Application Serial No. 10/331,800 filed December 30,2002.

BACKGROUND OF THE INVENTION Dental floss is defined in Webster's New World Dictiona7y, 1983, as".... thread for removing food particles between the teeth." The concept of using dental floss for cleansing interproximal spaces appears to have been introduced by Parmly in 1819, Practical Guide to the Managenze7at of Teeth, Cullins & Croft Philadelphia, PA. Numerous types of floss were developed and used for cleaning interproximal and subgingival surfaces, until finally in 1948 Bass established the optimum characteristics of dental floss, Dental Itenas of Interest, 70,921-34 (1948).

Bass cautioned that dental floss treated with sizing, binders and/or wax produces a"cord"effect as distinguished from the desired"spread filament effect".

This cord effect reduces flossing efficiency dramatically and visually eliminates splaying (i. e. , the flattening and spreading out of filaments) necessary to achieve the required interproximal and subgingival mechanical cleaning. This cleaning is then required to be followed by the entrapment and removal of debris, plaque and microscopic materials from interproximal spaces by the"spread"floss as it is removed from between teeth.

Proper use of dental floss is necessary to clean the considerable surface area on the interproximal surfaces of teeth, which cannot usually be reached by other cleaning methods or agents, e. g. , the bristles of a toothbrush, the swishing action of a rinse, or by the pulsating stream from an oral irrigator.

Historically, the purpose of dental floss was to: (1) dislodge and remove any decomposing food material, debris, etc. , that has accumulated at the interproximal surfaces, which could not be removed by other oral hygiene means, and (2) dislodge and remove as much as possible the growth of bacterial material (plaque, tartar, calculus) that had accumulated there since the previous cleaning.

Effective oral hygiene requires that three control elements be maintained by the individual: (1) Physical removal of stains, plaque and tartar. This is accomplished in the strongest sense by scraping and abrasion in the dentist's office.

Self administered procedures are required frequently between visits and range from tooth brushing with an appropriate abrasive toothpaste through flossing and water jet action down to certain abrasive foods and even the action of the tongue against tooth surfaces.

(2) Surfactant Cleaning. This is required to remove: food debris and staining substances before they adhere to the tooth surface; normal dead cellular (epithelial) material which is continually sloughed off from the surfaces of the oral cavity and microbial degradation products derived from all of the above. Besides the obvious hygienic and health benefits related to simple cleanliness provided by surfactants, there is an important cosmetic and sense-of-well-being benefit provided by surfactant cleansing. Research has shown that the primary source of bad breath is the retention and subsequent degradation of dead cellular material sloughed off continuously by the normal, healthy mouth.

(3) Frequency of Cleansing. This is perhaps the most difficult to provide in today's fast-paced work and social environment. Most people recognize that their teeth should be brushed at least 3 times a day and flossed at least once a day. The simple fact is that most of the population brush once a day, some brush morning and evening, but precious few carry toothbrush and dentifrice to use the other three or four times a day for optimal oral hygiene. Consumer research suggests that the population brushes an average of 1.3 times a day. Most surprising, less than 15% of adults floss regularly. Reasons offered for not flossing: difficult to do, painful, not effective, doesn't seem to do anything, and leaves a bad taste.

Until the introduction of micromesh dental floss as described in copending U. S. Patent Application, Serial No. 10/073,682, entitled, "Micromesh Interproximal Devices" ; there have been two types of interproximal devices, multifilament dental flosses and monofilament dental tapes.

Examples of multifilament dental flosses are described in the following U. S. Patents: 4,911, 927; 4,029, 113; 4,610, 872; 4,034, 771; 5,908, 039; 2,667, 443; 3,830, 246; 1,149, 376; 1,069, 874; 5,830, 495; 2, 748, 781 ; 1, 138, 479; 1,839, 486; 1,943, 856; 6,080, 481; 2,700, 636; 3,699, 979; 3,744, 499; 3,837, 351; 4,414, 990; 3,330, 732; 5,967, 155; 5,937, 874; 5,505, 216; 5,503, 842; 5,032, 387; 4,950, 479; 5,098, 711; 1,989, 895; 5,033, 488; 2,542, 518; 2,554, 464; 1,285, 988; 1,839, 483; 4,151, 851; 2,224, 489; 2,464, 755; 2,381, 142; 3,800, 812; 3,830, 246; 3,897, 795; 3,897, 796; 4,215, 478; 4,033, 365; 3,771, 536; 3,943, 949; 6,016, 816; 6,026, 829; 5,353, 820; 5,557, 900; 5,226, 435; 5,573, 850; 5,560, 377; 5,526, 831 ; 5,423, 337; 5,220, 932; 4,548, 219; 3,838, 702; 5,904, 152; 4,911, 927; 5,711, 935; 5,165, 913; and 5,098, 711.

Examples of monofilament dental tapes are described in the following U. S. Patents: Re. 35,439 ; 3,800, 812; 4,974, 615; 5,760, 117; 5,433, 226; 5,479, 952; 5,503, 842; 5,755, 243; 5,845, 652; 5,884, 639; 5,918, 609; 5,962, 572; 5,998, 431; 6,003, 525; 6,083, 208; 6,198, 830; 6,161, 555; 6,027, 192; 5,209, 251 ; 5,033, 488; 5,518, 012; 5,911, 228; 5,220, 932; 4,776, 358; 5,718, 251; 5,848, 600; 5,787, 758; and 5,765, 576.

It is generally accepted that both monofilament and multifilament dental flosses are not"user-friendly"products, i. e. , flossing with either is difficult to do.

Flossing is generally associated with pain and bleeding and it results in a bad taste in the mouth. Most market researchers agree that anything that can be done to make flossing more positive should be implemented to encourage more frequent flossing and more wide spread floss and/or tape use. The addition to floss and tape of : full spectrum flavor oils, mouth conditioning substances such as silicones along with cleaners and abrasives that are perceived as"working"as taught by the copending Patent Applications:"Coated Multifilament Dental Devices Overcoated with Imbedded Particulate"and"Coated Monofilament Dental Devices Overcoated with Imbedded Particulate"are all sources of positive feed back to the flosser that would be considered encouraging and supportive. To achieve these with micromesh dental floss requires basic changes in present micromesh floss manufacturing.

Most commercial monofilament and multifilament interproximal devices marketed at the present time contain various coatings of wax or wax like substances that function as: (1) binders for the various multifilament flosses to minimize fraying, (2) lubricants, (3) flavor carriers, and/or (4) fluoride carriers for both monofilament and multifilament devices.

An almost universal shortcoming common to most waxed multifilament dental flosses and monofilament tapes is the user perception during flossing that the dental floss or dental tape is"not working"and/or"not cleaning", etc.

In fact, most of these devices have only marginal efficacy with respect to removing biofilms (plaque). Biofilms generally require physical abrasive-type action to be effectively removed. Periodic professional cleaning is a recommended means for effectively controlling biofilm formation.

From 1960 thru 1982, numerous clinical studies reported that there is no clinical difference as to plaque removal and gingivitis scores between waxed and unwaxed multifilament dental floss. Note, both are"cord"flosses and contain sizing, binders, etc. These studies also confirmed that waxed and unwaxed floss are approximately 50% effective with respect to plaque removal and gingivitis scores.

Thus the"cord"effect severely restricts efficiency of flossing and especially physical abrasive-type action associated with multifilament flosses that splay as described by Bass.

O'Leary in 1970, and Hill et al. in 1973, found no difference in the interproximal cleansing properties of waxed and unwaxed dental floss. This was reconfirmed in 1982 by Lobene et al. who showed no significant clinical difference on plaque and gingivitis scores. Similar results, i. e. , no clinical difference between waxed and unwaxed multifilament dental floss with respect to reduced gingival inflammation were shown by Wunderlich in 1981. No differences in plaque removal were reported by Schmidt et al. in 1981 with multifilament flosses of various types.

