Patent Publication Number: US-2023148742-A1

Title: Interdental cleaning tool

Description:
TECHNICAL FIELD 
     The present invention relates to an interdental cleaning tool. 
     BACKGROUND ART 
     Conventionally, an interdental cleaning tool for cleaning an interdental space is known. For example, Patent Literature 1 discloses an interdental cleaning tool including a base structure portion made of synthetic resin, and a soft portion made of elastomer. The base structure portion includes a core base structure portion insertable in an interdental space, and a handling base structure portion having a shape that can be held by fingers. The soft portion includes a covering portion that covers a portion of an outer circumferential surface of the core base structure portion, and a plurality of protruding portions each protruding outward from the outer circumferential surface of the covering portion. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: WO 2013/176297 A 
       
    
     SUMMARY OF INVENTION 
     Problems to be Solved by the Invention 
     To enable a user to easily insert an interdental cleaning tool and to provide the interdental cleaning tool with a high cleaning capability will involve contradicting requirements for the thickness of a core frame portion. Specifically, the easy insertion prefers a thin core frame portion. On the other hand, in order to provide the interdental cleaning tool with a high cleaning capability, it is preferable that the interdental cleaning tool is formed with a thicker core frame portion to cause a soft portion covering the core frame portion to come into tight contact with oral tissues (that is, teeth and gum). Thus, it is difficult to obtain both the easy insertion and the high cleaning capability by the way of the conventional technique. 
     An object of the present invention is to provide an interdental cleaning tool configured to be easily inserted in an interdental space by a user, and to show a high capability of cleaning an interdental space. 
     Solution to Problem 
     An interdental cleaning tool according to an aspect of the present invention includes a base portion including a shaft portion having a shape insertable in an interdental space, a top end side cleaning portion including a top end side body covering a top end side portion of the shaft portion, and a plurality of top end side bristles protruding outward from an outer circumferential surface of the top end side body, and a base end side cleaning portion including a base end side body covering a portion of the shaft portion further in a base end side than the top end side body, and a plurality of base end side bristles protruding outward from an outer circumferential surface of the base end side body. The top end side cleaning portion has a lower hardness than the base end side cleaning portion. 
     In the configuration, since the top end side cleaning portion has a lower hardness than the base end side cleaning portion, the top end side bristle of the top end side cleaning portion is easily bent when the top end side cleaning portion is inserted in the interdental space, and does not cause an excessively large resistive force against insertion of the top end side cleaning portion in the interdental space. Thus, a user can easily insert the top end side cleaning portion in the interdental space. Meanwhile, since the base end side cleaning portion has a higher hardness than the top end side cleaning portion, the base end side bristle of the base end side cleaning portion abuts strongly against the oral tissues forming the interdental space (that is, the teeth and the gum), and can effectively remove the deposit from the oral tissues. 
     In the configuration, the top end side cleaning portion may have a hue different from a hue of the base end side cleaning portion. 
     In the configuration, since the top end side cleaning portion and the base end side cleaning portion have different hues, the user can visually recognize the difference in physical properties between the top end side cleaning portion and the base end side cleaning portion. In addition, provided with a colorful outer surface with a plurality of hues, the interdental cleaning tool is given an excellent appearance. 
     In the configuration, the base end side cleaning portion may be made of a composite material containing elastomer and a reinforcing material. 
     Since the base end side cleaning portion according to the configuration is made of a composite material containing elastomer and a reinforcing material, the base end side bristle of the base end side cleaning portion has a higher rigidity than a conventional cleaning portion made only of elastomer, and thus the interdental space can effectively be cleaned. 
     Advantageous Effects of Invention 
     An interdental cleaning tool allows easy insertion in an interdental space by a user and has a high capability of cleaning an interdental space. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic front view of an illustrative interdental cleaning tool. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
       FIG.  1    is a schematic front view of an illustrative interdental cleaning tool  1 . With reference to  FIG.  1   , the interdental cleaning tool  1  will be described. 
     In  FIG.  1   , a term “base end side” and a term “top end side” are given. The term “base end side” indicates a side close to fingers of a user when the interdental cleaning tool  1  is held by the user. The term “top end side” indicates the opposite side of the base end side. A structure of the interdental cleaning tool  1  will be described using these terms as reference. The terms given in  FIG.  1    are used only for clarifying the description and not by means of limiting the interpretation. 
