Intracanal treatment with a laser using an alcoholic indocyanine green solution

Abstract

【Solution means】 A method for endodontic therapy with improved disinfection and cauterization characteristics is characterized by the combined use of an alcohol or polyol-based indocyanine green (ICG) solution (14) and a laser system (20) that emits a wavelength (24) within the maximum absorption range of indocyanine green (ICG). By adapting the output of the dye and the laser, the utilization of radiant energy is maximized, enabling efficient cauterization and disinfection of the treatment tissue. Furthermore, by using alcohol or polyol as the solvent for the indocyanine green (ICG) solution, the inherent disinfection properties of the solution itself are improved. In one embodiment, an indocyanine green (ICG) solution is injected into the adjusted root canal (14), and the fiber laser is operated with its tip inserted into the solution. In an alternative embodiment, most of the solution is removed before the operation of the laser, but such removal is performed only after the necrotic tissue (16) is stained.

Description

Technical Field

[0001] Cross - reference to related applications This application claims priority to U.S. Patent Application No. 17 / 804,765, filed on May 31, 2022, the entire content of which is incorporated herein by reference.

[0002] The present invention relates to the field of dentistry, and more particularly, to a treatment method that combines laser treatment and indocyanine green ("ICG") to improve the disinfection and ablation effects of a tissue to be treated.

Background Art

[0003] In current root canal treatment, it is necessary to remove necrotic tissue and disinfect the root canal. The future use of lasers to carbonize necrotic tissue and disinfect the root canal with radiant energy is of great concern to clinicians because it significantly improves the operability of current standard procedures. Placing a dye in the root canal that is adapted to absorb the wavelength of the treatment laser is also a major concern as a possibility. Because in this case, a single laser that outputs one wavelength can be used, and there is no need to purchase multiple lasers for different material substrates. Also, since the dye is adapted to absorb the output of the radiant energy of the treatment laser, the surface where the dye is applied is efficiently laser - irradiated.

[0004] In the present invention, by introducing alcohol into an indocyanine green (ICG) solution, a synergistic effect has been found that enhances the penetration into soft tissue, improves the water - washing efficiency, enhances the staining of necrotic tissue, and further enhances the overall antibacterial effect while easily delivering indocyanine green (ICG) into the root canal. The present invention is distinct from the prior art in that, in its methodology, it efficiently utilizes indocyanine green (ICG) together with laser treatment to enhance the treatment effect.

Summary of the Invention

Means for Solving the Problem

[0005] In view of the aforementioned drawbacks existing in known endodontic therapies, in an improved method of endodontic therapy, an indocyanine green (ICG) solution is applied before irradiating the treatment area with an 810 nm diode laser. This method needs to achieve the objectives that it is easy to administer and implement, has a certain affinity with the current methodology, has a low manufacturing cost of the material, and is effective in assisting both tissue disinfection and cauterization in endodontic treatments. Therefore, in order to achieve these objectives, the new and improved method can have a step of introducing an organic-based indocyanine green (ICG) solution to the treatment area before irradiation.

[0006] For a more detailed description below and to deepen the understanding of the contribution of the present invention to the relevant technical field, the important features of the present invention have been outlined. The additional features of the present invention will be described below. Also, such additional features form the invention particulars of the following claims.

[0007] Many of the objectives of the present invention are believed to become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings that form a part of this specification. Here, like reference numerals indicate corresponding parts in several figures.

[0008] Before detailing at least one embodiment of the present invention, it should be understood that the present invention is not limited, in its application, to the details of the structures and the arrangements of the components described in the following description or shown in the drawings. In the present invention, other embodiments are possible and it can be implemented and carried out in various ways. Also, it should be understood that the expressions and terms used in this specification are for the purpose of explanation and should not be regarded as limiting.

[0009] Thus, those skilled in the art would understand that the concepts underlying the present disclosure can be readily utilized as a basis for designing other structures, methods, and systems for carrying out some of the objectives of the present invention. Therefore, it is important that the claims be regarded as including such equivalent structures insofar as they do not depart from the spirit and scope of the present invention.

Brief Description of the Drawings

[0010] To explain the above-described and other advantages of the present invention and how the features of the present invention are obtained, the present invention briefly described above will be described in more detail by referring to specific exemplary embodiments shown in the accompanying drawings. It should be understood that these drawings show only typical embodiments of the present invention and thus do not limit the scope of the present invention, and the present invention will be described and explained more specifically and in detail using the accompanying drawings.

