EP0516675B1 - Toothbrush - Google Patents

Abstract

A toothbrush comprising a bristle holder (5) and bristles which project approximately perpendicular from the plane of the bristle holder (5) or of the bristle field (12) can adapt to the contours of the marginal or interdental gingiva (see 10) and thus prevent the formation of periodontal pockets due to plaque. To this end, at least the ends of the bristles lie on the bristle holder and the bristle holes (7', 8', 15) lie advantageously on curves (11, 13, 16). Preferably, the bristle field (12) is located approximately centrally on an axis defined by two diagonals (17) of the bristle holder. The diagonals (17) make an angle (alpha) of 75 DEG to 105 DEG with each other.

Description

The invention relates to a toothbrush according to the preamble of claim 1.

Such toothbrushes have become known in a wide variety of embodiments. A particularly proven design is described in the PCT applications according to the publications WO 86/07527 and WO 89/01303. However, these known toothbrushes have in common with the rest of the prior art that the bristle holes on the bristle holder run in a straight line one behind the other, parallel to the main axis of the handle. The generic toothbrush according to DE-C-674 288 comprises three brush heads which are arranged essentially within a U-shaped carrier and which are intended to enable the teeth to be gripped around on three sides during cleaning. Although some of the bristles of the lateral bristle fields are not arranged parallel to one another on straight lines, the cleaning result does not achieve the desired positive effects. If the term "main axis" is used below in this context, this will generally be the longitudinal axis, which, however, is bent in many ways in some embodiments of known toothbrushes, which of course do not occur in the rows of bristles. The term "main axis" should therefore only refer to the general direction, neglecting bends and kinks.

A problem that is always a problem in modern dental hygiene is the formation of so-called tooth pockets, i.e. the cavities below the edge of the gums on the tooth neck. Food residues easily get caught in these tooth pockets, which then lead to inflammatory processes. A The main cause of this phenomenon is the plaque or plaque that slides under the gums and detaches them from the tooth neck. A number of special toothpaste compositions have already been developed to combat this phenomenon, but nothing was known to counter this on the part of toothbrush design.

The invention is based on the object of designing a toothbrush or a bristle holder in such a way that he or she counteracts the phenomenon discussed above in the best possible way. This is achieved in a surprisingly simple manner by the features of the characterizing part of claim 1.

Because the bristle holes are arranged in an arc shape or along an arc with different radii, they adapt more flexibly to the arches that form the gumline edges on normal teeth when the brush is appropriately held or arranged appropriately. As clinical trials to be discussed later, this is the best way to clean the marginal and interdental gingiva. This adaptation is particularly supported if the bristle holders are connected to the handle via elastic webs in a manner known per se and will be explained later and / or the bristles are of different lengths or hardness in the manner shown in the drawing. In particular, if the toothbrush is designed as an electric toothbrush, it is of course sufficient if the associated bristle holder, which can be releasably attached to it, is designed in the manner described in the characterizing part of claim 1.

The design of the toothbrush according to claim 1 and in particular also according to claim 3 also allows for some toothbrush constructions, in particular for simple toothbrushes, to be used in any position, and also allows cleaning of the upper and lower rows of teeth without having to change the position of the toothbrush.

But even in constructions such as those described in the WO documents mentioned at the outset, there is a surprising advantage, since brushes designed in this way bring an improved cleaning effect to an even greater extent, as has been demonstrated on the basis of comparative tests. The reason for this is not yet fully understood, but it may be due to the fact that the arched arrangement means that the individual completely enlightened, but it may be due to the fact that the arched arrangement means that the individual bristle holes - seen in the direction of the cleaning movement - overlap one another and thus not only push one another away from the tooth, but also point one to the side Develop a force component that - again seen in the direction of cleaning - has no bristle-free area, as is the case with conventional toothbrushes in which the bristles are arranged in rows and leave free "streets" in between. This street formation also leads to an uneven cleaning result.

If the toothbrush is designed according to claim 4, its shape approximates that of the optimized design as described in the two WO documents mentioned at the beginning.

A bristle holder according to the invention has the features of claim 7, as a result of which - in contrast to the usual rectangular shape in plan view - it becomes approximately square. This square shape is in connection with the above explanations for claim 1, because if it is important to adapt the toothbrush to the course of the gum line on the tooth neck, this is best achieved with such a shape. On the other hand, this shape is not necessarily tied to the realization of the features of claim 1, because it can - in place of the arcuate configuration - the bristles also be adjusted in that the holes fill a square area, but softer at the corners of this square Bristles are provided so that the hard bristles are again arranged approximately along an arc. Also by different angular positions of the bristles arranged at the corners relative to the arranged in between achieve the desired adaptation to the arches of the gum line.

The embodiment according to claim 9 will be of particular interest if the bristle holder is intended for electric toothbrushes, but it can also be used for manually operated toothbrushes.

