JP2017051440A - Sterilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sterilizer which is effective for sterilization of germ or the like inside an oral cavity while reducing an impact to a human body.SOLUTION: A sterilizer 100 includes: a semiconductor light-emitting element for emitting an ultraviolet light having a peak emission wavelength in a range from 300nm or more to less than 400nm; and an irradiation part 24 for irradiating the ultraviolet light emitted from the semiconductor light-emitting element to an object to be irradiated. The semiconductor light-emitting element may emit an ultraviolet light having a peak emission wavelength in a range from 300nm or more to 320nm or less. Also, the semiconductor light-emitting element may be configured to have an illumination intensity of 0.5 to 3 mW/cmat a part on which the ultraviolet light is irradiated. Further, a control unit can control an operation of the semiconductor light-emitting element so that the irradiation time of the ultraviolet light falls within a range of 10 to 60 seconds.SELECTED DRAWING: Figure 15

Description

  The present invention relates to a sterilizer.

  Conventionally, antibacterial agents such as antibiotics have been used to sterilize periodontal disease bacteria. In addition, a phototherapy device for periodontal disease using light has been devised (see Patent Document 1). This phototherapy device for periodontal disease includes a light source having an emission center wavelength in a wavelength range of 400 to 420 nm, and a probe that guides light from the light source and emits it to an affected part to be irradiated. Yes. In recent years, small-sized LEDs emitting ultraviolet light having a shorter wavelength than in the past have been put into practical use. Can such small-sized ultraviolet LEDs be applied to sterilization of the oral cavity or the like to efficiently treat them? Expected.

JP 2007-202891 A

  However, when antibiotics are used, there is a possibility that useful bacteria existing in a wide range of the human body may be sterilized. Further, light having a wavelength of about 400 to 420 nm has not so high sterilization performance. On the other hand, ultraviolet rays having a wavelength of about 250 to 260 nm have a great effect on the human body although the sterilization performance is very high.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a sterilizing apparatus effective for sterilizing bacteria in the oral cavity while reducing the influence on the human body.

  In order to solve the above-described problem, a sterilization apparatus according to an aspect of the present invention includes a semiconductor light emitting device that emits ultraviolet light having a peak emission wavelength in a range of 300 nm to less than 400 nm, and an irradiation target portion that is irradiated with ultraviolet light emitted by the semiconductor light emitting device. And an irradiating unit.

  According to this aspect, by irradiating ultraviolet rays having a peak emission wavelength in the range of 300 nm or more and less than 400 nm, oral bacteria such as periodontal disease bacteria can be sterilized while reducing the influence on the human body.

  The semiconductor light emitting element may emit ultraviolet rays having a peak emission wavelength in the range of 300 nm or more and 320 nm or less. Thereby, oral bacteria can be sterilized more efficiently.

The semiconductor light emitting device may be configured such that the illuminance at the ultraviolet irradiated portion is 0.5 to 3 mW / cm ² .

  The irradiation part may have a diameter of an opening irradiated with ultraviolet rays of 0.5 to 10 mm. Thereby, it becomes easy to selectively irradiate the desired affected part with ultraviolet rays.

  You may further provide the control part which controls the drive of a semiconductor light-emitting device so that an ultraviolet-ray may be irradiated for a predetermined time. Thereby, it can prevent irradiating an excess ultraviolet-ray to an affected part.

  The control unit may control the driving of the semiconductor light emitting element so that the irradiation time of ultraviolet rays is in a range of 10 to 60 seconds. Thus, oral bacteria can be appropriately sterilized while preventing the affected part from being irradiated with excessive ultraviolet rays.

  The irradiation unit may have a probe. The semiconductor light emitting element may be attached to the tip of the probe. Thereby, the ultraviolet-ray which a semiconductor light-emitting device emits can be directly irradiated to irradiation object parts, such as an intraoral area or an incision part.

  It should be noted that any combination of the above-described constituent elements and a representation of the present invention converted between a method, an apparatus, a system, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the effective sterilization apparatus for disinfection of bacteria etc. in an oral cavity is realizable, reducing the influence which it has on a human body.

