DESCRIPTION

BACKGROUND OF THE INVENTION

1. Field of the invention

The invention relates to an oral care equipment and in particular to a natural toothbrush comprising a handle with a head portion and bristles. The bristles of the toothbrush are pressure-sensitive. The invention further relates to a method for manufacturing such a toothbrush and the use of such a toothbrush.

2. Description of prior art

Vigorous brushing is one of the main problems in the field of dentistry. Most people apply 5-7 times more pressure than advised while brushing their teeth. The pressure applied should not exceed 2 Newtons. The more pressure users apply, the less dental plaque is removed. At the same time, irreversible damage, which leads to gum recession and dental abrasion, is caused on the surface of the teeth. There have been many attempts to address this problem by creating efficient dental products. Indeed, many toothbrushes have alert mechanisms that notify users every time they brush their teeth too hard. Temporarily bending handles, sound/light notifications, toothbrushes with heads that stop spinning, if not used properly etc are only a few examples of such mechanisms. However, none of these products or methods is derived from natural materials.

Toothbrushes are among the most difficult items to recycle. In fact, most of the toothbrushes produced from the 1930s onwards, have not been fully decomposed yet; they’re still out there. Toothbrushes consist of nylon fibers, metal wires and plastic handles. Recycling a toothbrush means disassembling it and placing its different parts in the respective recycling bins. As for nylon bristles and metal wires, they are almost impossible to recycle. Due to their small size, they often get stuck in the recycling machinery and may cause damage. Biodegradable or biobased plastics have been used in the toothbrush industry in the last few years. However, they are not necessarily more eco-friendly than conventional toothbrushes as they either don’t break down well or they have a high environmental footprint. Recycling is even more complicated in cases where load sensor mechanisms are part of the main body of the toothbrush.

In the prior art, pressure sensitive toothbrush designs have focused on developing mechanisms that detect the extra pressure applied during brushing, see for example, US5331707A, US20110016651 A1 , US5784742A, US5876207A, CN110419853B, CN110269389B, BR112015014466A2. Bristle ends detect the pressure applied on the surface of the teeth and convey the message to other parts of the toothbrush, which in turn notify users. There is currently no toothbrush that can detect pressure through its bristles. Nylon bristles that have been used by the dental industry to date didn’t have the properties to do so.

There have been some attempts to produce toothbrushes by using fibers derived from natural plants mainly due to their antimicrobial properties and their low carbon footprint, see for example, KR20190030366A, US5939049A, US2011297181A1, DE202012001097U1, CN201360690Y, CN101278778, CN1180738C, CN102038354A, CN1 11227496A, CN109008191 B,

WO2016064355A1 , GR1010114, but no proposals for a natural toothbrush with bristles that act like pressure-sensors have been made. Moreover, in the cases mentioned above, toothbrushes are still difficult to recycle, even in the cases of wooden handles as their handles contain metals.

There is a need for a low-cost, easily produced, eco-friendly, and/or pressuresensitive toothbrush that will enable users to brush their teeth correctly without applying excessive pressure. Another important issue is that toothbrushes become contaminated by microorganisms present in oral cavity and in the environment. These bacteria and fungi grow and multiply on toothbrush surfaces, being a potential threat to oral and general health. Various means have been proposed for minimizing microbial contamination of toothbrushes. Although several antimicrobial agents exist, most of them are not natural and the majority is not appropriate for contact with the sensitive mucosal tissues of the mouth on a repeated basis. Therefore, instead of using synthetic active agents, the present invention aims to employ natural materials with inherent antimicrobial properties.

SUMMARY OF THE INVENTION

Aspects of the present invention relate to a natural toothbrush with bristles that are sensitive to pressure. According to an aspect, the toothbrush comprises a handle made from olive wood, which has antimicrobial properties, and bristles made from soft antimicrobial agave fibers sewn in with biodegradable thread. Agave fibers have increased elasticity and softness thanks to the special mechanical procedures they go through. Elasticity and softness help the bristles of the toothbrush remove dental plaque efficiently and prevent users from applying additional pressure while brushing their teeth. In this way, they protect them from dental caries and periodontal disease as well as tooth abrasion and gingival recession. Pressure-sensitive bristles flare out and ‘alert’ users every time they apply excessive pressure while brushing their teeth. Users can then bring the bristles back to their original shape and continue brushing.

Moreover, a toothbrush according to another aspect of the present disclosure has natural antimicrobial characteristics that inhibit bacterial growth due to antimicrobial properties of the olive wood and the agave fibers.

