Light curing device for dental restoration materials and method of curing dental restoration materials

Abstract

The invention is directed to a light curing device, in particular for dental restoration materials, having a light source and a control device for the light curing device, which control device is capable of switching on the light source at different levels of power. The light curing device includes an actuation element which can be used to switch on the light curing device upon actuation by the user at a reduced dosage of light for pre-curing the dental restoration material. The control device in particular signalizes the reduced dosage.

Claims

1. A light curing device for dental restoration materials, comprising a light source (12), a control device (14) for the light curing device (10), and an actuation element for actuation of a regular curing mode and a separate actuation element for actuation of a pre-curing mode, wherein the pre-curing mode consists of a prefixed dosage consisting of a single prefixed power in the range of 800 mW/cm.sup.2 to 1000 mW/cm.sup.2 and a single prefixed time in the range of 1 msec to 10 seconds in order to prevent a material to fully harden, wherein the pre-curing mode is set by a manufacturer and cannot be changed by a purchaser or user.

2. The light curing device for dental restoration materials as claimed in claim 1, wherein the prefixed dosage consists of the single prefixed power at 950 mW/cm.sup.2 and the single prefixed time of 2 seconds.

3. The light curing device for dental restoration materials as claimed in claim 1, wherein the control device (14) is capable of switching on the light source (12) at different levels of power for the regular curing mode.

4. The light curing device for dental restoration materials as claimed in claim 1, wherein the control device (14) signalizes the prefixed dosage.

5. The light curing device for dental restoration materials as claimed in claim 4, wherein the signalizing comprises a change in color of the light source, a flashing of the light source, repeatedly switching on and off of the light source (12), a light-emitting diode, an acoustic signal, and/or an additional display which symbolizes the prefixed dosage.

6. The light curing device for dental restoration materials as claimed in claim 1, wherein the regular curing mode comprises a dosage having a period of time which is greater in power and time than the prefixed dosage.

7. The light curing device for dental restoration materials as claimed in claim 1, wherein the prefixed pre-curing mode can be switched on independently of the regular curing mode, and wherein a break can be selected between the prefixed pre-curing mode and the regular curing mode at discretion of the user.

8. The light curing device for dental restoration materials as claimed in claim 1, wherein the light curing device (10) returns to the mode that was previously used before the device was turned off, after the device has been switched back on.

9. The light curing device for dental restoration materials as claimed in claim 6, wherein the separate actuation element for actuation of a pre-curing mode comprises a first button for activating the pre-curing mode and the actuation element for actuation of the regular curing mode comprises a second button for adjusting the regular curing mode.

10. The light curing device for dental restoration materials as claimed in claim 9, wherein the light curing device is switched between the pre-curing mode and the regular curing mode by pressing the first button and the second button.

11. The light curing device for dental restoration materials as claimed in claim 6, wherein the light curing device comprises at least two LED chips with different emission maxima, one of the LED chips comprises a longer wavelength of the emission maximum and can only be switched on exclusively in the regular curing mode of the light curing device (10).

12. The light curing device for dental restoration materials as claimed in claim 1, wherein the light curing device (10) comprises a sensor which is directed at the target area of the light source (12) and detects at least one physical parameter of the dental restoration material while it is being cured.

13. The light curing device for dental restoration materials as claimed in claim 12, wherein the sensor of the light curing device which is directed at the target area of the light source (12) is connected to the control device (14) and switches off the light source (12) in the pre-curing mode and/or in the regular mode when the output signal of the sensor signalizes sufficient light exposure.

14. The light curing device for dental restoration materials as claimed in claim 1, wherein the light curing device (10) is configured as a hand-held device, wherein the control device (14) switches on the light curing device when it is picked up by the hand of a user, and wherein upon first actuation of the separate actuation element for actuation of the pre-curing mode, the light curing device (10) is switched to the pre-curing mode at a pre-fixed dosage.

15. The light curing device for dental restoration materials as claimed in claim 1, wherein when the pre-curing mode has been finished the light curing device (10) assumes a standby-mode from which it can be switched to the regular curing mode upon actuation of the actuation element (20) at a point in time selected by the user.

16. The light curing device for dental restoration materials as claimed in claim 1, wherein the actuation element (20) comprises several buttons comprising a button which can be used to activate a desired mode, and a control button which can be used to adjust a mode or a program of the light curing device (10).