Stevens, 1980, studied multifilament dental floss with variable diameters and showed no difference in plaque and gingival health. Carter et al. 1975, studied professional and self administered waxed and unwaxed multifilament dental floss, both significantly, reduced gingival bleeding of interproximal and gingival sulci. Unwaxed multifilament dental floss appeared slightly, but not significantly more effective.

In view of this clinical work, it is not surprising that most of the multifilament dental floss sold today is contrary to the teaching of Bass, bonded and/or waxed. The "bonding"in the yarn industry today is used more to facilitate processing and production during multifilament dental floss manufacture and packaging than for "flossing"reasons. Since clinical tests show no difference between waxed and unwaxed multifilament dental floss (both unfortunately are"bonded"), the multifilament dental floss industry has been comfortable with the yarn industry's propensity to use bonding agents in multifilament dental floss, thereby sacrificing splaying and physical abrasive-type cleaning. Of course, monofilament dental tapes do not splay and have a basic shortcoming with respect to abrasive-type cleaning.

The development of micromesh dental flosses, which combine the strengths and advantages of multifilament dental flosses and monofilament dental tapes, while minimizing the shortcomings of monofilament and multifilament devices, is described in detail in copending U. S. Patent Application, Serial No. 10/073,682, entitled "Micromesh Interproximal Devices".

The classification of plaque as a biofilm is considered a major advance in the development of more effective"self-treatment"oral care products. See the following biofilm references: Greenstein and Polson, J. Periodontol., May 1998,69 : 5: 507-520; van Winkelhoff, et al. , J. Clin. Periodontol., 1989,16 : 128-131 ; and Wilson, J. Med.

Microbiol., 1996,44 : 79-87.

Biofilms are defined as".... matrix-enclosed bacterial population adherent to each other and to the surface or intersurfaces. These masses secrete an exopolysaccharide matrix for protection. Considerably higher concentrations of drugs are needed to kill bacteria in biofilms than organisms in aqueous suspensions." Costerton, J. W. , Lewandowski, Z., DeBeer, D. , Caldwell, D. , Korber, D. , James, G. Biofilms, the customized microniche. J. Bacterio., 1994,176 : 2137-2142.

The unique attributes of biofilms are being recognized as increasingly important in the 1990's. Future studies into the mode of growth of biofilms will allow manipulation of the bacterial distribution.

Douglass, C. W. , Fox, C. H. Cross-sectional studies in periodontal disease: Current status and implications for dental practice. Adv. Dent. Res., 1993,7 : 26-31.

The number of adults over 55 who will need periodontal services will increase. The type of services will need to be adjusted to meet the need.

Greenstein, G. J. , Periodontal response to mechanical non-surgical therapy: A review. Periodontol., 1992,63 : 118-130.

Mechanical therapy remains effective with caveats of compliance and skill of therapists.

Marsh, P. D. , Bradshaw, D. J. Physiological approaches to the control of oral biofilms. Adv. Dent. Res., 1997,11 : 176-185.

Most laboratory and clinical findings support the concept of physiological control. Further studies will reveal details of biofilm diversity.

Page, R. C. , Offenbacher, S. , Shroeder, H. , Seymour, G. J., Kornman, K. S., Advances in the pathogenesis of periodontitis : Summary of developments, clinical implications and future directions. Periodont. 2000,1997, 14: 216-248.

Genetic susceptibility to three oral anaerobic bacteria play an important part in the progression of periodontitis. Acquired and environmental risk factors exacerbate the problem. Mechanical disruption will remain an effective and essential part of periodontal therapy.

Papapanou, P. N. , Engebretson, S. P. , Lamster, 1. B. Current and future approaches for diagnosis of periodontal disease. NYState Dent.. ., 1999,32-39.

New techniques are available such as a novel pocket depth measurement device, microscopic techniques, immunoassay, DNA probes, BANA hydrolysis tests. These more clearly define the nature of periodontitis.

The classification of plaque as a biofilm calls for more effective interproximal devices, with respect to removing, disrupting and/or controlling biofilms which requires physical particulate-abrasive-type cleaning interproximally and subgingivally when flossing. Such physical-abrasive cleaning is not available from commercial multifilament and monofilament interproximal devices marketed today.

SUMMARY OF THE INVENTION Micromesh dental floss is described in the referenced Patent Application, entitled"Micromesh Interproximal Devices"as a random: net, web or honeycomb- type integrated structure as distinguished from the more orderly monofilament and multifilament or woven structures used heretofore for interproximal devices. These micromesh structures are produced at low cost by integrating a rotating fibrillator device into a flat stretched film or tape producing operation, such as described in U. S.

Patent No. 5,578, 373. A wide range of fibrillators are available to produce an almost endless array of micromesh structures including those illustrated in Figs. la through 1 f and further shown in Figs. 2 through 4. All of these are suitable for use as particulate overcoated coated micromesh interproximal devices of the present invention.

The present invention is directed to biofilm-responsive, coated micromesh dental flosses suitable for physical-abrasive-type removal, disruption and/or control of biofilms that form on interproximal and/or subgingival tooth surfaces not reachable by brushing or rinsing. The coated micromesh dental flosses of the present invention are overcoated with an imbedded particulate abrasive that remains substantive to the micromesh floss coating until said base coating in which it is imbedded is eventually released or partially disrupted from the micromesh during flossing or remains as an effective abrasive throughout the use-life of the micromesh dental floss where the base coating on the micromesh floss is insoluble and remains substantive to the micromesh base during flossing.

During flossing, at the outset, the imbedded particulate abrasive overcoating functions as a"soft"abrasive version of an oral-type sandpaper removing, disrupting and/or controlling biofilms. Essentially the first pass through an interproximal space by the imbedded particulate, overcoated, micromesh dental floss results in a gentle "sandpaper"abrasive effect on the biofilms present, which effect is eventually followed by dissolving and/or breaking up of the base coating containing the particulate abrasive which is present on the micromesh net. In another embodiment of the invention, insoluble base coating materials are used. These do not readily release from the micromesh during flossing, and when impregnated with particulate abrasive, create a soft abrasive-type dental floss sandpaper, which is very effective in gently removing, disrupting and/or controlling biofilm throughout the use-life of the dental floss.

When a soluble base coating is used, the released wax/abrasive and/or particulate abrasive works in conjunction with the micromesh net to continue to remove, disrupt and/or control biofilms until the particulate abrasive is flushed away and/or dissolved by saliva. That is, the released particulate abrasive cooperates with the micromesh dental floss as the floss is being worked interproximally and subgingivally to continue to deliver physical-abrasive-type cleaning, disruption and/or control of biofilms formed on interproximal and subgingival tooth surfaces.

The physical-abrasive-type cleaning, disruption and/or control of biofilms achieved with the various imbedded particulate abrasive overcoated micromesh dental flosses of the present invention continues until: the micromesh dental floss is removed from the space and flossing of the area is discontinued, the particulate abrasive dissolves and/or is washed away, and/or the biofilm is physically removed, disrupted and/or controlled.

The physical-abrasive-type cleaning, disruption and/or control of biofilms with the imbedded particulate abrasive overcoated micromesh dental flosses of the present invention can be simultaneously improved further with a chemotherapeutic treatment by various chemotherapeutic substances contained in: (1) the base coating, (2) the particulate abrasive, and/or (3) other particulate overcoating substances used to introduce flavor, mouth feel, etc. , attributes into the particulate overcoated micromesh dental flosses of the invention. In the latter version which is preferred, these chemotherapeutic substances are released onto the tooth surfaces during flossing along with the saliva soluble particulate that releases from the base coating.

Surprisingly, the particulate abrasive overcoating imbedded in the base coating on the micromesh dental floss of the present invention exhibits unexpected gentleness along with lower than expected abrasivity which, for purposes of the present invention, allows more abrasive particulates to be used in the overcoating, such as pumice, alumina, silica, etc. This"soft abrasive"effect is attributed in part to the cushion effect contributed by the base coating to the imbedded particulate abrasive.