Furthermore, the toothbrush according to still another aspect of the present disclosure made of wood and natural fibers having pressure-sensitive properties provides advanced teeth- and gum-care without damaging the environment. According to another aspect, the present disclosure relates to a natural toothbrush consisting of an olive wood handle and bristles made from soft agave fibers sewn in with biodegradable thread. The bristles of the toothbrush are pressure-sensitive. Agave fibers have increased elasticity and softness thanks to the special procedures they go through, the sewing process followed during production and the features of the holes in the head of the toothbrush handle. Elasticity and softness of the bristle fibers help bristles remove dental plaque efficiently and prevent users from applying excessive pressure, while brushing their teeth. In this way, they protect them from dental caries and periodontal disease as well as teeth abrasion and gingival recession that result from vigorous brushing. Moreover, the natural materials of which the toothbrush is made have inherent antimicrobial properties inhibiting the contamination of microorganisms.

According to yet another aspect, the present disclosure further relates to a natural toothbrush that consists of a handle made from olive wood, which has antimicrobial properties, and bristles made from antimicrobial soft agave fibers sewn in with biodegradable thread. The bristles of the toothbrush are pressuresensitive. Every time users apply excessive pressure, while brushing their teeth, the bristles flare out and the toothbrush stops working properly. Moreover, the toothbrush has natural antimicrobial characteristics that inhibit bacterial growth.

Furthermore, another aspect of the disclosure relates to a method of manufacturing a toothbrush with pressure sensitive bristles and antimicrobial characteristics.

According to implementations, there is provided a toothbrush and a method for manufacturing a toothbrush as described in the present application.

According to a first aspect, a toothbrush may comprise an elongated handle, a tuft mounting head region formed on one end of the elongated handle, wherein the tuft mounting head region may have a tuft mounting side, and the tuft mounting side may have a plurality of tuft receiving through holes. The toothbrush furthermore may comprise a plurality of tufts, wherein each tuft of the plurality of tufts may comprise a plurality of bristles made of natural fibers. Each tuft of the plurality of tufts may have a first partial length inserted in a respective one of the plurality of tuft receiving through holes such that a second partial length of each tuft of the plurality of tufts may protrude from the tuft mounting side. Furthermore, the toothbrush may comprise a thread with which the plurality of tufts is secured on a back side of the tuft mounting head region located opposite to the tuft mounting side.

The holes permit the bristles to be inserted properly such that they remain in place. Since the holes are through holes the use of a thread to secure the tufts may be simplified. The thread stretches and firms up the bristles. This is how they obtain the proper elasticity to function as pressure-sensors.

According to another aspect, the elongated handle can be made of olive wood. This has the advantage that the handle is biodegradable and has antimicrobial properties.

According to another aspect, a first diameter of the plurality of tuft receiving through holes on the tuft mounting side may be greater than a second diameter of the plurality of tuft receiving through holes on the back side.

This prevents the tufts and bristles from falling through the holes during the manufacturing process thereby improving and simplifying the manufacturing process of the toothbrush.

According to a further aspect, the fibers can be made from agave sisalana. These fibers have a particularly good pressure sensing effect. According to another aspect, the fibers can be made from agave sisalana hybrid.

According to another aspect, the thread can be made of a biodegradable material.

According to another aspect, the elongated handle, the tuft mounting head region head, the tufts and the thread may be biodegradable and compostable.

According to another aspect, the plurality of bristles may be pressure-sensitive. This permits the toothbrush to act as a pressure sensor. The toothbrush can detect too much pressure on the teeth through the bristles.

According to another aspect, the plurality of bristles can be adapted to flare out in response to applying a force greater than a threshold value in longitudinal direction of the plurality of bristles.

The toothbrush detects pressure or force in longitudinal direction of the bristles through the bristles. While users brush their teeth, the ends of the bristles flare out and thereby prevent the users from continuing brushing and damaging their teeth. This is how they may be notified that excessive pressure has been applied. To resume brushing, users have to manually bring the bristles or tufts back to their original shape.

The toothbrush can detect pressure or force in longitudinal direction of the bristles through the bristles. This alerts the user of the toothbrush whether too much pressure or force is applied while brushing the teeth.

According to another aspect, the threshold value is 2 Newtons. According to another aspect, the plurality of bristles is adapted to be brought in an upright position after flaring out. This prevents the user of the toothbrush from continuing brushing to avoid damage to the teeth.

