BACKGROUND OF THE INVENTION

The present invention relates to toothbrushes in general and more specifically to a toothbrush bristle con¬ figuration providing improved and effective removal of micro- bial plaque accumulation from the teeth and adjacent gingival ^" surfaces.

Plaque control retards the formation of calculus and is critical in the prevention of peridontal disease.

In the past, the most dependable mode of controlling plaque has been mechanical cleansing with a toothbrush and other cleansing aids. However, conventional toothbrushes have not been entirely effective in removing the microbial plaque from beneath the gingival margin in the sulcus and the high plaque retaining areas in the interproximal embra- sures of adjacent teeth. This is due to several reasons. First, a straight tip of a conventional brush bristle does not tend to enter the gingival sulci when the brush is held in a plane generally perpendicular to the long axis of the tooth. Secondly, the sharp point of the bristle tends to damage the gingiva and ucosa if the brush is held at an acute angle to the long axis of the tooth in an attempt, to enter the sulci. Thirdly, the flex of the bristles tends to prevent the most effective bristle tip posture for cleansing when the brush is activated. Study shows that the most aggressive mechanica

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cleansing should be directed toward the tooth surface, much less so toward the gingival surface and none toward the base of the gingival sulcus . The basis for these observations is as follows. The development of gingival inflamation and dental cavities is most frequently caused by failure to remove dental plaque from the sub-gingival surface of the tooth and to a muc lesser extent materia alba from the gingival surface in the - sub-gingival space. Both dental plaque and materia alba can form within several hours and therefore frequent mechanical cleansing is essential. Materia alba which consists primarily of an acquired bacterial coating and desquamated epithelial cells, leucocytes and a mixture of salivary proteins and lipid is a soft sticky deposit less adherent than dental plaque. It can be flushed away with a water spray but more completely removed from the gingiva with mild mechanical cleansing.

Dental plaque is formed by oral micro-organisms which synthesize harmful products which are destructive to ^" the tooth and gum when not removed from the gingival sulcus. The toxins formed by the micro-organisms cause cellular damage to the gingiva with subsequent inflamation (gingivitis) and eventually destruction of the supporting structures (periodon- titis) . When gingivitis occurs, vascular dilatation, capil¬ lary proliferation, engorged vessels and sluggish venous return causes a stretched and thinned epithelium that is sensitive to mechanical trauma such as aggressive brushing.

Dental plaque with associated gingivitis also causes exposure of the root surface (recession) with increased occurrence of cavities (dental caries) . Exposure of the .root. surface. can also occur due to faulty brushing by repeated direct trauma to the base of the sulcus (gingival abrasion) . When a pathologically deepened gingival sulcus (peridontal pocket) occurs, the pathological condition may become exacerbated because plaque can more readily occur. If dental plaque is not removed calculus is formed by miner¬ alization of the bacterial plaque. Calculus can form within

several hours of plaque formation. Calculus has a bacterial plaque coating and exacerbates gingivitis and gingival reces¬ sion by both chemical irritation from the formed toxins and destruction from the mechanical irritation of the cal- culus mass. Sub-gingival calculus usually extends near but does not reach the base of peridontal pockets in chronic peridontal lesions. Calculus holds the plaque against the gingiva.

Since materia alba can be removed by light mechani- cal cleansing and gingival inflamation causes thinning of the gingival epithelium the mechanical cleansing requirement of the gingival surface is much less than the requirement for removing dental plaque from the surface of the teeth. Accord¬ ingly, a toothbrush which fulfills these requirements -while protecting the base of the gingival sulcus is desirable.

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SUMMARY. OF THE INVENTION

In view of the foregoing, a principal object of the present invention is an improved toothbrush in general and an improved cleansing head in particular which has a shape and surface configuration for removing dental plaque from the exposed and sub-gingival surfaces of a tooth including the in-terproximal embrasure surfaces while minimizing damage to the gingival tissues facing the tooth and in the base of the sulcus. Another object of the present invention is a toothbrush as described above comprising a cleansing head, wherein the opposite ends of the cleansing head are rounded for presenting a non-abrasive surface to the sub-gingival tissue surfaces surrounding a tooth when the cleansing ^' surface of the cleansing head is moved across the surface of the tooth during cleansing of the tooth.

Still another object of the present invention is a toothbrush as described above comprising a cleansing head with a cleansing surface, wherein the cleansing surface of the cleansing head comprises a plurality of cleansing elements located between the opposite ends of the cleansing head.

Still another object of the present invention is a toothbrush as described above comprising a cleansing head with a plurality of of cleansing elements, wherein each of the cleansing elements is provided with a sharp edge or tip for scraping the surface of the tooth during cleansing of the tooth.

Still another object of the present invention is a toothbrush as described above having a plurality of bristles in which each of the bristles comprises a stem and, located on one end of said stem, an elongated cleansing head having a cleansing surface comprising a plurality of cleansing ele¬ ments which extend perpendicularly in opposite directions from the stem.

