Interdental cleaning tools

Abstract

To provide an interdental cleaner which can smoothly move a wire to a desired interdental space even if it is a so-called Y-shaped interdental cleaner, can be easily inserted between the teeth, and has a high cleaning effect. [Solution] The interdental cleaning tool of the present invention comprises a pair of support pieces arranged at a predetermined distance, a handle portion connected to the pair of support pieces and capable of being held by hand, and a wire having two or more multifilaments extending between the pair of support pieces perpendicular to the direction in which the handle portions extend, wherein each support piece has opposing surfaces facing each other and to which both ends of the wire are respectively connected, and the length of the wire extending between the opposing surfaces is greater than the distance between the opposing surfaces.

Description

[Technical Field]

[0001] The present invention relates to an interdental cleaning tool. [Background technology]

[0002] Various interdental cleaning tools have been proposed for removing plaque trapped between teeth. For example, Patent Document 1 proposes an interdental cleaning tool that includes a resin cleaning tool body having support pieces arranged at a predetermined interval and a handle that connects the support pieces and can be held by hand, and a wire material called floss that is arranged between the support pieces. This type of interdental cleaning tool is called an F-shape, and is characterized by the wire material and the handle extending in the same direction.

[0003] Meanwhile, Patent Document 2 discloses an interdental cleaning tool called a Y-shaped tool. This interdental cleaning tool has a wire placed between support pieces spaced a predetermined distance apart, and the support pieces are connected by a handle. A feature of this tool is that the direction in which the wire extends is perpendicular to the direction in which the handle extends. For this reason, Y-shaped interdental cleaning tools are generally used to clean between molars (back teeth). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-141689 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-244117 Summary of the Invention [Problem to be solved by the invention]

[0005] In the Y-shaped interdental cleaner described above, the wire is perpendicular to the handle, and is therefore used as follows. For example, when cleaning between molars, the wire is moved along the upper surface of the molar (or the lower surface in the case of upper teeth) to the desired interdental space, then inserted between the teeth, and the wire is moved up and down to scrape off plaque. However, conventional Y-shaped interdental cleaners are not fully satisfactory in terms of cleaning plaque between teeth, and further improvements are desired. In particular, with Y-shaped interdental cleaners, when the wire is moved up and down to clean between molars, the wire strongly contacts the surfaces of the teeth on the outer side of the mouth that form the interdental spaces between the molars, removing plaque. However, the wire is less likely to contact the surfaces of the teeth on the inner side of the mouth, making it difficult to achieve a sufficient plaque removal effect.

[0006] The present invention has been made to solve this problem, and has an object to provide an interdental cleaning tool that has a high cleaning effect even if it is a so-called Y-shaped interdental cleaning tool. [Means for solving the problem]

[0007] The interdental cleaning tool of the present invention comprises a pair of support pieces arranged at a predetermined distance, a handle portion connected to the pair of support pieces and capable of being held by hand, and a wire having two or more multifilaments extending between the pair of support pieces perpendicular to the direction in which the handle portions extend, wherein each support piece has opposing surfaces facing each other and to which both ends of the wire are respectively connected, and the length of the wire extending between the opposing surfaces is greater than the distance between the opposing surfaces.

[0008] According to this configuration, the length L of the wire extending between the opposing surfaces is longer than the distance W between the opposing surfaces of the support pieces, and therefore the following effects can be obtained.

[0009] First, in the interdental cleaning tool according to the present invention, the wire is positioned perpendicular to the direction in which the handle extends. Therefore, for example, when cleaning between molar teeth, a finger can be placed directly above the wire, and even if the wire is not loose, the fingertip can easily manipulate the wire to be positioned directly above the molar interdental space. Unlike an F-shaped interdental cleaning tool, with a Y-shaped interdental cleaning tool, the wire is held at a greater distance than with an F-shaped tool, making it difficult to position the wire directly above the molar interdental space. For this reason, the user grasps the handle, inserts the wire into the oral cavity, and then moves the handle in the direction in which the molars are aligned. Then, while the wire is in contact with the upper surface of the molar (or the lower surface in the case of upper teeth), the user moves the wire along the direction in which the molars are aligned to the desired interdental space. At this time, because there are fine irregularities on the upper surface of the molar, by making the length L of the wire longer than the distance W to give the wire slack, as described above, the wire can be moved along the upper surface of the molar without accidentally getting caught on the fine irregularities. Furthermore, due to this slack, when the wire reaches the interdental space between the molars, the groove at the upper end of the interdental space can be felt as a distinct element from the fine irregularities on the upper surface of the molar. Therefore, the wire can be moved smoothly during the process of moving the wire to the desired interdental space between the molars, and can be easily positioned between the teeth. In contrast, if the wire were not slack, it would not be able to follow the irregularities on the upper surface of the molars, and the wire could get caught on the irregularities, preventing smooth movement. Furthermore, if there is no looseness, even if the wire reaches the space directly above the molar by moving it along the unevenness of the upper surface of the molar, it may be difficult to feel the difference between the unevenness of the upper surface of the molar and the groove at the top of the space, making it difficult to position the wire directly above the space.