It is the figure which showed typically the experiment for measuring a bactericidal action. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 265 nm, and Eschelichia coli (E.coli) survival rate. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 310 nm, and E. coli survival rate. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 265 nm, and Porphylomonas gingivalis (P. gingivalis) survival rate. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 310 nm, and P.gingivalis survival rate. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 265 nm, and Fusobacterium nucleatem (F. nucleatum) microbe survival rate. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 310 nm, and F. nucleatum survival rate. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 265 nm, and Streptococcus sanguinis (S.sanguinis) survival rate. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 310 nm, and S.sanguinis survival rate. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 265 nm, and Streptococcus mutans (S.mutans) survival rate. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 310 nm, and S.mutans survival rate. It is the figure which showed typically the experiment for measuring cytotoxicity. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 265 nm, and LDH discharge | release amount. It is a figure which shows the relationship between the irradiation time at the time of using UV-LED whose peak light emission wavelength is 310 nm, and LDH discharge | release amount. It is a mimetic diagram of a sterilizer concerning a 1st embodiment. It is a schematic diagram of the sterilizer which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. Moreover, the structure described below is an illustration and does not limit the scope of the present invention at all.

(Light source for sterilizer)
Light having a wavelength of about 400 to 420 nm does not have a high sterilization performance and tends to have a long sterilization time. Therefore, the sterilization apparatus according to the present embodiment uses a semiconductor light emitting element that emits ultraviolet light having a peak emission wavelength in the range of less than 400 nm as a light source. The semiconductor light emitting element is a light emitting diode or a laser. Therefore, the light source can be reduced in size.

  In the present embodiment, a light emitting diode that emits deep ultraviolet rays (hereinafter referred to as “UV-LED”) is used as the semiconductor light emitting element. The UV-LED according to the present embodiment includes a substrate made of sapphire, an AlGaN-based light emitting layer, and a lattice irregular buffer layer made of AlN stacked between the substrate and the light emitting layer. Thereby, a small and highly efficient sterilizer can be realized.

(Bactericidal action)
Next, the bactericidal action by UV-LED will be described. FIG. 1 is a diagram schematically showing an experiment for measuring the bactericidal action. The ultraviolet irradiator 10 includes a UV-LED 12.

  As shown in FIG. 1, the well 14 of a 96-well plate is filled with PBS (phosphate buffered saline) 18 containing Eschelichia coli (E. coli) 16 and irradiated with ultraviolet rays 10 (wavelength 265 nm or 310 nm). L was irradiated for 10, 30, 60, and 120 seconds, diluted, smeared on an agar medium, cultured overnight, and the formed colonies were counted. The well plate is adjusted to receive 1 mW / cm 2 of ultraviolet light (having wavelengths of 265 nm and 310 nm).

  FIG. 2 is a diagram showing the relationship between the irradiation time and the E. coli survival rate when a UV-LED having a peak emission wavelength of 265 nm is used. FIG. 3 is a diagram showing the relationship between the irradiation time and the E. coli survival rate when a UV-LED having a peak emission wavelength of 310 nm is used.

  As shown in FIG. 2, in the ultraviolet irradiator using the UV-LED having a peak emission wavelength of 265 nm, it can be seen that almost all E. coli is killed by irradiation for 10 seconds or more. In addition, as shown in FIG. 3, in an ultraviolet irradiator using a UV-LED having a peak emission wavelength of 310 nm, about 80% of E. coli is killed by irradiation for 10 seconds, and irradiation by 30 seconds or more. It can be seen that almost all E. coli is dead.

(Bactericidal action against other oral sterilization)
Porphyromonas gingivalis ATCC 33277, Fusobacterium nucleatem ATCC 25586 (periodontal disease-related bacteria), Streptococcus mutans ATCC 25175 (cariogenic bacteria), and Streptococcus sanguinis ATCC 10556 (non-pathogenic oral resident bacteria) Each bacterium was suspended in PBS and then irradiated for 0 to 120 seconds using an ultraviolet LED having a peak emission wavelength of 310 nm.

  Thereafter, the suspension containing the bacteria was applied to an agar plate medium, and the formed colonies were counted. Further, the bactericidal action was evaluated based on the bacterial survival rate of each irradiated group when the non-irradiated group not irradiated with ultraviolet rays was taken as 100%.

