Patent Publication Number: US-8539966-B2

Title: Multi-ribbed dental tape

Description:
This application is a divisional of U.S. patent application Ser. No. 12/184,067 filed Jul. 31, 2008 now U.S. Pat. No. 8,061,371, which is a continuation-in-part application of U.S. patent application Ser. No. 11/937,025, filed Nov. 8, 2007, the entirety of which are hereby incorporated by reference as if fully set forth herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to multi-ribbed dental tapes for the removal of food particles or debris and plaque from interstices between the teeth. 
     BACKGROUND OF THE INVENTION 
     Dental floss has been in use for more than 100 years for removing plaque and entrapped food particles from between teeth, as well as providing a clean feeling in the mouth. The original floss consisted of twisted silk placed in a jar. Since then, many improvements have been made to dental floss to make flossing more convenient and less problematic. Most improvements have been aimed at solving the negative aspects of flossing. These include reducing fraying and breakage, providing easier insertion between teeth and providing a softer, more gum and hand friendly floss. With the invention of nylon, a high tenacity fray-resistant yarn was used to replace the silk, providing more fray resistance. The addition of wax to twisted multifilament yarn helped anchor fibers together, while providing a lubricious coating for easier insertion. Similarly, the use of air-entangled fibers in combination with wax (see U.S. Pat. No. 5,908,039) provided a softer, more fray-resistant, and better cleaning multifilament floss. Low friction monofilament PTFE yarn coated with wax (see U.S. Pat. No. 5,518,012) provides good ease of insertion, depending upon the thickness and lack of twists or folds, as well as improved fray resistance. Unfortunately, PTFE monofilaments do not clean well, nor do they easily remove food particles from the space between teeth due to the low coefficient of friction of PTFE. 
     Improvement in the cleaning and particle removal characteristics was attempted by providing a pseudo monofilament product by encasing multifilaments in a soft polymer, (see U.S. Pat. Nos. 6,039,054 and 6,742,528). Such flosses slide easily between teeth, provide improved resistance to the PTFE products. Further improvements to flosses were attempted by providing monofilament tapes made of elastomeric materials which neck down when passing into the interdental space and then expand upon relieving tension. A low stretch variety is taught in U.S. Pat. No. 6,591,844. While this monofilament tape exhibits a higher elongation range than commercial floss, it is inferior in softness and mouth feel and fails to provide improved cleaning. A very soft “gel” floss is taught in U.S. Pat. No. 6,029,678, where the yarn is capable of being stretched to at least 200% of its original length, and as much as 2,000% of its original length. In tape form, this floss is at least 0.010 to 0.100-inch thick and more usually from 0.020 to 0.200-inch thick. This means that, while soft, the user will have to apply significant stretch to the product to make it pass between teeth. Once placed in the interdental cavity, this floss will expand and fill the interdental cavity. However, this floss has a smooth surface and is unlikely to remove much plaque or stuck food particles. With this degree of elongation, the consumer may find it difficult to maintain the necessary tension to move the floss up and down during the cleaning process. 
     Over the years, many improvements have been made to dental floss to make flossing more convenient and less problematic. However, each improvement is typically counterbalanced with a negative effect. Consumer-use tests and clinical studies have shown the monofilament flosses slide better with less fraying, while multifilament products clean better and remove more plaque, but are subject to fraying and breaking. The present invention provides a monofilament tape that not only cleans better than conventional monofilament flosses, but maintains the positive characteristics of monofilament flosses that make them desirable to consumers, such as mouth feel, easy slide between teeth and resistance to fraying or shredding. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to monofilament dental tapes, preferably elastomeric monofilament dental tape, for removing plaque and/or food debris from interdental spaces of a mammal, which tapes include a core body having an aspect ratio of greater than about 5:1 and a first cleaning surface and a second cleaning surface opposite the first cleaning surface, where at least one of the first and second cleaning surfaces includes a plurality of ribs disposed along the length thereof, and where the ratio of the width of the dental tape to the thickness of the dental tape is from about 3:1 to about 25:1. In certain embodiments the core body of dental tapes of the present invention has an aspect ratio of greater than about 10:1 and at least about 8 ribs are disposed along the first and second cleaning surfaces. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of one embodiment of the dental tape of the present invention; 
         FIG. 2  is a perspective view of  FIG. 1  looking from the top and front; 
         FIG. 3  is an enlarged cross-sectional view of the  FIG. 1 ; 
         FIG. 4  is an enlarged cross-sectional view of another embodiment of the dental tape of the present invention; and 
         FIGS. 5   a - 5   f  are enlarged cross-sectional views of other embodiments of the ribs of the dental tape of the present invention. 
         FIGS. 6   a - 6   c  are photographs (50×) of wet pressure sensitive papers after performance of depth of deposit removal (DDR) assessment for several dental tapes. 
         FIG. 7  is a schematic illustration of one embodiment of the manufacturing line for unwinding, coating and rewinding the dental tape of the present invention. 
         FIG. 8  is a schematic illustration of one embodiment of the rewind mechanism of the present invention. 
         FIG. 9  is a perspective view of a roller coating die according to an exemplary embodiment of the present invention. 
         FIG. 10  is an exploded perspective view of a roller coating die according to an exemplary embodiment of the present invention. 
         FIG. 11  is a perspective view showing movement of a vertically oriented, dental tape through the entrance and exit blocks and rollers of a roller coating die according to an exemplary embodiment of the present invention. 
         FIG. 12  is a top plan view of a roller coating die according to an exemplary embodiment of the present invention. 
         FIG. 13  is a cross-sectional view of a roller coating die according to the exemplary embodiment of  FIG. 12  along the 13-13 plane. 
         FIG. 14  is a cross-sectional view of a roller assembly of a coating die according to the exemplary embodiment of  FIG. 12  along the 14-14 plane. 
         FIG. 15  is a bottom plan view of a coating die according to an exemplary embodiment of the present invention. 
         FIG. 16  is a top plan view of an entrance block of a coating die according to an exemplary embodiment of the present invention. 
         FIG. 17  is a right side elevational view of an entrance block of a coating die according to an exemplary embodiment of the present invention. 
         FIG. 18  is a bottom plan view of an entrance block of a coating die according to an exemplary embodiment of the present invention. 
         FIG. 19  is a front elevational view of an entrance block of a coating die according to an exemplary embodiment of the present invention. 
         FIG. 20  is a cross-sectional view of a entrance block pool and coating bores of a coating die according to the exemplary embodiment of  FIG. 16  along the 20-20 plane. 
         FIG. 21  is a top plan view of an exit block of a coating die according to an exemplary embodiment of the present invention. 
         FIG. 22  is a right side elevational view of an exit block of a coating die according to an exemplary embodiment of the present invention. 
         FIG. 23  is a bottom plan view of an exit block of a coating die according to an exemplary embodiment of the present invention. 
         FIG. 24  is a rear elevational view of an exit block of a coating die according to an exemplary embodiment of the present invention. 
         FIG. 25  is a 3 dimensional schematic illustration of one embodiment of coated roll of dental tape showing the helix angle θ formed by the strands of dental tape and the plane rΦ perpendicular to the spool&#39;s longitudinal axis z. 
         FIG. 26  is a 2 dimensional schematic illustration of one embodiment of coated roll of dental tape showing the helix angle θ formed by the strands of dental tape and side r of plane rΦ and the spacing between the individual strands of dental tape in each layer of dental tape. 
         FIG. 27  is a perspective view of a bobbin spool core. 
         FIG. 28   a  is right side elevational view of a tape bobbin with tape wound around the bobbin spool core. 
         FIG. 28   b  is a front elevational view of a tape bobbin with tape wound around the bobbin spool core showing the bobbin spool core width relative to the bobbin tape width. 
         FIG. 29   a  right side elevational view of a tape bobbin movably positioned within a dispenser (phantom lined). 
         FIG. 29   b  is a front elevational view of a tape bobbin movably positioned within a dispenser (phantom lined) depicting the relative bobbin spool core, bobbin tape and dispenser widths. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The dental tapes of the present invention are in the form of a single monofilament. As used herein, the terms “tape”, “yarn” and floss are interchangeable. The Monofilament dental tapes according to the present invention comprise a core body having first and second opposing cleaning surfaces, where at least one of the cleaning surfaces comprise a plurality of ribs disposed along the length thereof. As used herein, the term “rib” means a structural element integral with and protruding from the core body of the dental tape, which element has a configuration and dimension effective to provide for removal of plaque and/or food debris from interdental spaces of a mammal. Ribs may protrude substantially perpendicularly from the core body of the dental tape or at an angle. As used herein, the term “cleaning surface” means that surface of the dental tape that contacts the surface of the tooth when placed within the interdental space of the mammal, thereby providing for removal of plaque and/or food debris from the interdental space. The monofilament dental tape provides the tensile strength and base structure required for good dental floss properties. The dental tape can be made using commercially available material and known monofilament melt extrusion technology and equipment, it does not fray or break, is easy to hold, and readily accepts coatings. 
     Optionally, the dental tape is made using a material that provides a high degree of compressibility when extruded in the cross-sectional configurations of this invention, allowing it to slip through the tight spaces between teeth. Once in the cavity between teeth and into the interdental space, the dental tape substantially recovers from compression, providing cleaning surfaces containing ribs that act as scrapers to remove plaque and food particles from between the teeth. 
     Turning to the drawings, exemplary monofilament dental tape  10  is illustrated in  FIGS. 1-3 .  FIG. 1  shows a cross-sectional view of an embodiment of dental tape  10  comprised of core body  12  with first cleaning surface  14  and second cleaning surface  16 . In the embodiment presented, ribs  18  protrude from both first cleaning surface  14  and second cleaning surface  16 . In other embodiments, ribs may protrude from only one cleaning surface of the monofilament dental tape. The width of dental tape  10  is represented by w t , while the thickness of dental tape  10  is represented by t t . 
     The embodiment depicted in  FIG. 1  shows a total of twenty-two ribs  18  protruding from cleaning surfaces  14  and  16  of monofilament dental tape  10 , eleven from cleaning surface  14 , and eleven from cleaning surface  16 . In other embodiments of the present invention, the total number of ribs protruding from the cleaning surfaces of the dental tape may be greater than about eight, or greater than about twenty.  FIG. 1  shows eleven ribs  18  protruding from both first and second cleaning surfaces  14 ,  16  of monofilament dental tape  10 . It is to be understood, however, that in other embodiments, the number of ribs protruding from the first cleaning surface of the dental tape may be the same, about the same, or significantly different than the number of ribs protruding from the second cleaning surface. In some embodiments, all ribs may be disposed along one of the first or second ribs. In addition, though the cross-sectional profile of the monofilament dental tape  10  shown in  FIG. 1  is flat, it is to be understood that in other embodiments the dental tape can have other profiles, such as, but not limited to, arch, wave, or zig-zag. 
       FIG. 2  shows a perspective view of the  FIG. 1  embodiment of dental tape  10  with first cleaning surface  14  and ribs  18  as seen from the top front. The length of dental tape  10  is represented by l t . In  FIG. 2  ribs  18  are disposed along the entire length (l t ) of dental tape  10 . 
       FIG. 3  shows an enlarged cross-sectional view of the  FIG. 1  embodiment of dental tape  10 . The thickness of core  12  of dental tape  10  is represented by t c . The height and width of ribs  18  are represented by h r  and w r , respectively.  FIG. 3  shows an embodiment in which all ribs are uniform in height and width. It is to be understood that rib height and width can vary across the cleaning surfaces of the dental tape. For example, in one embodiment, ribs could be shorter and/or thinner at the edges of the cleaning surfaces than at the center of the cleaning surfaces. 
     The spacing between neighboring ribs  18  on first or second cleaning surface  14 , 16  of dental tape  10  is represented by s r . In  FIG. 3 , s r  is depicted as the spacing between neighboring ribs  18  on first cleaning surface  14  of dental tape  10 . However, it is to be understood that s r  could be used to measure the spacing between neighboring ribs  18  on either the first or second cleaning surfaces  14 , 16  of dental tape  10 .  FIG. 3  shows an embodiment in which the spacing (s r ) between neighboring ribs  18  on cleaning surfaces  14 , 16  of dental tape  10  are about equal for all ribs  18 . However, it is to be understood that the spacing between neighboring ribs on either cleaning surface of the dental tape do not have to be about equal. So, for example, the spacing between the first two neighboring ribs could be represented as s r1-2 , while the spacing between the next two neighboring ribs could be represented as s r2-3 , etc. It is envisioned that in other alternative embodiments of the present invention, the spacing between some sets of neighboring ribs could be about equal, while the spacing between other sets of neighboring ribs are not about equal. 
     The term s ar  is used to show the spacing between alternating ribs, that is, the spacing between a rib  18  on first cleaning surface  14  and an adjacent rib  18  on second cleaning surface  16  of dental tape  10 .  FIG. 3  shows an embodiment in which spacing between alternating ribs s.sub.ar is about one-half the spacing between neighboring ribs s r . So, the ribs on second cleaning surface  16  of dental tape  10  are offset such that they are positioned about midway between those on first cleaning surface  14 .  FIG. 4  shows an embodiment in which spacing between alternating ribs s ar  is equal to the spacing between neighboring ribs s r . So, the ribs on second cleaning surface  16  of dental tape  10  are aligned with those on first cleaning surface  14 . 