17. A method of curing dental restoration materials using a light curing device (10) comprising a light source (12), a control device (14) for the light curing device (10), and an actuation element for actuation of a regular curing mode and a separate actuation element for actuation of a pre-curing mode, wherein the pre-curing mode consists of a prefixed dosage consisting of a single prefixed power in the range of 800 mW/cm.sup.2 to 950 mW/cm.sup.2 at a single prefixed time in the range of 1 msec to 10 seconds, wherein the pre-curing mode is set by a manufacturer and cannot be changed by a purchaser or user, said method comprising switching on the actuation element to the prefixed dosage for a pre-curing mode in which the prefixed dosage of the single prefixed power and the single prefixed time for pre-curing is supplied to the dental restoration material to prevent full hardening of the dental restoration material, examining and/or refinishing the dental restoration material, and switching the light curing device (10) to the regular curing mode at an increased power and/or time to fully cure the dental restoration material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, details and features may be taken from the following description of one exemplary embodiment in conjunction with the drawings.

(2) FIG. 1 shows an inventive light curing device in one embodiment;

(3) FIG. 2 shows a dental restoration in one embodiment; and

(4) FIG. 3 shows a schematic illustration of the wave lengths used for the light curing device and the dental restoration according to the invention.

DETAILED DESCRIPTION

(5) The light curing device 10 illustrated in FIG. 1 comprises a light source 12, a sensor 13, and a control device 14 which are received in a pistol-shaped housing 16 in a way known per se.

(6) A light-conducting rod 18 projects from the front side of the housing 16 of the light curing device 10 which light-conducting rod is cranked or bent in a way known per se at its distal end in order to allow for light exposure even from sites which are difficult to access.

(7) The inventive light curing device comprises an actuation element 20 which has a dual function in the exemplary embodiment illustrated. Actuation element 20 includes button 26 which can be used to activate a desired curing mode, and a control button 28 which can be used to adjust a mode or a program of the light curing device (10). In this example it is located at a position at which the trigger of a pistol would be arranged. By pressing on and thus actuating the actuation element with the help of the user's index finger the light curing device is initially switched into a mode which is referred to as pre-curing mode in which light is output by the light source 12, and thus from the front end of the light-conducting rod 18 at a reduced dosage. Here, the term dosage refers to the product of power and time such that the output of light is carried out at a dosage which is reduced compared to the dosage of the regular curing mode.

(8) If, for instance, in the regular curing mode the light source 12 is switched on at a power of 4 W for 10 seconds, in the pre-curing mode the output of light can, for instance, amount to 400 mW also for a period of time of 10 seconds, or—in the other extreme case—for only one second at 4 W, too. In both cases, the same reduced dosage is applied.

(9) By actuating the actuation element 20 the light source 12 can be switched on. In the exemplary embodiment illustrated it is switched to the mode in which the light curing device is, based on information stored in the control device 14. For instance, it can be determined that the light curing device is in the pre-curing mode when the device is switched on for the first time. In that mode light is output from the light-conducting rod 18 at a reduced dosage when the actuation element 20 is actuated.

(10) The output of light in the pre-curing mode can be signalized by flashing, a change in color or in any other desired manner, for instance via the signal LED 22 illustrated in FIG. 1 which signalizes the pre-curing mode.

(11) In order to change to another mode the actuation element 20 is actuated in any desired other, but unusual manner. Here, it is possible, for instance, to introduce the change of mode by pressing the actuation element 20 for more than one second. Another possibility is to introduce the change of mode by a temporary dual actuation of the actuation element 20. The change of mode can also be signalized, for instance, by a corresponding confirmative flashing of the signal LED 22, or by a temporary confirmative light output by the light source 12.

(12) In a modified embodiment it is provided to switch on the pre-curing mode via a separate on-button or any other separate on-function.

(13) Preferably, the light curing device remains in the current mode even if the device is turned off and put down.

(14) Alternatively, it is also possible to always select a specific mode, for instance the pre-curing mode, in a “cold start” of the light curing device such that as a rule pre-curing always takes place prior to the main curing step.

(15) The light curing device illustrated in FIG. 1 also comprises a mode referred to as an increased power output mode which is started with the help of a flash button 24. In this mode which is only available in the main curing mode very high luminous power is used for a short period of time, for instance 10 or 12 W, but only for a very limited period of time such as 1 second or 1.5 seconds. It is favorable to release this mode only by pressing the flash button in order to prevent any possible health hazards caused by burns due to an unintentional start-up of the device in the increased power output mode.

