The invention relates to a dental light polymerization device, and in particular for a dental light polymerization device having a polymerization light source, a camera and an actively movable light reflector.
Light hardenable or light curable materials are widely used in dentistry for the restoration of teeth. Many of such materials are made to provide optical characteristics that resemble those of natural teeth. Further, such materials typically can be placed precisely and conveniently before they are hardened in place instantly. These materials are often preferred alternatives to less pleasant looking and self-hardening materials, like for example amalgam.
Light hardenable materials often include a polymerizable matrix material and filler materials including colorants, and may initially be generally soft or flowable so that they can be applied in a desired location and shape. For example, for restoration of a tooth the dental material may be filled into a tooth cavity and shaped so that the restored tooth resembles a natural tooth. Once the desired shape has been formed, the material may be cured by exposing it to light of a desired wavelength. The light typically activates photoinitiators in the dental material that cause the matrix material to polymerize.
The use of dental materials that are hardenable by blue light of a wavelength of between about 450 and 500 nm (nanometers) has become common in dentistry. Accordingly, light-emitting devices used for hardening such dental materials typically emit light at such wavelengths. Such a light-emitting device is for example available from 3M Deutschland GmbH, Germany, under the trade designation Elipar™ S10.
A variety of light devices have been developed or proposed. Further, light devices having additional functionality have been developed recently. For example WO 2014/043488 A1 discloses a dental irradiation device which has a first light emitting unit for emitting blue light for light hardening of a dental material. The device has a second light emitting unit and an image sensing unit which are adapted for cooperation with each other for simultaneous illumination and image capturing.
Although there are a variety of light devices on the market there is still a desire to provide a device that provides a variety of functions and which is relatively convenient in handling. Further, such a device is desirably inexpensive.
The invention relates to a dental light polymerization device which comprises a polymerization light source, and a camera. The device further comprises an actively movable light reflector.
The invention is advantageous in that it allows for polymerization of a dental material and capturing of one or more images during the polymerization with the same device. Further, due to the movable mirror the two functions of light emission for polymerization and image capturing can be alternatively activated. Thus, each function can be activated generally at full performance level. Accordingly, the light for polymerization can be used at generally its full intensity while the camera is available for image capturing.
In one embodiment the reflector is movable between a first positional arrangement, in which the reflector establishes a first optical path between the polymerization light source and an object, and a second positional arrangement, in which the reflector establishes a second optical path between the object and the camera. This means that (if no object is present) in the first positional arrangement the reflector establishes the first optical path between the polymerization light source and an imaginary point outside the device, and in the second positional arrangement the reflector establishes the second optical path between the same point and the camera. Preferably, in the first positional arrangement the reflector does not establish the second optical path. Further, in the second positional arrangement the reflector does not establish the first optical path between the object and the camera.
An actively movable light reflector as referred to herein may comprise a motor for driving the reflector, for example on or more mirrors. For example, a micro motor may be provided which carries the reflector. Several techniques of providing a motor are available based on electrically controlled magnetic or electrostatic fields. For example, actively movable light reflector may be formed by a so-called Digital Mirror Device (DMD). Such a DMD comprises one or more (typically a multiplicity) of micro-mirrors which are individually movable by the force of electrostatic fields between two positions.
In the first positional arrangement the second optical path may be suspended or interrupted. Further, in the second positional arrangement the first optical path may be suspended or interrupted. Furthermore, in the first positional arrangement the second optical path may be suspended or interrupted and in the second positional arrangement the first optical path may be suspended or interrupted. The suspension or interruption may be caused by arranging the reflector in the first or second optical path so that the respective optical path is interrupted. Alternatively, the first and/or second optical path may be established by the reflector deflecting light along the respective path so that by removing the reflector the light no longer travels on that path.
In one embodiment in the first positional arrangement the reflector establishes the first optical path in that the reflector is arranged outside the first optical path. In this embodiment the first optical path is linear. In this embodiment in the second positional arrangement the reflector establishes the second optical path in that the reflector bends the second optical path. Accordingly the second optical path is bent or angled. In the first positional arrangement according to this embodiment the reflector may be also arranged such that the reflector does not establish the second optical path. Further, in the second positional arrangement according to this embodiment the reflector may be arranged within the first optical and thus interrupts the first optical path.