     In the exemplary monofilament dental tape  10  embodiments illustrated in  FIGS. 1-4 , the cross-sectional shape of ribs  18  is shown as rectangular with a single rounded tip on the distal end of the rib. It is to be understood that other cross-sectional rib shapes are also contemplated embodiments of monofilament ribbed dental tape of the present invention.  FIGS. 5   a - 5   f  show a number of other cross-sectional shapes of rib embodiments of the present invention. These rib shapes are just some of the shapes contemplated in the present invention, and it is to be understood that these shapes are not limiting to the spirit of the present invention. In  FIG. 5   a , the cross-sectional shape of rib  18  is shown as rectangular with a circular tip on the distal end of the rib. In other embodiments not shown, the tip on the distal end of the rib could be oval or semi-circular.  FIGS. 5   b  and  5   c  depict ribs  18  with cross-sectional shapes that are rectangular and triangular, respectively. Rib  18  shown in  FIG. 5   d  has a cross-sectional shape of similar to ribs  18  shown  FIGS. 1-4 , but rib  18  is shown protruding at an angle of alpha with respect to first cleaning surface  14  of dental tape  10 . The cross-sectional shape of rib  18  shown in  FIGS. 5   e  and  5   f  are approximately those of the English letters “T” and “V”, respectively. 
     It is to be understood that all ribs on a given embodiment of the present invention may be, but are not required to be, of the same cross-sectional shape. A mixture of cross-sectional shapes may be employed as determined by the use of the ribbed monofilament dental tape. 
     Effective flossing of teeth involves placing dental floss into the interdental space between the teeth and then drawing the floss up against the side of each individual tooth to scrub as much of the tooth surface as possible. The monofilament ribbed dental tape of the present invention is inserted into the interdental space and moved thusly. Due to the configuration and dimensions of the ribs, the ribs act like squeegees to remove and trap/hold plaque and food debris in the spacing between the respective ribs with a higher degree of efficiency than, for example, a tape that does not include such ribs disposed along the length thereof, thus providing improved cleaning of the irregular surfaces of teeth. 
     The floss must be able to pass between tight teeth, a gap of several thousandths of an inch. It must be sized to fit through the gap, or be made of a material and construction that can compress when passing into the interdental space. The monofilament ribbed dental tape of the present invention is thin in one dimension to allow it to slide between tight teeth. It is wide in the other direction to provide two substantial cleaning surfaces to contact teeth surfaces. In certain embodiments the aspect ratio of the core body will be at least about 5:1, or at least about 10:1, or even at least about 35:1. The ratio of the width of the dental tape to the thickness of the dental tape may range from about 3:1 to about 25:1, or from about 10:1 to about 20:1. 
     The monofilament ribbed dental tape of the present invention can be made using a number of materials known in the art. These materials can be elastomeric or non-elastomeric. Some non-elastomeric materials from which the dental tape can be made include nylon or polytetrafluoroethylene (PTFE). 
     In certain embodiments, the dental tape is made of a material that can compress when passing into the interdental space, and then recover a percentage of its original form upon passing into the interdental space. Accordingly, dental tapes of the present invention provide a percent compression of greater than about 50 percent and a percent recovery of greater than about 40 percent, or in certain embodiments, a percent compression of greater than about 60 percent and a percent recovery of greater than about 60 percent. Also, since teeth surfaces are not regular, the interdental space between the teeth will be irregular, having areas which are more or less open, depending on the structure of the particular adjacent teeth. As such, in certain embodiments, the ribs are flexible relative to the core body such that they easily deflect to allow passage into the interdental space. In order to achieve optimal cleaning, it is desirable to have the ribs substantially recover their original dimensions once the force is removed and regain the majority of their original height once the dental tape is in the larger area of the interdental spacing. In this way, the rib will conform to the tooth cross sectional profile, removing more plaque and food. 
     In certain embodiments, the dental tape is made using an elastomeric material. Elastomeric materials provide a high degree of compressibility when extruded in the cross-sectional configurations of this invention, allowing it to slip through the tight spaces between teeth. Once in the cavity between teeth and into the interdental space, the dental tape substantially recovers from compression, providing cleaning surfaces that act as scrapers to remove plaque and food particles from between the teeth. Elastomeric materials that may be used to form the dental tape of the present invention include, but are not limited to polyamide-polyether block copolymers sold under the tradename PEBAX (Ato Chimie, Hauts-de-Seine France), such as PEBAX 7033, 5533 MX1205, 4033, 3533, and 2533; polyester-polyether block copolymers and polyester-polyester block copolymers sold under the tradename HYTREL (E. I. du Pont de Nemours &amp; Co., Wilmington, Del.), such as HYTREL 7246, 5556, and 4056; aliphatic thermoplastic polyurethane elastomers sold under the tradename TECOFLEX (Lubrizol Advanced Materials, Inc., Cleveland Ohio); aromatic thermoplastic polyurethane elastomers sold under the tradename PELLETHANE (Dow Chemical Co., Midland, Mich.); and thermoplastic polyolefin elastomer sold under the name MULTI-FLEX (Dow Chemical Co., Midland, Mich.). A more detailed discussion regarding such elastomeric materials and their use in manufacturing dental tape can be found in U.S. Pat. No. 6,591,844 to Barlow et al. filed Aug. 23, 2001 and U.S. Pat. No. 6,029,678 to Tsao et al. filed Jan. 21, 1998, both of which are herein incorporated by reference in their entirety. 
     Dimensions of the monofilament ribbed dental tape of the present invention may be as follows. The width of the dental tape, or w t , is about 0.040 to about 0.100 inches, or about 0.070 to about 0.090 inches. The thickness of the dental tape, t t , is about 0.0035 to about 0.012 inches, or about 0.007 to about 0.009 inches. The thickness of the core body of the dental tape, t c , is about 0.001 to about 0.004 inches, or about 0.002 inches. The height of ribs  18 , h r , is about 0.0005 to about 0.004 inches, or about 0.002 inches. The width of the ribs, w r , is about 0.0005 to about 0.003 inches, or about 0.0015 inches. The spacing between neighboring ribs on the cleaning surface of the dental tape, s r , will depend on the width of the dental tape, and the number of ribs on the cleaning surface. For the monofilament ribbed dental tape of the present invention, spacing between neighboring ribs on a cleaning surface is about 0.003 to about 0.020 inches, or about 0.005 to about 0.010 inches. 
     The term s.sub.ar is used to show the spacing between alternating ribs, that is, the spacing between a rib on the first cleaning surface and a rib on the second cleaning surface of the dental tape. For the purposes of this disclosure, the ratio of s ar  to s r  defines the special relationship between alternating ribs. That ratio can vary from just greater than 0 when the ribs on the second cleaning surface are slightly out of alignment with those on the first cleaning surface, through 0.5 when the ribs on the second cleaning surface are positioned about midway between those on the first cleaning surface (see  FIG. 3 ), to 1.0 when the ribs on the second cleaning surface are aligned with those on the first cleaning surface (see  FIG. 4 ). In one embodiment of the monofilament ribbed dental tape of the present invention, the ratio of s ar  to s r  is about 0.5. 
     The monofilament ribbed dental tape of the present invention may be produced by commercial melt spinning process. In this process, the resin is fed into an extruder screw where the material is heated, melted and passed on to a melt pump. The melt pump meters the molten material into a die with a desired profile machined into the surface such that the profile is imparted on the molten extrudate as it exits the die. The extrudate passes from the die and is allowed to flow downwards and start the process of solidification. Some necking down is typical at that point. The material passes into a water bath where the solidification of polymer melt to solid tape is complete. The tape then undergoes a drawing process where it is stretched in the heated state and final characteristics are achieved. The final dental tape is wound onto spools. The spools can be placed on winding machines where the dental tape is wound into bobbins and the bobbins are placed into dispensers or, optionally, the spools are placed on coating machines first, where coatings can be applied prior to the winding operation. 
     Alternatively, the ribbed dental tape of the present invention may be comprised of multiple materials formed by co-extrusion, or lamination via rolling or adhesion processes. 
     Alternatively, the dental tape of the invention could also be produced from sheets of material. The resin would be extruded through a shaped die of the correct dimensions imparting the shape on the film. The extrudate passes from the die and is allowed to flow downwards and start the process of solidification. Some necking down is typical at this point. The material passes into a water bath where the solidification of polymer melt to solid tape is complete. The film could be slit at this point and drawn to final dimensions or it could be drawn first and then slit. 
     In certain embodiments of the monofilament ribbed dental tape of the present invention, coatings can be placed on the first or second cleaning surface of the dental tape. Coating compositions for use in the present invention must reliably adhere to the surface of the dental tape. The coating composition must have sufficient adherence to keep the coating on the surface of the dental tape during coating, winding, shipping and unwinding of the dental tape. 
     Suitable insoluble coatings include, but are not limited to, microcrystalline wax, beeswax, paraffin waxes, low molecular weight polyethylenes, silicone oils, essential oils, and mineral oil. Typically, the insoluble wax coatings have melting temperatures ranging from about 25° C. to about 100° C., optionally from about 35° C. to about 80° C. The waxes may be combined with water insoluble colorants that are FD&amp;C approved for use in the mouth. Suitable colorants include, but are not limited to, synthetically derived colorants such as FD&amp;C Blue #1 Lake, FD&amp;C Blue #2 Lake, FD&amp;C Red #40 Lake, Erythrosin Lake, Amaranth Lake, Ponceau 4R Lake, Carmoisosine Lake, Carmine Lake and colorants generated by converting a naturally derived dye to an aluminum or calcium based salt. Natural colorants such as titanium dioxide and the like may also be used. 
     The coating composition applied to the dental tape may be a soluble coating, i.e., the coating is such that it tends to dissolve or disperse in saliva present in the oral cavity. Such soluble coatings include soluble waxes or the like, which include, but are not limited to, low molecular weight polyethylene glycols (“PEGs”), such as PEG 1000 and PEG 1450. Combinations of higher molecular weight PEGs and lower molecular weight PEGs, such as a mixture of PEG 3350 and PEG 1000 may be used. Blends of liquid PEG&#39;s with high molecular weight PEG&#39;s may also be used. 
     Other coatings include meltable surfactants such as Polyoxamer 407; sialagogues; olfactory stimulants; sensates; essential oils; actives, such as fluoride; cetyl pyridinim chloride (CPC); tetra sodium pyrophosphate; whitening agents such as calcium peroxide, hydrogen peroxide, carbamide peroxide and other peroxide compounds capable of generating hydrogen peroxide in-situ; antimicrobials; anti-virals and mixtures thereof. 
     Such ingredients may be employed as solids, liquids, particles, gels, or the like, and may be encapsulated in conventional polymeric materials by conventional encapsulation techniques to form encapsulated materials having a polymeric shell and a core comprising the ingredient in one of the noted forms, as the case may be. Such ingredients also may be applied directly to the dental tapes of the present invention without the need for a coating carrier, where appropriate. 
     A coating comprising an insoluble wax may be applied, wherein the coating contains encapsulated components such as spray dried flavors, essential oils, or other ingredients protected and released from soluble spheres within the insoluble wax, or a soluble coating may be applied directly to the yarn or over the insoluble coating. The soluble coating may contain ingredients that are placed directly in the wax or through the use of spray dried or other encapsulation technologies commonly practiced within the art. 
     In certain embodiments, two insoluble coatings are applied to the dental tape. In these embodiments, the second coating composition must have a lower melting point than the first coating composition. 
     A soluble coating can be used by itself or as a second coating over an insoluble coating. One or both coatings can contain colorants, flavors, sweeteners, abrasives, anti-tartar agents, actives, such as fluoride salts, and like additives known in the art. 
     Additional components can be added to coatings for various benefits. These include flavor systems, such as spray dried flavors, flavor enhancers, and sweeteners, such as sodium saccharin. The amount of flavor added typically ranges from 10 percent to 25 percent, based on the total weight of the coating composition. The amount of sweetener typically ranges from 0.1 percent to 1 percent, based on the total weight is of the coating composition. 
     Other components can be added to coatings to assist in cleaning the teeth. These include actives including abrasives such as silica or di-calcium phosphate, and anti-tartar agents such as tetra-sodium-pyrophosphate. Where two coatings are used, actives are usually added in the second soluble coating to guarantee that a high percentage of the active will be released from the floss during use. 
     In formulating a coating, it is desirable to limit the amount of solid additives in the coating composition below about 30% by weight. Coating a dental tape with a coating composition having a solid additive content above this amount may cause difficulty in achieving uniformity of coating and reduce the ability of the coating to adhere to the tape surface. Coatings containing high amounts of solid additives may tend to flake off during processing and during use of the final product. 
     The dental tape coating may be anhydrous or hydrous. When the coating is hydrous, the water is evaporated upon drying. 
     The coating may be applied as an add-on typically ranging from about 10 percent to about 60 percent, optionally from about 20 percent to about 50 percent, based on the weight of the fiber substrate. 
     In certain embodiments, the dental tape is manufactured using equipment and processes capable of doing the following:
         1. Feeding monofilament tapes made of elastomeric materials to a coating die at a controlled speed and tension so as to avoid telescoping issues,   2. Pumping the coating composition in a uniform fashion into the coating die,   3. Uniformly and simultaneously applying the coating composition to both sides of the dental tape, and   4. Providing a sufficient period of time during which the coating composition is substantially undisturbed on the dental tape until it is solidified intact.       

