MXPA97009132A - Seda den - Google Patents

Abstract

The present invention relates to improved dental floss, including multi-component coextruded filaments, and / or filaments having a multiple lobe cross section. Some preferred silks of the invention are capable of bulking

Description

DENTAL FLOSS DESCRIPTION OF THE INVENTION Tooth decay and dental diseases can be caused by the bacterial action that results from the formation of a plaque around the teeth and / or in food particles trapped in the interstices between the teeth. The removal of plaque and trapped food particles reduces the incidence of caries, gingivitis, and mouth odors, as well as the general improvement of oral hygiene. It has been found that conventional brushing is inadequate to remove all trapped food particles and plaque. Silks and dental ribbons have been recommended to supplement brushing. Dental flosses have been developed that include a thick "brush" portion. These silks can also include a thin "silk" portion and a threaded portion. The brush portion, when it is dragged between the surfaces of the tooth, provides a good cleaning action, which removes the materials left by the use of a standard thin silk only. To form a silk with a brush, it is necessary to provide bulky filaments in a silk thread, that is, filaments which are separate and have a somewhat sinuous, random orientation. REF: 25998 Dental floss, both in the form of thin silk and brush, often include additives such as flavors or colors. These flavors have been applied in a conventional manner covering the additive on the surface of the silk. The present invention features improved dental floss and filaments for use in the manufacture of dental floss. Preferably, the filaments are co-extruded filaments of multiple components. "Multiple components" means that the filaments have two or more components; "coextruded" means that at least two of the components are present in the form of substantially separate phases, which have a well-defined interface therebetween, instead of being intermixed. The filaments are preferably formed by processes which are referred to in the art as "coextrusion", but the term "multiple component coextruded", as used herein, encompasses filaments having the structure described above, which are manufactured by other processes. In one aspect of the invention, the improved silks of the invention include filaments that are capable of "bulking" to form a brush silk. The filaments may include polymers that have been partially or fully oriented, ie, the polymer molecules have been extended from their normal position, during manufacture. The orientation is preferably obtained by pretensioning the filaments during the manufacturing process. When the tension is released, for example, unwinding the silk from a reel, the filaments relax, causing the silk to swell. These silks are referred to herein as "self-abrogating silks", since they will bulge when the tension is released without any further bulking stage. Alternatively, the filaments may include polymers that are not oriented (or not oriented to any appreciable extent) during manufacture. The silks containing these filaments, although they can be bulked using conventional methods, for example, bulked by steam or hot air, if desired, are preferably bulked, simply by applying tension to the silk, causing the orientation of the polymers, and then releasing the tension. If desired, these silks can be bulked up by the wearer of the silk immediately before use, or even while the silk is between the user's teeth. These silks are referred to herein as "silks with bulky stress induced". Advantageously, both "self-ablating" and "tension-induced bulky" silks can be bulked simply by applying tension to the silk. It is believed that bulky results from a combination of differences in the relaxed relationships of the various components of each multicomponent filament, the degree of adhesion to the interface between the components, and the geometry of the relative cross sections of the components of each filament. Thus, these silks can be easily manufactured without additional cumbersome manufacturing steps (for example, polymer coating, selective solvent removal, steam treatment or hot air). In the preferred embodiments, the silk is twisted and coated, either before the bulging (in the case of silks with bulging induced by tension) or after bulking (in the case of silks self-bulking). Some preferred silks include both bulky and non-bulky portions, achieved by applying tension selectively to predetermined portions of the silk. Other preferred silks include one or more additives incorporated in one or more of the components, for example, a color, which appears, or a flavor, essence or active ingredient which is released with the bulking. According to another aspect of the invention, the improved dental floss is formed of filaments that include two or more components selected to provide the desired properties of the floss. For example, the filaments may include an inner core selected to provide resistance to silk, and an outer layer selected to provide a desired surface property, eg, slip ability, smoothness, or abrasiveness. The silks according to this embodiment of the invention may or may not be capable of being bulked, depending on the combination of the selected components. A further aspect of the invention features improved dental floss including filaments in which one or more of the components of the filament includes an additive, e.g., a color, fragrance, flavor or active ingredient, which is releasable from the floss. Some preferred silks are capable of bulking up. Some preferred silks include a combination of components selected to give the desired silk properties, other than bulky, for example, surface properties such as slip ability, combined with good tensile strength. The additive-containing components can be water-soluble, to allow the additive to seep out of the silk during use, or the silk can release the additive with the bulky. The additive may be provided as supplied, in microencapsulated form, or adsorbed or absorbed in another additive, for example, a particulate filler. The additive may also be provided in charged microspheres, as described in U.S. Patent No. 5,300,290, the disclosure of which is incorporated herein by reference. Advantageously, the additives can be incorporated into the silks of the invention during the manufacture of the filaments, instead of applying the additives later during separate coating steps. This not only reduces the number of process steps, but also reduces the amount of additive needed. In yet another aspect, the invention features improved silks including filaments, which have a multiple lobe cross section. These silks may include single-component or multi-component filaments, and in the latter case, may or may not be capable of bulking. The cross section of multiple lobes can improve the comfort and cleaning properties of silk. The invention further characterizes methods for making the silks improved. A preferred method includes (a) co-extruding two or more polymers through a multi-component die to form a plurality of multi-component filaments; and (b) treating the filaments to form a fiber adapted to be used as a dental floss.

