US2577420A - Method and apparatus for preparing dental prosthesis - Google Patents

Description

1951 J. J. JABLONSKI ETAL 2,577,420

METHOD AND APPARATUS FOR PREPARING DENTAL PROSTHESIS Filed Dec. 15, 1949 A A 2 SHEETS--SHEET 1 INVENTORS Charlesl Hummer BYz f fi ATTORNEY dse h JJabZanskz' 2 SHEETS-SHEET 2 J. J. JABLONSKI ET AL METHOD AND APPARATUS FOR PREPARING DENTAL PROSTHESIS Filed Dec.

Dec. 4, 1951 INVENTORS 7' Joseph J. 'clzbla'nsltz Clza H 5 Patented Dec. 4, 1951 METHOD AND APPARATUS PREPARING DENTAL PROSTH-E S'IS Joseph J. .Jablonski and Charles I. Hummer, Detroit, Mich.

Application December 13, 1949, Serial No. 132,746

While the apparatus and method of use has been described more or less in detail, "itfils ob vious that changes-in the apparatus and method may be made without departing from the scope of the following claims defining our invention; This invention relates to the apparatus and method for preparing full or partial dentures which can be accurately reproduced and accurately conform to mouth conditions existing prior to any extractions.

At the present time practically all dentures are prepared by taking casts and measurements subsequent to extraction and relying rather heavily on the patients feeling of comfort.

Such reliance can not be trusted due to the fact I that a considerable time usually elapses between extraction and completion of the dentures. In cases where dentures are lost or crushed the patient has to go'through'the more or'less-standard procedure of taking mensurements and casts and it becomes almost impossible to produce-a comfortable and well fitted denture which will be most favorable to the 'patient's appearance.

The hard palate area, and particularly :the frontal portion thereof, being backed up by relatively thick and immovable skull bones :positioned some distance from the tooth supporting area, is not subject to any substantial change in the adult person .and is undoubtedly the :most suitable portion of the entire buccallcavity. The hard palate area with its rigid frontal arch is to the .buccal :cavity what finger prints are to the body and provided proper measurements are made, the true normal and natural arch :and

articulation can be accurately reproduced. It I is an object, therefore, of the present invention to provide apparatus and a method for1accurately producing dentures conforming to the natural shape most favorable to the patient.

A further object of .the invention is :the :provision of apparatus and a method wherebydup'licate dentures :can be readily produced without any inconvenience to the patient.

'Avstill further :object .ofthe invention is the provision of apparatus and a methodwhereby dentures can be produced in accordance with measurements and casts made long prior to any extractions whereby the true normal and natural dental arch and articulation can :bexreproduced whenever desired.

These and other objects of the invention will be apparent to persons skilled in the art from a study of the following description and :accompanying drawings, :in'which 1, is an elevational view oi'the improved 9 Olaims. (CI. 32-32) iii 2 apparatus located in a more .or less standard form of articulator;

"Fig. 2 :is :a plan view of the improved lower matrix former and index member;

Fig-3 is a sectional view taken substantially on &1ine 3. '3 of Fig. 2;

Fig. 4 is a sectional view through the improved lower .matrix former and showing the former filled with soft plaster;

Fig. 55 is a sectional view similar to Fig. 4 but showing the index member or locator pushed into the softiplaster;

Fig. 6 is a sectional view similar to Fig. 5 "but showing a subsequent step in which the cast of vthe Iupper natural'teeth :is pushed :into the soft plaster to the properposition;

Fig. '7 isa sectional view similar to Fig. .6 but showing a .still later step in the method and in whichathe cavity in the upper cast has been filled to :form the palatal index cast;

Fig. 8 is a sectional view showing thematrix removed from the former;

Fig.9 is an elevationalvi'ew and :Fig. 10 a plan view of the :palatal identification vcast iproduced asshown in Fig.7.;

'11 :is :a sectional view showing the upper cast mounted in its true position on the palatal identification cast and the lower. matrix;