[0010] Next, when the wire reaches the desired interdental space, the user moves the handle upward or downward to insert the wire between the teeth. At this time, the user often moves the wire up and down while pulling the handle slightly toward themselves (toward the outside of the mouth). Therefore, the wire is not inserted straight into the interdental space; instead, it moves up and down while contacting the surface of the tooth in front of the interdental space (the tooth on the outside of the mouth). Because the wire is loose, friction with the tooth surface causes the multiple multifilaments to rotate and move up and down. This causes the multiple multifilaments that make up the wire to become entangled, twisting the wire into a single thick wire. Therefore, the wire does not get caught on the unevenness of the upper edge and surface of the molar interdental space, allowing the wire to be inserted smoothly and moved up and down. Furthermore, the thick wire can thoroughly scrape not only the surfaces of the teeth on the outside of the mouth that make up the interdental space, but also the surfaces of the teeth on the inside of the mouth.

[0011] On the other hand, if there is no slack in the wire and the multiple multifilaments do not rotate and thus do not become tangled, the individual multifilaments will move separately, and the wire may get caught on the unevenness of the upper edge and surface of the molar interdental spaces. Furthermore, when cleaning the spaces between molars using a Y-shaped interdental cleaning tool, the wire is pressed firmly against the surface of the teeth on the outer side of the mouth that make up the spaces between the molars. Without this slack, the multiple multifilaments would not rotate and would not become tangled, so the wire would be crushed in the direction toward the surface and would not become a thick wire. Therefore, it is difficult to apply a pressing force to the surface of the teeth on the inner side of the mouth that make up the spaces between the teeth, and there is a high possibility that dirt will remain.

[0012] As described above, with the interdental cleaning tool of the present invention, the wire is loose, so that the wire can be moved smoothly along the upper surface of the molars and positioned between the molars, allowing it to be smoothly inserted between the teeth and moved up and down, while also reliably removing dirt between the teeth.

[0013] In the interdental cleaning tool, the looseness S=100×(LW) / W, which is defined by the length L of the wire extending between the opposing surfaces and the distance W between the opposing surfaces, can be set to, for example, 0.5 to 8%.

[0014] In each of the interdental cleaning tools, each of the multifilaments may have a denier of 70 to 500.

[0015] In each of the interdental cleaning tools, the number of multifilaments constituting the wire may be 2 to 6.

[0016] In each of the interdental cleaning tools, the number of monofilaments constituting each of the multifilaments can be set to 15 to 120.

[0017] In each of the interdental cleaning tools, the number of twists of the multifilaments constituting the wire may be 30 to 300 times per meter of the wire.

[0018] In each of the interdental cleaning tools, the number of twists per meter of each of the multifilaments can be set to 5 to 500 times.

[0019] In each of the interdental cleaning tools, the multifilament may be made of polyethylene.

[0020] In each of the interdental cleaning tools, at least some of the multifilaments constituting the wire can be fixed to the opposing surface in a contacting state. [Effects of the Invention]

[0021] According to the interdental cleaning tool of the present invention, even if it is a so-called Y-shaped interdental cleaning tool, the wire can be smoothly moved to the desired interdental space, and it can be easily inserted between the teeth, thereby further improving the cleaning effect. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view of an interdental cleaning tool according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of FIG. [Figure 3] FIG. 2 is a side view of FIG. [Figure 4] FIG. 2 is a front view of FIG. [Figure 5] FIG. 2 is a diagram showing a mold used to manufacture the interdental cleaner of FIG. 1. [Figure 6] 2A to 2C are diagrams showing how to use the interdental cleaning tool of FIG. 1. [Figure 7] 2A to 2C are diagrams showing how to use the interdental cleaning tool of FIG. 1. [Figure 8] 2A to 2C are diagrams showing how to use the interdental cleaning tool of FIG. 1. [Figure 9] FIG. 10 is a diagram showing another example of a molding die. [Figure 10] FIG. 10 is a plan view of an interdental cleaning tool according to a reference example. [Figure 11] 1 is a table showing the characteristics and test results of the interdental cleaning tools according to the examples. [Figure 12] 1 is a table showing the characteristics and test results of interdental cleaning tools according to comparative examples and reference examples. [Figure 13] Photograph showing a tooth model with artificial plaque applied. [Figure 14] FIG. 10 is a diagram showing an example of cleaning between teeth using an F-shaped interdental cleaner. [Figure 15] FIG. 10 is a diagram showing an example of cleaning between teeth using a Y-shaped interdental cleaner. [Figure 16] 1 is a photograph showing a model tooth after artificial plaque has been scraped off with the interdental cleaning tool according to Example 1. [Figure 17] 1 is a photograph showing a tooth model after artificial plaque has been scraped off with an interdental cleaning tool according to Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0023] An embodiment of an interdental cleaning tool according to the present invention will be described below with reference to the drawings. Fig. 1 is a perspective view of the interdental cleaning tool according to this embodiment, Fig. 2 is a plan view of Fig. 1, Fig. 3 is a side view of Fig. 1, and Fig. 4 is a front view of Fig. 1. For ease of explanation, the following description will be based on the directions in each figure. Among these directions, the up-down direction in Fig. 2 may be referred to as the width direction, the right side as the front end side, the left side as the rear end side, and the up-down direction in Fig. 3 as the height direction. However, the present invention is not limited by these directional specifications.