  FIG. 4 is a diagram showing the relationship between the irradiation time and the survival rate of P. gingivalis when using a UV-LED having a peak emission wavelength of 265 nm. FIG. 5 is a diagram showing the relationship between the irradiation time and the P. gingivalis survival rate when a UV-LED having a peak emission wavelength of 310 nm is used. FIG. 6 is a diagram showing the relationship between the irradiation time and the F.nucleatem survival rate when using a UV-LED having a peak emission wavelength of 265 nm. FIG. 7 is a diagram showing the relationship between the irradiation time and the F. nucleatem survival rate when using a UV-LED having a peak emission wavelength of 310 nm. FIG. 8 is a diagram showing the relationship between the irradiation time and the S. sanguinis survival rate when a UV-LED having a peak emission wavelength of 265 nm is used. FIG. 9 is a diagram showing the relationship between the irradiation time and the S. sanguinis survival rate when a UV-LED having a peak emission wavelength of 310 nm is used. FIG. 10 is a diagram showing the relationship between the irradiation time and the S. mutans survival rate when a UV-LED having a peak emission wavelength of 265 nm is used. FIG. 11 is a diagram showing the relationship between the irradiation time and the S. mutans survival rate when a UV-LED having a peak emission wavelength of 310 nm is used.

  As shown in each figure, when a UV-LED having a peak emission wavelength of 265 nm was used, the survival rate of each bacterium was almost 0% after irradiation for 10 seconds or longer. Further, when a UV-LED having a peak emission wavelength of 310 nm is used, the survival rate is 60 to 30% after 60 seconds of ultraviolet irradiation in P. gingivalis, and 70 to 30% of irradiation is performed for 30 seconds or more in F. nucleatem. 50%. The survival rate of S. sanguinis decreased to 40% after irradiation for 10 seconds or longer, and the survival rate of S. mutans decreased to 60-50% after irradiation for 60 seconds or longer. Thus, ultraviolet rays having a peak emission wavelength of less than 400 nm, more preferably ultraviolet rays having a peak emission wavelength of 320 nm or less, have a bactericidal action against oral bacteria.

(Cytotoxicity)
In the experiment of the above-mentioned sterilization action, it became clear about the sterilization effect by UV-LED. On the other hand, in order to use the sterilization apparatus for the treatment of periodontal diseases and the like, it is necessary to grasp the influence on the human body in addition to the sterilization action. FIG. 12 is a diagram schematically showing an experiment for measuring cytotoxicity.

  As shown in FIG. 12, the well 14 of a 96-well plate is filled with PBS 18 containing cultured cells 20 of human oral mucosal epithelial cells, and ultraviolet rays L are emitted at 10, 30, 60, Irradiated for 120 seconds, and after overnight culture, the activity of released LDH (lactate dehydrogenase) was measured. The well plate is adjusted to receive 1 mW / cm 2 of ultraviolet light (having wavelengths of 265 nm and 310 nm).

  FIG. 13 is a diagram showing the relationship between the irradiation time and the LDH emission amount when a UV-LED having a peak emission wavelength of 265 nm is used. FIG. 14 is a diagram showing the relationship between irradiation time and LDH emission when using a UV-LED with a peak emission wavelength of 310 nm.

  As shown in FIG. 13, in the ultraviolet irradiator using the UV-LED having a peak emission wavelength of 265 nm, the LDH release amount is increased about twice or more by irradiation for 10 seconds or more, and cell damage is recognized. On the other hand, as shown in FIG. 14, in the ultraviolet irradiator using the UV-LED having a peak emission wavelength of 310 nm, the LDH emission amount is less than 1.5 times by the irradiation up to 60 seconds, especially up to 30 seconds. It can be seen that the amount of LDH released is almost not increased by irradiation, and there is almost no cell damage.

(Sterilizer)
Based on the above-mentioned findings, a sterilization apparatus suitable for treatment of the oral cavity such as periodontal disease has been devised. FIG. 15 is a schematic diagram of the sterilizer according to the first embodiment.

  In order to transmit ultraviolet light, a fiber whose core that transmits ultraviolet light is quartz glass is required, but flexible silica fiber that can freely introduce ultraviolet light into the oral cavity or surgical incision by placing the light source outside is not available. It is hard to get.