Fig. l2zis an isometric view of the index memberror lo'cator, and

Fig. .1 3 is ea plan 'view of the articulator of Referring now to the drawings in detail it "will be :seen from Figs. 1 and 13 that a :moreor less standard form of articulator is used for illustrathteipurposes, but itis to be understood that other types of articulators can also be used while :still using the same apparatus and method laterto be described. As shown in Figs. l and 13 the articulator is formed with a base 12 from which a pair of posts 4 extend upwardly to the adiusta-ble 'condyle rod-joint 6. From the condyle red the upper jaw member 8 extends "forward-1y land has mounted therein th-eiincisal pin it adjnstably carried by the "upper jaw for clamping in any desired position by thumb screw .H. The lower end of the incisal .pin bears upon the incisal guide 12 which may be adjusted :in various angular positions and heights. The base 2 :and arm -8 are provided with positioning plates 14 slotted as at [-5 and having :a central opening therein through which an ejecting screw may more under operation by thumb screws [6 threaded into the'base and upper .arm.

Upper and lower .imatrix formers t8 Ian'dIZ'U respectively are provided and each of the formers is formed with a substantially circular base portion 22 counterbored as at 24 so as to closely fit over the positioning plates M. A pin 26 is fastened in each base and adapted to engage in the slot I so as to correctly and accurately locate the matrix former on either the articulator base 2 or arm 8. Extending upwardly from the base portion of the matrix formers are outwardly sloping walls 28 inclined at such an angle as to permit ready dischange of the plaster cast to assist in removal of the plaster cast. An ejecting screw 30 is threaded into the bottom portion of the cup-like matrix former and this screw is centrally located with respect to the screw [6 so that the entire matrix former can be readily removed from the articulator by pressure applied centrally thereof. One wall of the cup-like matrix former is provided with a flange 32 having a slot 33 formed therein and a hole is drilled or otherwise formed in the flange to receive a pin'34 preferably located centrally in the slot 33. This pin 34 is adapted to extend through a hole in an arm 36 extending outwardly from a truncated pyramidal projection 38, all as clearly shown in Figs. 2, 5, 6 and 12. The truncated pyramidal projection 38 is adapted to project into the cup shaped matrix former to provide an exact locating position for a cavity in the plaster cast in the former. For ready removal of the cavity locator or index member a projection 49 extends from the arm 36 in a direction opposite to the truncated pyramidal projection 38. From the preceding it will be seen that a new and improved apparatus has been devised for use with one type of articulator. It will be obvious that by slight changes, either in the base portion 22 of the matrix formers or by attaching standard 10- eating plates l4, the apparatus can be used with other types of articulators.

In using the apparatus just described it is preferable that the necessary facial readings for condyle and incisal guide settings be taken and recorded in any known manner and an upper denture cast 59 made of the natural teeth. All of this is preferably done prior to any tooth extraction and at least prior to any general extraction. After the upper denture cast 50 has been made it is mounted in an articulator with the condyle and incisal guide settings made in accordance with the previously recorded readings. Following this the lower matrix former is placed in the articulator and filled to the desired level with soft plaster 52 as shown in Fig. 4. While the plaster is still soft the index member or locator 38 is forced into the plaster as shown in Fig. 5, then the upper denture cast is closed into the soft plaster so as to get the tooth impression therein, all as clearly shown in Fig. 1. After the plaster has hardened the upper denture cast is lifted or swung back to the line and dash position of Fig. 1 and the index member or locator removed. The upper denture cast and lower matrix is then coated with a separating fluid and the palatal cavity filled with dental stone 54 as shown in Fig. '7. As soon as this has hardened the upper denture cast may be removed and the'palatal cast 54 as shown in Figs. 9 and 10 removed. All the parts may now be removed from the matrix formers and placed in their matching positions as shown in Fig. 11 with all the necessary readings for resetting the articulator recorded on the lower matrix 52. Whenever. at some subsequent date it is desired to produce a set of teeth for the patient the parts may again be readily assembled in the articulator and each part must assume its exact position. This is obvious since the tapering walls of the matrix former will definitely locate the position of the matrix 52 therein and the truncated pyramidal projection of the palatal cast 54 must fit into its exact position on the lower matrix thus placing the true cast of the palate in its exact relationship to the tooth impressions made in the lower matrix by the teeth of the natural denture cast 50. It will thus be seen that even though the gum lines change, requiring necessary changes in the dentures, the true location of the teeth can be reproduced at any time from the preserved record. It is believed unnecessary to go into the details of the denture manufaoture since any of the well known methods 7 may be followed and regardless of the method followed a natural shaped and well fitted denture can be prepared since all readings and positions originally taken can be exactly duplicated by use of the recorded readings and the permanent casts illustrated in Fig. 11.