     By “uniform” or “substantially uniform,” it is meant that, when manually (without the aid of measuring instrumentation) or visually (without the need for magnifying devices beyond corrective eyewear) inspected, the coating should have an even (or relatively [or, substantially] even) thickness and be free from (or sufficiently [or substantially] free from) defects (such as pinholes or voids) in the coated area. The above-mentioned process for manufacturing the elastomeric monofilament dental tape of the invention is illustrated in  FIG. 7 . In the first step, the coating composition  5 , typically a wax, is liquefied if necessary, as by heating, in a mix tank  40 . A high sheer mixer  42 , such as a Rotostat High Sheer Mixer Model #XPBL, made by Admix, can be used to keep coating composition  5  homogeneous. Typically, a Rotosolver head blade is used in the high sheer mixer  42  and is operated at, e.g., 1700 rpm. 
     The coating composition is then allowed to flow from mix tank  40 , via a first pipe  44  into a positive displacement pump  46  which, when driven at a given speed, delivers a constant amount of coating, via a second pipe  48 , to a coating die  50 . The positive displacement pump can be a vane type positive displacement pumps, piston pumps, or similar type pumps. In certain embodiments, a Kerr piston pump, supplied by Kerr Corp., Sulfur, Okla., is used. Piston pumps, generally, facilitate the evenness and uniformity of coatings where the coating composition  5  contains solid particulates such as abrasives. In certain embodiments, positive displacement pumps are used since the passages bores, pipes, channels or outlets used in such embodiments to deliver coating composition  5  are generally positioned or oriented such that the directional path or track of the passage bores, pipes, channels or outlets points upwardly and toward or horizontally level with and toward the position of the dental tape  10  to be coated such that gravity has no effect or minimal effect on the flow of the coating composition from mix tank  40  onto the dental tape  10 . 
     In certain embodiments, the dental tape  10  is simultaneously fed and pulled through the process by a combination of a powered unwinding system  20  and a floss rewinding system  70 . The dental tape  10  is fed or unwound at a low tension and, in certain embodiments, pulled perpendicularly from feed spool  22  across or through sensing arm assembly  30 . Sensing arm assembly  30  is provided for monitoring the tension of the dental tape  10  as it enters coating die  50 . In certain embodiments, the sensing arm assembly  30  has an arm  32 , a pivot point  34 , and rollers  36  over which the dental tape  10  passes. Sensing arm assembly  30  is used to maintain a substantially constant low feeding or unwinding tension on dental tape  10  by adjusting the speed of power unwinding system  20  as it is simultaneously fed and pulled into the coating process system. In certain embodiments, where the dental tape passes through the coating process at line speed rates greater than about 1000 fpm, or optionally from about 1500 fpm to about 2500 fpm, or optionally from about 2000 fpm, the constant low unwinding tension is generally maintained at from about 50 grams-force to about 100 grams-force, optionally at from about 60 grams-force to about 100 grams-force for dental tape  10  having denier of about 400 to about 1200. 
     After coating, dental tape  10  is collected on a take-up spool  72 . The speed at which take-up spool  72  operates is controlled by an electronic controller system. The controller may be a computer, a programmable logic controller or similar device. In the embodiment shown in  FIG. 7 , a speed sensing roll  74  rides on surface of the tape on take-up spool  72 . Speed sensing roll  74  generates a signal which is fed to an electronic controller, such as a Fenner M-drive. The controller controls the voltage of motor  80  (shown in  FIG. 8 ) which drives the speed of take-up spool  72 . The use of the signal generated by speed sensing roll  74  in controlling the speed of take-up spool  72  helps to maintain a constant speed or velocity of the dental tape  10  through the coating process, controlling and maintaining the tension on dental tape  10  to less than 250 or (about 250) grams-force. The electronic controller also controls the speed of positive displacement pump  46 . Thus the velocity of dental tape  10  is maintained while a constant amount of coating composition  5  is pumped into the coating die  50 . 
     In certain embodiments, not shown in  FIG. 7 , the coating die  50  contains at least two rollers around which elastomeric dental tape  10  has at least some wrap. In certain embodiments, the number of rollers can range from 2, optionally 3, optionally 4 or greater rollers, or optionally 2 to 7 rollers or, optionally, from 3 to 5 rollers. Generally, dental tape  10  wraps around the rollers at from about 90° to about 270°. The rollers assist in applying coating composition  5  to dental tape  10 . Downstream of the rollers there is typically a slot die region where coating composition  5  is smoothed onto the surface of dental tape  10 . In certain embodiments, the slot die is in the form of a groove having parallel sides or walls, the groove, optionally, having a radius at its bottom for guiding the dental tape into a slot. In certain embodiments, the slot is sized such that excess coating is removed from dental tape  10  as it passes through the die (as shown at  FIG. 14 ) while, at the same time, minimizing any additional tension on dental tape  10  caused by the slot die as the tape  10  passes through the die. As will be apparent to those skilled in the art, the dimensions of the groove and slot will depend upon such factors as the denier and type of elastomeric monofilament dental tape  10  and the amount of coating composition  5  being applied thereto. 
     In certain embodiments, a coating die useful in coating high surface area elastomeric dental tapes may be used. Such coating dies are adapted to receive or orientate the dental tape  10  such that the planar surface of the dental tape  10  is in a vertical position (or oriented such that the width dimension of dental tape  10  is perpendicular to horizontal plane of the coating die base) (as described in  FIG. 11 ). Without being limited by theory, it is believed that such a vertical orientation better facilitates evenness and uniformity of the coating across the sides of the planar surface of the dental tape  10  than does movement of a horizontally oriented tape through the coating die. 
     One embodiment of a coating die useful in coating high surface area elastomeric dental tapes is shown in  FIGS. 9 to 24 .  FIG. 9  is a perspective view of roller coating die  110 , including roller die base  120  and cover plate  140 . Uncoated elastomeric dental tape  250  enters coating die  110  such that the planar surface of the dental tape  250  is vertically oriented or oriented such that its width dimension of dental tape  250  is perpendicular to roller die base  120 . Dental tape  250  traverses vertically along cover plate die slot  144  and roller assemblies  200 , and exits as vertically oriented, coated dental tape  252 .  FIG. 9  shows three sections of cover plate slot  144 . Slot  144   a  traverses from the die entrance to entrance block window  142 . Slot  144   b  traverses from entrance block window  142  to roller assemblies  200 . Slot  144   c  traverses from roller assemblies  200  to the die exit. 
     Optionally, heaters can be incorporated into or associated with the coating dies of the present invention. The heaters are used to provide temperatures sufficient to keep the coating composition, typically a waxy material, flowable or in a liquid state. Such temperatures typically range from 180° F. to about 200° F.  FIG. 9  shows an exemplary embodiment of the present invention having two cartridge heaters  134 , which can be used for heating the rollers and/or other components of coating die  50 . 
       FIG. 10  is an exploded perspective view of roller coating die  110 , showing more details of roller die base  120  and cover plate  140 . In addition to the three sections of cover plate slot  144  and cover plate window  142 , five roller wheel windows  146 , and four cover plate attachment holes  152  are shown on cover plate  140 . Cover plate attachment holes  152  align with roller die base attachment holes  132 . Roller die base attachment holes  132  are threaded. Threaded handle  154  is used to hold together roller die base  120  and cover plate  140 . 
     Roller die base  120  includes entrance block recess  122 , roller assembly recesses  126 , exit block recess  128 , roller die base attachment holes  132 , and entrance and exit block attachment holes  136 .  FIG. 10  shows two sections of base slot  124 . Base slot  124   a  traverses from entrance block recess  122  to roller assembly recesses  126 . Slot  124   b  traverses from roller assembly recesses  126  to exit block recess  128 . Entrance and exit block attachment holes  136  are threaded. 
       FIG. 10  also shows entrance block  160 , exit block  180 , as well as five rollers  202 . Entrance block  160  and exit block  180  are positioned between roller die base  120  and cover plate  140 , and are used to guide uncoated dental tape  250  from the entrance of coating die  110  to roller assemblies  200 , and coated dental tape  252  from roller assemblies  200  to the exit of coating die  110 . 
       FIG. 11  is a perspective view showing details of how roller coating die  110  transforms uncoated elastomeric dental tape  250  to coated elastomeric dental tape  252 .  FIG. 11  shows uncoated dental tape  250  proceeding into entrance block  160  at a vertical orientation and travelling along entrance block slot  162 . Entrance block slot  162  is sized wide enough to produce minimal tension on the vertically oriented, uncoated dental tape  250 , but narrow enough that gravity does not cause the lower portion of the uncoated dental tape  250  to receive more coating than the upper portion of the uncoated tape  250 . Coating travels vertically through base passage hole  138  to entrance block pool  172 , and splits into two coating bores (or passages)  174 . In one embodiment, uncoated dental tape  250  is coated simultaneously on both sides as it passes coating bores  174 . Coated dental tape  252  then passes around rollers  202  with at least some wrap while maintained in its vertical orientation. Generally, coated dental tape  252  wraps around the rollers at from 90° to 270°. Rollers  202  assist in uniformly applying coating composition to coated dental tape  252 . Though  FIG. 11  shows five rollers, it is understood that coated dental tape  252  may pass around as few as one roller, or as many as about twenty or more rollers. Downstream of rollers  202  is exit block  180 . Coated dental tape  252  proceeds into exit block  180  still vertically oriented and travels along exit block slot  182  which aid in maintaining the vertical orientation of dental tape  252 . As mentioned above, the width  182   a  of exit block slot  182  is sized to provide coating composition  5  an additional opportunity to be smoothed onto the surface of coated dental tape  252  and also removes excess coating composition  5  while at the same time minimizing any additional tension caused by movement of dental tape  252  through exit block  180 . 
     Note that all slots discussed above, including cover plate slots ( 144   a ,  144   b ,  144   c ), base slots ( 124   a ,  124   b ), entrance block slot  162 , and exit block slot  182  may be in the form of a groove having parallel sides or walls, the groove optionally having a radius at its bottom. As will be apparent to those skilled in the art, the dimensions of the groove will depend upon such factors as the denier and type of uncoated dental tape  250  and the amount of coating composition being applied thereto. 
       FIG. 12  is a top view of an embodiment of coating die  110  showing details of the cover plate  140  and the monofilament coating path.  FIG. 12  shows uncoated dental tape  250  proceeding into entrance block  160  where it is coated. Coated dental tape  252  proceeds around roller assemblies  200  to exit block  180  and out of a coating die  110 . Entrance block  160  is partially hidden by cover plate  140 , but is visible through cover plate window  142 . Roller assemblies  200  can be seen through roller wheel windows  146 . Exit block  180  is hidden by cover plate  140 , but coated dental tape  252  is visible through cover plate slot  144   c .  FIG. 12  also shows threaded handle  154 , which are used to hold cover plate  140  to roller die base  120 , as well as alignment holes  156  to align cover plate  140  to roller die base  120  prior to attaching the two. 
       FIG. 13  is a cross-sectional view of the coat die  110  embodiment of  FIG. 12  along plane  13 - 13 .  FIG. 13  shows uncoated dental tape  250  proceeding into entrance block  160 . Coating travels vertically from second pipe  48  (or coating dispensing pipe receiving coating from displacement pump  46 ) through base hole  138  to entrance block pool  172 , and splits into two coating bores  174  ( FIG. 13  shows one of the two bores). In one embodiment, uncoated dental tape  250  is coated simultaneously on both sides as it passes coating bores  174 .  FIG. 13  also shows coated dental tape  252  travelling through exit block  180  and out of a coating die  110 . Threaded handles  154 , which are used to hold cover plate  140  to roller die base  120 , as well as cartridge heaters  134 , which can be used if needed to keep coating composition, in a liquid state, are also shown in the figure. 
       FIG. 14  is a cross-sectional view of the embodiment of  FIG. 12  along plane  14 - 14 .  FIG. 14  shows cover plate  140 , roller die base  120 , cartridge heaters  134 , as well as detailed view of roller assembly  200 . Roller assembly  200  includes roller  202  which assist in uniformly applying coating composition to coated dental tape  252 . In certain embodiments, one end of stub shaft  210  is disposed in center of roller  202 , and attached to roller  202  by cap screw  204 , flat washer  206 , and lock washer  208 . The central portion of stub shaft  210  is disposed in inner ring shield bearing  212 . The opposing end of stub shaft  210  is disposed in bearing retainer  220 , and attached to bearing retainer  220  by cap screw  204 , flat washer  206 , and lock washer  208 . Bearing retainer  220  is attached to roller die base  120  by bearing retainer cap screw  222  and bearing retainer lock washer  224 . In one embodiment, three sets of cap screws  222  and lock washers  224  are used to attach bearing retainer  220  to roller die base  120 . However, one skilled in the art could use more or less screws to attach the two, or other means of attachment known in the art. Finally, inner ring shield bearing  212  is kept approximately centered in roller assembly recess  126  and roller wheel window  146 , by outer race spacer  214 . 
       FIG. 15  is a bottom view of an embodiment of a roller coating die of the present invention. The  FIG. 15  shows five roller assemblies  200 , base hole  138 , cartridge heaters  134 , and alignment holes  156  on roller die base  120 . An O-ring  139 , is used to prevent leakage of coating composition between positive displacement pump and roller die base  120 . Alignment holes  156  are used to align cover plate  140  to roller die base  120  prior to attaching the two. 
       FIGS. 16 through 20  show details of entrance block  160 . The  FIG. 16  shows entrance block slot  162  and entrance block slot guide  164 . Entrance block slot guide  164  is a V-shaped or tapered cut in entrance block  160  to guide uncoated dental tape  250  into entrance block slot  162 . The entrance block slot  162  is sized at a width  162   a  such that it maintains the vertical orientation of uncoated dental tape  250  through the entrance block  160 , as well as facilitate coating as mentioned above, with little to no additional tension on the dental tape  250 . Uncoated dental tape  250  travels along entrance block slot  162  to where it is coated. Coating travels vertically from entrance block pool  172  into two coating bores  174 . Uncoated dental tape  250  is coated simultaneously on both sides as it passes coating bores  174 .  FIGS. 16 to 18  show two optional entrance block holes  166  which may be used to attach entrance block  160  to roller die base  120 . 
       FIGS. 21 through 24  show details of exit block  180 .  FIG. 21  shows exit block slot  182  and entrance block slot guide  184 . Entrance block slot guide  184  is a V-shaped cut in exit block  180  to guide coated dental tape  252  into exit block slot  182 . Exit block slot  182  allows coating composition an additional opportunity to be smoothed onto the surface of coated dental tape  252 . The width  182   a  of exit block slot  182  is sized to provide coating composition  5  an additional opportunity to be smoothed onto the surface of coated dental tape  252  and also removes excess coating composition  5  while at the same time minimizing any additional tension caused by movement of dental tape  252  through exit block  180 . Coated dental tape  252  travels along exit block slot  182  until it leaves roller coating die  110 .  FIGS. 21 to 23  show two optional exit block holes  186  which may be used to attach exit block  180  to roller die base  120 . 
     While illustrated as separate components, it will be readily understood by the skilled artisan that entrance block  160  and exit block  180  (along with their distinct structural characteristics) can be integral with roller die base  120  and/or cover plate  140  without changing the performance or function of coating die  110 . Maintaining entrance block  160  and exit block  180  as separate components, however, provides the convenience of interchangeability. For example, separate entrance block  160  and exit block  180  components allow for the interchange of entrance block  160  and/or exit block  180  with entrance and exit blocks of differing slot ( 162 ,  182 ) and slot guide ( 164  and  184 ) widths. 
     Coating composition  5  once applied to dental tape  10  must be solidified. Solidification can be accomplished by having a cooling area  60 . Cooling area  60  can be an open area where coating  5  cools under ambient conditions. Alternatively, cooling area  60  can be a chamber where refrigerated or room air is blown over dental tape  10  to increase the rate of cooling. In order to avoid undesirable discontinuities in coating  5 , dental tape  10  should not contact any surfaces until coating  5  has solidified. 
     Once coating  5  is cooled sufficiently to prevent any disruption of the outer surface, it is rewound on floss rewinding system  70 . Rewinding system  70 , shown in  FIG. 8 , has take-up spool  72  and speed sensing roll  74  as described before, as well as a drive motor  80 , a series of timing belts (all labeled  84 ) and timing belt pulleys (all labeled  82 ), and a traversing cam guide  76  disposed on a traverse barrel cam  86 . For 6 pound rolls or less, optionally 5 pounds or less, or optionally 4 pounds of less of dental tape rolled onto spool  72 , the tension of the dental tape  10  is monitored using conventional tension measuring devices (such as Checkline, supplied by Electromatic Equipment Co., Cedarhurst, N.Y.) prior to rewinding and the speed adjusted accordingly such that the tension of the dental tape  10  during rewinding process is less than 300 (or about 300) grams-force, optionally less than 250, (or about 250) grams-force or optionally from about 190 grams-force to about 200 grams-force. Traversing cam guide  76  and traverse barrel cam  86  are disposed in an traversing cam guide housing  78  which has a traversing cam guide housing slot  79 . 
     Rewinding system  70  is a traversing rewinder in that as take-up spool  72  rotates, traversing cam guide  76  is traversed back and forth along its length (see  FIG. 8 ). The take-up spool  72  has a longitudinal axis z; a plane rΦ which is perpendicular to longitudinal axis z. and a circumference C (equal to the product of the spool core diameter d s  and π) as shown in  FIG. 25 . Rewinding system  70  functions as follows: spindle  81  of motor  80  rotates to drive timing belt pulley  82   a , which, through timing belt  84   a , drives timing belt pulleys  82   b  and  82   c . Timing belt pulley  82   b  drives timing belt pulley  82   d , which, in turn, drives timing belt pulley  82   e  via timing belt  84   b . Timing belt pulley  82   e  is disposed on the end of take-up spool  72 , so as it rotates, take-up spool  72  rotates. Timing belt pulley  82   c , via timing belt  84   c , drives timing belt pulleys  82   f  and  82   g . Timing belt pulley  82   g  drives timing belt pulley  82   h  via timing belt  84   d . Timing belt pulley  82   h  is disposed on the end of traverse barrel cam  86 , so as pulley  82   h  rotates, traverse barrel cam  86  rotates. Traversing cam guide  76  is disposed on traverse barrel cam  86  such that when traverse barrel cam  86  rotates, traversing cam guide  76  traverses back and forth along its length. Suitable traversing rewinders can be readily built or purchased from companies such as Leesona Corporation. 
     In certain embodiments, the pulley sizes and traverse barrel cam are selected for the rewinding system as described below:
         a.) the pulleys are selected (or adjusted) such that the product of the pulley ratios or Ratio A (which determines the traversing movement of traversing cam guide (inches) per revolution of Spool  72  (inches)) is as follows:
 