That is, the base coating containing the partially imbedded particulate abrasive tends to cushion the impact of the exposed portion of the abrasive particulate onto tooth surfaces during flossing. See Fig. 10. This"soft abrasive"effect is particularly important where insoluble base coatings are employed and the"sandpaper"effect continues over the use-life of a particular segment of the floss. In those instances where the abrasive/coating mixture breaks free from the micromesh during flossing, the base coating tends to help lubricate the particulate abrasive/micromesh combination reducing further the abrasivity of the particulate abrasive on tooth surfaces.

Accordingly, one embodiment of the present invention comprises biofilm- responsive micromesh dental floss devices.

A further embodiment of the present invention comprises coated micromesh dental floss devices with particulate abrasives imbedded in the coating thereby rendering the floss biofilm-responsive during flossing.

Another embodiment of the invention comprises a self-treatment means for routinely removing, disrupting and/or controlling biofilms formed on interproximal and subgingival tooth surfaces.

Still another embodiment of the invention comprises a method for overcoating coated micromesh dental flosses with imbedded particulate abrasives of various particle sizes and particle size distributions, in order to more effectively remove, disrupt and/or control biofilms.

Yet another embodiment of the invention comprises a patient self-treatment method for periodically removing, disrupting and/or controlling biofilms that form on interproximal and subgingival tooth surfaces.

A further embodiment of the invention comprises biofilm-responsive micromesh dental devices overcoated with imbedded particulate abrasives and containing a releasable wax-type base coating which contains an antimicrobial.

Another embodiment of the invention comprises biofilm-responsive micromesh dental devices overcoated with active imbedded particulate abrasives such as whitening and tartar control abrasives.

Still another embodiment of the invention comprises biofilm-responsive micromesh dental devices overcoated with imbedded dental particulate abrasives including silica, pumice, alumina, calcium carbonate and dicalcium phosphate dihydrate.

Yet another embodiment of the invention comprises biofilm-responsive, micromesh dental devices overcoated with imbedded particulate abrasives, where said abrasives contain other substances ranging from flavorants, antimicrobials and cleaning substances to mouth conditioners and various pharmaceutical substances.

A further embodiment of the invention comprises improved waxed micromesh dental flosses with an overcoating of imbedded particulate abrasive.

Still another embodiment of the invention comprises improved waxed micromesh dental flosses with overcoatings of imbedded particulate abrasive and saliva soluble particulate substances containing flavorant and mouth conditioning substances.

Another embodiment of the invention comprises improved waxed micromesh dental flosses with an overcoating of imbedded particulate abrasive containing a saliva soluble, substance containing flavorant and mouth conditioners.

Yet another embodiment of the invention comprises a method for improving micromesh dental flosses comprising sequential overcoating of said base coated micromesh dental flosses with two or more particulates having substantially different densities, wherein said various particulates are imbedded into the base coating prior to cooling and solidifying said base coating.

Still another embodiment of the invention comprises improved commercial, emulsion coated micromesh dental floss with an overcoating of imbedded particulate abrasive.

Another embodiment of the invention comprises improved coated, extensively fibrillated, micromesh dental floss with an overcoating of imbedded particulate abrasive.

A further embodiment of the invention comprises a method to overcome the "cord"effect of waxed micromesh floss while imparting physical abrasive properties to waxed micromesh dental flosses.

For purposes of describing the present invention, the following terms are defined as set out below: The terms fiber and filament are used synonymously throughout this specification in a manner consistent with the first three definitions of"fiber"and the first definition of"filament"as given in the New Illustrated Webster's Dictionary, 01992 by J. G. Ferguson Publishing Co. the relevant disclosure of which is hereby incorporated herein by reference.

"Base coatings"for the micromesh dental devices are defined as those substances that coat micromesh dental devices for purposes of : lubrication and ease of floss insertion for carrying flavors and other additives, providing"hand"so the device can be wound around the fingers, etc. , such as described in detail in Tables 3 to 4 below. These coatings generally comprise from about 25 to about 100% by weight of the micromesh floss.

Preferred base coatings include: Insoluble, partially soluble and soluble wax coatings, Those emulsion coatings described in the following U. S. Patents, 4,950, 479; 5,032, 387; 5,538, 667; 5,561, 959; and 5,665, 374, which are hereby incorporated by reference, Various dental floss coatings, such as described in U. S. Patents: 5,908, 039; 6,080, 495; 4,029 ; 113; 2,667, 443; 3,943, 949; 6,026, 829; 5,967, 155 and 5,967, 153, and Those saliva soluble coatings described and claimed in co-pending U. S. Patent Applications, Serial Nos. 09/935, 922; 09/935, 920; 09/935, 921 and 09/935, 710, all filed on 8/23/01, which are hereby incorporated by reference.

"Particulate abrasives"are defined as saliva soluble, semi-soluble and insoluble abrasive substances having a wide range of particle sizes and particle size distribution.

Preferred particulate abrasives include various insoluble inorganics such as glass beads, and various insoluble organics such as particles of polyethylene, polypropylene, etc.

Particularly preferred inorganic particulate abrasives include various: (1) insoluble dental abrasives such as: pumice, silica, alumina, silicon dioxide, magnesium oxide, aluminum hydroxide, diatomaceous earth, sodium potassium aluminum silicate, zirconium silicate, calcium silicate, fumed silica, hydrated silica, and (2) soluble dental abrasives such as: dicalcium phosphate dihydrate, anhydrous dicalcium phosphate, sodium tripolyphosphate, calcium carbonate, etc. See also Table 1 below.

Particularly preferred"active"particulate abrasives include: Peroxides such as: carbamide peroxide, calcium peroxide, sodium perborate, sodium percarbonate, magnesium peroxide, sodium peroxide, etc.; Phosphates such as: sodium hexametaphosphate, tricalcium phosphate, etc.; and Pyrophosphates such as: tetrasodium pyrophosphate, tetrapotassium pyrophosphate, sodium acid pyrophosphate, calcium pyrophosphate, etc. See also Table 2 below.

See also the following relevant U. S. Patents: U. S. 6,221, 341; 3,491, 776; 3,330, 732; 3,699, 979; 2,700, 636; 5,220, 932; 4,776, 358; 5,718, 251; 5,848, 600; 5,787, 758; and 5,765, 576, which describe various oral care abrasives suitable for the present invention and are incorporated herein by reference.

"Releasable"particulate abrasive is defined as the property whereby particulate abrasive, which is imbedded into the base coating on micromesh dental floss, remains substantive to said base coating until flossing begins, after which time the imbedded particulate abrasive in the base coating eventually separates from the micromesh along with the base coating which eventually dissolves and releases the particulate abrasive into saliva. Thus, the particulate abrasive remains available interproximally and subgingivally to work with the micromesh floss, responding to biofilms encountered on subgingival, interproximal and supragingival tooth surfaces with physical-abrasive-type cleaning.

Permanent and/or semi-permanent particulate abrasives are defined as those particulate abrasives imbedded in insoluble coatings which are generally not released from the micromesh net during flossing.

"Particulate abrasive load"is defined as the percent by weight of imbedded particulate abrasive contained on the coated micromesh dental device as a percent by weight of the device. See Tables 1,2, 3 and 5 below.

"Base coat micromesh device load"is defined as the percent by weight of the base coating contained on the micromesh device as a percent by weight of the coated micromesh device.

"Total coating load"is defined as the percent by weight of the base coating plus the particulate abrasive overcoating imbedded in said coating on the micromesh device as a percent by weight of the device.

"Perceived Abrasive Factor (PAF) "is defined as the subjective level of perceived abrasivity when: (1) winding the coated micromesh device with imbedded particulate abrasive around the fingers (i. e. ,"hand"), and (2) when working the device across tooth surfaces with a sawing action.

PAF grades range from 0 through 4, i. e. , imperceptible (0), slightly perceptible (1), perceptible (2), very perceptible (3) and very abrasive (4). See Tables 1, 2 and 9 below. PAF values of about 2 or greater are preferred. PAF values above 3 are particularly preferred. Permanent abrasives generally exhibit higher PAF values than releasable abrasives.

