the flasks by the anchor members. Thus the acids of the mouth do not have a chance to attack the reenforcing members and make them uncomfortable or distasteful to the persons wearing them.

Fig. 14 illustrates the application of a lingual reenforcing bar as applied to a partial plate such as the horseshoe plate with the two molars on each side thereof. Such a plate is exceedingly fragile but when provided with a reenforcing bar it is stronger than ordinary full upper plates and cannot be broken by squeezing or dropping it.

I claim:-

1. In reenforcing means for artificial denture plates, the combination of a bar to be permanently embedded in the plate, and anchor members arranged to be detachably connected to the bar and having their ends adapted to be partially embedded in the mold material to properly position the bar in the mold cavity while the plate is being formed therein.

2. In reenforcing means for artificial denture plates, the combination of a bar to be permanently embedded in the plate and provided with holes, and anchor members having their inner ends arranged to be temporarily held in said holes and having their outer ends adapted to be partially embedded in the mold material to properly position the bar in the mold cavity while the plate is being formed therein. t

3. In a denture the combination of a pair of arcuately shaped reenforcing metal bars, said bars being embedded in the plastic material of the denture in the horizontal plane of the necks of the teeth and in spaced relation thereto, the

in spaced relation to the outer sides of the necks of the teeth, and means defining offset portions.

in said labial bar to provide clearance for the frenum cord and the buccinator muscles of the human mouth. WILLIAM R. A. GUYTON.

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