While the apparatus and method of use has been described more or less in detail, it is obvious that changes in the apparatus and method may be made without departing from the scope of the following claims, defining our invention.

What is claimed is:

1. In a dental apparatus the combination of, an articulator adapted to reproduce movements and spacings of a patients jaws, a locator plate attached to the articulator, a lower matrix former engageable with said locator plate and adapted to receive plaster for casts, and a cavity locator adapted to be mounted on said matrix former and projecting into the same.

2. In a dental apparatus the combination of, an articulator adapted to reproduce movements and spacings of a patients jaws, a locator plate attached to the articulator, a lower matrix former engageable with said locator plate and adapted to receive plaster for casts, and a cavity locator adapted to be mounted on said matrix former and projecting into the same, said cavity locator having the projecting portion thereof formed as with a downwardly projecting inverted truncated pyramid.

3. In a dental apparatus the combination of, an articulator adapted to be set to facial measurements of a patient, a matrix former carried by said articulator, and a cavity producing 10- cator mounted on said matrix former and projecting into the same.

4. In a dental apparatus the combination of, an articulator adapted to be set to facial measurements of a patient, a matrix former carried by said articulator, a recess formed in the rim of said matrix former, and a cavity producing locator having a portion thereof positioned in said recess and an inwardly directed portion terminating in a downwardly directed projection having tapered sides.

5. In a dental apparatus the combination of, an articulator adapted to be set to facial measurements of a patient, a matrix former carried by said articulator, and a cavity producing 10-- cator having a slot and pin connection with said matrix former, and projecting into said matrix former to form a cavity in a cast produced in said matrix former. 6. The method of producing dentures conformmouth comprising in part, securing the pre-extraction facial measurements of the patient, making an upper denture cast and mounting the same in an articulator in accordance with the facial measurements, attaching a lower matrix former to the articulator and substantially filling the same with plaster or other hardenable material, pushing an index member into the hardenable material and closing the upper denture cast into the material, allowing the material to harden then lifting the upper denture cast and removing the index member, reclosing the denture cast onto the hardened material and filling the palatal arch and cavity left by the index member with a hardenable material, and allowing this material to harden to produce an exact pattern of the patients palatal area whereby the exact natural configuration of the patients mouth may be reproduced in conjunction with the facial measurements.

7. The method of producing dentures conforming to the natural configuration of a patients mouth comprising in part, securing the facial measurements of the patient, making an upper denture cast, placing said upper denture cast in an articulator set to the facial measurements, and filling in the palatal area of the upper denture cast to produce a palatal index cast whereby the exact natural configuration of the patients mouth may be reproduced in conjunction with the facial measurements.

8. Dental apparatus comprising, a matrix former adapted to be mounted on an articulator set to facial measurements of a patient, and a cavity producing locator mounted on said matrix former and projecting into the same.

9. Dental apparatus comprising, a matrix former adapted to be mounted on an articulator set to facial measurements of a patient, a recess formed in said matrix former, and a cavity producing locator having a portion thereof positioned in said recess and an inwardly directed portion terminating in a downwardly directed projection having tapered sides.

JOSEPH J. JABLONSKI. CHARLES I. HUMMER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,457,385 Morison June 5, 1923 2,200,058 Chott May 7, 1940 2,234,411 McDonald Mar. 11, 1941 OTHER REFERENCES The Dental Cosmos, 1914, page 418.

Images