From the above explanation it will be understood that an optimal adaptation of the shape and a good cleaning effect also requires a certain minimum density of the bristle field. Therefore, it is preferred if the features of claim 10 are realized.

Fig. 1

die Frontansicht einer bekannten Zahnbürste, an der die Erfindung bevorzugt verwirklicht wird;

Fig. 2

einen stark vergrösserten Schnitt nach der Linie II-II der Fig. 1, wobei zum Vergleich das Bild einer Zahnreihe strich-punkt-punktiert eingezeichnet ist;

Fig. 3

eine Variante zu Fig. 2 in einem entsprechenden Schnitt; und

Fig. 4

eine weitere Variante, jedoch in einer Draufsicht entsprechend der Linie IV-IV der Fig. 1.

Further details of the invention result from the following description of exemplary embodiments schematically shown in the drawing. Show it:

Fig. 1

the front view of a known toothbrush on which the invention is preferably implemented;

Fig. 2

a greatly enlarged section along the line II-II of Figure 1, with the image of a row of teeth is shown dash-dot-dashed for comparison;

Fig. 3

a variant of Figure 2 in a corresponding section. and

Fig. 4

a further variant, but in a plan view along the line IV-IV of FIG. 1st

On a handle, of which only the cross section 1 extending behind the plane of the drawing is indicated, A connecting web 3 extends transversely or perpendicular to the main axis 2 of the handle 1. This connecting web 3 carries bristles 4 which are intended to act on the chewing surfaces of the teeth upwards and downwards. At the end of the connecting web 3, bristle holders 5 are articulated transversely thereto via a plastic joint 6, so that they can be elastically bent apart with deformation of the plastic joint 6 when a tooth is inserted between two bristle holders 5 with bristles 7, 8 facing one another. It has been found that in the sense of a good massage of the gums lying in the area of the bristles 8, it is advantageous not to let the elastic restoring force become too great in the position shown, because otherwise the opposite of the desired effect, namely inflammatory Processes. On the other hand, the massage is largely avoided if the plastic joints 6 are too soft, that is, they develop too little restoring force. An optimal dimensioning is achieved on average if the restoring force is in the range of 0.35 to 0.65 kp, preferably approximately 0.5 kp. A plastic in which this can be achieved with reasonable dimensions and which also meets the hygienic requirements is sold under the name Hostaform.

Another inexpensive measure that takes into account the condition of gently massaging the gums, while vigorously brushing the tooth necks and surfaces, is that the hardness of the bristles extends from the bristles 7 to the bristles 8 that extend from the handle 1 distal end of the bristle holder decreases. This does not have to take place gradually, but can (preferably) be done in stages, for example in the form that only one or two rows of bristles removed from the handle 1 are softer than the bristles 7 facing the handle 1.

Finally, it can also be seen that the bristle length increases from the bristles 7 to the bristles 8, so that the bristles of two bristle holders 5 lying opposite one another delimit a space that opens towards the handle. This seems unusual in itself because the tooth to be inserted between them forms a cross-section of an oppositely directed triangle with its gingiva, but it has been shown that such a shape goes hand in hand with optimal cleaning effect and improved massage of the gums.

While all these features already belong to the prior art, but are of particular importance in combination with the present invention, a preferred embodiment of a toothbrush or a bristle holder to solve the problems explained at the outset will now be described with reference to FIG. 2. It should be mentioned that with reference to FIG. 1, as a bristle holder 5, only a very narrowly limited part of a joint 6 is described, but that the bristle holder 5 may also include connection attachments, in particular if it is a pluggable or bristle holder that can be detachably attached.

In Fig. 2 three teeth next to each other are indicated by dash-dot-dotted lines at 9. The teeth 9 sit in the upper jaw and are covered at the top by the marginal gingiva 10, which runs in an arch-like manner in 90% of the inhabitants of cultivated countries. So that the dental plaque can be optimally removed in this area, at least one edge zone of the bristles 8 (FIG. 1) is arranged in a corresponding arc shape in bristle holes 8 '. "Correspondingly" preferably means that the dash-dotted arc 11 on which the holes 8 'are located has a radius in the region from 3 mm to 10 mm, the latter digit actually representing the top area. It is cheaper to measure the arc radius not larger than 8 mm. In practice, radii of 5 mm ± 20% have proven particularly useful, although, as will be explained below, it is entirely conceivable and desirable to dimension the arc radii of different bristle hole arcs on the bristle holder or within the bristle array 12 arranged thereon.

