WO2009016667A1

WO2009016667A1 - Device and method for melting and shaping wax or similar materials, in particular for making trial dental prostheses and models in the goldsmiths' sector

Info

Publication number: WO2009016667A1
Application number: PCT/IT2007/000559
Authority: WO
Inventors: Luca Bullentini
Original assignee: Luca Bullentini
Priority date: 2007-08-02
Filing date: 2007-08-02
Publication date: 2009-02-05
Also published as: WO2009016667A4

Abstract

A device (1) for melting and shaping wax is described, in particular for making trial dental prostheses and models in the goldsmiths' sector comprising: at least one container (2) adapted to contain the wax, heating means (7, 70) to bring to temperature and melt the wax inside said container (2), flow regulating means (4, 40, 5) to regulate the outflow of the wax melted in said container, and spreading and shaping means (6) adapted to receive the molten wax leaving the container and spread and shape the wax on the model to be created.

Description

DEVICE AND METHOD FOR MELTING AND SHAPING WAX OR SIMILAR MATERIALS, IN PARTICULAR FOR MAKING TRIAL DENTAL PROSTHESES AND MODELS IN THE GOLDSMITHS' SECTOR

DESCRIPTION

The invention concerned relates to a device and a method for melting and shaping wax, in particular for making trial dental prostheses and models in the goldsmiths' sector.

In various fields, in particular in the dental sector and in the goldsmiths' sector, models or prototypes are made by means of processes of melting and shaping wax, or similar materials.

In the dental sector, production of a prosthesis, whether fixed or removable, passes through the following stages:

- taking an impression of the oral cavity with arginate or similar materials;

- creating a plaster model, made from the preceding impression;

- creating trial prostheses made of "dental wax" poured onto the plaster model to define the optimum shape of the prosthesis; - creating the final prosthesis of resin or alloys and porcelain, according to the type of prosthesis.

The trial prosthesis according to the prior art is made of "dental wax". Various types of dental wax are available on the market with different physical and mechanical characteristics. The use of wax allows easy shaping and, through fittings on the patient, it is possible to carry out any modifications and touching up until the prosthesis has been optimised and the final prosthesis, made of resin or alloys and porcelain, is then created.

At present the trial prosthesis is made using a metal spatula which is heated by bringing it into contact with a flame (generally using the flame of a Bunsen burner). The hot spatula is placed on the dental wax, available commercially in sheets measuring about 10 cm x 7 cm and 1 mm thick. The part of the wax in contact with the hot spatula melts and remains on the spatula. The operator pours the wax from the spatula onto the trial prosthesis being created and waits for the wax to cool, then repeats the successive steps up to the end of creation of the trial prosthesis. The hot spatula can be used directly to shape the wax prosthesis. The above described manual process presents various drawbacks, in particular:

• extremely long throughput times,

• a high impact of labour costs in the manufacture of models,

• waste of the material used for modelling (wax), • those responsible for creating the model have to perform repetitive, alienating work.

Object of the present invention is to overcome the drawbacks of the prior art by providing a device and a method for melting and shaping wax that are practical, versatile and simple to use.

This object is achieved, in accordance with the invention, with the device and method whose characteristics are listed respectively in the appended independent claims 1 and 13.

Advantageous embodiments of the invention are apparent from the dependent claims.

The device according to the invention carries out melting of the wax, allows application thereof to the trial prosthesis and can also be provided with an air spraying nozzle to carry out rapid cooling. Such a device allows throughput times and production costs to be decreased and shaping operations to be reduced and simplified, thus tiring the operator less. The device further allows all the raw material to be used without waste.

Further characteristics of the invention will be made clearer by the detailed description that follows, referring to a purely exemplary and therefore non-limiting embodiment thereof, illustrated in the appended drawings, in which:

Figure 1 is a side view of the device for melting and shaping wax according to the invention, and

Figure 2 is an axial sectional view of the device of Figure 1.

The device for melting and shaping wax according to the invention, denoted as a whole with reference numeral 1, is described with the aid of the figures.

The device 1 comprises a container body or "cartridge" 2, substantially cylindrical in shape and hollow on the inside, made up of a rear portion 20, proximal with respect to the operator, and a front portion 30 distal with respect to the operator. The front portion 30 has a smaller diameter than the rear portion 20. In the rear portion 20 of the body there is defined a chamber 21 which serves to contain inside it the wax in the solid state. The chamber 21 is open at the rear; in this manner introduction of the wax can take place from the rear of the body, in which a hole is formed for introduction of the material. The rear hole is closed by a stopper 9 to prevent the material from coming out and foreign bodies from entering.

A duct 31 communicating with the chamber 21 and coaxial therewith is defined within the front portion 30 of the body.

The cartridge body 2 also forms the handle of the device 1 and for this purpose can be coated, at least partially, with insulated coating materials 22, suitably shaped to ensure a grip and thermally insulate the chamber 21.

A nozzle 4, provided with a delivery hole or outlet aperture 40 for discharge of the wax, is situated at the front end of the front portion 30 of the body. The delivery hole 40 is tapered in shape and communicates with the duct 31. The nozzle 4 can be fixed or removable, so as to choose the optimal shape of the delivery hole 40 for the working stage of the type of dental wax used.

An opening lever 5 is hinged, by means of a hinge 50, to the nozzle 4. The lever 5 can be operated by means of pressure exerted by the operator to open/close the delivery hole 40 of the nozzle. The lever 5 is provided with a spring to return the lever to the closed position.