Additionally, the invention features methods of flossing the teeth of a mammal, e.g., a human, by inserting a length of a dental floss of the invention between two teeth of the mammal. The term "dental floss," as used herein, is defined to include dental flosses, dental ribbons, and the like. Other features and advantages of the invention will be apparent from the drawings, in the following detailed description, and the claims. Figure 1 is a schematic, highly magnified side view of a length of dental floss before bulging. Figure 1 is a schematic, highly magnified side view of the dental floss of Figure 1 after bulging. Figure 2 is a schematic view of a production line for the manufacture of a dental floss with self-ablating brush, according to one embodiment of the invention. Figures 3-3d are cross-sectional views, taken radially, of multi-component coextruded filaments having several cross sections.

Figure 4 is a cross-sectional view, taken radially, of a filament of a single trilobal component, according to an embodiment of the invention. Figure 4a is a cross-sectional view, taken radially, of a filament of multiple trilobal components having a shell / core cross-section. Figure 4b is a cross-sectional view, taken radially, of a trilobal multi-component filament, having a pointed cross-section. Figure 5 is a filament electronmicrograph containing kaolin particles in its shell component.

Silks that are bulky With reference to Figures 1 and 1, a length of dental floss before and after bulging is shown. Prior to bulking, the filaments, which comprise the silk, are arranged together to form a fiber and are substantially parallel to each other in the axial direction (Figure 1) . After the bulge, as shown in Figure 1, the dental floss is in the form of a brush, i.e., the filaments are widely spaced relatively apart, and are no longer substantially axially parallel, but instead are somewhat sinuous and oriented in a random way. Preferably, the brush silk has, in its relaxed state, a diameter that is at least 300 to 550 percent of the original diameter of the fiber before bulking, and a denier of approximately 500 to 700. Silks with Preferred brushes have sufficient strength to resist wear and tear during use, typically a breaking strength of at least 5 N, preferably at least 10 N, more preferably, approximately 25 N. Under tension, during In use, the brush is stretched to become a thread, suitable for easy insertion between the teeth and for a scraping movement up and down along the opposite surfaces of the tooth. When not under tension, the brush is similar to a thread, suitable for cleaning between the teeth in a brushing action, pushing the silk with brush back and forth across the surfaces of the tooth and gingival. The silk is formed of a fiber comprising a plurality of multi-component filaments formed of two or more polymeric components. The components are selected to exhibit different relaxed relationships, as a result of their viscoelasticities and / or crystalline structure, and / or to have relative cross sections, and / or to have a degree of adhesion at their interface, which will result in the bulked with the orientation and subsequent relaxed of the filaments. A difference in the relaxed ratio can be achieved by using different polymers, for example, nylon and polyester, or different grades of the same polymer, that is, grades that have different Melt Flow Index (MFI), relative viscosity (RV) or molecular weight. . The polymers preferably have different viscoelasticities, and / or different crystal structure, for example, a different ratio of crystalline to amorphous material. It is noted that even if one or more of the components (although not all components of the filament) is stretched to a point that exceeds the elastic limit of the component, so that for all practical purposes, the relaxed of these components does not occur, the filament will generally still be able to bulge. A difference in cross section can be achieved, for example, by arranging the components so that their cross sections are asymmetric, or so as to occupy unequal percentages of the filament volume. Suitable cross sections for the filaments include the side-to-side (Figure 3), cover / eccentric core (Figure 3a), shell / core (Figure 3b), circular hollow (Figure 3c) and circular (Figure 3d). A degree of adhesion can be easily determined empirically, which will result in bulking. In general, materials that have less adhesion to one another, will have a greater tendency to cause bulky when combined in a filament. If desired, agents may be added to modify the adhesion of the materials, decreasing the adhesion of compatible components or increasing the adhesion of otherwise incompatible components. These agents are well known in the plastics art. Suitable combinations of materials include, but are not limited to, nylon and polyester; high MFI polypropylene (e.g., having an MFI of 20 to 50) and low MFI polypropylene (e.g., 5 to 20); high RV nylon (for example, having an RV of 3 to 5) and low RV nylon (for example, 1 to 3); polyester and polypropylene; and nylon and propylene. Preferably, the two components are provided in a volumetric ratio of about 5:95 to 95: 5. The methods of forming the self-ablative and brush-with-bulked silks with preferred tension-induced bulking will now be described.