Ratio  A=P   1   /P   2   ×P   3   /P   4   ×P   Z-1   /P   Z  
           Where P.sub.1 through P.sub.Z are the pulley sizes of the sequentially ordered pulleys from the pulley rotating the take-up spool  72  or P.sub.1 to the pulley rotating traverse barrel cam  86  or P.sub.Z used in association with   
           b.) the traverse barrel cam  86 , which is selected such that the product of the cam advance (or, total length [end to end] traversed by traversing cam guide  76  divided by the turns of the traverse barrel cam  86  needed to achieve the total traverse of traversing cam guide  76 ) and Ratio A when divided by the circumference C of the core of take-up spool  72  (i.e., take-up spool  72  without tape  10 ) produces a Ratio B, where
 
Ratio  B =(cam advance  × Ratio  A )/Circumference  C  
           and where Ratio B provides a helix angle θ of from about 3.5 degrees to about 5 degrees, where the helix angle θ is formed by a strand of dental tape and plane rΦ of the spool  72  which is perpendicular to the longitudinal axis z of the spool  72  as shown in  FIGS. 25 and 26  and is determined by formula:
 
sin−1(Helix Angle θ)=Ratio  B  
   
               

     Without being limited by theory, it is believed that obtaining a helix angle θ of about 3.5 degrees to about 5.5 degrees provides take-up spool rolls  72  of dental tape  10  such that:
         i) in any given layer of the dental tape, the strands of dental tape  10  forming that layer do not overlap, or optionally do not touch or optionally have a space therebetween t.sub.s of up to 1/32 (or about 1/32) of an inch and   ii.) the strands of dental tape  10  forming each layer of dental tape  10  overlap with the strands of dental tape  10  forming the preceding layer of dental tape  10  to form intersection angles of about 7 to about 11 degrees (or twice the helix angle θ)       

