There is thus obtained a maximum reduction of irritation of the gums as well as of wear of the dentine when the same is uncovered.

Background of the Invention The toothbrushes that are sold in the market worldwide usually have 3 or 4 rows of bristles with an average height of 10 mm. Some have the peripheral bristles thinner than the median rows, these latter being stronger. The purpose of this principle is to prevent the gums to suffer with the contact of the more aggressive median bristles. However, when brushing such brushes over the teeth, the pressure applied by the user makes the peripheral bristles bend, thereby brushing and pushing the gums and uncovering the dentine. Furthermore, since the dental creams sold in the market are more or less abrasive, such abrasion-thought to be necessary to a certain extent and not affecting the high-hardness teeth enamel-also acts upon the mucous of the gums, which it irritates, as well as on the dentine, wearing the same.

In order to avoid the above mentioned damage caused by known toothbrushes, there has been developed the toothbrush that is the object of the present invention.

Summary of the Invention The present invention provides therefore a toothbrush comprising a head part, a neck part and a handle part, characterized by the fact of the head, which forms an angle of about 170° relative to the handle by means of a neck part with elongate sinusoid shape, being provided with a peripheral row made of thick tufts with 3 mm diameter, wherein the bristles are very thin and have a height in the range of 5 mm to 7 mm.

The head of the toothbrush of the present invention, having a length of 34 mm and a width of 13 to 15 mm, is also provided with one single median row comprised of small plastic bodies intended to attack the bacterial plaque. For this purpose those plastic bodies have preferentially a parallelepiped shape, with a square base of 3 mm by 3 mm and a height within the range from 4.5 to 6.5 mm. Each of those plastic bodies has at the top thereof 3 transversal platelets with 0.6 mm of thickness, the

central platelet being separated from the other two by a groove with 0.6 mm of width and 2 mm of depth. Each of those platelets is serrated with six triangle-shaped teeth, with 0.5 mm at the base and 0.5 mm in height. That type of"bristles"of the median row shall simultaneously evidence a good degree of aggressiveness and an adequate rigidity capable of preventing, with any slight inclination of the toothbrush, the thin and short peripheral bristles from bending thereby irritating the gum.

This type of minute-sized blocks may be substituted by tufts comprised by bristles adequate for their purpose and also having a diameter of 3 mm and a height of 4.5 to 6.5mm.

Regarding a possible children's toothbrush, the median row must adopt that substitution, due to the extremely difficult miniaturization of the minute-sized plastic blocks and the indispensable correct choice of the peripheral and median bristles, having in view the delicate mucous and teeth of children. All the dimensions of such children's toothbrush shall have to be carefully studied in practice.

This toothbrush is characterized, finally, by being provided with a"neck" having an elongate sinusoid shape attaching the handle to the head, the purpose thereof being to offset the said head 5 mm upwards maintaining the same at the angle of about 170° relative to the handle. This position facilitates the contact of the bristles and the minute-sized blocks upon the teeth.

Brief Description of the Drawings In order to better illustrate the present invention, there are presented the attached drawings, wherein: Figure 1 shows a side view of an embodiment of a toothbrush according to the invention, the total length of the toothbrush being 18 cm, the handle width being 8 mm and the thickness being 5 mm.

Figure 2 is a detailed front view of the head itself of the toothbrush, having a length of 34 mm by a width of 13 to 15 mm and a thickness of 5 mm, wherein are implanted the sixteen tufts of bristles of the median row, provided at both ends thereof with the addition of a protecting tuft identical to the peripheral tufts. The median row of six minute-sized blocks, provided at each end thereof with a protective tuft identical to the peripheral tufts, is slightly

offset relatively to the two peripheral rows due to its quincunx position. The spaces between the lateral tufts and between tufts and between minute-sized blocks are of 1 mm, except for the tufts located at the two ends of the median row.

Figure 3 shows a perspective view of the minute-sized plastic blocks used in the toothbrush according to the present invention.

Figure 4 is a side sectional view of a set of coarse bristles that may substitute the minute-sized plastic blocks shown in Figure 3.

Description of the Invention in Reference to the Drawings Therefore, as may be seen in Figures 1 and 2, the toothbrush 1 that is the object of the present invention comprises a head part 2, a neck part 3 and a handle 4. The head 2 is provided with a peripheral row of sixteen tufts 5-seven of these on each side and one at each of the two ends-these tufts being comprised of very thin bristles with a diameter of 3 mm and a height in the range between 5 mm and 7 mm. The neck 3, which has an elongate sinusoid shape, connects the handle 4 to the head 2, and raises the head 2 by 5 mm keeping the same at the 170° angle relative to the handle 4.

The head 2 is also provided with one single median row of plastic blocks 6 of minute size, which are shown in detail in Figure 3, that may be substituted by tufts of coarse bristles 7, shown in Figure 4.

As is more clearly shown in Figure 3, the minute-sized plastic blocks 6 have parallelepiped shape with a square base and have at the top thereof three transversal platelets, wherein the central platelet has a thickness of 0.6 mm and is separated from the other two side platelets, also with 0.6 mm in thickness, by a groove with 0.6 mm in width and 2 mm in depth.

The upper edge of each platelet is serrated with six teeth of triangular shape with 0.5 mm at the base and 0.5 mm in height. Such minute-sized blocks may be substituted by tufts of coarse bristles 7, shown in Figure 4, with a diameter of 3 mm. Both the minute-sized plastic blocks 6 and the tufts of coarse bristles 7 have a maximum height in the range between 4 and 6.5 mm.