In a further embodiment the reflector establishes the first optical path and the second optical path in that the reflector alternatively bends both, the first and second optical path. Accordingly, the first and second optical path of this embodiment each are bent or angled. In the first positional arrangement according to this embodiment the reflector may be also arranged such that the reflector does not establish the second optical path, and in the second positional arrangement according to this embodiment the reflector may be arranged such that the reflector does not establish the first optical path.
In a further embodiment the reflector is formed by a prism. For example the reflector may be formed by a mirror that is formed by a mirrored surface of the prism. Further, the reflector may be formed by any mirror. The mirror is preferably planar.
In one embodiment the reflector is rotatable between the first and the second positional arrangement. For example the reflector may be continuously rotatable over 360 degrees. Accordingly, the mirror positions successively at the first and second positional arrangement (and optionally further intermediate positions). Further, the mirror may position continuously and successively at the first and second positional arrangement during a time period that is determined for polymerization of a dental material. Such time period may be a few second up to several minutes.
In a further embodiment the dental light polymerization device is operable for periodically moving the reflector between the first and second positional arrangement. For example, the reflector may be continuously rotatable or pivotable by an angle of less than 360 degrees. One period or cycle may comprise maintaining the reflector in the first positional arrangement for a first time period, moving the reflector to the second positional arrangement, maintaining the reflector in the second positional arrangement for a second time period, and moving the reflector to the first positional arrangement. The first and second time periods are different, preferably at a ratio of between about 40:1 and about 2:1, more preferably at a ratio of between about 20:1 and about 10:1.
In one embodiment the reflector is formed by a multiplicity of micromirrors provided by a Digital Micromirror Device. Such a device is for example available from Texas Instruments Inc., Dallas, Tex., USA.
In one embodiment in the first positional arrangement the camera is deactivated, and in the second positional arrangement the polymerization light source is deactivated. In particular, the dental light polymerization device may have a control unit which is configured to activate (switch on) and deactivate (switch off) the polymerization light source in coordination with the mirror being arranged in the first and second positional arrangement, respectively. Further, the control unit may be configured to activate (switch on) and deactivate (switch off) the camera in coordination with the mirror being arranged in the second and first positional arrangement, respectively. Further in the second positional arrangement an illumination light source may be activated. The illumination light source may be deactivated in the first positional arrangement. The activation and deactivation of the illumination light source is preferably also controlled by the control unit of the dental light polymerization device.
In a further embodiment the illumination light source is configured to emit visible light having a spectrum comprising light at wavelengths of between 380 nm and 750 nm. The illumination light source comprises a plurality of white LEDs.
In still a further embodiment the polymerization light source is configured to emit visible light predominantly within a wavelength range 450 nanometers-495 nanometers. The polymerization light source preferably consists of a single high power LED.
Preferably, the dental light polymerization device has a rechargeable battery. Further, the battery, the polymerization light source, the camera, the illumination light source and the reflector are preferably encapsulated in a closed housing. The housing has at least partially a transparent wall for permitting the polymerization light source and the illumination light source to emit light from the inside of the housing toward an outside point or area. The transparent wall or wall portion further preferably allows for the camera to receive an image from the outer point or area. The housing is preferably shaped so that a portion of the housing fits into the oral cavity of a patient. Preferably, that portion comprises the transparent wall or wall portion.
In
In operation of the dental light polymerization device 1 in the first positional arrangement (
In
In operation of the dental light polymerization device 1 the mirror 13 continuously rotates about the rotation axis R and thus alternately changes between the first and second positional arrangement. It is noted that the first positional arrangement of the mirror in this example includes at least a first range of different particular angular positions in which the mirror 13 is positioned outside the first optical path 15.
As illustrated the polymerization light source 11 is arranged in the dental light polymerization device 1 to emit light in a light emitting direction 17 (along optical path 15) and the camera 12 is arranged in the dental light polymerization device 1 to receive light from an image receiving direction 18 which is transverse or inclined to light emitting direction. The light emitting direction 17 and the image receiving direction 18 in the example intersect outside the object.
The light polymerization device 1 of
The light polymerization device 1 of
Number | Date | Country | Kind |
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16165494.2 | Apr 2016 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/US2017/026890 | 4/11/2017 | WO | 00 |