Self-abrogating silks In Figure 2, a method for forming a self-ablating, preferred dental floss is shown schematically. First, two or more polymers are co-extruded through a two-component extrusion die, to form a two-component filament, the physical properties and / or the relative cross-sections of the polymers are selected, as described above, to allow that the silk be ablated. Preferably, the extrusion die includes a spinner, as is known in the filament forming technique, through which a plurality of these two-component filaments are extruded at one time. Preferred silks contain from 72 to 288 filaments and have a total denier of about 500-3000. The filaments emerging from the spinner are put together to form a fiber, which then passes through a cooling chamber, preferably from 0 to 30 ° C, and is placed under light tension as it travels between two extraction rollers, the which are rotating at different speeds. The tension applied to the fiber is expressed as the "extraction ratio", which is the differential speed between the two extraction rollers. The preferred extraction ratios are from about 1.0 to 5.0, more preferably from about 1.5 to 4.0. The fiber then passes through a relaxed roller and gathers in a winder. As soon as the tension is removed from the fiber, the filaments of the fiber separate or "bulge", forming a brush. The bulked fiber can then be further processed to form a finished brush silk. For example, preferred silks are twisted, preferably, with about 1 to 1.5 twists per inch, and coated with a bonding solution. Twisting and coating reduce excessive strand separation and improve wear resistance. The twisting processes are well known, for example, using a standard ring twisting equipment. The coating can be achieved in any suitable way, for example, by dip coating, that is, soaking the filament in a coating bath, removing the excess coating as the filament leaves the bath, and drying the filament to remove the solvent in an air stream. The drying speed can be accelerated by heating the air stream, for example, at 60 ° C. Suitable coating solutions include a coating of GENTAL 101 of 80/20 nylon polymer (General Plastics, Bloomfield, NJ) in ethanol, polyurethane coating, SPENLITE L89 or SPENKEL M21 (Reichold Chemicals, Research Triangle Park, NC). The coating must be flexible enough not to inhibit bulging, but heavy enough to properly join the filaments to avoid excessive wear.

Silks with Bulk Stress Induced Tension-induced bulky silks are manufactured in a manner similar to that described above, except that the tension is not applied to the fiber at any time (apart from the minor incidental amounts of stress that result from the movement of the fiber through the fiber). processing equipment). Thus, the extraction ratio is approximately 1.0, if equipment that includes extraction rollers is used (these rollers are not necessary if tension is not going to be applied, but they can be left in place if you want to use the same production line to make both self-ablaying silks and bulky ones induced by tension). Ideally, for silk with stress-induced bulking, the fiber has, before bulking, a denier of about 1750-2800, so that when pulled to its natural extraction limit that varies from about 3 to 4, it has a final denier of 500-700.

Filaments Of two specialty components.