     The interdental cleaning tool  1  includes a base portion  10  of which base end side can be held by the fingers of the user and top end side is insertable in an interdental space by the user, and a cleaning portion  40  that covers the top end portion of the base portion  10 . The base portion  10  provides the interdental cleaning tool  1  with a suitable hardness to prevent the interdental cleaning tool  1  from unnecessarily bending when inserted in the interdental space. The cleaning portion  40  covering the top end portion of the base portion  10  is made of a material having a lower hardness than the base portion  10 , and prevents the hard base portion  10  from directly making contact with the oral tissues (that is, the teeth and the gum). The cleaning portion  40  is formed to directly contact the oral tissues and scrape out the deposit from the oral tissues. The top end portion of the base portion  10  covered by the cleaning portion  40  and having a suitable hardness as described above serves as a core material that prevents the cleaning portion  40  from unnecessarily bending when the interdental cleaning tool  1  is inserted in the interdental space. 
     The base portion  10  is made of a synthetic resin such as polypropylene, polyethylene, ABS, polybutylene terephthalate, polycarbonate, polyethylene terephthalate, polystyrene, and polyacetal. In the embodiment, the base portion  10  is made of polypropylene. 
     To describe the shape of the base portion  10 , a central axis CL extending from the base end side to the top end side (or in the opposite direction) and a perpendicular axis IA that is perpendicular to the central axis CL are illustrated in  FIG.  1   . Hereinafter in the description, the extending direction of the central axis CL is referred to as “axial direction”. 
     The base portion  10  includes a grip portion  30  disposed in the base end side, and a shaft portion  20  having a bar shape extending from the grip portion  30  to the top end side along the central axis CL. The grip portion  30  has a form of a thin plate having a large dimension in the extending direction of the perpendicular axis IA, and a small dimension in a virtual axis (not shown) perpendicular to both the perpendicular axis IA and the central axis CL to be held by the fingers of the user. The shaft portion  20  extending from the grip portion  30  to the top end side along the central axis CL has a form of a bar having a thickness insertable in the interdental space. The shaft portion  20  is longer than the grip portion  30  in the axial direction. An end portion at which the shaft portion  20  is connected to the grip portion  30  is hereinafter referred to as “base end portion  28   a ”. An end portion of the shaft portion  20  opposite to the base end portion  28   a  is hereinafter referred to as “insertion end portion  22   a ”. The shaft portion  20  gradually becomes thinner from the base end portion  28   a  to the insertion end portion  22   a.    
     A predetermined section of the shaft portion  20  from the insertion end portion  22   a  to the base end side is covered by the cleaning portion  40 . The section covered by the cleaning portion  40  is hereinafter referred to as “covered section  22 ”. The section of the shaft portion  20  other than the “covered section  22 ” is an exposed section  28  which is not covered by the cleaning portion  40 . In the embodiment, the covered section  22  has approximately the same length in the axial direction as the exposed section  28 . 
     The cleaning portion  40  covering the covered section  22  of the shaft portion  20  is formed of a top end side cleaning portion  40   a  covering the predetermined section of the shaft portion  20  from the insertion end portion  22   a  to the base end side, and a base end side cleaning portion  40   b  covering the outer circumferential surface of the shaft portion  20  further in the base end side than the top end side cleaning portion  40   a . A length ratio of the top end side body  40   a  to the base end side cleaning portion  40   b  is preferably from 1:0.2 to 1.3. When the top end side body  40   a  is longer than the base end side body  40   b , the interdental cleaning tool  1  can move back and forth by a longer length through the interdental space without receiving a large resistive force. Meanwhile, when the base end side body  40   b  is longer than the top end side body  40   a , a length used for effectively removing the deposit from the interdental space becomes longer. In the embodiment, the top end side cleaning portion  40   a  and the base end side cleaning portion  40   b  each constitute approximately a half of the covered section  22  in the axial direction. 