[0024] <1. Overview of interdental cleaning tools> As shown in FIG. 1, this interdental cleaning tool comprises a resin cleaning tool body 10 and a wire 3 attached to the cleaning tool body 10 for removing plaque between teeth. The cleaning tool body 10 comprises a handle portion 1 extending like a rod that can be held by hand, and a pair of support pieces 21, 22 extending so as to branch off from the front end of the handle portion 1. Here, the support piece on the left side of FIG. 4 is referred to as the first support piece 21, and the support piece on the right side is referred to as the second support piece 22. The wire 3 described above is disposed between the support pieces 21, 22 so as to be perpendicular to the extension direction of the handle portion 1. Both ends of the wire 3 are connected to the support pieces 21, 22, respectively. Each component will be described in detail below.

[0025] <2. Cleaning tool body> The handle portion 1 has a first section 11, a second section 12, a third section 13, and a fourth section 14 aligned from the front to the rear, and these four sections 11 to 14 are integrally connected. The pair of support pieces 21, 22 described above are connected to the front end of the first section 11. As shown in FIG. 2, the first section 11 is formed so that its width increases from the front end to the rear end.

[0026] As shown in FIG. 2, the second section 12 is formed so that its width gradually narrows from its front end connected to the first section 11 toward its middle section, and gradually widens from its middle section toward its rear end. That is, arc-shaped recesses are formed on both side surfaces of the second section 12. As shown in FIG. 3, the height of the second section 12 in the vertical direction gradually increases from its front end toward its middle section, and gradually decreases from its middle section toward its rear end. That is, the upper and lower surfaces of the second section 12 are formed in arc shapes that are convex in both vertical directions. Furthermore, a plurality of ribs 121 extending in the vertical direction are arranged in the front-rear direction at predetermined intervals on both side surfaces of the second section 12.

[0027] As shown in Fig. 2, the third section 13 connected to the rear end of the second section 12 is formed so that its width narrows from the front end to the rear end, and the fourth section 14 is connected to its rear end. As shown in Fig. 3, the thickness of the third section 13 in the up-down direction is approximately the same as that of the first section 11. As shown in Fig. 2, the fourth section 14 extends rearward while maintaining approximately the same width as the middle section of the second section 12.

[0028] With the above-described configuration, the user can easily grip the side surface of the second portion 12 with, for example, the thumb and index finger. The rib 121 formed on the side surface of the second portion 12 serves as an anti-slip device.

[0029] Next, the support pieces 21, 22 will be described. Each support piece 21, 22 extends forward in an arc shape so as to form a U-shape from the front end of the handle portion 1 in a plan view. Also, as shown in FIG. 3, in a side view, each support piece 21, 22 curves downward as it extends forward, so that the front end of each support piece 21, 22 faces downward. Furthermore, the surfaces of each support piece 21, 22 that face each other are formed flat. Hereinafter, these surfaces will be referred to as first surfaces (facing surfaces) 211, 221, and the surfaces opposite thereto that face outward will be referred to as second surfaces 212, 222. The wire 3 described above is arranged so as to connect the facing surfaces near the front ends of each support piece 21, 22.

[0030] The handle 1 and the two support pieces 21, 22 that make up the cleaning tool body 10 can be made of various materials, but can be integrally formed from flexible resin materials such as polypropylene, polystyrene, polyethylene, polyethylene terephthalate, etc. However, they can also be formed as separate members.

[0031] <3.Wire rod> Next, the wire 3 will be described. The wire 3 is a bundle of multiple multifilaments 31. Each multifilament 31 is made by twisting multiple monofilaments made of various resin materials, and can be made of thermoplastic synthetic resins such as polyethylene, nylon, Teflon (registered trademark), vinylon, polyethylene terephthalate, polybutylene terephthalate, polyacrylonitrile, polystyrene, and polypropylene. Among these, polyethylene has a particular advantage in that it has a small coefficient of friction, making it easy to slide between teeth and scrape off plaque.