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0011] In this specification, preferred embodiments of a method of endodontic therapy are described. It should be noted that the articles "a", "an", and "the" used in this specification include plural references unless it is clear from the context that they indicate a different meaning.

[0012] A preferred dye of the present invention is indocyanine green (ICG), and a preferred laser is an 810 nm laser, both of which are commercially available. Since indocyanine green has a maximum absorption range of 780 nm to 820 nm, any laser that emits radiant energy within these wavelength parameters is sufficient to activate indocyanine green with relatively high efficiency. Therefore, an easily available 810 nm diode laser is optimal for use in this method.

[0013] Indocyanine green is soluble in water, alcohol, and liquid polyols, but is known to be unstable in water. In one embodiment of the present invention, monohydric alcohols such as ethyl alcohol, methyl alcohol, isopropyl alcohol, n-propyl alcohol, butyl alcohol, and other alcohols that are liquid are used as the solvent for indocyanine green (ICG). In another embodiment of the present invention, polyols (which are generally classified as "alcohols" for the purposes of this application), such as glycerin, propylene glycol, polyethylene glycol, and other polyols that are liquid, are used. In an additional embodiment of the present invention, a mixture of organic solvents with and without water is utilized to customize individual properties for delivering soluble indocyanine green (ICG), such as capillary action, water washing efficiency, antibacterial properties, substrate staining efficacy, and other properties. Ethanol has excellent properties, including low toxicity, excellent water washing ability, excellent antibacterial properties, and in particular, improved tissue staining properties when staining necrotic tissue. Therefore, in a preferred embodiment of the present invention, ethanol is selected as the best alcohol from among many available alcohols.

[0014] In many embodiments of the present invention, the content of the organic solvent is 100% during the production of the indocyanine green (ICG) solution, but in other embodiments, the formulation contains at least a predetermined amount of water. The possible ratio ranges of alcohol to water are as follows.

[0015] Most preferred formulation range: 90% - 100% alcohol + 10% - 0.0% water.

[0016] Preferred formulation range: 70% - 99.9% alcohol + 30% - 0.1% water.

[0017] Less preferred formulation range: 5% - 99% alcohol + 95% - 1% water.

[0018] When the ratio of the organic solvent to water in the indocyanine green (ICG) solution is high, upon activation by a compatible laser, the flammability increases, and as a result, it becomes easier to disinfect and remove necrotic tissue in the root canal. However, it is important to note that this is not possible with a 100% water indocyanine green (ICG) solution. These organic alcohols that make up these indocyanine green (ICG) solutions burn or ignite locally when activated by sufficient radiant energy. By using a laser compatible with the alcohol-based indocyanine green (ICG) solution in combination, extremely intense cauterization occurs locally within a very short time (usually within a few seconds). Due to the synergistic effect of the laser, ICG dye, and organic solvent, a local "synergistic firestorm" is generated that is designed to appropriately cauterize necrotic tissue and disinfect the root canal.

[0019] Although many embodiments of indocyanine green (ICG) solutions can be identified, it has been found that two methodologies are particularly promising in root canal treatment using a laser compatible with the indocyanine green (ICG) solution. In the first method, the indocyanine green (ICG) solution is injected into the extirpated root canal, and the tip of the optical fiber cable is designed to be inserted into the root canal while the root canal is filled with the solution. Next, the laser is activated with the tip of the optical fiber cable placed in the indocyanine green (ICG) solution. The radiant energy generated by the laser is transmitted to the indocyanine green (ICG) solution, resulting in local heat, combustion, cavitation, and secondary luminescence.

[0020] In the preferred treatment method of this embodiment shown in FIG. 1, first, access is made to the pulp chamber of the tooth (10) by conventional means such as a high-speed handpiece. Next, the necrotic root is extirpated with an endodontic file (by the prior art) within the tooth. After these initial steps, an indocyanine green (ICG) dye solution is introduced into the root canal and fills the exposed root canal (14) (26). A time may be provided for the solution to penetrate the remaining soft tissue. After sufficient time has elapsed (in some cases, the passage of time may not be necessary), the uncoated end (22) of the optical fiber (20) connected to a radiation energy source (in this preferred embodiment, an 810 nm diode laser) is inserted into the root canal (14), and the 810 nm diode laser is activated. By absorbing the emitted radiation energy (24), the indocyanine green (ICG) dye is efficiently heated to the extent that boiling and evaporation are initiated. Next, after the solution has evaporated, the remaining necrotic tissue (16) stained in the presence of the dye is cauterized by the laser. By slowly inserting and removing the tip of the optical fiber cable into and out of the root canal (14) several times, treatment is performed on the entire length of the root canal (14) from the tooth apex (12) to the crown portion (18). After the laser treatment, as is usually done in the prior art, the root canal (14) can be further treated with a disinfectant rinse to kill residual pathogens and wash away the burned tissue from the root canal (14).