"Incidental Release Factor (IRF) "is defined as the percent by weight of the particulate abrasive retained on the coated micromesh dental device, when an 18 inch piece of the device is removed from a dispenser and wrapped around two fingers prior to flossing. (See Tables 1,2 and 9. ) IRF values over 90% reflect the degree to which the particulate abrasives are imbedded in the base coating, as well as the tenacity of this imbedded particulate in the solidified base coating. When a cross-section of a bundle of filaments is viewed under a microscope, it is apparent that from between about 20 to about 90% of the total surface of each particulate is imbedded into the base coating on the micromesh. This extent of particulate surface imbedding into the base coating is primarily responsible for the"it's working"perception which registers during flossing along with the particulate abrasive retained during handling of the floss prior to flossing (IRF). Permanent abrasives generally exhibit higher IRF values than releasable abrasives.

"Biofilm responsive"is defined as the property of particulate abrasives and saliva soluble particulates to work cooperatively with micromesh dental flosses and other cleaning and/or chemotherapeutic substances in the base coating to remove, disrupt and/or control biofilms during flossing.

"Fluidized bed"is defined as a means of converting solid particulate abrasives into an expanded, suspended, solvent-free mass that has many properties of a liquid.

This mass of suspended particulate abrasive has zero angle of repose, seeks its own level, while assuming the shape of the containing vessel.

"Sequential fluidized beds"are defined as a means of converting solid particulate abrasives and solid particulate saliva soluble substances separately into expanded, suspended, solvent-free masses that have many properties of a liquid.

These separate fluidized masses of suspended particulate abrasive and suspended solid, saliva soluble substances each have zero angle of repose and seek their own level, while assuming the shape of the containing vessel.

"Fibrillating"is generally defined as a means of converting various high tensile strength, stretched film stocks including tapes to various mesh constructions such as illustrated in Figs. la through If and shown in photographs in Figs. 2 through 4 by subjecting the stretched tapes to contact with various rotary fibrillator means such as shown and described in U. S. 5,578, 373; 2,185, 789; 3,214, 899; 2,954, 587; 3,662, 930; 3,693, 851 and Japanese Publications : 13116/1961 and 16909/1968.

During fibrillating, the transfer speed of the stretched polyethylene tape is from between about 1 and about 1000 m/min and the rotational line speed of the fibrillator means in contact with the stretched polyethylene tape is from between about 10 and about 3000 m/min. These fibrillating conditions produce fibrillated micromesh substrates suitable for various types of coating including compression loading for use as interproximal devices. See Figs. la through If and photographs in Figs. 2 through 4.

"Fibrillation density"is generally defined as the level of perforations in the interproximal device as determined on the basis of the percent of the device surface that is perforated. Perforations between from about 5% and about 90% of the total tape surface area are suitable for purposes of the present invention. There appears to be a correlation between"fibrillation density"and the capacity of the device to entrap and removal loosened substances from interproximal and subgingival areas, i. e. , the "entrapment factor".

"Entrapment factor"is generally defined as the level of biofilm, tartar, debris, etc. , which has been dislodged from tooth surfaces during flossing and subsequently entrapped by the micromesh interproximal device after various coating substances have been released from the"spent"interproximal device. The"entrapment factor"is determined by a visual comparison of the spent micromesh interproximal device with a spent commercial monofilament tape used by the same subject at the alternative interproximal site. The micromesh interproximal devices of the present invention generally exhibit entrapment factors from between about 2 and about 10 which indicates a two-fold to ten-fold increase in entrapped debris, biofilm, etc. , over the commercial monofilament tape.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. la through If are illustrations of uncoated micromesh tapes suitable for the present invention produced by various fibrillations of stretched, ultra-high molecular weight polyethylene tapes.

Figs. 2a through 2c are actual photographs of uncoated micromesh tapes of the present invention. Figs. 2d and 2e are photographs of uncoated monofilament dental tape and uncoated micromesh dental tapes, respectively.

Figs. 3a and 3b are actual photographs of coated micromesh tapes of the present invention where the tapes are at two different levels of fibrillation.

Figs. 4a through 4c are actual photographs of micromesh tape. Fig. 4a is the tape uncoated. Fig. 4b and 4c show the tape coated.

Fig. 5 is a schematic side view of a particulate overcoating system of the invention suitable for overcoating wax-type coated micromesh devices with imbedded particulate abrasive and imbedded, saliva soluble, solid substances containing flavorants, mouth conditioners, nutraceuticals and/or active therapeutic ingredients.

Fig 5a is a schematic side view of a particulate overcoating system as shown in Fig. 5, with the filter means replaced by fitted with means to recover the particulate overspray that does not contact the multifilament during the overcoating operation.

Fig. 6 is an enlarged top view of the system shown in Fig. 5 showing base coated micromesh dental floss passing through the particulate coating chamber.

Fig. 7 is an expanded, schematic, three-dimensional view of a coated micromesh dental device showing a liquid coating on the micromesh dental floss prior to the coated floss entering the particulate coating chamber.

Fig. 8 is an expanded, schematic, three-dimensional view of wax-type coated micromesh dental floss showing particulate abrasive imbedded into the liquid base coating after the micromesh dental floss passes through the particulate abrasive coating chamber.

Fig. 9 is an expanded, schematic, three-dimensional view of a base coated micromesh dental floss showing particulate abrasive partially imbedded into the solidified coating after the particulate abrasive overcoated, micromesh dental floss has been passed through a cooling zone, thereby solidifying the base coating (the cooling zone is not shown).

Fig. 10 is a blown up schematic, partial cross-sectional view of coated micromesh dental floss showing particulate abrasive partially imbedded into the solidified base coating which functions as a cushion for the abrasive.

Fig. 11 is a blown up schematic, horizontal, three-dimensional view of coated micromesh dental floss showing a mixture of particulate abrasive and saliva soluble flavor/mouthfeel containing particulates partially imbedded into the solidified base coating.

Fig. 12 is a schematic side view of an alternative particulate overcoating system of the present invention suitable for overcoating base coated micromesh devices.

Fig. 13 is a schematic side view of another alternative particulate overcoating system of the present invention suitable for overcoating wax-type coated micromesh devices where the particulate used for overcoating is not detailed.

Fig. 14 is similar to Fig. 9, with the particulate used for overcoating shown in detail.

Fig. 15 is a schematic flow chart for particulate overcoating of coated micromesh dental floss.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figs. 1 through 4, micromesh devices are distinct from and superior over multifilament dental flosses, as well as monofilament dental tapes.

These superior performing interproximal devices are neither multifilament nor monofilament in structure. Rather, they are characterized by a unique micromesh honeycomb or web-type structure, hereinafter described as a micromesh structure shown in Figs. la through If. These micromesh devices are not produced from a bundle of fibers like multifilament dental flosses nor are they produced by slitting shred-resistant films used to manufacture PTFE tape or by extrusion used to manufacture elastomeric monofilament tapes and/or the extrusion and slitting processes used to make typical high density polypropylene or polyethylene tapes.

Rather, these ultra shred-resistant micromesh devices are produced by fibrillating, meshing, webbing, etc. , high-tensile strength, ultra-high molecular weight, stretched, polyethylene films. Generally, this is a penetrating, tearing-type function. This fibrillation of stretched polyethylene films produces various micromesh structures such as illustrated in Figs. la through If and further depicted in the photographs in Figs. 2 through 4.

The photographs in Fig. 2 compare typical uncoated multifilament and monofilament devices with uncoated micromesh tapes of the present invention. The photographs in Fig. 3 show coated micromesh interproximal devices at two different levels of fibrillation. The photographs in Fig. 4 illustrate a micromesh tape with a base coat coated and uncoated. Particulate overcoated, coated micromesh flosses of the invention are illustrated in Figs. 8 through 11.

Referring to Fig. 5 which is a schematic side view of a particulate abrasive overcoating system comprising: particulate coating system, 1, consisting of fluidized bed means, 2, comprising: fluidized particulate abrasive, 3, membrane, 4, fluidizing air means, 5, stand pipe, 6, in communication with particulate abrasive nozzle means, 7, provided with pump means, 8, which contains nozzle air input means, 9, and pump cleaning means, 10.