[0032] The thickness of each multifilament 31 is not particularly limited, but is preferably 70 to 500 denier, more preferably 100 to 250 denier, and even more preferably 100 to 160 denier. When the thickness of each multifilament 31 is set as described above, the multiple multifilaments 31 tend to rotate and become entangled when inserted, as will be described later, making it easier to insert the wire 3 between teeth and improving cleaning performance.

[0033] Furthermore, the number of multifilaments 31 constituting the wire 3 is not particularly limited, but is preferably 2 to 6, and more preferably 3 to 5. When the number of multifilaments 31 is 2 or more, as will be described later, the multifilaments 3 tend to rotate and become tangled when inserted, improving the effectiveness of scraping off plaque. On the other hand, when the number is 6 or less, the wire 3 can be easily inserted between teeth, improving operability and, as a result, improving the effectiveness of scraping off plaque.

[0034] The number of monofilaments constituting the multifilament 31 is preferably 15 to 120. This is for the following reason: if the number of monofilaments is 15 or more, the multiple multifilaments 31 tend to rotate and become tangled when inserted, as will be described later, and therefore a high cleaning effect can be obtained. On the other hand, if the number of monofilaments is too large, the multifilament becomes thick and may become difficult to insert between teeth, so the number is preferably 120 or less.

[0035] The number of twists of the multiple multifilaments 31 per meter of the wire 3 is preferably 30 to 300, and more preferably 10 to 200. This is because if the number of twists is 30 or more, the multiple multifilaments 31 will gather together and tend to rotate and become tangled as described below, thereby achieving a high cleaning effect. On the other hand, if the number of twists is too high, the wire 3 may become thin, which may make it difficult to achieve a cleaning effect, so the number of twists is preferably 300 or less.

[0036] The number of twists per meter of each multifilament 31 is preferably 5 to 500, more preferably 5 to 300, and particularly preferably 5 to 200. This is because if the number of twists is 5 or more, the multiple multifilaments 31 tend to rotate and become tangled when inserted, resulting in a high cleaning effect. Also, if the number of twists is 30 or more, the multiple multifilaments 31 tend to gather together, resulting in excellent ease of insertion between teeth. On the other hand, if the number of twists is too high, each multifilament 31 may become thin, which may make it difficult to achieve a cleaning effect, so the number of twists is preferably 500 or less.

[0037] <4. Connecting the wire and support piece> Next, a method for connecting the wire rod 3 to the support pieces 21, 22 will be described. As shown in FIGS. 2 and 4, both ends of the wire rod 3 penetrate through the support pieces 21, 22. Specifically, the left end of the wire rod 3 passes through the first surface 211 of the first support piece 21 and protrudes from the second surface 212, and the multifilaments 31 of the protruding wire rod 3 are heat-fused to each other and integrated to form a mass 32. Similarly, the right end of the wire rod 3 passes through the first surface 221 of the second support piece 22 and protrudes from the second surface 222, and the multifilaments 31 of the protruding wire rod 3 are heat-fused to each other and integrated to form a mass 32. These masses 32 are larger in outer diameter than the bundled multifilaments 31.

[0038] 4, the length L of the wire 3 extending between the first surfaces 211, 221 of the support pieces 21, 22 is longer than the distance W between these first surfaces 211, 221. That is, the wire 3 is in a slightly loose state between the first surfaces 211, 221. Such looseness can be defined as a looseness degree S (%) by the following formula (1). S = 100 × (LW) / W (1) The distance W between the first surfaces 211 and 221 is preferably 14 to 17 mm.

[0039] The degree of looseness S is preferably 0.5 to 8%, and more preferably 1 to 7%.

[0040] <5. Manufacturing method of interdental cleaning tool> Next, a method for manufacturing the interdental cleaning tool configured as above will be described with reference to FIG.

[0041] First, a molding die 100 for injection molding as shown in FIG. 5 is prepared. This molding die 100 has a plurality of cavities 101 for molding a plurality of cleaning tool bodies 10. In this molding die, a gate 102 for injecting resin is provided in the handle portion 1. When performing injection molding, a wire 3 is placed in the molding die. At this time, the wire 3 is placed so as to extend across the plurality of cavities 101 between the portions corresponding to both support pieces 21, 22 of each cavity 101. Furthermore, this wire 3 is made by twisting multifilaments 31 as described above. At this time, the tension of the wire 3 is adjusted in advance to provide slack in the wire 3, as will be described later.