In a preferred embodiment of the present invention, the toothbrush comprises a plurality of special bristles each

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having a T-shape and, when mounted to the handle of a toothbrush, are located side by side forming substantially three sets of bristles of varying stem length. The vary¬ ing length of the stems in each set generally conforms the set of bristles to the contour of the surface of a tooth for improved cleansing in the interproximal embrasure of adjacent teeth. Of course, various stem lengths, cleans¬ ing-head sizes, and different shapes of sets of bristles may be employed in a particular application.

In an alternative embodiment of the present inven¬ tion, the toothbrush comprises a handle having a hand-held portion and, a smaller brush-supporting portion on which a generally rectangular-shaped cleansing head is directly mounted. A portion of the cleansing head is offset from the handle and includes a plurality of cleansing elements. The cleansing elements comprise an elongated rectangular member terminated by a sharp edge. The opposite ends of the cleansing head are rounded to present a non-abrasive sur¬ face to the sub-gingival surfaces. Singular or multiple cleansing heads, which are removable and replaceable on the handle, may be used and may be of various sizes, shapes and flexibility.

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BRIEF DESCRIPTION OF THE DRAWING

The above and other objects , features and advanta of the present invention will become apparent from the fol¬ lowing detailed description of the accompanying drawing in which :

Fig. 1 is a side view of a toothbrush according t the present invention.

Fig. 2 is an enlarged side view of a portion of the bristles and handle of Fig. 1. Fig. 3 is an enlarged side view of the tips of a part of the bristles of Fig. 2.

Fig. 4 is a plan view of Fig . 2. Fig . 5 is an enlarged plan view of the tips of two of the bristles of Fig. 4. Fig. 6 is an end view of the bristles and handle of Fig. 4.

Fig. 7 is an end view of the toothbrush and bristles of Fig. 6 , shown in a flexed condition.

Fig. 8 is a plan view of a cleansing head accordi to an alternative embodiment of the present invention.

Fig. 9 is an enlarged plan view of a portion of the cleansing head of Fig. 8.

Fig. 10 is an end view of a portion of the cleans ing head of Fig. 8. Fig. 11 is a side view of an alternative embodi¬ ment of the present invention.

Fig. 12 is a cross-sectional view taken through lines 12-12 of Fig. 11.

Fig. 13 is a plane view of the cleansing head of Fig . 12.

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DETAILED DESCRIPTION OF THE DRAWING

Referring to Figs. 1-7, there is provided in accord¬ ance with the present invention a toothbrush designated generally as 1. In the toothbrush 1 there is provided a handle 2 having a hand-held portion 3 and a brush-supporting portion 4 on which is mounted a plurality of bristles 5. As shown in Fig. 1, the bristles 5 essentially comprise three sets of bristles of varying lengths designated 5a, 5b and 5c, respectively.

Referring to Fig. 2, the bristles 5 in each one of the sets of bristles 5a, 5b and 5c are provided with a stern 10. An elongated cleansing head 11 comprising a plurality of cleansing elements 12 located between the opposite ends of the cleansing head 11, extends perpendicularly in oppo¬ site directions from said stem 10 for forming a T-shaped bristle. The length of the head 11 is sufficient for providing at least a portion thereof offset from the handle 2 as seen in Fig. 1 at 5a.

Each of the plurality of cleansing elements 12 of a cleansing head 11 comprises a conically shaped member ter- minated by a relatively sharp -tip for scraping the surface of a tooth during cleansing of the tooth. The opposite ends of the cleansing head 11 are rounded, as shown at 13 in Figs. 3, 5 and 6, for presenting a non-abrasive surface to the sub-gingival surfaces, as shown at 17 in Fig. 6, surrounding a tooth when the cleansing surface 12 of the cleansing head 11 is moved across the surface of a tooth during cleansing of the tooth.

Extending laterally along each of the cleansing ele¬ ments 12, there is provided a wall 14 and 15, which has an upper edge somewhat lower than the height of the tip portion of the cleansing elements 12. The walls 14 and 15, together with the elements 12, form pockets for receiving and containing cleansing compound such as conventional toothpaste.

Each of the cleansing elements 12 has a diameter of approximately .010 inches. Between the ends 13 of the cleansing

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head 11 there are provided approximately 36 of the tip mem¬ bers 12. With 36 of the tip members 12 located between the ends 13 of each of the cleansing heads 11, each of the clean ing heads 11 has a length of approximately .36 inches. The dimension, .010 inches, for each of the cleansing elements 1 was chosen because it is somewhat larger than the minimum dimension which can be reliably held using current molding techniques. In fabricating the toothbrush, approximately 10 of the bristles 5 are mounted in a line on the portion 4 of the handle 1. With 100 bristles 5 mounted on the handle 1, the brush mass is approximately one inch in length. Having a length of one inch and a width of about .36 inches, the brush is approximately the same size as a conventional tooth brush. In use, the cleansing elements 12 of the bristles scour the tooth surface while the ends 13 penetrate below the sub-gingival surface into the sub-gingival sulcus 18 so to remove foreign matter from the tooth and sub-gingival sur faces 17, as shown in Fig. 6. In cleaning the tooth and sub gingival surfaces 17, gum and tooth life are promoted.