According to another aspect, there is provided a method for manufacturing a toothbrush, the method comprising, providing an elongated handle, and providing a plurality of tuft receiving through holes on a tuft mounting head region formed on one end of the elongated handle, wherein the tuft mounting head region has a tuft mounting side. The method furthermore comprising providing a plurality of tufts, wherein each tuft of the plurality of tufts is provided by putting together one or more bristles made of natural fibers. The method also comprising, inserting on the tuft mounting side a first partial length of each tuft of the plurality of tufts in a respective one of the plurality of tuft receiving through holes such that a second partial length of each tuft of the plurality of tufts protrudes from the tuft mounting side, and securing the plurality of tufts on a back side of the tuft mounting head region located on opposite to the tuft mounting side by a thread.

According to another aspect, the method comprises securing of the plurality of tufts by sewing the tufts by passing the thread from one tuft receiving through hole of the plurality of tuft receiving through holes to another tuft receiving through hole of the plurality of tuft receiving through holes.

According to another aspect, providing the plurality of tuft receiving through holes comprises drilling of the plurality of tuft receiving through holes into the tuft mounting head region.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the (i) top view, (ii) cross section and (iii) bottom view of an embodiment of the toothbrush according to the present invention. Figure 2 shows the (i) top view, (ii) cross section and (iii) bottom view of the olive wood handle as well as the holes in the toothbrush head (i.e. openings where bristles are placed).

Figure 3 shows the (i) top view, (ii) cross section and (iii) bottom view of one hole on the toothbrush head.

Figure 4 shows a cross sectional view of one hole in the head of the toothbrush handle. Plant fibers are sewn with biodegradable thread in the openings on the toothbrush head.

Figure 5 illustrates the pressure-sensitive bristles of the toothbrush. When pressure greater than a threshold is applied during brushing, (i) the ends of the agave fibers bend out temporarily. Users (ii) bring the bristles back to their original and continue brushing their teeth.

DETAILED DESCRIPTION

The present invention relates to oral care equipment, specifically a toothbrush 100, that comprises a handle 110, a head region 120 and bristles 130 secured by a thread. Bristles 130 show users how much pressure to apply while brushing and protect their teeth and gums from damage. The toothbrush ‘alerts’ users every time they apply pressure greater than a threshold, while brushing their teeth; the ends of the bristles spread out and the toothbrush stops working temporarily (Figure 5i). That’s how users are notified that they have to reduce the pressure applied; all they have to do now is bring bristles back to their original shape (Figure 5ii) and continue brushing their teeth.

According to one embodiment, the handle 110 is made of olive wood, which has antimicrobial properties.

According to another embodiment, the bristles 130 are made from soft agave fibers sewn in 150 with biodegradable thread 160. According to a further embodiment, the bristles 130 flare out when the pressure or force applied in longitudinal direction to the bristles exceeds a critical value. The critical value can be seen as a threshold value. According to a preferred embodiment, the threshold value is a value between 0,5 Newton and 2,5 Newtons and more preferably a value of approx. 0,5 Newton, 0,75 Newton, 1 Newton, 1 ,25 Newtons, 1 ,5 Newtons, 1 ,75 Newtons, 2 Newtons, 2,25 Newtons, 2,5 Newtons.

According to another embodiment the natural fibers can be natural plant fibers derived from Agave sisalana that are sewn with biodegradable thread in an olive wood handle.

According to an embodiment, there is provided a method for manufacturing a toothbrush. The method comprises providing a handle 110, providing a plurality of tuft receiving through holes 140 on a tuft mounting head region 120 formed on one end of the elongated handle, wherein the tuft mounting head region has a tuft mounting side. The method furthermore comprises providing a plurality of tufts, wherein each tuft of the plurality of tufts is provided by putting together one or more bristles made of natural fibers. The method also comprises, inserting on the tuft mounting side a first partial length of each tuft of the plurality of tufts in a respective one of the plurality of tuft receiving through holes such that a second partial length of each tuft of the plurality of tufts protrudes from the tuft mounting side, and securing the plurality of tufts on a back side of the tuft mounting head region located on opposite to the tuft mounting side by a thread.

According to another embodiment, the method comprises sewing 150 the tufts by passing or threading the thread from one tuft receiving through hole of the plurality of tuft receiving through holes to another tuft receiving through hole of the plurality of tuft receiving through holes. The quality of the agave fibers, the features of the holes as well as their arrangement and their shape allow to produce toothbrushes with special bristles that act as natural pressure sensors. Unlike other dental care products, the pressure-sensitive bristles move freely, while users brush their teeth, and are beneficial for oral care and hygiene as they ensure maximum microbial plaque removal.