[0042] Next, resin for the cleaning tool body is injected into the cavity 101. After the resin injection is complete, a predetermined time elapses, and the multiple cleaning tool bodies 10 are removed from the mold 100. At this time, in each cleaning tool body 10, the wire 3 is embedded in both support pieces 21 and 22, forming an integrated unit. The multiple cleaning tool bodies 10 are also connected by a single wire 3. Therefore, in the next step, the wire 3 is burned off on the second surface 212 side of the first support piece 21 and the second surface 222 side of the second support piece 22 of each cleaning tool body 10. The means for burning off the wire 3 is not particularly limited, but may include, for example, burning off with a flame or a heated blade, irradiating with heat rays such as far infrared rays, or burning off by electrical discharge. This forms multiple interdental cleaning tools in which the wire 3 and the cleaning tool body 10 are integrated.

[0043] When the wire 3 is burned off in this manner, the heat causes the multiple multifilaments 31 that make up the wire 3 to melt and integrate, forming a mass 32 .

[0044] <6. How to use and features of interdental cleaning tools> Next, a method of using the interdental cleaning tool described above will be explained. Here, as an example, cleaning between the lower molars (back teeth) will be explained as shown in FIGS. 6 to 9. First, the user holds the handle portion 1 with the wire 3 facing downward, inserts the wire 3 into the oral cavity, and moves the handle portion 1 in the direction of the molars 51 to 54. For ease of explanation, the four molars lined up from the outside to the inside of the mouth will be referred to as the first to fourth molars. The outside side of the mouth will be referred to as the proximal side, and the inside side of the mouth will be referred to as the distal side. Then, as shown in FIG. 6, while the wire 3 is in contact with the upper surfaces of the molars 51 to 54, the wire 3 is moved in the direction of the molars 51 to 54 to the desired interdental space. At this time, because the upper surfaces of the molars 51 to 54 are uneven, as described above, by making the length L of the wire 3 longer than the distance W and providing slack in the wire 3, the wire 3 can be moved while conforming to the unevenness of the molars 51 to 54 (absorbing the unevenness). Furthermore, due to this slack, when the wire 3 reaches the interdental spaces, the grooves at the upper end of the interdental spaces can be distinguished from the fine unevenness on the upper surfaces of the molars, allowing the wire 3 to be positioned above the interdental spaces. In contrast, if the wire 3 does not have slack, the wire 3 will not conform to the unevenness of the molars 51 to 54, and the wire 3 may get caught on the convex or concave portions of the molars 51 to 54, preventing smooth movement. Furthermore, if the wire 3 does not have slack, even if the wire 3 reaches the interdental spaces at the upper ends, it may be difficult to sense the difference between the unevenness on the upper surfaces of the molars and the grooves at the upper end of the interdental spaces, making it difficult to position the wire 3 directly above the interdental spaces.

[0045] Next, when the wire 3 reaches the desired interdental space (for example, between the third molar 53 and the fourth molar 54), the user moves the handle portion 1 downward to insert the wire 3 between the teeth, as shown in FIG. 7. At this time, the user often moves the wire 3 downward while pulling the handle portion 1 slightly toward the user (toward the outside of the mouth). As a result, the wire 3 is not inserted straight between the teeth, and the wire 3 moves downward while contacting the surface from the upper edge of the third molar 53 to the distal side. If the wire 3 is loose at this time, as shown in FIG. 8, the multiple multifilaments 31 will move while rotating around the axial direction (the direction in which the wire 3 extends) due to friction with the upper edge and the distal surface of the third molar 53. As a result, the multiple multifilaments 31 constituting the wire 3 will become entangled, and the wire 3 will be twisted into a single thick wire. Therefore, the wire 3 does not get caught on the unevenness of the upper edge and surface between the molars 53, 54, particularly on the upper edge and distal surface of the third molar 53, and can be moved up and down smoothly.

[0046] In this regard, the wire 3 is not inserted straight between the teeth, but moves downward while contacting the distal surface of the third molar 53. Therefore, if there is no slack in the wire 3, the multiple multifilaments 31 will not rotate or become tangled, and the wire 3 may get caught on the unevenness of the upper edge and distal surface of the molar 53, preventing it from moving up and down smoothly.

[0047] Furthermore, the twisted wire 3 in which the multiple multifilaments 31 rotate and become entangled can be pressed firmly against the distal surface of the third molar 53, and can firmly scrape off plaque from the distal surface of the third molar 53. Furthermore, since the wire 3 is a thick wire and can be brought into firm contact with the proximal surface of the fourth molar 54, dirt from the proximal surface of this fourth molar 54 can also be firmly scraped off.