     Each of the top end side cleaning portion  40   a  and the base end side cleaning portion  40   b  may be molded with an elastomer material such as styrene elastomer, silicone, olefinic elastomer, and polyester elastomer or a composite material of an elastomer material containing a small amount of a reinforcing material such as glass fibers and talc. The composite material preferably contains the reinforcing material by 3% by weight to 50% by weight, inclusive, more preferably 5% by weight to 35% by weight, inclusive. However, the top end side cleaning portion  40   a  and the base end side cleaning portion  40   b  are molded with different molding materials different in hardness (that is, elastomer material or a composite material). 
     The top end side cleaning portion  40   a  is molded with a molding material having a lower hardness than the base end side cleaning portion  40   b . A hardness ratio of the molding materials molded into the top end side cleaning portion  40   a  and the base end side cleaning portion  40   b  (=(hardness of top end side cleaning portion  40   a )/(hardness of base end side cleaning portion  40   b )) is preferably from 0.9 to 0.3, more preferably from 0.8 to 0.5, and particularly preferably from 0.7 to 0.6. The top end side cleaning portion  40   a  is preferably molded with a molding material having a Shore hardness of A1 to A50, more preferably a molding material having a Shore hardness of A10 to A45, and particularly preferably a molding material having a Shore hardness of A15 to A40. The base end side cleaning portion  40   b  is preferably molded with a molding material having a Shore hardness of A2 to A90, more preferably a molding material having a Shore hardness of A15 to A85, and particularly preferably a molding material having a Shore hardness of A20 to A80. The Shore hardness of each of the top end side cleaning portion  40   a  and the base end side cleaning portion  40   b  may be adjusted by changing the type of elastomer or by changing the added amount and/or the type of the reinforcing material. For example, the reinforcing material may be added to the elastomer material used for molding the base end side cleaning portion  40   b  by a larger amount than the reinforcing material to be added to the elastomer material used for molding the top end side cleaning portion  40   a  to provide the base end side cleaning portion  40   b  with a higher hardness than the top end side cleaning portion  40   a.    
     The top end side cleaning portion  40   a  and the base end side cleaning portion  40   b  may be different not only in hardness but also in hue. The hue of the top end side cleaning portion  40   a  and the base end side cleaning portion  40   b  may be determined from a view point of fine appearance of the interdental cleaning tool  1 . For example, the top end side cleaning portion  40   a  may be molded with a pink molding material while the base end side cleaning portion  40   b  may be molded with a green molding material. 
     The top end side cleaning portion  40   a  includes a top end side body  42   a  covering the top end side portion of the shaft portion  20  (that is, a portion of the shaft portion  20  extending from the insertion end portion  22   a  by a length of approximately half the length of the covered section  22 ), and a plurality of top end side bristles  48   a  each having a shape of a thin projection protruding outward from the outer circumferential surface of the top end side body  42   a . The top end side body  42   a  prevents a direct contact between the oral tissues and the hard shaft portion  20 . Each of a plurality of top end side bristles  48   a  protruding outward from the outer circumferential surface of the top end side body  42   a  elastically deforms while the top end side portion of the shaft portion  20  is passing the interdental space and recovers the shape after the top end side portion has passed the interdental space. As a result, each of the top end side bristles  48   a  can scrape out the deposit from the oral tissues. The lengths of a plurality of top end side bristles  48   a  are set so that the top end side bristle  48   a  disposed further in the base end side has a larger protruding amount from the top end side body  42   b.    
     The base end side cleaning portion  40   b  is disposed further in the base end side than the top end side body  42   a  from which a plurality of top end side bristles  48   a  protrude. The base end side cleaning portion  40   b  includes a base end side body  42   b  covering a portion of the outer circumferential surface of the shaft portion  20  further in the base end side than the top end side body  42   a , and a plurality of base end side bristles  48   b  each having a shape of a thin projection protruding outward from the base end side body  42   b . The base end side body  42   b  forms a covering layer (an elastomer layer or a composite material layer) which is continuous in the axial direction from a layer (an elastomer layer or a composite material layer) of the top end side body  42   a , and prevents a direct contact between the oral tissues and the hard shaft portion  20  in the rest of the section of the covered section  22 . Like the top end side bristles  48   a  described above, when the base end side body  42   b  is inserted in the interdental space, each of a plurality of base end side bristles  48   b  protruding outward from the base end side body  42   b  elastically deforms and recovers the shape to scrape out the deposit from the oral tissues. Like a plurality of top end side bristles  48   a , the lengths of a plurality of base end side bristles  48   b  are set so that the base end side bristle  48   b  disposed further in the base end side has a larger protruding amount from the base end side body  42   b . The base end side bristle  48   b  disposed at the most top end side is longer than the top end side bristle  48   a  disposed at the most base end side. Thus, the protruding amount of the whole brush portion including the base end side bristles  48   b  and the top end side bristles  48   a  decreases from the base end side to the top end side. 