The part of the lever 5 destined to come into contact with the user's skin is coated with thermally insulating material 51. The remaining part of the lever 5 and the nozzle 4, on the other hand, must be kept heated to avoid the wax setting inside the delivery hole 40.

Beneath the nozzle 4 is disposed a spatula 6 adapted to receive the molten wax leaving the delivery hole 40. It must be considered that during creation of the trial prosthesis, depending upon the operational stage reached and/or the type of prosthesis to be made, it may be necessary to use spatulas having different shapes and sizes. A movable connection of the spatula 6 to the cartridge body 1 has therefore been provided. Said movable connection can be realised by means of fixing means 60, such as screws, snap coupling, bayonet coupling or other systems that perform the same function. The front part 30 of the cartridge body is heated by contact with a hot surface 7. The heating surface 7 is made up of a metal body containing at least one electrical resistance 70 supplied by an electric cable 71 suitable to be connected to a supply network. An on/off switch 72 that can be operated from the outside by the user is interposed between the resistance assembly 70 and the electric cable 71. In the event of there being a plurality of resistances, the switch 72 can have a plurality of positions to enable different resistance values, according to the temperature required to melt the wax used.

The resistance 70 can also be powered by means of an electric battery, so as to be able to eliminate the cable 71 and have greater freedom of movement.

A thermostat 73 which serves to maintain the temperature in the device at a value set according to the physical characteristics of the dental wax used is also disposed in the heating element 7.

The front part 30 of the body which is directly in contact with the surface of the heating element 7 has a greater thickness 33 and does not have the coating 22. The wax in contact with the surface of the duct 31 melts and can be discharged through the delivery hole 40 of the nozzle 4 to pour onto the spatula 6. The amount of wax that is poured onto the spatula 6 depends upon the shape of the nozzle 4 and the time the aperture 40 is opened by means of the lever 5.

The spatula 6 must be kept heated to prevent the wax that is deposited thereon from cooling. For this purpose the metal spatula 6 is in contact with the hot body 7 and through a heat conduction effect is heated throughout its length. The spatula 5, being kept heated, can also be used for shaping operations.

Even if in the drawing the spatula 6 is illustrated joined to the body 1, it can be connected to the heating element 7 or even to the nozzle 4.

The device 1 can be provided with a nozzle 8 connected, by means of a tube 81, to a compressed air circuit from which a jet of air is discharged. The aperture of the nozzle 8 is controlled manually by the operator, by means of a lever 80. Alternatively, the control can also be of the pedal type. The jet of compressed air suitably directed allows the wax poured onto the "work" to be cooled rapidly. Numerous changes and modifications of detail within the reach of a person skilled in the art can be made to the present embodiment of the invention without thereby departing from the scope of the invention as set out in the appended claims.

Claims

1. A device (1) for melting and shaping wax, in particular for making trial dental prostheses and models for the goldsmiths' sector, characterised in that it comprises: - at least one container (2) adapted to contain the wax,

- heating means (7, 70) to bring to temperature and melt the wax inside said container (2),

- flow regulating means (4, 40, 5) to regulate the outward flow of the wax melted in said container, and

- spreading and shaping means (6) adapted to receive the molten wax leaving the container and spread and shape the wax on the model to be created.

2. A device (1) according to claim 1, characterised in that said heating means (7, 70) comprise a heating element (7) provided with at least one electric heating resistance (70) and disposed in contact with a part (33) of the body of said container and with said spreading and shaping means (6).

3. A device (1) according to claim 2, characterised in that it comprises an electric cable (71) which can be connected to the electric supply network to power said electric heating resistance.

4. A device (1) according to claim 2, characterised in that it comprises a battery to power said electric heating resistance.

5. A device (1) according to any one of claims 2 to 4, characterised in that it comprises a switch (72) disposed between said resistance (70) and the power source, said switch (72) being operated by the operator to power said at least one resistance.

6. A device (1) according to any one of the preceding claims, characterised in that it further comprises regulating and control means (73) to regulate and control the temperature inside said device (1).

7. A device (1) according to claim 6, characterised in that said temperature regulating and control means comprise a thermostat (73).

8. A device (1) according to any one of the preceding claims, characterised in that said flow regulating means (4, 40, 5) comprise a nozzle (4) provided with an outlet aperture (40) for the molten wax and a lever (5) that can be operated by the user to open and close said outlet aperture (40).

9. A device (1) according to claim 8, characterised in that said spreading and shaping means (6) comprise a spatula (6) disposed beneath said outlet aperture (40) of the nozzle and in contact with said heating element (7).

10. A device (1) according to any one of the preceding claims, characterised in that it comprises cooling means (8, 81) to cool the wax poured onto the model to be realized.

11. A device (1) according to claim 10, characterised in that said cooling means comprise a nozzle (8) connected by means of a tube (81) to a compressed air circuit to deliver a jet of air.

12. A device (1) according to claim 11, characterised in that on said tube (81) mounted upstream of the nozzle (8) is a lever (80) that can be operated by the operator to open and shut off delivery of air from the nozzle (8).

13. A method of melting and shaping wax, in particular for making trial dental prostheses and models in the goldsmiths' sector, comprising the following steps:

- introducing the wax in the solid state into a container (2),

- heating part of the container (2) to bring the wax to melting temperature,

- pouring the molten wax from the container onto the spreading and shaping means (6) and regulating the outflow of the wax, - spreading and shaping the wax on the model to be created by means of said spreading and shaping means (6).

14. A method according to claim 13, characterised in that it further comprises forced cooling of the wax poured onto the model.

15. A method according to claim 14, characterised in that said forced cooling is obtained by means of blowing in air.