This is already the case with the arch 13 with the bristle holes 7 '. Because its radius r is about 10% smaller than the radius R of the arc 11. If the radius r is, for example, 5.0 mm, the radius R will be 5.5 mm. If one now imagines that the direction of the cleaning movement defined by the handle 1 is that of the arrow 14, it can clearly be seen from the bristle holes 8 'that they overlap one another - seen parallel to the direction 14 - so that the bristles when pushing against each other, a force component will be communicated to each other transversely to direction 14, ie that this row will fan out more, so that the bristles better fill the space between the central bristle holes 15. The more uniform distribution of the bristles over the bristle field 12 in this way now prevents during the cleaning movement 14 that "streets" not reached by the bristles form on the tooth surface.

The same applies analogously to the bristles of the holes 7 'if one takes into account that the bristles rise out of the holes in an approximately fan-shaped manner and that there is an overlap there as seen in the cleaning direction 14. However, in order to support the cleaning and massage effect of the row of bristles along the arch 11, the central bristles 15 are arranged in such a way that they together with the two bristle holes at the end of the arch 13 also result in an arc 16 which is parallel to the arc 11.

It goes without saying that more than just three arches 11, 13, 16 can also be provided and that on the other hand the two arches 11 and 13 bordering the bristle field 12 can also be sufficient, the number of bristles per bristle hole also of course being important . However, it was found that just the number of three sheets 11, 13 and 16 shown here produced excellent effects in practical tests. It is also understandable that arcs 11, 13 and 16 need not necessarily be arcs; in principle, elliptical arches, cycloids and the like would be. It is also possible if a circular arc - viewed purely from the construction side - is cheaper.

However, the arrangement of the bristle holes shown here means that the bristle holder 5 - as can be seen - is almost square in plan view of the bristle field 12 (although it would be entirely possible for simple toothbrushes with only one bristle holder and handle, corresponding to the contour 10 in succession Bends 11)), the diagonals through the bristle holder 5, which are shown here as dashed lines 17, enclosing an angle with one another in the range from 75 ° to 105 °, that is to say on average about 90 ° ± 10%. It is irrelevant whether this angle is measured at the point alpha shown in FIG. 2 or its associated complementary angle, because both angles must necessarily lie in this range.

The resulting weakly rectangular to square shape is not only advantageous for toothbrushes of the type shown in FIG. 1, although it is also most easily applicable there and in combination with whose peculiarities (see above) exorbitantly improve the cleaning result in a synergetic way. Rather, the explanation based on tooth contours 9, 10 shows that such a shape is also particularly suitable for conventional toothbrushes for cleaning and massaging the marginal gingiva and its neighboring areas on the tooth surface. Here, too, the density of the bristle holes plays a role, which should be about 25 to 30 holes per cm ² in order to achieve favorable results.

Of course, the angle alpha does not say anything about the specific size of the bristle holder 5, which is supposed to be adapted to the average size of the sheets 10. Tests have shown that an edge length 1 or L (cf. FIG. 3) of the order of 5 to 15 mm and in particular 5 to 10 mm corresponds best to the average. These figures show that the lower limit of about 5 mm (-10%) is somewhat more critical than the upper limit.

In the embodiment according to FIG. 3, parts with the same function are designated with the same reference symbols, but parts with a similar function are added with the addition of hundreds. It can be seen that in addition to the bristle holes 7 ', 8' and 15, the bristle field 112 here also has bristle holes 18 which, together with the other bristle holes, delimit an - at first almost conventional-looking, bristle field of rectangular shape. The difference from the prior art, however, lies in the fact that the bristles of the bristle holes 18 are only very soft, whereas the hard bristles of the bristle holes 7 ', 8' and 15 again, as in FIG. 2, along arches 11, 13 and 16 are arranged. In many cases it will be seen that the middle bristle holes 15 can also be viewed as being located on an arc 19 running parallel to the arc 13.

If, however, this is constructive but not feasible, it is preferred if at least one arc 16 parallel to the arch 11 of the outer row of bristles 1 (see FIG. 1) is realized, since this supports, as explained above, Massage and cleaning of the marginal, but ultimately also the interdental, gingiva, which counteracts the formation of tooth pockets.

From the above explanation of the exemplary embodiment according to FIG. 3 it follows that at least the harder bristles (if bristles of different hardness are used) are expediently arranged along arches 11, 13 and 16. The bristles of the bristle holes 7 ', 8' and 15 can also be of different hardness, as explained above with reference to FIG. 1. However, the bristles of holes 18 will be the softest.