Particulate coating system, 1, is provided with hinged access means, 11 and 15, and filter means, 12, particulate filling means, 13, and coated micromesh dental floss particulate coating zone, 14, and coated micromesh dental flosses, 15. Filter means, 12, can be assisted by a vacuum cyclone means which captures all unused particulate, 3, overspray and recycles same. This is detailed in Fig. 5a.

Coated micromesh dental floss, 15, with a liquid coating contained thereon, passes through particulate coating zone, 14, where particulate, 3, is imbedded into the liquid coating on micromesh dental floss, 15, from nozzle means, 7.

Referring to Fig. Sa, vacuum cyclone means, 60, replaces former filter means, 12, and is connected to the top of particulate coating system, 1, at juncture 61, via tubing means, 62. Vacuum cyclone means, 60, maintains a slight negative pressure within particulate coating system, 1, by drawing air and some dispersed particulate from coating system, 1, and introducing this air/particulate mixture into vacuum cyclone chamber, 63, where particulate, 3, is introduced into holding means, 64, and the remaining air substantially free from particulate, 3, passes through the top of chamber, 63, through tubing, 65, via motor, 67, into filter means, 66 and 66.

Alternatively, particulate, 3, is captured by collecting means, 68, with air regulator, 69, and returned to particulate coating system, 1, via tubing, 70.

Referring to Fig. 6, which is an enlarged top view of particulate coating system, 1, shown in Fig. 5. Micromesh dental floss, 15, with liquid base coating, 16, thereon, passes through particulate coating zone, 14, where particulate abrasive, 3, from nozzle means, 7, is imbedded via impinging into liquid base coating, 16, which is substantive to the micromesh dental floss, 15, as micromesh dental floss, 15, passes through particulate coating zone, 14.

Referring to Fig. 7, which is an expanded, schematic, three-dimensional view of coated micromesh dental floss, 15, with fibrillations, 17, showing base wax-type liquid coating, 16, thereon before the floss, 15, passes into particulate coating zone, 14. The base wax-type coating, 16, has been heated and is in a liquid state and is substantive to the micromesh floss web, 15.

Referring to Fig. 8, which illustrates an expanded, schematic, three- dimensional view of wax-type coated micromesh floss, 15, with fibrillations, 17, showing base liquid coating, 16, containing particulate abrasives, 3, imbedded into the liquid coating, 16, with the imbedded portion of the particulate abrasive shown via dotted lines designated as 3'.

Referring to Fig. 9, which is an expanded, schematic, three-dimensional view of wax-type coated micromesh dental floss, 15, with fibrillations, 17, showing base coating, 16, that has been passed through a cooling zone (not shown) sufficient to solidify said base coating, 16, with particulate abrasive, 3, firmly imbedded into said solidified base coating, 16, with the imbedded portion of the particulate abrasive represented by the dotted lines designated as 3'.

Referring to Figs. 5 and 9, in a particularly preferred embodiment of the invention, the particulate overcoating system, 1, set forth in Fig. 5, is replicated and in line, in order to sequentially imbed two distinct particulate substances having substantially different densities onto the liquid base coating, 16, on micromesh, 15.

Under this sequential particulate coating operation, particulate substance abrasive, 3, imbeds into coating, 16, prior to the particulate overcoated floss, 15, passing directly from a first particulate coating zone, 14, into a second similar particulate coating zone, where a high impact particulate mouth conditioning substance is also imbedded into base coating, 16, prior to the multi-particulate overcoated floss, 16, passing to the cooling zone, not shown. In this sequential arrangement, two distinct particulates having substantially dissimilar densities are imbedded into the liquid base coating, 16, using this sequential fluidized bed arrangement prior to said base coating solidifying.

Referring to Fig. 10, which is an expanded, schematic, partial cross-sectional view of wax-type coated micromesh dental floss, 15, showing solidified base coating, 16, with particulate abrasive, 3, firmly partially imbedded in solidified wax-type base coating, 16, with"cushion", 19, extending from the bottom of particulates, 3, to the surface of micromesh dental floss, 15. The imbedded portion of the particulate abrasive is designated as 3'.

Referring to Fig. 11, which is an expanded, schematic, horizontal, three- dimensional view of wax-type coated micromesh dental floss, 15, showing a mixture of particulate abrasive, 3, and saliva soluble particulate, mouth feel, mouth conditioning, substance, 18, each shown firmly partially imbedded into said solidified base coating, 16, with the imbedded portions of 3 and 18 shown by dotted lines, 3' and 18', respectively.

Referring to Fig. 12, which is a schematic side view of an alternative particulate overcoating system, 20, for delivering a particulate, 21, from a vessel or fluidized-bed means, 30, to a conveying agent means, 22, with gear drive means, 23.

The speed of conveying auger, 22, is controlled by motor driven gear means, 23, which is slaved to a surface speed controller, not shown, for micromesh floss, 24. As the micromesh floss, 24, moves faster, auger means, 22, speeds up and delivers more particulate, 21, to the surface of molten-coated micromesh floss, 24. This system then allows for the delivery of a constant density of particulate, 21, per square millimeter of micromesh floss, 24. This alternative particulate overcoating system requires substantially lower volumes of air with corresponding reductions in overspray of particulates. This system requires minimal recovery of unused particulate and/or recycling of unused particulates.

In the foregoing system, the particulate, 21, may be an abrasive such as pumice, having an average particulate size of 37 microns which are fluidized with a porous plate of sintered polyethylene powder of 0.5 inch thickness. The plate has an average pore size of 20 microns. As the fluidized pumice is presented to auger means, 23, it is pulled down the shaft and presented to venturi means, 25. Control of the air flow in proportion to the speed allows uniform delivery of pumice to a surface of micromesh floss, 24, passing under the outlet of venturi means, 25. This arrangement allows delivery of uniform particle density with very low air speed, consistent with little perturbation of the floss traverse.

Referring to Figs. 13 and 14, which are two separate schematic side views of another alternative particulate overcoating system, 40, for delivering particulates, 41, from a fluidized bed means, 42, to micromesh flosses, 43 and 43'.

Air chamber means, 44, introduces air under low pressure through distributor plate means, 45, which in turn fluidizes particulates, 41, in fluidized bed means, 46.

Particulates, 41, are introduced from fluidized bed, 46, into particulate coating chamber, 47, by particulate metering means, 48. Particulate coating chamber, 47, is provided with venturi means, 49. Modulating particulate dispensing means, 50, is provided with high velocity, low volume air means (not shown) providing turbulence to fluidized particulate, 41, prior to said particulate imbedding coatings, 51 and 51', on the micromesh web, 43 and 43', respectively. Particulate dispensing means, 50, enhances the uniformity of the particulate, 41, overcoating, 52 and 52', imbedded into coatings, 51 and 51', respectively.

Referring to Fig. 13, generally the pressure in air chamber, 44, is between 4 and 8 psi. Distributor plate, 45, is preferably a porous polyethylene means that creates air bubbles required to fluidize particulates, 41, in fluidized bed, 42. The air pressure in fluidized bed, 42, is preferably in the 0.2 to 0.5 psi range. Particulate metering means, 48, can take many shapes other than that of the threaded means depicted. For example, metering means can be a plug or ram without threads that controls the flow of particulates, 41, from fluidized bed, 42, into particulate coating chamber, 47. Lowering metering means, 48, into particulate coating chamber, 47, as shown by dotted lines, 52, further restricts the flow of fluidized particulate, 41, through distance, 53. Thus, particulate metering means, 48, determines the quantity of fluidized particulate, 41, to enter particulate metering area, 47. This control in combination with modulated air flow through particulate dispersing means, 50, produces a substantially uniform density particulate on coating, 51, with imbedded particulates, 52, being dispersed substantially uniformly throughout coating, 51.

For a production system comprising up to 32 micromesh lines running side- by-side, the particulate overcoating system, 40, will be replicated in groups of 8, with two such groups covering the total of 32 lines running side-by-side.