[0048] In contrast, for example, if there is no slack in the wire 3, the multiple multifilaments 31 will not rotate or become tangled even when the wire 3 is placed along the distal surface of the molar 53. As a result, the individual multifilaments 31 may move independently and become easily caught on the unevenness of the upper edge and distal surface of the molar 53. As described above, the user moves the wire 3 downward while pulling the handle portion 1 toward the outside of the mouth, so that the wire 3 is pressed firmly against the distal surface of the molar 53. However, if there is no slack, the multiple multifilaments 31 will not rotate or become tangled, and the wire 3 will be crushed toward the distal surface of the molar 53 and will not become a thick wire. As a result, it is difficult to apply a pressing force to the proximal surface of the fourth molar 54, which increases the likelihood of stains remaining.

[0049] As described above, in the interdental cleaning tool according to this embodiment, the wire 3 is loose, so that the wire 3 can be smoothly moved along the upper surfaces of the molars 51 to 54 and dirt between the teeth can be reliably removed. When cleaning between the upper molars, the wire 3 is oriented upward, and the interdental cleaning tool is operated in the same manner as described above.

[0050] <7. Variations> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications are possible without departing from the spirit of the present invention. The following modifications can be combined as appropriate.

[0051] There are various methods for loosening the wire rod 3, including adjusting the tension when placing the wire rod 3 in the forming die 100 as described above, as well as the following method. First, as shown in FIG. 9, gripping members 105 protruding perpendicularly from one molding surface of the forming die 100 are placed on the outside of the portions corresponding to the second surfaces of the support pieces 21 and 22 of each cavity 101 (for ease of explanation, in FIG. 9, the gripping members 105 are placed only near the upper cavity 100 in FIG. 9). Then, the wire rod 3 placed in the forming die 100 is gripped by the gripping members 105. In this state, when the forming die 100 is closed, the gripping members 105 are configured to move in directions approaching each other. This allows the wire rod 3 to be loosened between the support pieces 21 and 22.

[0052] Alternatively, the following can be done. That is, a groove in which the wire 3 is placed is formed on one molding surface of the mold 100. This groove is formed deep between the cavities corresponding to the support pieces 21 and 22. Furthermore, a protrusion is formed on the other molding surface so that this protrusion fits into the groove between the support pieces 21 and 22. In this way, when the mold 100 is closed, the protrusion presses the wire 3 placed in the groove, and the wire 3 is pulled between the support pieces 21 and 22. This allows the wire 3 to be loosened between the support pieces 21 and 22.

[0053] Furthermore, the following can also be done. That is, a protruding member is provided in the molding die 100 near the portion where the wire rod 3 is placed. This protruding member is configured to press the wire rod 3 toward the handle portion 1 between the support pieces 21, 22 when the molding die 100 is closed. This allows the wire rod 3 to be loosened between the support pieces 21, 22.

[0054] In the above embodiment, all of the multifilaments 31 are integrated by thermal welding at both ends of the wire 3, but this is not limiting. For example, it is sufficient that two or more of all the multifilaments 31 are integrated by thermal welding. That is, it is sufficient that the multifilaments 31 are thermally welded to each other so that a plurality of thermally welded lumps 32 are present. In addition to thermal welding, various types of welding, such as ultrasonic welding, can also be used. Furthermore, it is also possible to simply fix both ends of the wire 3 to the support pieces 21, 22 without forming the lumps 32.

[0055] The wire 3 may be formed by simply bundling or twisting a plurality of multifilaments 31. Furthermore, if the plurality of multifilaments 31 are supported between the support pieces 21, 22 in a state where at least a portion of the multifilaments 31 are in contact with each other, the plurality of multifilaments 31 become more easily entangled, resulting in excellent insertability and improved cleaning effectiveness. By doing so, even if the plurality of multifilaments 31 constituting the wire 3 are not twisted, excellent insertability and improved cleaning effectiveness are achieved. In particular, it is preferable that the multifilaments 31 are in contact with each other at both ends of the wire 3 on the first surfaces 211, 221, because this further improves the insertability and cleaning effectiveness.

[0056] The shape of the cleaning tool body 10 is not particularly limited, as long as it has at least a handle portion 1 and a pair of support pieces 21, 22, with the wire 3 supported between these support pieces 21, 22 so as to be perpendicular to the handle portion 1.

[0057] Furthermore, medicines such as cooling agents, powdered flavoring ingredients, and agents for preventing or treating tooth decay can be applied to the wire 3. These medicines can be held in a liquid state on the wire 3, or can be left attached in a dry state at room temperature (e.g., 25°C). [Example]

[0058] Examples of the present invention will be described below, but the present invention is not limited to the following examples.

