Multi-wavelength oral phototherapy applicator

This application is a continuation of U.S. application Ser. No. 10/777,022 filed Feb. 10, 2004 entitled “Multi-Wavelength Oral Phototherapy Applicator,” which claims the benefit of priority to U.S. Provisional Application Ser. Nos. 60/446,300, filed Feb. 10, 2003 entitled “Light Emitting Toothbrush and Method of Its Application for Oral Bacteria Reduction and Periodontal Disease and Caries Lesion Treatment and Prevention;” 60/446,342, filed Feb. 10, 2003 entitled “Light Emitting Toothbrush and Method of Its Application for Tooth Whitening and Brightening;” 60/449,188, filed Feb. 21, 2003 entitled “Method and Apparatus for Rejuvenation of Hard and Soft Oral Tissue and Perioral Facial Skin and for Prevention and Healing of Diseases Thereof;” and claims priority as a continuation-in-part to U.S. Utility application Ser. Nos. 10/680,705, filed Oct. 7, 2003 entitled “Methods and Apparatus for Performing Photobiostimulation” and 10/702,104, filed Nov. 4, 2003 entitled “Methods and Apparatus for Delivering Low Power Optical Treatments,” which is a continuation-in-part of 09/996,662 (now U.S. Pat. No. 6,648,904), filed Nov. 29, 2001 entitled “Methods and Apparatus for Controlling the Temperature of a Surface.”

The present invention relates to methods and apparatus for treating the oral cavity, including light emitting oral appliances such as light emitting toothbrushes and light emitting mouthpieces.

There are a wide spectrum of bacteria and other microorganisms found in the oral cavity. Although the presence of microorganisms does not indicate an unhealthy condition, if not attended to these microorganisms will cause a variety of undesirable effects including oral disease and cosmetic degradation. Tooth discoloration, caries formation, periodontitis and tooth loss are all possible results.

Oral bacteria creates plaque, a sticky, colorless film of bacteria on the surfaces of teeth and other tissue, and these plaque forming bacteria create toxins. Over time the plaque begins combining with other materials and hardens into a rough, porous deposit, calculus. The eventual result is gingival irritation (gingivitis) symptomized by gum swelling, bleeding, and fibrous enlargement of the gingival. In addition, the growth of plaque and calculus can cause the gums to move away from the teeth, resulting in pockets between the teeth and gums where bacteria can thrive. The bacteria toxins can also destroy gum tissue and even lead to bone loss.

Thus, the prevention and treatment of periodontal gum disease and early caries requires effective bacteria killing or growth suppression within all regions of the oral cavity. In particular, bacteria killing within the junction of gingival tissue and tooth root surface and under the enamel surface is important, as well as, difficult using traditional means.

Application of available, on the market, toothbrushes, toothpastes, mouth rinsing solutions and/or mouth irrigators containing chemical antibacterial agents, for prevention of periodontal disease is only partly successful. In addition, once tissue damage has started, conventional treatments are not effective at reversing the results.

In addition, the oral cavity can host a variety of other conditions which may or may not be a direct result of bacterial growth, including, tongue diseases, inflammation of salivary glands and small sublingual ducts, damaged nerves, oral pain, sore throat/tonsillitis, tooth hypersensitivity, and tooth discoloration. These conditions and others would benefit from a novel oral treatment regimen.

Thus, there is a need in the art for improved oral treatments which can effectively kill and/or suppress microorganisms, help to reverse the damaging effects of bacteria, and/or provide treatment for conditions in, near, or related to the oral cavity.

The present invention provides methods and apparatus for treating tissue in, through, or around the oral cavity. The invention further includes light emitting oral applicators for performing phototherapy in the oral cavity.

In one aspect, the invention provides an oral phototherapy applicator having a body sized and shaped so as to fit at least partially within a user\'s oral cavity and includes at least one radiation emitting element for irradiating a portion of the oral cavity with phototherapeutic radiation. The applicator can be capable of emitting radiation in multiple distinct spectral bands, and/or radiating multiple areas within the oral cavity.

In further aspect of the invention, the oral applicator can be adapted to conform to the shape of at least a portion of the oral cavity. For example, the oral applicator body can be compliant to facilitate conformation to at least a portion of the oral cavity and/or can be adapted for positioning between a user\'s teeth and gums.

The oral applicator can optionally include a plurality of bristles that are substantially transparent to phototherapeutic radiation within at least one wavelength range. In one embodiment, the bristles can act as waveguides via optical coupling to a radiation emitter to receive and propagate radiation therefrom. The bristles can alternatively act to diffuse light based on an enhanced shape and/or a scattering agent disposed in the bristles to diffuse radiation. In addition, the bristles can have light refractive characteristics selected to inhibit light transmission to the oral cavity in the absence of contact between the bristle and a surface of the oral cavity.

In another aspect of the invention, the oral applicator can include an optical element for delivering radiation primarily to tissue other than teeth. For example, where the oral applicator includes bristles, the radiation can be emitted in a direction which is not parallel to the bristles.

In other aspects, the present invention provides methods of biostimulation by irradiating at least a portion of a subject\'s oral cavity with radiation having at least one selected wavelength component so as to induce a biostimulating effect. By way of example, the biostimulating effect can cause any of an increased blood and lymph microcirculation in the irradiated portion, activation of blood microcirculation in tooth pulp, increased local macrophage activity, increased fibroblast, osteoblast and odontoblast proliferation, killing of at least one of bacteria, fungi, and viruses in the oral cavity, normalization of the oral cavity pH, killing of viruses within the subject\'s blood microcirculatory system, light-induced destruction of selected metabolic blood components, reduction of gum bleeding, reduction of tooth hypersensitivity, pain reduction in teeth and throat, periodontal and bone regeneration, implant connection, reminaralization of enamel, prevention of caries, root canal sterilization, inflammation prevention and periodontial disease prevention and healing. In a further embodiment, multiple treatments session of the radiation are administered so as to reach a selected total radiation dose and thereby provide biostimulation.

In a related aspect, the biostimulating effect is achieved by irradiating the oral cavity during multiple treatment sessions with a radiation power in range of about 1 mW/cm² to about 10 W/cm² so as to deposit a radiation dose in a range of about 1 Joules/cm² to about 1000 Joules/cm², and more preferably in a range of about 10 Joules/cm² to about 100 Joules/cm², in the irradiated tissue. The treatment sessions, each of which can last for about 10 seconds to about 1000 seconds, or longer if needed, can be repeated until a total therapeutic dose of radiation is reached.

In another aspect, the biostimulating radiation is primarily directed to soft tissue in the oral cavity, e.g., facial tissue. In some embodiments, the oral cavity is irradiated so as to deposit a dose of radiation below the facial skin dermatological or cosmetic condition, such as acne.

In another aspect, the present invention provides a method of dental treatment that includes applying non-toxic chromophores to the oral cavity and delivering a low dose of radiation to the chromophores during a session. The radiation can have a wavelength in the absorption band of the non-toxic chromophore and the dose can be lower than the power density to which the chromophore is normally responsive. In subsequent sessions, the step of applying radiation is repeated until the chromophore is activated. The chromophore is preferably a tooth whitening and brightening agent and/or an antimicrobial agent, which in one embodiment, is applied as a film having chromophores positioned therein. As an additional step, heat and/or an additional chromophore can be applied to the oral cavity.

In another aspect of the invention, the oral cavity is directly photobleached with optical radiation in a spectrum absorbed by endogenous photosensitizers. Preferably, the endogenous chromophores are tooth stains present in the dentine.