The sterilizer 100 according to the first embodiment includes an irradiation unit 24 and a control unit 26. The irradiation unit 24 includes a probe 11, a miniaturized UV-LED 12 and a cover 13, and the UV-LED 12 is attached to the tip of the probe. A wiring for supplying power to the UV-LED 12 is housed in the probe 11. A metal such as aluminum or stainless steel or a resin can be used for the probe 11. The cover 13 can be made of quartz glass, resin, or the like that hardly absorbs ultraviolet rays. As the power source, battery or external power supply can be considered. The UV-LED 12 emits ultraviolet rays having a peak emission wavelength in a range of 300 nm to less than 400 nm, preferably a peak emission wavelength in a range of 300 nm to 320 nm. The irradiation unit 24 directly irradiates the irradiation target part such as an intraoral cavity or an incision part with ultraviolet rays emitted from the UV-LED 12. Thereby, the oral cavity or the incision can be sterilized more efficiently. In addition, the illumination intensity of an ultraviolet-ray is the range of 0.5-3 mW / cm < ² >, for example in the irradiation object part which is an ultraviolet irradiation part.

  FIG. 16 is a schematic view of a sterilizer according to the second embodiment. In recent years, resin materials that transmit ultraviolet rays (for example, Asahi Glass Cytop) have been developed. In this embodiment, it is possible to use an optical fiber having such a UV transparent resin as a core. The sterilizer 102 includes a light source unit 32 and an optical fiber 34. The diameter R of the optical fiber core opening 34a for irradiating ultraviolet rays is about 0.5 to 10 mm. Thereby, it becomes easy to selectively irradiate a desired affected part with ultraviolet rays without irradiating the normal region in the oral cavity with ultraviolet rays. Note that the tip of the optical fiber 34 may be tapered. In this case, the taper part which became thin is put in a periodontal pocket, and an ultraviolet-ray is irradiated from a taper part front-end | tip, and it sterilizes. The fiber may be disposable and can be changed from patient to patient.

  The sterilization apparatuses 100 and 102 configured in this way can sterilize the oral cavity or incision while reducing the influence on the human body. The therapeutic use of such a sterilizer includes periodontal disease treatment, root canal sterilization treatment, cancer treatment and the like.

  The control unit 26 controls the driving of the UV-LED 12 so that ultraviolet rays are irradiated for a predetermined time. Thereby, it can prevent irradiating an excess ultraviolet-ray to an affected part. For example, once the button 28 is pressed, the control unit 26 controls the driving of the UV-LED 12 so that the ultraviolet irradiation time is in the range of 10 to 60 seconds. Thus, oral bacteria can be appropriately sterilized while preventing the affected part from being irradiated with excessive ultraviolet rays.

  As described above, the present invention has been described with reference to the above-described embodiment. However, the present invention is not limited to the above-described embodiment, and the present invention can be appropriately combined or replaced with the configuration of the embodiment. It is included in the present invention. In addition, it is possible to appropriately change the combination and processing order in the embodiment based on the knowledge of those skilled in the art and to add various modifications such as various design changes to the embodiment. The described embodiments can also be included in the scope of the present invention.

  10 UV irradiator, 11 probe, 12 UV-LED, 13 cover, 14 well, 16 E. coli, 18 PBS, 20 cultured cells, 21 power supply unit, 24 irradiation unit, 26 control unit, 28 button, 32 light source unit, 34 light Fiber, 100, 102 Sterilizer.

Claims (7)

A semiconductor light emitting device emitting ultraviolet rays having a peak emission wavelength in a range of 300 nm or more and less than 400 nm;
An irradiation unit for irradiating the irradiation target unit with ultraviolet rays emitted from the semiconductor light emitting element;
A sterilizing apparatus comprising:   The sterilizing apparatus according to claim 1, wherein the semiconductor light emitting element emits ultraviolet rays having a peak emission wavelength in a range of 300 nm or more and 320 nm or less. The semiconductor light-sterilizer according to claim 1 or 2 illuminance in the ultraviolet irradiated portion is characterized by being configured such that 0.5~3mW / cm ^2.   The sterilization apparatus according to any one of claims 1 to 3, wherein the irradiation section has an opening having a diameter of 0.5 to 10 mm irradiated with ultraviolet rays.   The sterilizer according to any one of claims 1 to 4, further comprising a control unit that controls driving of the semiconductor light emitting element so as to irradiate ultraviolet rays for a predetermined time.   The sterilization apparatus according to claim 5, wherein the control unit controls the driving of the semiconductor light emitting element so that the irradiation time of ultraviolet rays is in a range of 10 to 60 seconds. The irradiation unit has a probe,
The sterilizer according to any one of claims 1 to 6, wherein the semiconductor light emitting element is attached to a tip of the probe.

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