According to an embodiment, the bristles are adapted to move freely and function as pressure sensors without tooth abrasion and gingival recession caused by excessive pressure. The bristles have the property to flare out temporarily and alert the user in case excessive pressure greater than a critical value is applied.

In the following description, reference is made to the attached drawings, which are part of the present disclosure. Specific examples concerning the use of the toothbrush are illustrated.

Figure 1 illustrates the macroscopic view of one embodiment according to the invention. The toothbrush 100 disclosed consists of an olive-wood handle 110, however note that any other type of handle may be used, and a head 120 with bristles 130, which are placed in the holes 140 in the head 120 of the toothbrush handle 110. The bristles 130 are inserted into the through holes 140 in the toothbrush head 120 and are sewn in 150 with biodegradable thread 160.

Figures 2, 3 and 4 illustrate bristles 130 placed in the holes 140 in the head region of the toothbrush handle 110. They are placed and sewn in 150 at the bottom 170 of each hole 140 with high-resistance biodegradable thread 160.

According to one embodiment the thread 160 has a thickness between 0.2 mm and 1 mm, preferably between 0.4 mm and 0.7 mm, and more preferably approx. 0.5 mm or less than 0.5 mm. The holes 140 have an opening at their bottom 170 on the backside of the head region that allows natural bristles 130 to be sewn in 150 with threads 160 that pass from one hole to another 180. The diameter of the openings at the bottom of each hole 170 is slightly bigger than 1 mm. Their size prevents bristles 130 from going through the holes 140 to the back side of the toothbrush head 190, while sewing. It also allows the thread 160 that holds bristles 130 together to pass through each hole twice 200. The inner parts of the holes are rounded 210 to ensure that the thread 160 is not cut during sewing. To attach bristles 130 in each hole 140, the thread 160 passes through each opening from the bottom of each hole 170 at the back side of the toothbrush head 110 and exits from the opening at the top of each hole 220 at the upper side of the toothbrush head 230. A loop 240 in which a number of bristles made from natural agave fibers form a tuft and are then inserted into the tuft receiving through holes is also illustrated in Figure 4.

According to one embodiment each tuft of the plurality of tufts comprises more than 10 bristles and preferably more than 15 bristles and more preferably between 20 and 30 bristles. The bristles are formed to tufts by putting together a plurality of bristles and then, the thread 160 is stretched until the bristles 130 reach the bottom of the hole 140 at the toothbrush head 120. When the placement and sewing of the bristles 130 is completed, the thread 160 passes through adjacent holes 140 in the same way. The sewing process is complete when the bristles or tufts 130 are sewn in all holes 140.

The biodegradable thread 160 according to one embodiment has a tensile strength greater than 25 Newtons and preferably greater than 35 Newtons, is durable, resistant to abrasion and can stretch easily, see for example EP2842406A1.

According to one embodiment the thread is also less than 0.5mm thick and allows for enough space in each hole in the head of the toothbrush handle. This enables the possibility to add 20-30 agave fibers (40-60 free ends) in each hole and to ensure the maximum removal of microbial plaque as bristles can now move freely without causing a domino effect during brushing.

According to an embodiment, the non-porous surface of the olive wood as well as its antimicrobial properties are a result of multiple polishes with sandpaper after the toothbrush handle is soaked into olive oil, which is a natural polish. The inherent antimicrobial and antibacterial properties of natural agave fibers are preserved through the gentle mechanical process they go through in order to be suitable as pressure sensitive bristles for the toothbrush disclosed in the present invention.

Figure 5 illustrates how every time users apply a pressure greater than the threshold value while brushing their teeth, the ends of the bristles 130 flare out thereby preventing the users from continuing brushing their teeth (Figure 5). This is how they are notified that excessive pressure has been applied. To resume tooth brushing, users have to bring the bristles or tufts back to their original shape (Figure 5). The more the users use the toothbrush, the better they ‘sense’ it. Over time, they learn how to apply an appropriate amount of pressure while brushing their teeth.

The use and processing of a specific variety of natural fiber from the moment it gets harvested to the moment it is sewn into the toothbrush may improve the pressure-sensing effect of the bristles. All stages of production are equally important from plant selection and fiber extraction to the mechanical treatment of plant fibers.