     A plurality of base end side bristles  48   b  molded with a molding material having a hardness higher than a plurality of top end side bristles  48   a  as described above is less susceptible to elastic deformation than a plurality of top end side bristles  48   a . Thus, each of a plurality of base end side bristles  48   b  contacts the oral tissues with a higher contact force than a plurality of top end side bristles  48   a . As a result, a plurality of base end side bristles  48   b  can scrape out the deposit from the oral tissues more effectively than a plurality of top end side bristles  48   a.    
     A plurality of top end side bristles  48   a  is less capable in scraping out the deposit than a plurality of base end side bristles  48   b  but contributes to easy insertion of the interdental cleaning tool  1  in the interdental space. The resilience caused when a plurality of top end side bristles  48   a  contacts the oral tissues and elastically deforms acts as a resistive force against the movement of the interdental cleaning tool  1  inserted in the interdental space. Since a plurality of top end side bristles  48   a  is molded with a molding material having a hardness lower than a plurality of base end side bristles  48   b , the resilience caused by elastic deformation of a plurality of top end side bristles  48   a  is relatively small. That is, a user who wants to insert a portion having a plurality of top end side bristles  48   a  in an interdental space can insert the interdental cleaning tool  1  in the interdental space almost without feeling a resistive force acting on the interdental cleaning tool  1 . 
     Since the molding material used for molding a plurality of top end side bristles  48   a  is different from the molding material used for molding a plurality of base end side bristles  48   b  not only in hardness but also in hue, the difference in physical properties described above (difference in hardness and difference in the resistive force resulting from the difference in hardness) between a plurality of top end side bristles  48   a  and a plurality of base end side bristles  48   b  can be visually recognized. That is, the difference in hue improves not only a fine appearance of the interdental cleaning tool  1  but also an appeal for excellent functions (that is, the function of allowing easy insertion and the function of effectively scraping out oral tissues) of the interdental cleaning tool  1 . 
     In the embodiment described above, the hue of the top end side body  42   a  and a plurality of top end side bristles  48   a  is different from the hue of the base end side body  42   b  and a plurality of base end side bristles  48   b . However, these hues may be the same. 
     In the embodiment described above, the top end side body  42   a  and the base end side body  42   b  form the molding material layers which are axially continuous. However, the top end side body and the base end side body may be formed at an interval in the axial direction. 
     In the embodiment described above, the top end side body  42   a  and the base end side body  42   b  each cover a part of axially extending section of the shaft portion  20  (that is, the covered section  22 ). However, the top end side body and the base end side body may cover the entire length of the shaft portion. 
     In the embodiment described above, the length of the top end side body  42   a  in the axial direction is approximately the same as the length of the base end side body  42   b  in the axial direction. However, the lengths of the top end side body and the base end side body may be determined so that the length ratio in the axial direction of the top end side body to the base end side body takes a different value. 
     In the embodiment described above, the grip portion  30  continuing from the shaft portion  20  covered by the base end side body  42   b  and the top end side body  42   a  has a form of a thin plate. However, the grip portion may have a different form that can be held by the fingers of the user. 
     In the embodiment described above, the cleaning portion contributing to cleaning of the interdental space has two portions different in hardness (that is, the top end side cleaning portion  40   a  and the base end side cleaning portion  40   b ). However, the cleaning portion may have more than two portions that are different in hardness. 
     INDUSTRIAL APPLICABILITY 
     The structure of the embodiment described above can suitably be used in a field of oral health. 
     REFERENCE SIGNS 
     
         
           1  interdental cleaning tool 
           10  base portion 
           20  shaft portion 
           40   a  top end side cleaning portion 
           40   b  base end side cleaning portion 
           42   a  top end side body 
           42   b  base end side body 
           48   a  top end side bristle 
           48   b  base end side bristle