Referring to Fig. 15, which is a schematic flow chart for particulate overcoating of coated micromesh dental floss, micromesh floss is passed through liquid base coating zone where the base coating is applied. Particulate overcoating is applied by introducing the coated micromesh into one or two particulate overcoating zones, after which the particulate overcoated micromesh floss passes through a cooling zone, followed by passing the overcoated micromesh through a particulate compression means before being introduced to a take-up winder means.

The micromesh floss devices of the present invention can contain a broad range of coating substances which are best loaded onto and/or into the micromesh structure by one of three loading means. Specifically: 1. The high melt viscosity mixtures and emulsions are loaded onto and/or into the micromesh by compression means; 2. The medium melt viscosity mixtures and emulsions are loaded onto and/or into the micromesh by injection loading means; and 3. The low melt viscosity mixtures and emulsions are loaded onto and/or into the micromesh by contact loading means.

The improved interproximal devices of the present invention contain base coatings that: (a) comprise from 10 to 120% by weight of the micromesh substrate, (b) are preferably saliva soluble and (c) in a preferred embodiment are crystal free, and accordingly, exhibit a minimum of flaking. Some of these base coatings are released in total into the oral cavity during flossing.

In a preferred embodiment, these base coatings contain ingredients such as: (a) Soft Abrasives that work with the micromesh structure to help physicall, remove biofilm (plaque) from interproximal and subgingival surfaces, (b) chemotherapeutic ingredients affecting oral health and subsequent systemic diseases caused or exacerbated by poor oral health, (c) cleaners that introduce detersive effects into the areas flossed, and (d) mouth conditioners. These base coatings are particularly adapted to loading into and/or onto the micromesh tapes using the compression, injection or contact loading means described above to produce the innovative interproximal devices of the present invention.

The particulate abrasives and other saliva soluble particulate substances of the present invention are overcoated into the coated micromesh dental floss base coatings as solid materials totally free from solvents.

A preferred method of imbedding particulate abrasive overcoatings and saliva soluble particulate overcoatings into the base coat of the micromesh device is by means of a series of innovative fluidized bed systems such as the system shown in Fig. 5.

Referring to Fig. 5, membrane means, 4, is used to maintain the particulate abrasive, 3, or saliva soluble particulate, 18, in a state of continued fluidization, i. e., fluidized bed, 2. Particulate abrasive, 3, or saliva soluble particulate, 18, can each be maintained in a fluidized state using fluidizing bed, 2. These fluidized particulates are introduced essentially at a 90° angle to the traverse of coated micromesh dental floss, 15, via nozzle means, 7 and 7', through stand pipe means, 6, via pump means, 8.

Referring to Fig. 5, coated micromesh dental floss, 15, passes through particulate coating zone, 14, and is imbedded with particulate abrasive, 3, as shown in Figs. 8 thru 10, or with saliva soluble particulate, 18, as shown in Fig. 11. Particulate abrasive, 3, and saliva soluble particulate, 18, are each separately introduced under high impact conditions into liquid base coating, 16, on micromesh floss, 15, via nozzle means, 7 and 7', via separate particulate overcoating system positioned sequentially in a series immediately prior to the particulate overcoated micromesh flosses entering the cooling zone, not shown.

Imbedding of the particulate abrasive, 3, into the base coating, 16, throughout the coating on the micromesh, 15, is achieved by means of impinging said particulate into the hot, liquid, base coating that is present over the entire outer surface of said micromesh device at the time the particulate abrasive, 3, impinges the coating, 16.

See Figs. 8 thru 10.

That is, the particulate abrasive, 3, impinges into liquid coating, 16, which is substantive to micromesh web, 15, as the device passes through particulate coating zone, 14, and particulate abrasive, 3, is imbedded into coating, 16, as shown in Fig. 9 and in solidified coating, 16, as shown in Figs. 10 and 11.

That is, particulate abrasive, 3, impinges into the hot, viscous base coating, 16, which is a viscous liquid generally at a temperature between about 48°C and 110°C with a viscosity between 10 and 10,000 cs. This is illustrated in Figs. 8 and 9, with the exposed portion of particulate abrasive designated as 3, and the imbedded portion of the particulate abrasive indicated by dotted lines and designated as 3'.

The micromesh dental floss overcoated with imbedded particulate then proceeds through a cooling means (not shown), where the base coating, 16, cools and solidifies with the particulate abrasive, 3, imbedded therein, as illustrated in Figs. 9 through 11.

Fig. 11 illustrates high-impact particulate overcoating into a micromesh dental floss base coating. That is, the particulate abrasive, 3, and particulate saliva soluble substances, 18, that contain mouth conditioners, flavorants, active ingredients, etc. are imbedded into the base coating, 16, as illustrated in Fig. 11. Particulate abrasive, 3, along with saliva soluble particulate substance, 18, are sequentially imbedded into base coating, 16, on micromesh floss, 15, from separate fluidized bed sources prior to base coating, 16, solidifying.

The overcoatings of particulate abrasive and various saliva soluble particulate substances containing flavorants and/or mouth conditioners and/or chemotherapeutic substances can include a broad range of these substances. For example, particulate ratios of particulate abrasives to saliva soluble substances such as nonionic surfactants (PLURONICS), emulsions such as MICRODENTS and/or ULTRAMULSIONS and/or polyols such as PEG in these hi-impact particulate overcoatings can range from 10: 90 to 90: 10.

The innovative fluidized bed coating process of the present invention is most effective in imbedding: (1) particulate abrasive loads between about 2 and about 45 percent by weight into the coated device, (2) particulate, saliva soluble loads between about 2 and about 45% by weight into the coated device, (3) particulate abrasive overcoating into coated micromesh devices with a perceived abrasive factor (PAF) between about 2 and 4, and (4) particulate abrasive, overcoating into coated micromesh devices with an Incidental Release Factor (IRF) value well above 80%, and preferably over 90%, and most preferably over 95%.

It has been discovered that in order to produce a coated micromesh dental device with PAF values in the 3 to 4 range, it is necessary: (1) to embed particulate abrasive loads at between about 10 and 34 percent by weight of the device, (2) to restrict the average particle size of the imbedded particulate abrasive to between about 7 microns and about 200 microns, (3) to restrict the particle size distributions of the imbedded particulate abrasive to from between about 5 microns and about 300 microns, and (4) to imbed the particulate abrasive into the liquid base coating under a high velocity charge from several nozzle means positioned at 90° to the traverse of the coated micromesh floss through the particulate coating chamber, thereby maximizing the impingement of the particulate abrasive into the base coating.

Overcoating coated micromesh floss with saliva soluble particulate can be carried out by imparting a static charge to the saliva soluble particulate prior to discharge from the nozzle means. Means are provided for grounding the liquid, base, coated micromesh in order to receive the charged saliva soluble particulate.

Alternatively, saliva soluble particulate can be imbedded into liquid base coatings on micromesh dental flosses by various spraying means.

In addition to various types of fluidized bed/nozzle arrangements, the particulate abrasive overcoatings can be imbedded into the coated micromesh dental flosses by several other means for impinging particulate abrasives onto liquid coated micromesh. These include various powder coating processes including fluidized bed, plastic frame-spraying, electrostatic spraying and sonic spraying. In the latter, sound waves are used to suspend the particulate abrasives before introducing the fluidized particulate abrasive into a nozzle means.

Other particulate abrasive overcoating processes are described in U. S. Patents 6,037, 019; 3,848, 363; 3,892, 908; 4,024, 295; 4,612, 242; 5,163, 975; 5,232, 775; 5,273, 782; 55,389, 434; 5,658, 510; 2,640, 002; 3,093, 501; 2,689, 808; 2,640, 001 and 5,194, 297. These can be adapted to particulate abrasive impingement on coated micromesh as taught by the present invention and are incorporated herein by reference.

Particularly preferred particulate overcoating means include various Nordson (g) automatic powder coating systems such as the Nordsons Tribomatic II powder coating system, which includes various Nordson (g) powder pumps, as well as ITW Gema Powder coating systems including their Easysystem and Electrostatic Equipment Co's 7R FLEXICOAT (D system.