[0059] First, interdental cleaning tools according to 16 examples, two comparative examples, and one reference example were produced. The shapes of the cleaning tool bodies according to the examples and comparative examples were all the same, as shown in Figures 1 to 4. Meanwhile, the cleaning tool body according to the reference example is shown in Figure 10. In this interdental cleaning tool according to the reference example, multiple multifilaments constituting the wire are aligned in a vertical line. Each cleaning tool body was made of polypropylene. Furthermore, the distance W between the support pieces of each cleaning tool body in the examples was 15 mm, and the distance W between the support pieces of the cleaning tool body in the reference example was also 15 mm.

[0060] The wires according to the examples, comparative examples, and reference examples were formed by twisting a plurality of multifilaments, each of which was formed by twisting monofilaments made of polyethylene.

[0061] The details of these Examples, Comparative Examples, and Reference Examples are shown in FIGS. 11 and 12.

[0062] Next, evaluation tests using the above-mentioned Examples, Comparative Examples, and Reference Examples will be described. Three types of evaluation tests were carried out.

[0063] (Test 1) In Test 1, the ease of positioning the interdental cleaner between the lower molars was evaluated. That is, the ease of moving the wire to the desired interdental space was evaluated by sliding the wire downward over the molars. However, due to its shape, the Reference Example differs in usage from so-called Y-shaped interdental cleaners in that the wire is not slid along the upper surfaces of the molars, but is moved to the desired upper interdental space without contacting the upper surfaces of the molars. After 10 subjects used each of the above Examples, Comparative Examples, and Reference Example, they completed a visual analogue scale questionnaire with a rating ranging from 0 (difficult to position) to 10 (easy to position). The average of the 10 questionnaire results was rounded to the nearest tenth to obtain the evaluation score.

[0064] (Test 2) In Test 2, the ease of insertion between the lower molars (freedom of getting caught on the upper end and surface of the interdental space) was evaluated after the wire was placed between the desired molars. Ten subjects used each of the above-mentioned Examples, Comparative Examples, and Reference Examples, and then completed a questionnaire using a visual analogue scale, scoring from 0 (difficult to insert) to 10 (easy to insert). The average of the 10 survey results was rounded to the nearest tenth to obtain the evaluation score.

[0065] (Test 3) In Test 3, the cleaning effect was evaluated. That is, artificial dental plaque was applied to the lower molars of a tooth model, and then the model was cleaned using the above-mentioned Examples, Comparative Examples, and Reference Examples. The cleaning effect on the mesial surfaces of the teeth that make up the interdental spaces between the molars, and that are located on the inner side of the mouth, was evaluated. The following instruments were used: (1) NISSIN Artificial Plaque for Models (NISSIN Co., Ltd.) (2) Jaw model (mesial side of mandibular first molar (lower right 6))

[0066] The artificial plaque was applied as follows: First, the model teeth were thoroughly wiped with ethanol. Next, the vial containing the artificial plaque was vigorously shaken. After this, as shown in Figure 13, the artificial plaque was evenly applied to the model teeth with a brush, and then left to stand in a 60°C thermostatic bath for 5 minutes.

[0067] Next, we will explain the plaque removal method. First, when using each interdental cleaner, the teeth were secured to the jaw model with screws to prevent them from falling out. Next, the wire of each interdental cleaner was positioned parallel to the interdental space, then lowered vertically and moved back and forth three times along the surface coated with artificial plaque. The mesial surface of the lower right mandibular first molar (6) (the surface of the molar tooth on the inner side of the interdental space) was then photographed with a microscope, and the plaque removal rate was calculated through image analysis. This was performed three times for each interdental cleaner. When positioning the wire of each interdental cleaner parallel to the interdental space, in the case of a so-called F-shaped interdental cleaner like the reference example, the user would not move the wire 3 downward while pulling the handle 1 slightly forward (toward the outside of the mouth), even when cleaning between molar teeth. Instead, the wire 3 was positioned directly above the interdental space and inserted straight into the interdental space, as shown in Figure 14. In the case of a so-called Y-shape as in the examples and comparative examples, the wire 3 was arranged as shown in FIG.

[0068] The plaque removal rate was calculated as follows: First, an arbitrary area on the photograph of the tooth surface was taken as the area of ​​the entire interdental tooth surface, and the area where plaque had been removed was designated freehand, and the area was calculated using ImageJ. The plaque removal rate (%) was then calculated as follows: Plaque removal rate (%) = area of ​​plaque removed / total area between teeth x 100

[0069] From the obtained plaque removal rate, the cleaning effect was evaluated based on the following evaluation scores A to E. A: 60% or more B: 55% or more but less than 60% C: 50% or more but less than 55% D: 45% or more but less than 50% E: Less than 45%