     If it is desired to apply a second coating to dental tape  10 , this may be done by locating another coating line and cooling chamber downstream of cooling area  60 . 
     In certain embodiments, spool  72  dental tape  10  is then removed for later processing into bobbins  90 . Bobbins of tape as shown in  FIGS. 28   a  and  28   b  are formed from dental tape  10  unwound from spool  72  onto bobbin spool cores  92  of selected width w c  as shown in  FIG. 27  and packaged into dispensers  95  of selected width w d  for use by consumers as shown in  FIGS. 23   a  and  23   b . In certain embodiments, the bobbin spool cores  92  have an aspect ratio of greater than about 2:1, optionally about 3:1, where the aspect ratio is the ratio of bobbin spool diameter to width. The dental tape  10  winds from spool  72  onto the bobbin spool cores  92  to form tape bobbins where the wound tape widths w b  such that wound tape width w b  exceeds the width of the bobbin spool core w c  by no more that 10% (or about 10%), optionally, 5% (or about 5%), optionally 2.5% (or about 2.5%), optionally 1% (or about 1%). Hence, the inventive rewinding system  70  which produces helix angles θ of from about 3.5 degrees to about 5.5 degrees ensures that the wound tape widths w b  of the finished tape bobbins formed from spool  72  do not telescope so as to interfere with the packaging of the finished tape bobbin into dispensers  95  specifically designed to movably accommodate bobbin spool cores  92  of widths w c . More generally, the inventive rewinding system  70  permits the use of narrower width dispensers particularly in cases where the tape or floss is made of an elastomeric material. 
     EXAMPLES 
     Dental tapes illustrated in following examples illustrate specific embodiments of the dental tapes of the present invention, but are not intended to be limiting thereof. Other modifications can be undertaken by the skilled artisan without departing from the spirit and scope of this invention. 
     Example 1 
     Dental tape of the invention was produced using PEBAX MX 1205 resin. The resin was dried for over 3 hours at 75° C., fed into a Haake 20 mm extruder with a Slack and Parr gear melt pump attached and extruded through a shaped die formed of stainless steel, and having a cross-section similar to that of the dental tape shown in  FIG. 1 . The extruded dental tape included eleven ribs protruding from both the first and second cleaning surfaces. The overall width of the slot (w t ) was 0.303 inches. The thickness of the core body of the die (t c ) was 0.0035 inches. The height and width of the rib portions of the die (h r  and w r ) were 0.0075 inches and 0.0035 inches, respectively. The spacing between neighboring ribs on both cleaning surfaces (s r ) was 0.026 inches, and the ratio of s ar  to s r  was 0.5, i.e. the ribs on the second cleaning surface were positioned about midway between those on the first cleaning surface. 
     The extruded tape passed through a room temperature water bath and was wound on a spool. 
     One extrusion was performed using the shaped die to prepare the dental of the invention. For comparison, two extrusions were performed through a flat die to prepare comparative dental tapes with no ribs. For Run 2, the die thickness and width were 0.085 inches and 0.490 inches, respectively. For Run 3, the die thickness and width were 0.012 inches and 0.350 inches, respectively. 
     The conditions for the three extrusions are shown on Table I: 
     
       
         
           
               
             
               
                 TABLE I 
               
             
            
               
                   
               
               
                 Extrusion conditions. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 1 
                 Run 2 
                 Run 3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Die 
                 shaped 
                 flat 
                 flat 
               
               
                   
                 Barrel T (Zones 1-6), ° C. 
                 195 
                 220 
                 213 
               
               
                   
                 Die T, ° C. 
                 203 
                 233 
                 216 
               
               
                   
                 Flow rate, cc/min 
                 4.8 
                 4.3 
                 6.4 
               
               
                   
                 Die to water bath, inches 
                 1 
                 3 
                 7 
               
               
                   
                 Take-up speed, feet/min 
                 20 
                 24 
                 24 
               
               
                   
                   
               
            
           
         
       
     
     The tapes from the three extrusion runs were subjected to drawing operations to produce the final dental tapes. In the drawing operation, the tape was unwound from the spool, passed over a heated roller, across a hot plate, and rewound on a second roller. Conditions for the three drawing runs are shown on Table II: 
     
       
         
           
               
             
               
                 TABLE II 
               
             
            
               
                   
               
               
                 Drawing conditions. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 1 
                 Run 2 
                 Run 3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Roll 1 T, ° C. 
                 60 
                 60 
                 60 
               
               
                   
                 Plate T, ° C. 
                 100  
                 90 
                 60 
               
               
                   
                 Roll 1 Speed, meter/min 
                  2 
                  2 
                  2 
               
               
                   
                 Roll 2 Speed, meter/min 
                 18 
                 14 
                 12 
               
               
                   
                 Draw ratio 
                 9 to 1 
                 7 to 1 
                 6 to 1 
               
               
                   
                   
               
            
           
         
       
     
     Some of the tape from Run 1 was coated with a microcrystalline wax, W445 supplied by Crompton (Petrola, Pa.). This tape was designated as Run 1 a . To coat the tape, the tape was pulled through a bath containing the wax at 88° C. Upon leaving the bath, excess wax was removed. The average weight of wax applied was 52% of the weight of the final tape. 
     The overall width, thickness, and denier of the tapes were measured and are summarized on Table III: 
     
       
         
           
               
             
               
                 TABLE III 
               
             
            
               
                   
               
               
                 Tape dimensions. 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Run 1 
                 Run 1a 
                 Run 2 
                 Run 3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                 Width, inches 
                 0.075 
                 0.080-0.090 
                 0.073 
                 0.072 
               
               
                 Thickness, inches 
                 0.005 
                 0.006-0.008 
                 0.005 
                 0.002 
               
               
                 Denier 
                 1008 
                 NA 
                 1586 
                 861 
               
               
                   
               
            
           
         
       
     
     The compression and recovery expansion of the tapes made above were measured using an apparatus comprised of 2 steel shafts that are used to simulate two adjacent teeth surfaces. One of the steel shafts was stationary, while the other shaft pivoted. A thickness indicator was set to zero when the moving shaft was resting on the fixed shaft. The tape was placed at a ninety-degree angle to the axis of the stationary shaft. The moveable shaft, constructed so as to exert little pressure on the nip point, was allowed to rest on top of the tape, and the original thickness (t o ) reading was taken from the indicator. Next, a one-pound weight was applied directly above the nip point, and the compressed thickness (t c ) reading was recorded. The percent compression was calculated as
 
Percent Compression=100×( t   o   −t   c )/ t   o  
 
     A measure of the recovery expansion of the tape was obtained using this device by removing all force and noting the recovery thickness (t r ) reading on the indicator. The percent recovery was calculated as:
 
Percent Recovery=100×( t   r   −t   c )/( t   o   −t   c )
 
     The percent compression and percent recovery of each of the tapes were measured, and the results are summarized on Table IV: 
     
       
         
           
               
             
               
                 TABLE IV 
               
             
            
               
                   
               
               
                 Tape compression and recovery. 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Run 1 
                 Run 1a 
                 Run 2 
                 Run 3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                 Original Thickness, 
                 0.005 
                 0.006-0.008 
                 0.005 
                 0.002 
               
               
                 inches 
               
               
                 Compression, % 
                 70 
                 54 
                 31 
                 25 
               
               
                 Recovery, % 
                 67 
                 52 
                 93 
                 100 
               
               
                   
               
            
           
         
       
     
     Next, the tensile properties and tenacity of the tapes were measured using an Instron universal testing machine with a specimen length of 10 inches, and a cross-head speed of 10 inches per minute. 
     The tensile strength, percent elongation at break and tenacity of each of the tapes were measured, and the results are summarized on Table V: 
     
       
         
           
               
             
               
                 TABLE V 
               
             
            
               
                   
               
               
                 Tape tensile properties. 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Run 1 
                 Run 1a 
                 Run 2 
                 Run 3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                 Tensile strength, lbs 
                 7.5 
                 8.1 
                 9.8 
                 6.5 
               
               
                 Elongation at Break, % 
                 64 
                 165 
                 87 
                 52 
               
               
                 Tenacity, grams/denier 
                 3.7 
                 3.6 
                 2.8 
                 3.1 
               
               
                   
               
            
           
         
       
     
     A comparison of the cleaning ability of a number of flosses and tapes was next conducted. The process used is summarized in a paper by Yankel, S. L., et al., “Laboratory Evaluations of Three Dentifrices with Polishing or Brushing”, Journal of Clinical Dentistry, 9(3):61-63 (1998). In short, the wet pressure-sensitive paper described in Yankel was placed on the ⅜″-diameter upright shaft. The floss or tape being tested was strung through the eyelets, which pulled the floss back 0.100 inch on either side of the shaft. The eyelets were located equal distance and 1 inch from the centerline of the shaft. A tension of approximately 250 grams force was placed on the floss. The floss was wetted with deionized water from a spray bottle, and the tape or floss was passed up and down on the paper (¾-inch stroke distance), abrading the paper fibers and exposing the various colored surfaces. The paper was removed after 5 cycles and saved for comparison. The Depth of Deposit Removal (DDR) was recorded using a 0-4 scale from a comparative color chart. 
     The tape from Run 1, made as discussed above, was tested, as were two commercially available dental flosses. The commercially available dental flosses were a monofilament coated floss sold under the trade name GLIDE ORIGINAL (Proctor &amp; Gamble, Cincinnati, Ohio), and a wax-coated multifilament floss sold under the trade name REACH MINT WAXED (PPC Division of McNeil-PPC, Inc. Skillman, N.J.). 
       FIGS. 6   a - 6   c  are photographs of wet pressure sensitive papers after performance of depth of deposit removal (DDR) assessment described above for the noted dental flosses and tapes. The images are at magnifications of 50×. The flossing pattern is diagonal with respect to the image from the top right to bottom left. Table VI shows a comparison of the Depth of Deposit Removal (DDR) values for the tapes tested. 
     
       
         
           
               
             
               
                 TABLE VI 
               
             
            
               
                   
               
               
                 Depth of Deposit Removal (DDR) for Noted Flosses and Tapes 
               
            
           
           
               
               
               
               
            
               
                   
                 Floss/Tape 
                 DDR 
                 Figure 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 REACH MINT WAXED 
                 1.0 
                 6b 
               
               
                   
                 GLIDE ORIGINAL 
                 0.25 
                 6a 
               
               
                   
                 Run 1 
                 1.25 
                 6c 
               
               
                   
                   
               
            
           
         
       
     
     The results showed that the ribbed dental tape of the invention performed as well as or somewhat better than the multifilament REACH MINT WAXED floss, and superior to the monofilament GLIDE ORIGINAL floss. 
     Finally, a comparison of the toughness of a number of tapes and flosses was conducted. In brief, a toughness tester as described in U.S. Pat. No. 5,908,039 (FIGS. 3 and 4), which is incorporated by reference herein, was used. Rather than using teeth in this test, two metal posts were used to replace teeth, shown in FIG. 4 of U.S. Pat. No. 5,908,039. Item 21 was a steel cylinder, 0.375 inch diameter by 0.725 long with a threaded surface. The thread was 0.01 inches deep with a pitch of 0.02 inches. This represents a rough, although not sharp, surface. Item 22 was a conical smooth cylinder, 0.725 inches long. The base of the cone was 0.15 inches in diameter. The cone diameter increased to 0.375 inched in diameter over a length of 0.57 inches, and remained 0.375 inches for 0.025 inches. The diameter then decreased to 0.125 over the remaining length. A spring force, item 24, was set to exert 1.75-lbs force on tooth 22. The floss or tape to be tested was strung between the simulated teeth. The floss or tape was held with a tension of approximately 250 grams force and the cylinders were move up and down. This was repeated until the tape or floss broke. The test was repeated ten times on each of the tapes or flosses being tested. 
     The tapes from Runs 1, 1 a , and 2, made as discussed above, were tested, as were commercially available dental flosses. The commercially available dental flosses were GLIDE ORIGINAL, GLIDE COMFORT, a lightly waxed monofilament flosses, and REACH MINT WAXED. 
     A comparison of the cycles to failure for each of the tapes and flosses tested are summarized on Table VII: 
     
       
         
           
               
             
               
                 TABLE VII 
               
             
            
               
                   
               
               
                 Cycles to Failure for Various Flosses and Tapes 
               
            
           
           
               
               
               
            
               
                   
                 Floss 
                 Average 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 MintWaxed 
                 4.8 
               
               
                   
                 Glide Original 
                 7.6 
               
               
                   
                 Glide Comfort 
                 4.7 
               
               
                   
                 Run 1 
                 8.2 
               
               
                   
                 Run 1a 
                 10.3 
               
               
                   
                 Run 2 
                 2.4 
               
               
                   
                   
               
            
           
         
       
     
     Table VII shows the floss of Run 1a has higher average cycle to failure than all others. Run 2 used the same material as Run 1 and 1a, but with a flat cross-section. Surprisingly, Run 1 exhibited a significantly higher cycle to failure than Run 2. While not intending to be bound by the theory, it is believed that the presence of ribs along the surface of the core body of the monofilament tape protects the monofilament tape from shredding, thereby providing a dental tape that not only cleans better than a tape without ribs, as shown in Table VI, but that is stronger and more resistant to shredding. 
     Example 2 
     Dental tape of the invention was produced using several other resins. The resins used are listed on Table VIII. 
     