In another embodiment of the invention, the filaments used to form dental floss include two or more components, each of which contributes a desired property in the filament. These filaments may or may not impart bulking capacity to silk, depending on the factors discussed above (relative relaxation ratios, adhesion, geometry of the cross section). These filaments can be manufactured using the same process described above, preferably with applied tension during manufacture, as described above for the self-ablaying silks. (Depending on the selected components and the geometry of the cross section, the applied tension may or may not cause bulging, however, it is generally preferred to apply tension in any case, since this has been found to improve the resistance to tension of the filaments). Some preferred filaments include an outer cover, which is soft, slippery, or abrasive, to improve the ease of insertion, comfort, and cleanability, respectively, of the silk, and an inner core that provides other desired physical properties such as strength. and elasticity and / or serves as a carrier for additives, such as flavors, essences and medications. Where the outer layer is intended to provide softness, for ease of insertion, preferred polymers include TPE (thermoplastic elastomers), for example, polyether block amides such as those available under the trademark PEBAX from ELF Atochem, elastomers of polyester such as those available under the trademark HYTREL from DUPONT, and block copolymers of butadiene styrene such as those available under the trademark KRATON from Shell; EVA (vinyl ethylene acetate); and ethylene-propylene copolymers; low MFI polypropylene and mixtures thereof. Where it is intended that the outer layer provide sliding ability, for comfort during use; preferred polymers include polyethylene, extrudable molten fluoropolymers (e.g. polyvinylidene fluoride (PVDF), and fluorinated copolymers of ethylene propylene), polymers containing polytetrafluoroethylene (PTFE) particles and / or silicone oil, molten extrudable polymer polymers (e.g. , polyoxyethylene such as that which is commercially available from Union Carbide under the tradename Polyox®, or triblock copolymers of polyethylene oxide and polypropylene oxide, such as those available from BASF under the trademark Pluronic®), and polymer alloys extrudable molten lubricants (eg, Lubriloy® polymers, available from LNP engineering plastics). If the outer layer includes an abrasive, for improved cleaning, the preferred abrasive / polymer combinations include nylon containing kaolin particles, calcium carbonate, zinc oxide, silica, PTFE, or mixtures of these particles which are compatible. If desired, one or more additives may be absorbed or adsorbed onto the surface of the abrasive particles, for example, by drum drying, spray drying, fluidized bed processing, or other suitable methods as are known in the art. In all the above cases, one of the polymers is preferably a reinforcing polymer, for example nylon, polyester or polypropylene, to impart tensile strength and / or stiffness to the silk. In one embodiment, one of the polymers may be selected to have a suitable melting temperature, and other properties to allow the filaments to attach to each other to form the finished floss without the coating and twisting procedure described above. A multi-component fiber suitable for use in this embodiment is described in Example 4, Sample 1. The filaments are joined by softening and flattening the fiber in a heated extraction roller as it passes through the rollers. The cover and the core can have any suitable cross section, preferably a symmetrical core / shell cross section (Figure 3b) or an eccentric shell / core cross section (Figure 3a). The filament may also have a hollow circular cross section (Figure 3c), and, if desired, the hollow core may be filled with an additive, for example, a flavor, color or active ingredient. The specialty two-component silks can also be formulated to include one or more additives, eg, a color, fragrance, or active ingredient, in one or both of the components. For example, the outer layer may be polyester, nylon or other thermoplastic, and the inner core may be a different thermoplastic (or a different grade of the same thermoplastic) which contains an additive such as chlorhexidine (or a salt thereof), Sodium fluoride, flavor (eg, Polyiff®, International Flavors and Fragrances), fragrance, a tooth desensitizer, a tooth bleach or other suitable additives for use in dental flosses. The thermoplastic to be used for the inner core will be determined by the additive used, as will be readily appreciated by someone skilled in the art. Suitable polymers include nylon, polyester, polypropylene, ethylene vinyl acetate (EVA), polyvinyl alcohol, polyethylene, and the like. The internal and external polymer can be soluble in water to allow the additive to filter out of the polymer. Alternatively, the polymers can be selected to return to the silk capable of being bulked, and the additive can be released with the bulking. The one released with bulking may occur due to several mechanisms, or a combination of mechanisms. For example, the additive may be provided in an encapsulated form, and the shear action of the bulge may rupture the capsules, or the portion of the additive present at the interface of the components may be exposed by the separation of the components at the interface during bulking. A preferred material for the additive-containing component in this embodiment is polypropylene, since its low extrusion temperature minimizes the degradation of temperature-sensitive additives. The additive can be a color, which is incorporated in a way that the color is only visible either before or after bulging, that is, so that the silk changes color to indicate bulky. This can occur by several mechanisms, for example, by the dilution of the color by the expansion of the fiber during bulking, so that the silk changes from a color to white, selecting the cross section so that the bulky exposes a component of a different color, or that one of the components is a polymer, such as ABS, which changes color when tension is applied. The additive, if desired, can be incorporated in an encapsulated form. The encapsulation can be used for thermal protection or moisture protection of the additive, and can be achieved by any of a number of conventional techniques such as spray drying, drum drying or evaporation of the solvent. The additive may also be provided in a charged microsphere, as described in U.S. Patent No. 5,300,290. Suitable cross sections include cover / core, cover / eccentric core, side by side, circular and hollow circular (see Figures 3-3d).