According to an embodiment, sisal fibers are used derived from mature leaves, preferably greater than 1m of the Agave sisalana variety (Agavaceae family) (3- 10 y.o.), which grows on rocky and tropical soils (altitude>2,000m). Sisal fibers from Hybrid Agave sisalana can also be used. The leaf pulp as well as the outer layer of the leaf are scraped away through decortication: leaves are beaten and crushed by a rotating wheel with controlled pressure. What remains are high- quality fibers, having a diameter between 10 and 500 pm and preferably between 50 and 400 pm and more preferably between 100-300pm, which are then put together into small clusters. The clusters having a diameter between 1 cm and 5 cm and preferably between 2 cm and 4 cm and more preferably between 2.5 cm and 3.5 cm and are thoroughly washed. Through the process of hornification, they go through 1 to 8, preferably 4 to 6, or more preferably through approx. 5 cycles of wetting and drying. They are washed with distilled water at 60 °C for 3 hours and are oven dried at 100 °C for 30 minutes.

According to an embodiment, before the fibers get dried for the last time and while they are still moist, they are combed and stretched with a stainless comb. This makes them easier to separate. Then, they are placed in a humidity- controlled room until they dry out. One day before their use, they are placed in an oven (135 °C) for 30 minutes. They are then combed again and are cut into pieces (5 cm length) before sewing starts.

According to an embodiment, the softness of each batch is tested by a visual and mechanical sensor during sewing.

The proper placement of fibers or bristles as well as the placement of a number of fibers or bristles forming tufts in each hole may further improve the pressuresensing effect of the bristles. The fibers or bristles are sewn in with a thread. They are stretched and straightened. A proper number of bristles is placed in each hole at the head of the toothbrush. Sewing with a highly-resistant biodegradable thread stretches and firms up the bristles. This is how the proper elasticity can be obtained to function as pressure-sensors.

According to one embodiment each thread has a thickness between 0.2 mm and 1 mm, preferably between 0.4 mm and 0.7 mm, and more preferably approx. 0.5 mm or less than 0.5 mm that allows for the placement of more than 10 bristles and preferably more than 15 bristles and more preferably between 20 and 30 bristles in each opening. This ensures the maximum removal of microbial plaque. Placing fibers in such a way helps them to move freely and not to bump into each other, while users brush their teeth.

The diameter and the arrangement of the openings at the head of the toothbrush may further improve the pressure-sensing effect of the bristles.

According to one embodiment, the diameter of each opening at the bottom of each hole is between 0.5 mm and 2 mm, preferably 0.7 mm and 1.5 mm and more preferably between 0.8 mm and 1.2 mm and the upper part of the hole is between 0.7 mm and 2.2 mm, preferably between 1 mm and 2 mm and more preferably between 1.5 mm and 1.9 mm. This allows bristles to stay put during sewing and not pass through the holes. At the same time, the thread, which holds bristles together, is passed through the opening twice in order to stabilize bristles. Bristles are placed firmly at the bottom of the hole but their upper end is free to move. This is how they act as pressure sensors while brushing.

According to an embodiment, the distance between holes as well as their arrangement, as shown in figure 2.iv, gives the bristles the chance to move freely and ensures their overall functioning as pressure-sensors as users brush all sides of their teeth. According to an embodiment the distance between the holes is 0.5 mm to 5 mm, preferably 1 mm to 4 mm or more preferably 2 mm to 3 mm.

The length of the bristles may further improve the pressure-sensing effect of the bristles. The length of the bristles ranges from 5 to 15 mm, preferably from 7 to 12 mm and more preferably from 9 to 11 mm (from the upper surface of the toothbrush head to the bristle ends) and corresponds to exceeding the critical value of preferably approx. 0,5 Newton, 0,75 Newton, 1 Newton, 1 ,25 Newtons, 1 ,5 Newtons, 1,75 Newtons, 2 Newtons, 2,25 Newtons, 2,5 Newtons. Unless otherwise stated, the foregoing aspects, embodiments, implementations, and examples are not mutually exclusive, but may be implemented in various combinations to achieve unique advantages. As these and other variations and combinations of the features discussed above can be utilized without departing from the subject matter defined by the claims, the foregoing description of the embodiments should be taken by way of illustration rather than by way of limitation of the subject matter defined by the claims. In addition, the provision of the aspects, embodiments, implementations, and examples described herein, as well as clauses phrased as "such as", "including" and the like, should not be interpreted as limiting the subject matter of the claims to the specific examples; rather, the aspects, embodiments, implementations, and examples are intended to illustrate only one of many possible embodiments. Further, the same reference numbers in different drawings can identify the same or similar elements.