       
         
           
               
               
             
               
                   
                 TABLE VIII 
               
               
                   
                   
               
               
                   
                 Resin 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Run 4 
                 HYTREL 4056 
               
               
                   
                 Run 5 
                 HYTREL 4056 
               
               
                   
                 Run 6 
                 PELLETHANE 2363-90AE 
               
               
                   
                 Run 7 
                 MULTIFLEX 1047S 
               
               
                   
                 Run 8 
                 TECOFLEX EG-100A 
               
               
                   
                   
               
            
           
         
       
     
     The resins were dried for over 3 hours at 75° C. They were processed in the extruder of Example 1, using the ribbed die described in Example 1. 
     The conditions for the extrusions are shown on Table IX: 
     
       
         
           
               
             
               
                 TABLE IX 
               
             
            
               
                   
               
               
                 Extrusion conditions. 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Run 4 
                 Run 5 
                 Run 6 
                 Run 7 
                 Run 8 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Barrel T (Zones 1-6),° C. 
                 230 
                 225 
                 200 
                 260 
                 187 
               
               
                 Die T, ° C. 
                 239 
                 235 
                 202 
                 262 
                 189 
               
               
                 Flow rate, cc/min 
                 NA 
                 NA 
                 3.2 
                 4.3 
                 3.2 
               
               
                 Die to water bath, 
                  1 
                  4 
                 2.5 
                 8 
                 4 
               
               
                 inches 
               
               
                 Take-up speed, 
                  20 
                  20 
                 20 
                 14 
                 17 
               
               
                 feet/min 
               
               
                   
               
            
           
         
       
     
     The tapes from the extrusion runs were drawn following the procedure of Example 1. Conditions for the three drawing runs are shown on Table X: 
     
       
         
           
               
             
               
                 TABLE X 
               
             
            
               
                   
               
               
                 Drawing conditions. 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Run 4 
                 Run 5 
                 Run 6 
                 Run 7 
                 Run 8 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Roll 1 T, ° C. 
                 cold 
                 cold 
                 50 
                 55 
                 70 
               
               
                 Plate T, ° C. 
                 100 
                 100 
                 90 
                 115  
                 70 
               
               
                 Roll 1 Speed, 
                  2 
                  2 
                  2 
                  2 
                  2 
               
               
                 meter/min 
               
               
                 Roll 2 Speed, 
                  16 
                  15 
                 14 
                 12 
                 16 
               
               
                 meter/min 
               
               
                 Draw Ratio 
                 8 to 1 
                 7.5 to 1 
                 7 to 1 
                 6 to 1 
                 8 to 1 
               
               
                   
               
            
           
         
       
     
     The overall width, thickness, and denier of the tapes were measured, and are summarized on Table XI: 
     
       
         
           
               
             
               
                 TABLE XI 
               
             
            
               
                   
               
               
                 Tape dimensions. 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Run 4 
                 Run 5 
                 Run 6 
                 Run 7 
                 Run 8 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Width, inches 
                 0.080 
                 0.080 
                 0.090 
                 0.070 
                 0.060 
               
               
                 Thickness, inches 
                 0.0065 
                 0.0065 
                 0.0065 
                 0.007 
                 0.0045 
               
               
                   
               
            
           
         
       
     
     The tensile properties of the tapes were measured as described in Example 1. The tensile strength and percent elongation at break are summarized on Table XII: 
     
       
         
           
               
             
               
                 TABLE XII 
               
             
            
               
                   
               
               
                 Tape tensile properties. 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Run 4 
                 Run 5 
                 Run 6 
                 Run 7 
                 Run 8 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Tensile strength, lbs 
                 9.5 
                 8.7 
                 7.6 
                 3.1 
                 3.5 
               
               
                 St. Dev. 
                 0.3 
                 0.6 
                 0.4 
                 0.2 
                 0.4 
               
               
                 Elongation at Break, % 
                 102 
                 87 
                 105 
                 25 
                 68 
               
               
                 St. Dev. 
                 4 
                 5 
                 10 
                 6 
                 6 
               
               
                   
               
            
           
         
       
     
     Example 3 
     Dental tape of the invention was produced using PEBAX MX 1205 resin where the drawing conditions were modified to change the dimensions of the final tape. The resins were dried for over 3 hours at 75° C., and processed in the extruder of Example 1, using the ribbed die described in Example 1. 
     The conditions for the extrusions are shown on Table XIII: 
     
       
         
           
               
             
               
                 TABLE XIII 
               
             
            
               
                   
               
               
                 Extrusion conditions. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 9 
                 Run 10 
                 Run 11 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Barrel T (Zones 1-6), ° C. 
                 205 
                 195 
                 210 
               
               
                   
                 Die T, ° C. 
                 207 
                 197 
                 212 
               
               
                   
                 Flow rate, cc/min 
                 3.2 
                 3.2 
                 3.2 
               
               
                   
                 Die to water bath, inches 
                 6 
                 2 
                 1.5 
               
               
                   
                 Take-up speed, feet/min 
                 22 
                 22 
                 22 
               
               
                   
                   
               
            
           
         
       
     
     The tapes from the extrusion runs were drawn following the procedure of Example 1. Conditions for the three drawing runs are shown on Table XIV: 
     
       
         
           
               
             
               
                 TABLE XIV 
               
             
            
               
                   
               
               
                 Drawing conditions. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 9 
                 Run 10 
                 Run 11 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Roll 1 T, ° C. 
                 cold 
                 cold 
                 50 
               
               
                   
                 Plate T, ° C. 
                 80 
                 80 
                 80 
               
               
                   
                 Roll 1 Speed, meter/min 
                  2 
                  2 
                  2 
               
               
                   
                 Roll 2 Speed, meter/min 
                 18 
                 18 
                 18 
               
               
                   
                 Draw Ratio 
                 9 to 1 
                 9 to 1 
                 9 to 1 
               
               
                   
                   
               
            
           
         
       
     
     The overall width, thickness, and denier of the tapes were measured, and are summarized on Table XV: 
     
       
         
           
               
             
               
                 TABLE XV 
               
             
            
               
                   
               
               
                 Tape dimensions. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 9 
                 Run 10 
                 Run 11 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Width, inches 
                 0.055 
                 0.055 
                 0.060 
               
               
                   
                 Thickness, inches 
                 0.0035 
                 0.0035 
                 0.0045 
               
               
                   
                   
               
            
           
         
       
     
     The tensile properties of the tapes were measured as described in Example 1. The tensile strength and percent elongation at break are summarized on Table XVI: 
     
       
         
           
               
             
               
                 TABLE XVI 
               
             
            
               
                   
               
               
                 Tape tensile properties. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 9 
                 Run 10 
                 Run 11 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Tensile strength, lbs 
                 6.4 
                 6.6 
                 5.0 
               
               
                   
                 St. Dev. 
                 0.1 
                 0.5 
                 0.5 
               
               
                   
                 Elongation at Break, % 
                 37 
                 34 
                 138 
               
               
                   
                 St. Dev. 
                 4 
                 6 
                 10 
               
               
                   
                   
               
            
           
         
       
     
     Example 4 
     Dental tape of the invention was produced using PEBAX MX 1205, 3533, and 2533 resins. The resins were dried for over 3 hours at 75° C., and processed in the extruder of Example 1, using the ribbed die described in Example 1. 
     The conditions for the extrusions are shown on Table XVII: 
     
       
         
           
               
             
               
                 TABLE XVII 
               
             
            
               
                   
               
               
                 Extrusion conditions. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 1 
                 Run 12 
                 Run 13 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 PEBAX Resin 
                 MX 1205 
                 3533 
                 2533 
               
               
                   
                 Barrel T (Zones 1-6), ° C. 
                 195 
                 220 
                 200 
               
               
                   
                 Die T, ° C. 
                 203 
                 222 
                 202 
               
               
                   
                 Flow rate, cc/min 
                 4.8 
                 4.8 
                 4.8 
               
               
                   
                 Die to water bath, inches 
                 1 
                 4 
                 3 
               
               
                   
                 Take-up speed, feet/min 
                 20 
                 17 
                 18 
               
               
                   
                   
               
            
           
         
       
     
     The tapes from the extrusion runs were drawn following the procedure of Example 1. Conditions for the three drawing runs are shown on Table XVIII: 
     
       
         
           
               
             
               
                 TABLE XVIII 
               
             
            
               
                   
               
               
                 Drawing conditions. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 1 
                 Run 12 
                 Run 13 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Roll 1 T, ° C. 
                 60 
                 60 
                 70 
               
               
                   
                 Plate T, ° C. 
                 100 
                 100 
                 85 
               
               
                   
                 Roll 1 Speed, meter/min 
                 2 
                 1 
                 2 
               
               
                   
                 Roll 2 Speed, meter/min 
                 18 
                 9 
                 17 
               
               
                   
                 Draw Ratio 
                 9 to 1 
                 9 to 1 
                 8.5 to 1 
               
               
                   
                   
               
            
           
         
       
     
     The overall width, thickness, and denier of the tapes were measured, and are summarized on Table XIX: 
     
       
         
           
               
             
               
                 TABLE XIX 
               
             
            
               
                   
               
               
                 Tape dimensions. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 1 
                 Run 12 
                 Run 13 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Width, inches 
                 0.075 
                 0.080 
                 0.080 
               
               
                   
                 Thickness, inches 
                 0.005 
                 0.0055 
                 0.005 
               
               
                   
                   
               
            
           
         
       
     
     The tensile properties of the tapes were measured as described in Example 1. The tensile strength and percent elongation at break are summarized on Table XX: 
     
       
         
           
               
             
               
                 TABLE XX 
               
             
            
               
                   
               
               
                 Tape tensile properties. 
               
            
           
           
               
               
               
               
            
               
                   
                 Run 1 
                 Run 12 
                 Run 13 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Tensile strength, lbs 
                 7.5 
                 6.1 
                 4.8 
               
               
                   
                 Elongation at Break, % 
                 64 
                 142 
                 194 
               
               
                   
                   
               
            
           
         
       
     
     Example 5 
     Dental tape of the invention was produced using PEBAX MX 1205 resin where the number of ribs was modified to change the structure of the final tape. 
     The die was formed of stainless steel, and had a cross-section similar to that in Example 1. The difference is that in Example 1, there were eleven ribs protruding from both the first and second cleaning surfaces. Here, there were five ribs protruding from both the first and second cleaning surfaces. The overall width of the slot, or w t , was 0.305 inches. The thickness of the core body of the die t c  was 0.0035 inches. The height and width of the rib portions of the die (h r  and w r , respectively) were 0.0075 inches and 0.0035 inches. The spacing between neighboring ribs both cleaning surfaces was (s r ) is 0.050 inches, and the ratio of s ar  to s r  is 0.5, i.e. the ribs on second cleaning surface were positioned about midway between those on first cleaning surface. 
     The resin was dried for over 3 hours at 75° C., and processed in the extruder of Example 1. The conditions for the extrusions are shown on Table XXI: 
     
       
         
           
               
             
               
                 TABLE XXI 
               
             
            
               
                   
               
               
                 Extrusion conditions. 
               
            
           
           
               
               
               
            
               
                   
                 Run 1 
                 Run 14 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Number of Ribs 
                 22 
                 10 
               
               
                   
                 Barrel T (Zones 1-6), ° C. 
                 195 
                 195 
               
               
                   
                 Die T, ° C. 
                 203 
                 196 
               
               
                   
                 Flow rate, cc/min 
                 4.8 
                 4.3 
               
               
                   
                 Die to water bath, inches 
                 1 
                 2 
               
               
                   
                 Take-up speed, feet/min 
                 20 
                 23 
               
               
                   
                   
               
            
           
         
       
     
     The tapes from the extrusion runs were drawn following the procedure of Example 1. Conditions for the three drawing runs are shown on Table XXII: 
     
       
         
           
               
             
               
                 TABLE XXII 
               
             
            
               
                   
               
               
                 Drawing conditions. 
               