The particulate overcoating of the invention can be affected with various other means for delivering particulate to the liquid base coating. For example, the particulate can be introduced by a simple screening technique where the particulate drops from the screening means onto the liquid means onto the liquid base-coated micromesh.

The preferred means of the invention for overcoating includes a fluidized bed in combination with a nozzle means. This combination provides the most uniform overcoatings while controlling the extend of the particulate imbedding into the liquid base coating and optimizing PAF and IRF values.

Various dental particulate abrasives imbedded into a standard coated micromesh dental floss having an average denier of 840 and a base coating of about 25 mg/yd, suitable for purposes of the present invention, are illustrated in Examples 1 through 7, as described in detail in Table 1 below: Table 1<BR> "Dental" Particulate Abrasives suitable for imbedding into coated micromesh dental flosses Particulate Projected Projected Estimated % of total particulate Avg. Particle Size Abrasive Load Incidental Perceived abrasive surface area imbedded Example Particulate Particle Size Distribution as % by wt. of Release Factor Abrasive Factor into coated micromesh floss # Abrasive(s) (in microns) (in microns) device (IRF) in % (PAF) 1 pumice 35 4-120 23 95 3.5 14 to 19 2 silica 10 2-18 10 98 1.5 6 to 9 3 pumice & silica 12 2-120 16 96 2.5 13 to 15 4 dicalcium phosphate 55 18-100 15 98 1.5 12 to 14 dihydrate 5 alumina 25 10-75 20 94 3.7 15 to 18 6 calcium carbonate 50 15-80 16 97 2.0 13 to 15 7 polyethylene 20 8-40 12 98 1.5 9 to 11 Various"active"particulate abrasives imbedded into a standard coated micromesh dental floss having a denier of 840 and containing about 30mg/yd base coating, suitable for purposes of the present invention, are illustrated in Examples 8 through 12 as described in detail in Table 2 below: Table 2<BR> "Active" Particulate Abrasives suitable for imbedding into coated micromesh dental flosses Avg. Particle Size Particulate Projected Projected Estimated % of total particulate Example Particulate Particle Size Distribution Abrasive Load Incidental Perceived abrasive surface area imbedded # Abrasive(s) (in microns) (in microns) as % by wt. of Release Factor Abrasive Factor into coated micromesh floss device (IRF) in % (PAF) 8 tricalcium 60 10-150 10 90 3.0 7 to 9 phosphate & silica 9 tetrapotassium pyrophosphate & 65 20-175 12 90 2.5 8 to 11 pumice 10 tetra sodium 70 20-150 8 90 2.5 5 to 7 pyrophosphate 11 sodium hexametaphosphate 75 20-175 17 85 3.0 12 to 15 & pumice 12 calcium pyrophosphate & 9 4-35 20 98 2.0 15 to 19 silica Suitable particulate abrasives for the present invention can also contain active ingredients"dusted"thereon. For example, antimicrobials such as cetylpyridinium chloride, triclosan, chlorhexidine, etc., can be dusted onto the particulate abrasives prior to overcoating the coated micromesh floss. During flossing, these antimicrobial coatings on the particulate abrasives are released therefrom during flossing and remain available interproximally and subgingivally to work with the particulate abrasive imbedded micromesh dental floss during flossing as biofilms are being removed, disrupted and/or controlled.

Wax is a preferred base coating. The term wax is used as a generic classification of many materials that are either natural or synthetic, and generally these materials are considered wax-like because of their functional characteristics and physical properties. They are solid at ambient temperatures with a relatively low melting point, and capable of softening when heated and hardening when cooled. In general, the higher the molecular weight of a wax, the higher is the melting point.

Waxes are usually classified by their source as natural or synthetic waxes.

The waxes obtained from natural sources include animal waxes, such as beeswax; vegetable waxes such as candelilla and carnauba ; mineral waxes and petroleum waxes such as paraffin and microcrystalline wax. The synthetic waxes include Fischer- Tropsch waxes, polyethylene waxes, fatty acid waxes and amide waxes.

One preferred embodiment of the invention employs certain insoluble waxes coated onto micromesh flosses. These insoluble waxes do not readily release and/or break away from the fibers during flossing. When impregnated with particulate abrasive, these insoluble waxes continue to impart the"soft abrasive"sandpaper effect throughout the flossing procedure.

Natural Waxes: Petroleum waxes are, by far, the largest markets of the naturally occurring waxes. Petroleum waxes are further classified into paraffin and microcrystalline waxes.

Paraffin wax is obtained from the distillation of crude oil, and consists mainly of straight-chain saturated hydrocarbons. The molecular weight ranges from 280 to 560 (C20 to C40) and the melting point is about 68°C.

Microcrystalline wax is produced by deoiling the petrolatums or greases obtained by dewaxing deasphalated residual lube stocks or by deoiling the deasphalated tank bottoms that settle out during the storage of crude oil. These waxes are referred to as microcrystalline because the crystals are much smaller than those of paraffin wax. Microcrystalline waxes are composed predominantly of isoparaffinic and naphthenic saturated hydrocarbons along with some n-alkanes. The molecular weight ranges from 450 to 800 (C35 to C60), and produced in two grades with lower (65°C) and higher (80°C) melting points.

Animal Waxes are usually of insect or mammalian origin.

Beeswax is one of the most important commercially available animal waxes and is derived from honeycomb by melting the comb in boiling water and skimming off the crude wax. It is composed of nonglyceride esters of carboxylic and hydroxy acids with some free carboxylic acids, hydrocarbons and wax alcohols. The melting point of this wax is about 62-65°C with a flash point of 242°C.

Vegetable waxes are obtained either from leaves and stems or from fruits and seeds. Candelilla and carnauba waxes are the most important commercial vegetable waxes.

Candelilla wax is composed of hydrocarbons (50%), nonglyceride esters, alcohols and free acids. It has a low volume expansion or contraction upon phase change, and melts at about 68-72°C.

Carnauba wax is the hardest and highest melting point of the vegetable waxes.

It is composed primarily of nonglyceride esters with small amounts of free acids, resins and hydrocarbons. It melts at about 83-86°C.

Synthetic Waxes: Fischer-Tropsch wax is a by-product in the synthesis of liquid Riels, such as gasoline and diesel oils, obtained by catalytic hydrogenation of carbon monoxide at high temperature and pressure. It is composed of n-alkanes in the molecular weight range of 600-950 with a melting point of 95-120°C.

Polyethylene wax, with molecular weights of 2,000-10, 000, have properties of high molecular weight hydrocarbon waxes. These low densities, low molecular weight polyethylenes are made by high-pressure polymerization, low-pressure polymerization with Zeigler-type catalysts, or by thermal degradation of high molecular weight polyethylene. They have a melting point of 90-120°C.

Synthetic grades of beeswax, candelilla and carnauba waxes are also available with similar properties as the natural grades.

Water-Soluble Waxes: Polyethylene glycol, polymers of ethylene oxide, in the form of relatively low molecular weight liquids and waxes, are commonly referred to as poly polyethylene glycol- (PEG). Typically, polymers with molecular weight below 20,000 are defined as PEG and those above 20,000 are polyethylene oxide- (PEO). PEGs are available in molecular weights ranging from 1,000 to 20,000, and are all water-soluble. The solubility decreases with increases in molecular weight. The melting point of PEG varies from 45-60°C depending on molecular weight.

Tables 3 and 4 below describe in detail various coatings suitable for coating micromesh flosses and suitable for imbedding with the particulate particles of the present invention. Key compliance factors, such as Gentleness, Hi-impact Flavor and Mouth Feel of these overcoated micromesh dental flosses are attributed in part to the various base coatings such as described in Table 4, Examples 25 through 39 and to the various saliva soluble particulate substances imbedded into the base coating. The particulate abrasive overcoatings imbedded into these coated micromesh flosses impart the unexpected perception that the floss"is working", a key compliance factor.