Multiple Lobes Filaments Other preferred silks include a plurality of filaments having a cross section of multiple lobes, as shown in Figure 4. Preferred filaments include from 3 to 8 lobes; a suitable filament has 3 lobes. The filaments are preferably formed by extrusion through a die having a suitable multiple lobe cross section.

These filaments may be of multiple components or of a single component, and, in the former, may have a cross-section of cover / core (Figure 4a), pointed (Figure 4b) or other suitable. Polymers suitable for use in forming multiple-lobed filaments include, but are not limited to, polyester, polypropylene and nylon. In the multi-component filaments, if desired, the polymers can be selected, as described above, to return to the silk capable of bulking. Suitable methods of silk formation using these multi-lobed filaments include any conventional silk manufacturing methods.

The twisting and coating methods described above are preferred. The following examples are intended to be illustrative and not of a limiting effect.

EXAMPLES Equipment Assembly The following assembly of the equipment and manufacturing process, shown schematically in Figure 2, was used in all the examples.

Two 1.5-inch diameter extruders were connected to a two-component extrusion die. The two extruders included screws for general purpose, with an L / D ratio of 30/1. The extrusion of two components included a measuring plate, a distribution plate, engraved plates, and a spinner. After being coextruded through the extrusion die, the extrudate was processed with a filament spinning assembly downstream to produce filaments. The downstream assembly included a cooling chamber, a final applicator, a tensioner, extraction rollers, relaxed roller, and a winder. The extrudate was cooled in the cooling chamber, stretched and relaxed by the extraction and relaxed rollers, and collected in the winder.

Example 1 Manufacture of Dental Silk from Silk Filaments Self-Abrasive A fiber containing 144 filaments of two nylon 6 / PET 70/30 components (with a cross-section from side to side) was extracted using an extraction ratio of 3.28, using the equipment and procedure described above, was converted to silk from the following way The silk was first twisted to reduce the separation of the filament during the use of the silk and to add resistance to wear. The twisting was carried out using a standard twist-ring equipment, at a twist level of 1.5 kinks per inch. Once twisted, the filament was covered by immersion in a nylon polymer coating in 80/20 GENTAL 101 ethanol. Removal of the solvent after the dip coating was accelerated by heating the air stream to 60 ° C.

Silks Bulk by Stress A fiber containing 144 two-component filaments was used, with a cross-section from side to side, an extraction ratio of 1.0, of nylon 6 / PET 80/20. A blue dye was incorporated into the nylon resin, and the PET was white (pigmented with Ti02). To convert the fiber to a silk, the fiber was twisted to between 1 and 1.5 twists per inch, and subsequently coated with a bonding solution and allowed to dry at 65 ° C to its final shape. The bonding solution used was a SPENLITE L89 polyurethane coating.

Example 2 The following self-ablaying silks were formed using the equipment assembly and the procedure described above, to form the initial fiber, and a procedure similar to that described in Example 1, to form the final silk: Lp O < _p n ro Example 3 The following tense-induced bulking silks were formed using the assembly of the equipment and method described above to form the initial fiber, and a procedure similar to that described in Example 1 to form the final silk: Example 4 The following silks of two specialty components were formed using the same assembly of the equipment and the procedures described above.

Example 5 The following silks of two specialty components were formed using the same assembly of the equipment and the procedures described above.

Other embodiments are within the claims.

For example, while the two-component filaments described above have been described in the detailed description, the filaments may contain any desired number of components, and in this case, they would be manufactured by extrusion through a suitable multi-component die, using the Appropriate number of extruders. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following:

Claims (36)

1. A dental floss characterized in that it comprises a plurality of coextruded filaments of multiple components.

2. The dental floss according to claim 1, characterized in that each of the filaments consists of two components.

3. The dental floss according to claim 1, characterized in that the longitudinal axes of the filaments are arranged substantially parallel to each other to form a fiber.

4. The dental floss according to claim 3, characterized in that the fiber is twisted.

5. The dental floss according to claim 1, characterized in that each filament comprises a first component having a predetermined viscoelasticity and a second component having a different viscoelasticity.