While the bristle holder 105 of FIG. 3 is shown in a section similar to that of FIG. 2, FIG. 4 illustrates a top view of a further embodiment variant. In principle, it can be assumed (and shown in FIG. 1) that the bristles 7, 8 protrude approximately perpendicular to the plane of the bristle holder or the bristle field 12, or that there is no great deviation from the vertical (maximum 10 °). 4, it can also be achieved that individual bristles 8 and 15 'are arranged perpendicular to the plane of the bristle holder 205 or of the bristle field 212, but that the bristles 8''and 7 ″ are inclined in opposite directions in such a way that their ends lie on an arc 11 ′ or 13 ′, although it would be ascertained when cutting through the bristles that their bristle holes are on or within a Rectangle 20 lie. In order to reinforce this arch shape, the bristles 7 ″ ″ located at the end of the arch 13 ′ can also be arranged obliquely, as can be seen from FIG. 4, namely opposite to the inclination of the bristles 7 ″. But this also results in an arc 16 'from a line connecting the ends of the bristles 15' with those of the bristles 7 '''.

It was mentioned at the beginning that the dimensioning and arrangement of the bristles 7, 8 is decisive for the effects achieved. If one therefore selects an inclination of the bristles that differs from this basic shape, as shown in FIG. 4, then the optimum will probably not be fully attainable, which is why an arrangement according to FIG. 2, at most according to FIG. 3, is preferable. But seen in this way, it is important for achieving the desired cleaning and massage effect that at least the ends of the bristles, preferably also the bristle holes of a row of bristles, are arranged along an arc.

A clinical trial example will be described below.

18 subjects of male sex, with intact teeth (with the exception of the 3rd molars), free from crowns, dentures and deep-seated inlays and healthy gums, used a conventional manually operated toothbrush, an electric toothbrush and a toothbrush as they did for two weeks in a row has been described with reference to FIGS. 1 and 2. After each two-week trial, two weeks were inserted in which the subject only used the manual brush according to the state of the art and 2 professional tooth cleaning was carried out, whereby the gingival epithelium was stimulated evenly. The professional tooth cleaning was done before the test weeks, to ensure an even inflammation and plaque-free initial state. Cytological swabs were also made.

After each week, the approximal space plaque index according to Quigley-Hein (plaque distribution over the tooth surface) and Lange (intensity-related), the gingival margin plaque index (GMPI), the plaque index according to Quigley / Hein (PI) and the sulcus Bleeding index (SAI) according to Mühlemann and Son. The results with a toothbrush according to the invention were, in some cases even clear, superior to those with prior art toothbrushes.

It can be seen from the above explanations that the effect which can be achieved by the invention will at least partially already result if at least one of the arches 11, 13 or 16 is realized. Namely, even if the bristle holes 8 'were arranged along a straight line, bristle holes 15, 7' arranged along an arc 16 would support the bristles of the holes 8 'in an arcuate manner, so that their action was increased towards the center of this arc.

It can also be seen that the centers of the circles of the radii R and r (FIG. 2) lie along a cleaning movement 14 defined perpendicularly (or at least transversely) to the cleaning movement defined by the course of the axis 2 (FIG. 1) of the handle 1, as shown in FIG. 3 clarifies.

Claims (7)

1. A toothbrush comprising a handle and at least one bristle holder connected thereto and comprising a number of bristle holes from which the bristles (7, 8, 15') of a bristle zone of the toothbrush extend, at least the free ends of two rows of bristles being disposed in each case along an arc (11, 13) bordering the bristle zone (12), the concave sides of the arcs facing one another, characterised in that the arcs (11, 13) bordering the brush zone (12) and having their concave sides facing one another have different radii (R, r).
2. A toothbrush according to any one of the preceding claims, characterised in that the bristle hole arcs (11, 13, 16) have a radius (R; r) of at least 3 mm and a maximum of 10 mm, preferably a maximum of 8 mm and preferably about 5 mm ± 20%.
3. A toothbrush according to any one of the preceding claims, characterised in that at least one additional bristle hole (15), preferably a row of bristle holes (15), is situated between two bristle hole arcs (11, 13) bounding the bristle zone (12, 112), and is advantageously either itself arcuate or is disposed, at least together with at least one bristle hole (7', 8') of an adjacent bristle hole arc (11, 13), along another arc (16; 19) which, if required, has a smaller radius (r) than an arc (11) parallel to it (16), e.g. a radius of about 10% less.
4. A toothbrush according to any one of the preceding claims, characterised in that the bristle zone (12; 112; 212) are situated at least approximately centrally on an axis defined by two diagonals (17) of the bristle holder (5; 105; 205), which diagonals (17) form an angle (α) of 75° to 105° with one another.
5. A toothbrush according to any one of the preceding claims, characterised in that the two diagonals form an angle (α) of 90° ± 10% with one another and/or in that the edge length of the bristle holder (5; 105; 205) is 5 mm to 15 mm, more particularly 5 mm to 10 mm.
6. A toothbrush according to any one of the preceding claims, characterised in that it is fixed, e.g. releasably, on a connecting web (3) disposed transversely of a handle (1) (Fig. 1).
7. A toothbrush according to any one of the preceding claims, characterised in that the bristle holes (7', 8', 15) have a density of 10 to 25, preferably 15 to 20, holes per square centimetre.

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