Table 3<BR> Suitable Wax Coatings for Various Micromesh Dental Flosses Ex. Micromesh Fibrillation Level Wax Base Coating Imbedded Particulate Projected IRF Projected PAF Estimated % of total No. Floss-Type Type (Mg/yd) Abrasive-Type (in%) (in %) particulate abrasive Denier (filament) (mg/yd) surface area imbedded into wax coating 13 Nylon 6,6 2.4 microcrystalline wax pumice 92 3.6 17 to 24 840 (408) (28) (20) 14 Nylon 6,6 1.6 microcrystalline wax pumice 98 3.2 13 to 16 840 (408) (34) (12) 15 Nylon 6,6 1.6 microcrystalline wax pumice 96 3.4 15 to 18 840 (408) (34) (16) 16 Nylon 6,6 1.6 microcrystalline wax Silica 98 2.8 19 to 26 840 (408) (34) (15) 17 Nylon 6,6 1.6 microcrystalline wax Silica 99 2.5 15 to 18 840 (408) (34) (9) 18 Nylon 6,6 1.6 Bees wax Pumice 94 3.5 16 to 25 840 (408) (24) (20) 19 Nylon 6,6 1.6 Bees wax Pumice 97 3.1 12 to 16 840 (408) (24) (11) 20 Nylon 6,6 1.6 Bees wax Silica 98 2.5 18 to 20 840 (408) (24) (16) 21 Polyethylene 1.6 PEG 3350 Pumice 90 3.7 18 to 26 660 (220) (30) (21) 22 Polyethylene 1.6 PEG 3350 Pumice 95 3.2 13 to 18 660 (220) (30) (13) 23 Polyethylene 1.6 PEG 3350 Pumice 98 2.9 10 to 13 660 (220) (30) (9) 24 Polyethylene 1.6 Bees wax Pumice 94 3.6 16 to 23 660 (220) (27) (18) Suitable emulsion, saliva soluble and flake-free base coatings for various micromesh dental flosses are described in Examples 25 through 39 in Table 4 below: Table 4<BR> Suitable Base Coatings other than Wax for Micromesh Dental Flosses to be overcoated with particulate abrasive EXAMPLE NO. 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 Ingredients Ultramulsion 10/2.5 57.4 52.1 49.4 56.9 64.8 45.4 77.1 78.6 Microwax 445 7.0 7.0 7.0 7.2 7.0 PEG 40 Sorbitan diiso. 3.0 3.0 3.0 3.0 3.0 Stearyl alcohol 15 15 15 15 15 Insoluble saccharin 2.3 1.6 1.3 1.0 2.1 1.8 1.8 2.3 2.3 1.8 2.3 2.3 2.3 2.1 2.3 Propyl Gallate 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Flavor 9.6 10.0 10.0 7.5 5.4 8.5 10.0 8.8 8.6 10.0 4.0 4.0 8.0 6.0 6.0 Dicalcium dihydrate phosphate 6.0 3.0 13.3 15.0 13.0 Pumice 3.0 EDTA 0.2 0.2 0.2 0.2 0.2 0.2 0.2 TSPP 13.2 6.0 4.0 26.6 Silica 5.0 10.0 4.0 4.0 4.0 10.0 Calcium Peroxide 5.0 Calorhexidine digluconate 4.4 3.2 Poloxamer 407 53.0 35.0 20.0 44.4 61.2 45.0 19.4 PEG 8000 11.7 33.0 PEG 1450 35.0 53.0 71.1 7.6 10.0 8.0 33.0 Sodium fluoride 0.1 0.1 0.2 Carrageenin 13.3 Silicone (PDMS) 17.6 10.0 SnF2 4.8 Example 40: A saliva soluble base coating for micromesh dental floss was prepared having the following formula: Ingredient Grams Ultramulsion 10/2.5 479 Stearyl alcohol 150 Emsorb 2726 30 PG 1 Mult wax ML-445 70 Insoluble saccharin 18 Sident 10 100 Peppermint flavor 100 TSPP 50 EDTA 2 Total 1000 The foregoing was added to micromesh dental floss at various rates. This coated micromesh was overcoated with various particulate abrasives at various rates also, as indicated in Table 5 below.

Table 5<BR> Coated Micromesh Dental Floss, Particulate Abrasive Overcoating Data Micromesh Dental Floss Base Coating Particulate Overcoating Base Coat & Particulate Denier Base Coat Particulate Load Particulate Particulate Abrasive Ex Micromesh Dental Floss (grams/ Base Coat Load Particulate (mg/yd) Abrasive Load Abrasive % % of Total No. Type yd) Formula (mg/yd) Type (mg/yd) of total load Device PAF Micromesh flattened fibrillated 300d 41 Softmint 0.046 Ex 40 0.0552 Granular DCP 0.069 0.0138 20.0 12.0 2.0 42 Softmint 0.044 Ex 40 0.057 Silica 0.0755 0.0185 2.6 43 Softmint 0.04 Ex 40 0.0512 3F Pumice 0.0788 0.0276 35.0 23.2 3.4 Comparing the particulate abrasive overcoated versions of coated micromesh dental flosses, as described in Examples 41 to 43, with the corresponding coated micromesh flosses without the particulate abrasive overcoating indicates a dramatic improvement in the"hand"of the particulate abrasive overcoated version, as well as in the perception that the particulate abrasive overcoated micromesh dental floss is "working". See PAF values. These improvements are considered substantial and relevant and contribute to the overall enhanced perceived value of these particulate abrasive overcoated versions of micromesh dental flosses, compared to the commercial versions without these overcoatings.

Comparing particulate abrasive overcoated versions of micromesh floss with Johnson & Johnson (J&J) Waxed Mint multifilament dental flosses and J&J Whitening Dental Tape, indicates the particulate abrasive overcoated versions of these two micromesh dental flosses are preferred over J&J Whitening Dental Floss and J&J Waxed Mint Floss. This preference is in part attributed to the ease of use and ease of insertion indicated for the particulate abrasive overcoated micromesh dental flosses along with the perception that these particulate abrasive overcoated versions are "working"as further indicated by the PAF values.

A particularly preferred embodiment of the present invention is the enhanced perceived value imparted to a wide range of coated micromesh dental flosses with very modest increases in cost-of-goods. This enhanced perceived value can be achieved by the addition of a modest priced particulate abrasive overcoating using an overcoating operation that can be installed in-line with current waxing and/or coating operations.

Commercial, coated, micromesh dental flosses such as described in Examples 41 through 43 in Table 5 can be further improved beyond the"it's working" perception, which is indicated by recorded PAF values. That is, a second overcoating with a saliva soluble particulate containing flavor, mouth feel agents, etc. , can be imbedded into the wax base coating using a second separate fluidized bed and nozzle means to imbed this particulate into the liquid base coating before the micromesh floss enters the coating zone.

Table 6<BR> Coated Micromesh Dental Floss Overcoated with Particulate Abrasive and Saliva Soluble Particulate Particulate Overcoatings Saliva Micromesh Dental Floss & Base Coating Abrasive Type & Soluble Particulate Type Projected Impact of Ex. Denier Type & Load Load Projected Projected & Load Saliva Soluble No. (grams/yd) (mg/yd) (in mg/yd) PAF IRF (in mg/yd) Particulate 44 nylon 6,6 microcrystalline pumice PEG 3350/flavor 3 X over 840 wax (21) 3.4 96 (14) wax flavor 0.085 (33) 45 nylon 6,6 microcrystalline pumice PEG 3350/flavor 4 X over 840 wax (14) 3.2 98 (18) wax flavor 0.085 (33) 46 nylon 6,6 microcrystalline silica PEG 3350/flavor 2 X over 840 wax (16) 2.8 97 (12) wax flavor 0.085 (33) 47 nylon 6,6 bees wax pumice PEG 3350/flavor 2 X over 840 (27) (22) 3.5 92 (14) wax flavor 0.085 47 nylon 6,6 bees wax pumice PEG 3350/flavor 3 X over 840 (27) (14) 3.0 96 (17) wax flavor 0.085