            
           
           
               
               
               
            
               
                   
                 Run 1 
                 Run 14 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Roll 1 T, ° C. 
                 60 
                 Cold 
               
               
                   
                 Plate T, ° C. 
                 100  
                 80 
               
               
                   
                 Roll 1 Speed, meter/min 
                  2 
                  2 
               
               
                   
                 Roll 2 Speed, meter/min 
                 18 
                 17 
               
               
                   
                 Draw Ratio 
                 9 to 1 
                 8.5 to 1 
               
               
                   
                   
               
            
           
         
       
     
     The tape was coated with a microcrystalline wax, W445, as described in Example 1, where the coated tape was designated as Run 1a. 
     The compression and recovery expansion of the tapes was measured as described in Example 1. The percent compression and percent recovery of each of the tapes were measured, and the results are summarized on Table XXIII: 
     
       
         
           
               
             
               
                 TABLE XXIII 
               
             
            
               
                   
               
               
                 Tape compression and recovery. 
               
            
           
           
               
               
               
            
               
                   
                 Run 1a 
                 Run 14 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Original Thickness, inches 
                 0.007 
                 0.007 
               
               
                   
                 Compression, % 
                 58 
                 61 
               
               
                   
                 Recovery, % 
                 42 
                 78 
               
               
                   
                   
               
            
           
         
       
     
     The toughness of the tapes was conducted by measuring the cycles to failure for each of the tapes as described in Example 1. The results are summarized on Table XXIV: 
     
       
         
           
               
             
               
                 TABLE XXIV 
               
             
            
               
                   
               
               
                 Cycles to Failure for Tapes 
               
            
           
           
               
               
               
            
               
                   
                 Tape 
                 Average 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 Run 1a 
                 10.3 
               
               
                   
                 Run 14 
                 4.7 
               
               
                   
                   
               
            
           
         
       
     
     While utilizing fewer ribs per cleaning surface may provide as dental tape that is not as strong as one having greater than about 8 per surface, for example 10 or greater, Run 14 demonstrates that having a plurality of ribs disposed along both cleaning surfaces of dental tape improves strength when compared to a dental tape having no ribs, as seen in Run 2, Table VI. 
     Example 6 
     Dental tape of the invention was produced using PEBAX MX 1205 resin where the width of ribs was modified to change the structure and dimensions of the final tape. 
     The die was formed of stainless steel, and had a cross-section similar to that in Example 1. There were eleven ribs protruding from both the first and second cleaning surfaces. The overall width of the slot, or w t , was 0.303 inches. The thickness of the core body of the die t c  was 0.0035 inches. The height and width of rib portions of the die (h r  and w r , respectively) were 0.0075 inches and 0.0025 inches. In Example 1, the width of rib portions of the die (w r ) was 0.0035 inches. The spacing between neighboring ribs both cleaning surfaces is (s r ) was 0.026 inches, and the ratio of s ar  to s r  was 0.5, i.e. the ribs on second cleaning surface were positioned about midway between those on first cleaning surface. 
     The resin was dried for over 3 hours at 75° C., and processed in the extruder of Example 1. The conditions for the extrusions are shown on Table XXV: 
     
       
         
           
               
             
               
                 TABLE XXV 
               
             
            
               
                   
               
               
                 Extrusion conditions. 
               
            
           
           
               
               
               
            
               
                   
                 Run 1 
                 Run 15 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Width of Ribs, inches 
                 0.0035 
                 0.0025 
               
               
                   
                 Barrel T (Zones 1-6), ° C. 
                 195 
                 193 
               
               
                   
                 Die T, ° C. 
                 203 
                 193 
               
               
                   
                 Flow rate, cc/min 
                 4.8 
                 4.3 
               
               
                   
                 Die to water bath, inches 
                 1 
                 2 
               
               
                   
                 Takeup speed, feet/min 
                 20 
                 20 
               
               
                   
                   
               
            
           
         
       
     
     The tapes from the extrusion runs were drawn following the procedure of Example 1. Conditions for the three drawing runs are shown on Table XXVI: 
     
       
         
           
               
             
               
                 TABLE XXVI 
               
             
            
               
                   
               
               
                 Drawing conditions. 
               
            
           
           
               
               
               
            
               
                   
                 Run 1 
                 Run 14 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Roll 1 T, ° C. 
                 60 
                 Cold 
               
               
                   
                 Plate T, ° C. 
                 100  
                 85 
               
               
                   
                 Roll 1 Speed, meter/min 
                  2 
                  2 
               
               
                   
                 Roll 2 Speed, meter/min 
                 18 
                 18 
               
               
                   
                 Draw Ratio 
                 9 to 1 
                 9 to 1 
               
               
                   
                   
               
            
           
         
       
     
     The tape was coated with a microcrystalline wax, W445, as described in Example 1, where the coated tape was designated as Run 1 a.    
     The compression and recovery expansion of the tapes was measured as described in Example 1. The percent compression and percent recovery of each of the tapes were measured, and the results are summarized on Table XXVII: 
     
       
         
           
               
             
               
                 TABLE XXVII 
               
             
            
               
                   
               
               
                 Tape compression and recovery. 
               
            
           
           
               
               
               
            
               
                   
                 Run 1a 
                 Run 15 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Original Thickness, inches 
                 0.007 
                 0.006 
               
               
                   
                 Compression, % 
                 54 
                 63 
               
               
                   
                 Recovery, % 
                 52 
                 77 
               
               
                   
                   
               
            
           
         
       
     
     The toughness of the tapes was conducted by measuring the cycles to failure for each of the tapes as described in Example 1. The results are summarized on Table XVIII: 
     
       
         
           
               
             
               
                 TABLE XXVIII 
               
             
            
               
                   
               
               
                 Cycles to Failure for Tapes 
               
            
           
           
               
               
               
            
               
                   
                 Tape 
                 Average 
               
               
                   
                   
               
               
                   
                 Run 1a 
                 10.3 
               
               
                   
                 Run 15 
                 10.0 
               
               
                   
                   
               
            
           
         
       
     
     Example 7 
     Dental tape of the invention is produced using PEBAX MX 1205 resin where the height of the ribs was modified to change the structure and dimensions of the final tape. 
     The die is formed of stainless steel, and had a cross-section similar to that in Example 1. There were eleven ribs protruding from both the first and second cleaning surfaces. The overall width of the slot, or w t , was 0.303 inches. The thickness of the core body of the die t c  was 0.0035 inches. The height and width of the rib portions of the die (h r  and w r , respectively) were 0.0038 inches and 0.0035 inches. In Example 1, the height of rib portions of the die (h r ) was 0.0075 inches. The spacing between neighboring ribs both cleaning surfaces is (s r ) was 0.026 inches, and the ratio of s ar  to s r  was 0.5, i.e. the ribs on second cleaning surface were positioned about midway between those on first cleaning surface. 
     The resin was dried for over 3 hours at 75° C., and processed in the extruder of Example 1. The conditions for the extrusions are shown on Table XXIX: 
     
       
         
           
               
             
               
                 TABLE XXIX 
               
             
            
               
                   
               
               
                 Extrusion conditions. 
               
            
           
           
               
               
               
            
               
                   
                 Run 1 
                 Run 16 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Height of Ribs, inches 
                 0.0075 
                 0.0038 
               
               
                   
                 Barrel T (Zones 1-6), ° C. 
                 195 
                 197 
               
               
                   
                 Die T, ° C. 
                 203 
                 199 
               
               
                   
                 Flow rate, cc/min 
                 4.8 
                 4.3 
               
               
                   
                 Die to water bath, inches 
                 1 
                 2 
               
               
                   
                 Take-up speed, feet/min 
                 20 
                 20 
               
               
                   
                   
               
            
           
         
       
     
     The tapes from the extrusion runs were drawn following the procedure of Example 1. Conditions for the three drawing runs are shown on Table XXX: 
     
       
         
           
               
             
               
                 TABLE XXX 
               
             
            
               
                   
               
               
                 Drawing conditions. 
               
            
           
           
               
               
               
            
               
                   
                 Run 1 
                 Run 14 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Roll 1 T, ° C. 
                 60 
                 Cold 
               
               
                   
                 Plate T, ° C. 
                 100  
                 85 
               
               
                   
                 Roll 1 Speed, meter/min 
                  2 
                  2 
               
               
                   
                 Roll 2 Speed, meter/min 
                 18 
                 18 
               
               
                   
                 Draw Ratio 
                 9 to 1 
                 9 to 1 
               
               
                   
                   
               
            
           
         
       
     
     The tape was coated with a microcrystalline wax, W445, as described in Example 1, where the coated tape was designated as Run 1a. 
     The compression and recovery expansion of the tapes was measured as described in Example 1. The percent compression and percent recovery of each of the tapes were measured, and the results are summarized on Table XXXI: 
     
       
         
           
               
             
               
                 TABLE XXXI 
               
             
            
               
                   
               
               
                 Tape compression and recovery. 
               
            
           
           
               
               
               
            
               
                   
                 Run 1a 
                 Run 16 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Original Thickness, inches 
                 0.007 
                 0.005 
               
               
                   
                 Compression, % 
                 54 
                 57 
               
               
                   
                 Recovery, % 
                 52 
                 76 
               
               
                   
                   
               
            
           
         
       
     
     The toughness of the tapes was conducted by measuring the cycles to failure for each of the tapes as described in Example 1. The results are summarized on Table XXXII: 
     
       
         
           
               
             
               
                 TABLE XXXII 
               
             
            
               
                   
               
               
                 Cycles to Failure for Tapes 
               
            
           
           
               
               
               
            
               
                   
                 Tape 
                 Average 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 Run 1a 
                 10.3 
               
               
                   
                 Run 16 
                 2.0 
               
               
                   
                   
               
            
           
         
       
     
     Example 8 
     Dental tape spool rolls were formed in accordance with the coating and winding processes of the present invention and using the component sizes and/or type described below and summarized in Table XXXIII. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE XXXIII 
               
               
                   
                   
               
               
                   
                 Component 
                 Type/Size 
               
               
                   
                   
               
             
            
               
                   
                 Pulley 82e 
                 14 Teeth 
               
               
                   
                 Pulley 82d 
                 17 Teeth 
               
               
                   
                 Pulley 82c 
                 19 Teeth 
               
               
                   
                 Pulley 82f 
                 14 Teeth 
               
               
                   
                 Pulley 82g 
                 16 Teeth 
               
               
                   
                 Pulley 82h 
                 20 Teeth 
               
               
                   
                 Traversing Cam 
                 11.5 inches, 6 turns 
               
               
                   
                 Guide Traverse 
                 end to end cam 
               
               
                   
                   
               
            
           
         
       
     
     Ordering the above pulley sizes sequentially (e.g.,  82   e  is connected to  82   d  which is connected  82   c  etc. as shown in  FIG. 8 ) and determining the product of the ratios of the sizes of the sequentially ordered pulleys or Ratio A (as shown in I below)
 
Ratio  A=P   1   /P   2   ×P   3   /P   4   ×P   Z-1   /P   Z   I
 
Where P 1  to P Z  are the sizes of the pulleys sequentially ordered from spool  72  and to the traverse barrel cam  86  of rewinding system  70 , results in the following ratio:
 
     
       
         
           
             
               Ratio 
               ⁢ 
               
                   
               
               ⁢ 
               A 
             
             = 
             
               
                 
                   ( 
                   
                     Pulley 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     82 
                     ⁢ 
                     e 
                     ⁢ 
                     
                       / 
                     
                     ⁢ 
                     Pulley 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     82 
                     ⁢ 
                     d 
                   
                   ) 
                 
                 × 
                 
                   ( 
                   
                     Pulley 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     82 
                     ⁢ 
                     c 
                     ⁢ 
                     
