Patent Application
20080166677
Photo curable dental adhesives are frequently used to bond orthodontic brackets to teeth. The dental adhesives are cured by exposure to light from a dental curing device. Dental curing devices are used to create a beam of light of an appropriate wavelength to cause curing of photosensitive materials. Various sources of light have been used within curing lights. The source of light may be a halogen bulb, a Xenon bulb, plasma arc and, more recently, light emitting devices herein referred to as LEDs. Radiant energy is transmitted from the lamp in the lamp assembly through an optic light guide. Optic guides have been necessary on the larger dental curing lights due to the accessibility and size constraints of the mouth. Optic light guides are typically 8-13 mm in diameter, and utilize a round tip at the distal end.
The procedure of bonding metal brackets on teeth has posed a particular problem for the light cure technique. The bracket adhesive is on the back side of the orthodontic bracket, away from the line of sight of the dental curing light. More powerful lights are more effective in curing the adhesive under the orthodontic bracket, but are expensive, large, often cumbersome and generate considerable heat, requiring cooling fans.
LED dental curing lights have become increasingly more popular due to the fact they require little energy, generate very little heat and are compact and portable. Further, the LED light does not require cooling fans and holds a charge for an extended period of time. Another advantage of using LEDs as the light source arises from the fact that the emission spectrum of some LEDs, in particular, blue LEDs, are in a very narrow band which coincides with the peak of the absorption spectrum of camphorquinone, the most common photo activator in dental photosensitive materials. Because of the narrow band, almost all of the light energy reaching the material is useful in the process of activating polymerization. No unnecessary heat is applied to the tooth. One of the problems with LED curing lights, however, is that their light output intensity is relatively low. Because of the low light intensity output, LED-curing lights are at a disadvantage in the speed of cure as compared with more intense light sources, such as halogen bulbs, plasma arc or xenon light sources. Most existing LED curing lights do not provide a light output intensity of greater than 500 mW/cm2, whereas curing lights using more typical light sources can reach outputs of 2,500 mW/cm2.
The weaker dental curing lights, such as the LED light, have required the time-consuming extra step of curing the light cure adhesive from different angles in an attempt to reach behind the orthodontic bracket.
The present invention is directed to a light directing and amplifying device for attachment to a dental curing device. Many of the dental curing devices have an optic light guide that transmits the light to the tooth surface. The present invention attaches to the end of the optic light guide and in turn transmits the light to the tooth surface. The optic light guides range in diameter from 8-14 mm. The invention is a hollow internally mirrored tube sized to fit the light-emitting end of each of the different sized optic light guides. The light directing and amplifying devise is also sized to fit dental curing lights, such as LED lights, which do not contain an external optic light guide. The mirrored internal surface of the invention reflects the light which increases, or amplifies, the light reaching the surface of the tooth.
The light directing and amplifying device is most useful for bonding metal orthodontic brackets to teeth wherein the light cure adhesive is on the tooth side of the orthodontic bracket. The embodiment of the light directing and amplifying device for bonding orthodontic brackets to teeth is comprised of an internally mirrored tubular body with a first end sized to fit the light source and a second end sized to fit over an orthodontic bracket. The second end has an internal curvature, ideally 45 degrees, which directs the light 90 degrees from the light source, directly under the backside of the bracket, thus directly curing the light cure adhesive. The result is the dental curing light need not be directed at the orthodontic bracket from multiple directions, which is time consuming. The light directing and amplifying device provides an amplified light which is directed simultaneously from the buccal and under the bracket base from the occlusal, mesial, gingival and distal directions. The result is a more thorough cure of the orthodontic bracket adhesive in a greatly reduced length of time.
In one embodiment, the light directing and amplifying device is opaque which shields the patient and operator from any harmful light rays. In another embodiment, the light directing and amplifying device is clear, allowing the operator to see the orthodontic bracket during the curing process. The clear may be amber colored which filters out any harmful light rays. In another embodiment, fiber optic strands are positioned longitudinally on the inner wall of the tubular body and turn inwards 90 degrees at the second end in order to direct the light under the bracket base.
The light directing and amplifying device is also useful in the curing of dental light cure restorations.
Referring to
The preferred embodiment of the light directing and amplifying device with a lip 20 is disclosed in
In another embodiment,
In the above embodiments, the light directing and amplifying device 10 may be removable or permanently affixed to the dental curing device 1. A clear plastic cover is often placed over a dental curing light 1 in order to prevent contamination of the dental curing device 1. Dental curing devices 1 are difficult or impossible to sterilize thoroughly. A light directing and amplifying device 10 attached to the light emitting tip of a dental curing device 1 prevents the light emitting end 5 of the dental curing light 1 from being contaminated. The second end 13, as shown in
The invention has been described with specific embodiments. However, the intent of the invention is to provide a light amplifier for light cure dental fillings. The further the intent of the invention is to provide a directional light source which is redirected to the underside of an orthodontic bracket 4 during the placement of an orthodontic bracket 4 upon a tooth 3.