(16) It is also preferred to provide the flash button 24 with an actual push-button function such that the increased power output mode is only started if the flash button 24 is pressed down effectively when the actuation element 20 is actuated. In addition, this mode can also be signalized optically.

(17) According to the invention, it is favorable if the on-times in the pre-curing mode and in the main curing mode are set independently of one another, or if they can be programmed independently of one another. If the exposure time settings in the regular curing mode are changed, this does not have to lead to a change of the exposure time in the pre-curing mode.

(18) In an advantageous embodiment, it is provided to attach a sensor which is not illustrated herein in such a way that it is directed at the target area of the light source of the light-conducting rod 18. In this way, it can be checked if the light exposure of the dental restoration material is sufficient both in the main curing mode and in the pre-curing mode.

(19) According to the invention, it is favorable if the light curing device is turned off between the pre-curing mode and the main curing mode and if in this respect a “modeling mode” is produced virtually.

(20) FIG. 2 shows schematically how a dental restoration can be applied. Initially, a cavity 30 is filled with a first layer 32 of dental restoration material in a way known per se. In this condition, this layer is still fluid, although not highly fluid. The light curing device is turned on and the first layer 32 is thus converted from the fluid into a highly viscous state. At the same time, due to this process a slight reduction in volume 34 takes place which corresponds to a respective lowering of the layer level on its upper side. In this condition, the layer 32 is still easily deformable and slightly cohesive such that it easily adheres to a further layer II.

(21) This second layer 36 is applied subsequently, wherein it combines well with the hardness layer 32 already during the application.

(22) Subsequent to this step, the second layer is also subjected to a pre-curing mode. In this step, the second layer is also converted into a highly viscous state and binds itself more closely to the first layer 32 at the same time.

(23) Subsequently, the light curing device is turned off or at least removed from the dental restoration material. The filling of the cavity 30 with the dental restoration material is checked visually and, if necessary, the dental restoration material is again pressed on with the help of a dental instrument suitable for this purpose. In this way, marginal gaps can be avoided reliably. Furthermore, it is possible to change the shape of the surface of the second layer, and this is symbolized by the hatched change in layer 40 according to FIG. 2. In this respect, this sleep mode can also be referred to as modeling mode.

(24) In a further modified embodiment, it is provided to remove excess material without further ado instead of or in addition to the modeling step. This can be realized, for instance, with the help of a polishing rubber or a cutter. After the pre-curing process the material exhibits a certain hardness on its surface, while its hardness does not yet require any expensive machining in order to remove excess material.

(25) It is to be understood that, if necessary, the material can be pressed on correspondingly and checked at least visually between the application of the first and the second layer.

(26) In a modified embodiment only one layer is provided. Here too, subsequent to the application of the layer and to the pre-curing step in the pre-curing mode the material can be checked visually and, if necessary, pressed on and/or modeled according to the change in layer 40 of FIG. 2.

(27) FIG. 3 shows how a change in mode can also be symbolized by a change in color of the light output of the light source 12. The light source 12 which comprises a plurality of LED chips being arranged substantially next to one another comprises its emission peak at a wave length of 470 nm for most chips. One chip comprises a maximum emission of 420 nm such that according to FIG. 3 the curve 50 showing the emission of the light source 12 in the regular mode is produced.

(28) It overlaps the sensitivity curve 52 of champhorquinone significantly which is commonly used as a photo initiator for polymerizable dental material.

(29) In the embodiment illustrated a further chip is provided which comprises an emission peak of 520 nm and whose emission spectrum corresponds to the curve 54 to that effect.

(30) This chip can possibly be turned on solely for the pre-curing mode, or if necessary together with one of the chips whose emission peak is at 470 nm. In this way, the emitted light obtains a greenish hue, and thus the user of the light curing device receives a visual feedback on the switched-on state.

(31) In a modified embodiment, it is provided that the pre-curing step is signalized by exclusively turning on a chip emitting a green-colored light. In this way it is possible to provide the pre-curing step by means of a light output of blue color at reduced power, possibly with an additional signal function such as flashing and the like, of blue color with a hint of green or of green color exclusively and to implement it at the same time.

(32) It is to be understood that in addition to or instead of it further optical signals are possible, such as a flashing, an increase/reduction of the light output in the pre-curing mode or a turning on of the signal LED 22, or for instance an acoustic signal.