                       / 
                     
                     ⁢ 
                     Pulley 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     82 
                     ⁢ 
                     f 
                   
                   ) 
                 
                 × 
                 
                   ( 
                   
                     Pulley 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     82 
                     ⁢ 
                     g 
                     ⁢ 
                     
                       / 
                     
                     ⁢ 
                     Pulley 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     82 
                     ⁢ 
                     h 
                   
                   ) 
                 
               
               = 
               
                 
                   
                     ( 
                     
                       14 
                       ⁢ 
                       
                         / 
                       
                       ⁢ 
                       17 
                     
                     ) 
                   
                   × 
                   
                     ( 
                     
                       19 
                       ⁢ 
                       
                         / 
                       
                       ⁢ 
                       14 
                     
                     ) 
                   
                   × 
                   
                     ( 
                     
                       16 
                       ⁢ 
                       
                         / 
                       
                       ⁢ 
                       20 
                     
                     ) 
                   
                 
                 = 
                 0.8941 
               
             
           
         
       
     
     A traverse barrel cam was selected to provide a traversing cam guide traverse of 11.5 inches end to end for every 6 revolutions of traverse barrel cam  86 . This results in a cam advance equal to the following: 
     
       
         
           
             
               
                 
                   
                     Cam 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     Advance 
                   
                   = 
                     
                   ⁢ 
                   
                     Traversing 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     Cam 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     Guide 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     traverse 
                     ⁢ 
                     
                       / 
                     
                     ⁢ 
                     6 
                   
                 
               
             
             
               
                 
                     
                   ⁢ 
                   
                     Revolutions 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     of 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     Traverse 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     Barrel 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     Cam 
                   
                 
               
             
             
               
                 
                   = 
                     
                   ⁢ 
                   
                     
                       11.5 
                       ⁢ 
                       
                         / 
                       
                       ⁢ 
                       6 
                     
                     = 
                     
                       1.9166 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       inches 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       per 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       Traverse 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       Barrel 
                     
                   
                 
               
             
             
               
                 
                     
                   ⁢ 
                   
                     Cam 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     revolution 
                   
                 
               
             
           
         
       
     
     Ratio A indicates that for each revolution of the spool  72 , the traverse barrel cam travels 0.8941 of the spool revolution. This results in the following travel distance for the traversing cam guide  76  per revolution of spool  72 : 
     
       
         
           
             
               Travel 
               ⁢ 
               
                   
               
               ⁢ 
               Distance 
               ⁢ 
               
                   
               
               ⁢ 
               of 
               ⁢ 
               
                   
               
               ⁢ 
               traversing 
               ⁢ 
               
                   
               
               ⁢ 
               cam 
               ⁢ 
               
                   
               
               ⁢ 
               guide 
               ⁢ 
               
                   
               
               ⁢ 
               per 
               ⁢ 
               
                   
               
               ⁢ 
               revolution 
               ⁢ 
               
                   
               
               ⁢ 
               of 
               ⁢ 
               
                   
               
               ⁢ 
               spool 
             
             = 
             
               
                 Cam 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 Pulley 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 Ratio 
                 × 
                 Cam 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 Advance 
               
               = 
               
                 
                   
                     0.8941 
                     . 
                     times 
                   
                   ⁢ 
                   .1 
                   ⁢ 
                   .9166 
                 
                 = 
                 
                   1.71 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   inches 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   per 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   spool 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   revolution 
                 
               
             
           
         
       
     
     The core diameter d s  of spool  72  was measured to be 6.21 inches, therefore, the distance traveled by any point on the outer surface of the core of spool  72  after one revolution of spool  72  or circumference C can be calculated as follows:
 
Circumference  C= 6.21 inches×π=(6.21)3.1411=19.5 inches
 
     The helix angle θ (the angle formed by a strand of dental tape and plane rΦ of the spool which is perpendicular to the longitudinal axis z of the spool  72  as shown in  FIG. 25 ) formed by dental tape  10  as it is initially wound around the core of spool  72  can then be calculated as follows:
 
Travel Distance of traversing cam guide per spool revolution/Circumference C =1.71/19.5
 
1.71/19.5=0.0876=sin −1  θ(Helix Angle)
 
     Where Helix Angle θ′=5.03° 
     As will be understood by the skilled artisan, as the spool  72  roll grows, the helix angle θ decreases. For example, as one inch of dental tape is wound onto the core of spool  72 , helix angle decreases. This is exemplified as follows:
 
The diameter of spool after 1 adding one inch layer of tape=6.21 inches+2 inches (1 inch of added layer results in diameter increasing by 2 inches)=8.21 inches, hence:
 
                     Circumference   ⁢           ⁢   of   ⁢           ⁢   Spool   ⁢           ⁢   with   ⁢           ⁢   Tape     =       ⁢     diameter   ⁢           ⁢   of   ⁢           ⁢   spool   ⁢           ⁢   with                     ⁢     tape   ×   π                 =       ⁢       (   8.21   )     ⁢   3.1411                   =       ⁢     27.7   ⁢           ⁢   inches       ,   hence               Travel distance of traversing cam guide per spool revolution/Circumference of Spool and Tape=1.71/25.7 inches=0.066=sin −1 θ′(Helix Angle)
 
Where Helix Angle θ′=3.8°
 
     Therefore, as about an inch of material is wound around the spool, the helix angle chances by about 1° (θ-θ′=5.03°−3.8°=1.5°). 
     Using the above traverse barrel cam and pulley sizes, Rolls 1-7 (representative of spool  72  in  FIG. 8 ) were formed and, then, Rolls 1-7 were subsequently used to form separate bobbins (representative bobbins formed on bobbin spool  90  in  FIG. 8 ) The parameters of the formed rolls and coating and rewinding process are summarized in Tables XXXIV and XXXV. 
     
       
         
           
               
             
               
                 TABLE XXXIV 
               
             
            
               
                   
               
               
                 (Wax Coating Formulation) 
               
            
           
           
               
               
               
            
               
                   
                 Ingredient 
                 Amount (%) 
               
               
                   
                   
               
               
                   
                 Microcrystaline Wax 1   
                 82% 
               
               
                   
                 Flavor 
                 17% 
               
               
                   
                 Sodium Saccharin 
                  1% 
               
               
                   
                   
               
               
                   
                   1 Multiwax-W445, supplied by Crompton Corp. Petrolia, Pa 
               
            
           
         
       
     
                                                 TABLE XXXV               Process Parameters   Roll 1   Roll 2   Roll 3   Roll 4   Roll 5   Roll 6   Roll 7                                                                Line Speed (feet per min.)   1600   1600   1600   1600   1600   1600   1600       Tape Tension prior to   190   190   200   205   205   200   210       rewinding on rolls (grams-force)                                   Tank Temp ° F.   200   200   200   200   200   200   200       Die Temp ° F.   200   200   200   200   200   200   200       Tape (yarn) Start Wt (grams).   3738   2907   3994   2998   2257   3804   2977       Tape (yarn) Finish Wt (grams).   2907   2079   2998   2257   1364   2977   2131       Tape (yarn) Wt. (grams)   831   828   996   741   893   827   846       Coated Tape and Core (grams)   2578   2661   2704   2637   2654   2704   2630       Core Tare (grams)   1398   1462   1309   1367   1357   1474   1370       Coated Tape Wt. (grams)   1180   1199   1395   1270   1297   1230   1260       Wax Added 1 (grams)   349   371   409   329   406   403   414       Wax Add-on % 2     29.5   31.3   306   30.7   31.2   32.7   32.8       Wt. Roll 3  (lbs.)t   2.60   2.65   2.94   2.35   2.86   2.71   2.77                 1 Wax Added = Tape Wt. − Coated Tape Wt.         2 Wax Add-on % = (Waxed Added/Coated Tape Wt.) (100)         3 Wt. Roll = Coated Tape Wt./454 grams/lb.            
The bobbins produced on bobbin spools of width 10.3 mm and percent of bobbins rejected as exhibiting unsatisfactory telescoping are summarized in Table XXXVI.
 
     
       
         
           
               
               
               
               
               
               
               
               
             
               
                 TABLE XXXVI 
               
               
                   
               
               
                 # Bobbin Produced 
                 236 
                 240 
                 261 
                 213 
                 259 
                 296 
                 251 
               
               
                   
               
             
            
               
                 # Rejects 1   
                 0 
                 0 
                 0 
                 8 
                 1 
                 0 
                 0 
               
               
                   
               
               
                   1 Rejected bobbins rolls are bobbin rolls in which the width of the wound tape on bobbin exceeded the bobbin dispenser width of 11.2 mm. 
               
               
                 Total Bobbins Produced = 1711 
               
               
                 Total Rejects = 9 
               
               
                 % Rejects = 0.5% 
               
            
           
         
       
     
     Example 9 
     The effectiveness of the ribbed dental tape of the present invention is demonstrated in the following clinical tests. 
     Two clinical studies (Trial 1 and Trial 2) were performed, employing a single-center, three-way crossover design. The observers were blinded and the comparative groups were coded. 
     The subjects participated in 3 treatment visits (at least 24-hour between each crossover period). Subjects refrained from oral hygiene procedures for 18-24 hours prior to each visit. During the treatment visit, pre-flossing Proximal/Marginal Plaque Index (PMI) assessments were made on each subject prior to surrogate flossing by a trained dental hygienist. The surrogate flossing of the subjects was followed by a post-flossing PMI assessment. The flosses tested included a dental tape prepared in accordance with the conditions of and having the properties of Examples 1-8 of the present invention (Tape A); Crest.®. Glide.®. Mint dental floss (Floss A); and Oral-B SATINfloss.®. dental floss (Floss B). 
     Supragingival plaque levels on the facial and lingual surfaces of the mandibular and maxillary lateral and central incisors were assessed using the Proximal/Marginal Plaque Index (PMI) following disclosing. The facial and lingual surfaces were divided into three unequal segments: distal proximal, marginal and mesial proximal; however, the marginal surfaces were not scored. Effectiveness was determined by change from baseline in mean PMI. Plaque was scored using the following criteria: 
     0=No plaque. 
     1=Separate flecks of plaque covering less than ⅓ of the area. 
     2=Discrete areas or bands of plaque covering less than ⅓ of the area. 
     3=Plaque covering ⅓ of the area. 
     4=Plaque covering more than ⅓ but less than ⅔ of the area. 
     5=Plaque covering ⅔ or more of the area 
     The results are summarized in Tables XXXVII and XXXVIII 
     
       
         
           
               
             
               
                 TABLE XXXVII 
               
             
            
               
                   
               
               
                 Trial 1 
               
            
           
           
               
               
               
               
            
               
                   
                 Tape A 
                 Floss A 
                 Floss B 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                 No. of Participants per 
                 39 
                 40 
                 37 
               
               
                 testing group 
               
               
                 Pre-Flossing PMI Mean 
                 2.885 
                 2.955 
                 2.928 
               
               
                 Post-Flossing PMI Mean 
                 1.681 
                 2.385 
                 2.296 
               
               
                 Change from Pre-Flossing 
                 −1.2176 
                 −0.5601 
                 −0.6397 
               
               
                   
                 (42.20%) 
                 (18.95%) 
                 (21.85%) 
               
               
                 % Difference vs. Floss A 
                 117.4% 
               
               
                 % Difference vs. Floss B 
                 90.3% 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE XXXVIII 
               
             
            
               
                   
               
               
                 Trial 2 
               
            
           
           
               
               
               
               
            
               
                   
                 Tape A 
                 Floss A 
                 Floss B 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                 N 
                 30 
                 30 
                 30 
               
               
                 Pre-Flossing PMI Mean 
                 2.499 
                 2.350 
                 2.517 
               
               
                 Post-Flossing PMI Mean 
                 1.180 
                 1.674 
                 1.764 
               
               
                 Change from Pre-Flossing 
                 −1.3099 
                 −0.6974 
                 −0.7406 
               
               
                   
                 (45.42%) 
                 (29.68%) 
                 (29.42%) 
               
               
                 % Difference vs. Floss A 
                 87.8% 
               
               
                 % Difference vs. Floss B 
                 76.9%