Referring to Fig. 7, to insure intimate contact between the surface of a tooth and the cleansing element 12 at all times, the head 11 may be formed to be flexibly con¬ cave to conform to the contour of a typical tooth. Referring to Fig. 8-10, there is shown in an alter native embodiment of the present invention a T-shaped bris¬ tle 20 comprising a stem 21 and a cleansing head 22. Betwee the opposite ends of the cleansing head 22 there is provided for forming a cleansing surface 23, a plurality of cleansing elements 24. Each of the elements 24 comprises an elongated rectangular member terminated by a sharp edge 25. The oppo¬ site ends 26 and 27 of the head 22 are rounded for presentin a non-abrasive surface to the sub-gingival surfaces 17 sur¬ rounding the tooth when the cleansing surface 23 and specifi cally the cleansing elements 24 are moved across the surface of the tooth during cleansing of the tooth.

Around the periphery of the cleansing head 22, there is provided a wall 28. The height of the wall 28 is somewhat lower than the height of the cleansing elements 24 so as not to interfere or otherwise impair the cleansing action of the cleansing members 24. The wall 28, together with the space between the cleansing elements 24, form pockets for receiving cleansing compound such as conventional toothpaste. —

In use, as described above, the shape of the cleans¬ ing heads 11 and 26 allows the cleansing head to readily enter the gingival sulci when the brush is held in the most common positions used in brushing the teeth. In addition, the shape of the tips of the elements 12 and 24 minimize gingi¬ val damage. Also the mechanical cleansing action of the cleansing elements is more effective than the conventional straight tip bristle when the bristles are in a flexed condi¬ tion. The point of a straight-tip bristle is effective only when the brush is held in a narrowly defined relationship to the sulci and under minimal flex. Referring to Figs. 11-13, there is provided in an alter¬ native embodiment of the present invention a toothbrush 30 comprising a handle 31 and a brush-supporting portion 32 and a cleansing head 33 having a cleansing surface 34. Extending from the center of the cleansing head 33, there is provided a dovetailed shaped tongue member 35 for fitting in a correspond¬ ingly shaped groove provided therefor in the handle portion 32. The tongue member 35 and the groove provided therefor allow for removal and replacement of the cleansing head 33. Other tongue and groove shapes as well as suitable adhesive may be used in the absence of tongue and grooves for mounting the cleansing head 33 to the brush-supporting portion 32.

On the cleansing surface 34, between the rounded end portions 36 and 37, there is provided a plurality of rectangu¬ larly shaped cleansing elements 38. Each of the elements 38 is terminated by a sharp edge 39. Extending about the peri¬ phery of the cleansing head 33, partially enclosing the cleans¬ ing elements 38, there is provided a rectangularly shaped wall 40.

The wall 40 is terminated by a sharp edge 41. Interior of th wall 40, surrounding the cleansing elements 38, there is pro¬ vided a second rectangularly shaped wall 42. The wall 42 is also terminated by a sharp edge 43. The interior surfaces of the wall 43 and the cleansing elements 38 form recesses or pockets 44 for receiving and containing cleansing compound, s as conventional toothpaste. Similarly, the interior surfaces of the wall 40 and the exterior surfaces of the wall 42 form recesses or pockets 45 for also containing cleansing compound such as conventional toothpaste.

As in the previous embodiments described above, a plurality of the cleansing heads 33 are mounted on the brush- supporting portion 32 of the toothbrush 30 for forming a brus 46 having substantially the same overall length and width as conventional toothbrushes.

While a plurality of embodiments of the present invention are described, together with suggested alternative features, it is contemplated that still other changes and modifications may be made to the embodiments described without departing from the spirit and scope of the present invention. For example, instead of having a brush comprising a plurality of bristles of varying stem length, it is possibl to have a brush in which the length of the stem of the bristles is uniform throughout the brush. Similarly, the size of the bristle and the length and slope of the stem and cleansing head may be changed for any particular appli¬ cation. Also, the cleansing head need not necessarily be T-shaped, but may be round or some other shape. So long as at least a portion of the cleansing surface is offset from rhe handle, the cleansing head can penetrate into the sub- gingival sulcus region. For these reasons, it is intended th the scope of the present invention not be determined by reference to the embodiments described, but rather be deter¬ mined by reference to the claims hereinafter provided and their equivalents.