[0070] The results are shown in FIGS. 11 and 12. (Test 1 results) In Test 1, a comparison between the Example and Comparative Example 1 showed that the looseness of the wire made it less likely to get caught on the unevenness of the upper surface of the molars, making it easier to slide along the upper surface of the molars, and also made it possible to distinguish the groove at the upper end of the interdental space from the fine unevenness of the upper surface of the molars, making it easier to place the wire 3 between the molars. Comparative Example 2, which has loose wire, received the same evaluation as the Examples, but was inferior in plaque removal effectiveness, as described below. Furthermore, although the wire of the interdental cleaner in the Reference Example was not loose, the interdental cleaner was a so-called F-shaped interdental cleaner, which eliminated the need to move the wire while it was in contact with the upper surface of the molars, and instead adopted a method of use in which the wire was placed directly above the desired interdental space, resulting in a higher evaluation.

[0071] (Test 2 results) In Test 2, a comparison between Example and Comparative Example 1 showed that the looseness of the wire made it less likely to get caught on the upper edge between the molar teeth and the unevenness of the surface of the molar teeth, thereby improving ease of insertion between the molar teeth. Furthermore, a comparison between Examples 1 to 8 and 10 to 15 and Example 9 showed that having a thickness of each multifilament of 300 denier or less improved ease of insertion. Furthermore, a comparison between Examples 1 to 8 and 10 to 15 and Example 16 showed that having a twist count of 100 or more per meter of wire caused multiple multifilaments to become entangled, which made it easier for the multiple multifilaments to rotate and become entangled during insertion, thereby improving ease of insertion. Comparative Example 2, which used a single wire, was less likely to get caught on the upper edge and surface between the molar teeth and was easier to insert; however, as described below, the plaque removal effect was inferior.

[0072] (Test 3 results) In Test 3, a comparison of the Example with Comparative Examples 1 and 2 showed that a wire with slack and including multiple multifilaments improved the cleaning effect on the mesial surfaces of molars inside the mouth. Furthermore, a comparison of Examples 1 to 12, 14, and 16 with Example 13 showed that when the number of twists of the multifilaments per meter of the wire was 300 or less, the wire did not become too thin, improving the cleaning effect on the mesial surfaces of molars inside the mouth. While the wire in the interdental cleaner in the Reference Example was not slack, in the F-shaped interdental cleaner, the wire 3 was positioned directly above the molar interdental space and the handle was inserted between the molars without being pulled toward the user (toward the outside of the mouth). Therefore, unlike the Y-shaped interdental cleaner, the wire was not pressed strongly against the distal surfaces of the molars outside the mouth, and the wire evenly contacted both tooth surfaces between the molars, which is likely to have resulted in a high cleaning effect on the proximal surfaces of the molars inside the mouth.

[0073] The following Table 1 shows the details of the evaluation of Test 3 for Example 1 and Comparative Example 1. Also, Fig. 16 shows a photograph of the model teeth after cleaning with the interdental cleaner of Example 1, and Fig. 17 shows a photograph of the model teeth after cleaning with the interdental cleaner of Comparative Example 1. These photographs also show that artificial plaque was scraped off more thoroughly in Example 1 than in Comparative Example 1. [Table 1] [Table 2]

[0074] From the above, it was found that the interdental cleaning tool according to the embodiment of the present invention is easy to place between teeth, easy to insert between teeth, and has a high interdental cleaning effect. [Explanation of symbols]

[0075] 1 Handle 21,22 Support piece 3 wire rod 31 Multifilament

Claims

1. A pair of support pieces arranged at a predetermined interval; a handle portion connected to the pair of support pieces and capable of being held by hand; a wire having two or more multifilaments extending between the pair of support pieces so as to be perpendicular to the extending direction of the handle portion; Equipped with The support pieces have opposing surfaces that face each other and to which both ends of the wire are respectively connected, The length of the wire extending between the opposing surfaces is greater than the distance between the opposing surfaces, a degree of looseness S=100×(L−W) / W, which is defined by a length L of the wire extending between the opposing surfaces and a distance W between the opposing surfaces, is 2 to 7%, the number of multifilaments constituting the wire is 3 to 5, The thickness of each multifilament is 100 to 300 denier, the number of twists of the multiple multifilaments constituting the wire rod per meter is 100 to 200; the wire passes through the pair of support pieces, The interdental cleaning tool, wherein the portions of the wire rod that protrude from the pair of support pieces are formed by the multifilaments being heat-welded together to form an integrated mass.

2. 2. The interdental cleaning tool according to claim 1, wherein the number of monofilaments constituting each of the multifilaments is 15 to 120.

3. The interdental cleaning tool according to claim 1 or 2, wherein the multifilament is made of polyethylene.

4. The interdental cleaning tool according to claim 1 , wherein at least some of the multifilaments constituting the wire are fixed to the opposing surface in a contacting state.

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