6. The dental floss according to claim 1, characterized in that each filament comprises a first component having a predetermined crystalline structure and a second component having a different crystalline structure.

7. The dental floss according to claim 1, characterized in that the components of each multi-component filament have geometries of different radial cross-section.

8. The dental floss according to claim 1, characterized in that at least a portion of the filaments is pretensioned during manufacture and, when the tension is released, the filaments relax causing the silk to bulge.

9. The dental floss according to claim 1, characterized in that the filaments of multiple components include two or more components selected to have different relaxed ratios.

10. The dental floss according to claim 1, characterized in that the filaments of multiple components are selected to have a degree of interfacial adhesion that allows the filaments to be bulked with the application of tension to the filaments.

11. The dental floss according to claim 1, characterized in that the silk is adapted to be ablated by a wearer of the silk, immediately before or during use, applying tension to the silk.

12. The dental floss according to claim 1, characterized in that the filaments include a first component that is selected to provide resistance to silk, and a second component selected to provide a surface having predetermined physical characteristics.

13. The dental floss according to claim 12, characterized in that the first component forms an internal core, and the second component forms a cover that surrounds the core.

14. The dental floss according to claim 12, characterized in that the first component comprises a polymer selected from the group consisting of nylon, polyester and polypropylene.

15. The dental floss according to claim 12, characterized in that the second component comprises an extrudable molten polymer selected from the group consisting of thermoplastic elastomers, ethylene vinyl acetate, ethylene propylene copolymers, fluoropolymers, lubricating polymers, and lubricating polymer alloys. .

16. The dental floss according to claim 12, characterized in that the second component comprises a mixture of an extrudable molten polymer and a silicone oil.

17. The dental floss according to claim 12, characterized in that the second component comprises a mixture of an extrudable molten polymer and a particulate filler selected from the group consisting of kaolin, calcium carbonate, silica, and polytetrafluoroethylene.

18. The dental floss according to claim 17, characterized in that an additive is absorbed or adsorbed on a surface of the particulate filler.

19. The dental floss according to claim 1 or 12, characterized in that one or more of the components of the multi-component filaments include an additive.

20. The dental floss according to claim 19, characterized in that the additive is selected from the group consisting of colors, fragrances, flavors, active ingredients, and agents, which modify the interfacial adhesion between the components of the filaments.

21. The dental floss according to claim 19, characterized in that the additive is incorporated in a manner to allow it to be released from the floss during use.

22. The dental floss according to claim 19, characterized in that the components of the multicomponent filaments are selected to return to dental floss capable of being bulked up.

23. The dental floss according to claim 22, characterized in that the additive is a color and is incorporated in a manner to allow the floss to change color with the floss.

24. The dental floss according to claim 19, characterized in that one or more of the components of the multi-component filaments is soluble in water, to allow the additive to filter out of the silk during use.

25. The dental floss according to claim 22, characterized in that the additive is incorporated in a manner to allow it to be freed from the silk with the bulking.

26. A dental floss comprising a plurality of filaments having a radial cross section of multiple lobes.

27. The dental floss according to claim 26, characterized in that at least a portion of the filaments individually comprises two or more co-extruded components.

28. The dental floss according to claim 27, characterized in that two or more components are selected to return dental floss capable of being bulked up.

29. The dental floss according to claim 26, characterized in that the filaments have from 3 to 8 lobes.

30. The dental floss according to claim 27, characterized in that the filaments have a radial cross section of cover / core.

31. The dental floss according to claim 27, characterized in that the filaments have a pointed radial cross-section.

32. A method of making a dental floss containing a plurality of filaments constructed of multiple components, the method is characterized in that it comprises: (a) coextruding one or more polymers through a multiple component die to form a plurality of multicomponent filaments . (b) treating the filaments to form a fiber adapted to be used as a dental fiber.

33. A method for cleaning the teeth of a mammal with a dental floss, characterized in that it comprises inserting between two teeth of a mammal a length of a dental floss comprising a plurality of multi-component coextruded filaments.

34. The method according to claim 33, characterized in that it also comprises the step of bulking the silk before insertion.

35. The method according to claim 33, characterized in that it comprises the step of bulking the silk while it is between the teeth.

36. The method in accordance with the claim 34 or 35, characterized in that the passage of the bulging comprises holding the dental floss at two separate points and stretching the region of the dental floss between the two points.