[0021] In the second embodiment of the present method (Figure 2) as well, first, an indocyanine green (ICG) solution is injected into the root canal (14), and the solution is allowed to penetrate into the necrotic tissue (16). After a sufficient residence time, most of the indocyanine green (ICG) solution is removed with paper points so that only a predetermined amount of the indocyanine green (ICG) solution remains in the root canal (14) and the stained necrotic tissue (16). Next, the tip (22) of the optical fiber cable is inserted into the dried root canal (14), and the laser is activated. The generated radiant energy (24) is transmitted to the remaining indocyanine green (ICG) solution, thereby causing local heat, combustion, carbonization, and secondary luminescence. This activation method generates a much larger amount of local heat than the first method described above.

Industrial Applicability

[0022] The present invention is particularly applicable in the dental field. Although the present invention has been described with reference to preferred embodiments, various changes and modifications can be made, and such modified embodiments and alternative embodiments are also included within the scope of the present invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The specific embodiments disclosed herein are not intended to be limiting, nor should any limitation be inferred therefrom. Accordingly, the scope of the present invention is shown not by the foregoing description but by the appended claims. All changes that come within the meaning and range of equivalency of the claims are embraced within their scope.

Claims

1. A root canal treatment method for removing necrotic tissue and disinfecting the root canal, comprising: a first step of adjusting the root canal, including removing most of the necrotic tissue in the root canal and leaving a part of the remaining necrotic tissue, said first step; a subsequent step of injecting indocyanine green solution into the root canal and filling the root canal with the indocyanine green solution; a further step of inserting the tip of an optical fiber laser into the root canal such that the tip is disposed in the indocyanine green solution filling the root canal; a step of operating a laser linked to the tip of the optical fiber laser to emit a laser beam having sufficient radiation energy to carbonize the remaining necrotic tissue in the root canal A root canal treatment method comprising the above steps.

2. The root canal treatment method according to claim 1, wherein the radiation energy is applied with energy sufficient to evaporate the indocyanine green solution filled in the root canal.

3. The root canal treatment method according to claim 1, wherein the laser has a wavelength of 780 nm to 820 nm.

4. The root canal treatment method according to claim 1, wherein ethanol is used as a solvent in the indocyanine green solution.

5. The root canal treatment method according to claim 1, wherein a solvent having an alcohol concentration of at least 90% is used in the indocyanine green solution.

6. The root canal treatment method according to claim 1, further comprising: a step of moving the tip of the optical fiber laser in the root canal during operation of the laser, whereby the root canal is well exposed to the radiation energy of the optical fiber laser.

7. A root canal treatment method for removing necrotic tissue and disinfecting the root canal, comprising: a first step of adjusting the root canal, including removing most of the necrotic tissue in the root canal and leaving a part of the remaining necrotic tissue, said first step; a subsequent step of injecting indocyanine green solution into the root canal and filling the root canal with the indocyanine green solution; a further step of inserting the tip of an optical fiber laser into the root canal such that the tip is disposed in the indocyanine green solution filling the root canal; Actuating a laser interlockingly connected to the tip of the optical fiber laser to emit a laser beam having radiation energy sufficient to cauterize the remaining necrotic tissue in the root canal A root canal treatment method comprising the above.

8. The root canal treatment method according to claim 7, wherein the radiation energy is applied with energy sufficient to evaporate the indocyanine green solution filled in the root canal.

9. The root canal treatment method according to claim 7, wherein the laser has a wavelength of 780 nm to 820 nm.

10. The root canal treatment method according to claim 7, wherein ethanol is used as a solvent in the indocyanine green solution.

11. The root canal treatment method according to claim 7, wherein a solvent having an alcohol concentration of at least 90% is used in the indocyanine green solution.

12. In the root canal treatment method according to claim 7, further, A root canal treatment method, which includes a step of moving the tip of the optical fiber laser within the root canal during the operation of the laser, whereby the root canal is well exposed to the radiation energy of the optical fiber laser.

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