Since long ago, it is well-known that the risk of the growth of bacteria on tooth surfaces, being difficult or impossible to clean by means of a tooth brush, may be effectively reduced by regular use of dental floss. However, the original classic manner of using dental floss, which is based on holding the dental floss manually by means of the fingers of both hands, is regarded as very troublesome and difficult by many people.

Therefore, in order to facilitate and promote the use of dental floss, various dental floss holders have been proposed. These holders may be divided into two different groups, namely on the one hand, a first group of holders, intended for repeated use and based on the assumption that a user affixes a fresh piece of dental floss to the holder each time he is going to use the holder, and, on the other hand, a second group of holders which are provided with dental floss pieces previously affixed thereto and which together with said dental floss pieces form prefabricated dental floss devices intended for single use.

In both cases, the holders have usually had a york of fork-like shape and been provided with two legs which are rigidly connected to each other and between which the dental floss is mcunted in a taut state. How- ever, such a mounting of the dental floss does not permit the dental floss to be wrapped around a tooth and brought to follow the contour of the tooth. Therefore, the possible cleaning of the teeth is strongly restricted.

Furthermore, it may very well happen that the dental floss, taut between the two legs, will cut into raised

portions of the gumline and hereby cause injuries on the latter.

In order to avoid the above disadvantages and make it possible to achieve a cleaning effect which is just as good as in the case of the classic entirely manual procedure without having to put fingers of both hands into the mouth, also various prefabricated dental floss devices intended for single use have been pro- posed, comprising a dental floss holder, having the general shape of an elongate rod-like body and consisting of two interconnected but easily separable holder por- tions, and a piece of dental floss, received in a cavity in the dental floss holder and anchored to the two holder portions with opposite ends thereof and adapted to become uncovered along the major portion of its length when the holder portions are separated from each other. However, despite the obvious advantages offered by dental floss devices of this kind, any such devices have nct found any substantial use in practice.

No dcubt, the reason is that the devices hitherto pro- posed, for instance those dislosed in US-A 4 403 625 and US-A 5 174 314, have not been designed in a manner that could be accepted when considering the required manufacturing process.

The invention has for its purpose to provide an improved dental floss device of said kind which can be produced in a much more simple and inexpensive manner than the devices previously known.

The device, according to the invention proposed for said purpose, is primaily characterized in that said cavity in the dental floss holder is formed by a narrow groove, running in the longitudinal direction of the holder and extending into the holder from one side of the holder, said groove containing the dental

floss piece within the same in a position adjacent to the bottom of said groove, the end portions of the den- tal floss piece being permanently fixed to the holder at places located near mutually opposite er. ds of the holder.

As a consequence of the design of the dental floss device proposed in accordance with the invention, the manufacture of the dental floss holder as well as the fixation of the dental floss piece to said holder may be effected in an easy and inexpensive manner.

According to a preferred embodiment of the in- vention, the dental floss holder may suitably be formed by an injection moulded integral member which consists of a rigid plastic material and wherein the two holder portions are connected to each other by a weakened easily breakable ccnnection portion.

The dental floss holder may advantageously consist of a styrene acrylonitrile plastic.

In order to facilitate a convenient and firm holding of each of the two holder portions by a user, said portions may preferably have a non-circular cross- sectional shape. For instance, the two holder portions may advantageously have a cross-sectional shape con- sisting of a square or a rectangle with rounded corners.

The two end portions of the dental floss piece, which suitably may consist of a multifilament thread consisting of a polyamide plastic, may be fixed to the dental floss holder in many different ways. For instance, they may be fixed to the holder each by means of a plug, inserted into and secured in a bottom hole in the cor- responding holder portion. However, they may preferably be fixed to the holder by glue joints or melt joints.

Below the invention is described in further detail with reference to the accompanying drawings, in which Figure 1 shows a perspective view of a prefabricated

dental floss device according to an embodiment of the invention, selected by way of example only, Figure 2 shows a plan view of the dental floss device according to Figure 1, Figure 3 shows a partial view on an enlarged scale and in section taken along line III-III in Figure 2, Figure 4 shows a cross-sectional view, taken along line IV-IV in Figure 2, Figure 5 shows a cross-sectional view, taken along line V-V in Figure 2, and Figure 6 shows a perspective view of the device according to Figure 1 after a separation of two holder portions of said device from each other.

The dental floss device shown in the drawings comprises a dental floss holder, generally designated 10, and a piece of dental floss 11, fixed to said holder.

As a whole, holder 10 has a generally rod-like shape and it consists of two holder portions 12 and 13, respectively, which are located in line with each other and each of which as a cross-sectional shape consisting of a square or rectangle with rounded corners. At their adjacent ends, the two holder pcrtions 12 and 13 are ccnnected to each other by a short connection portion 14, the cross-section of which is strongly reduced in relation to the cross-section of said two portions.

At one side thereof, holder 10 is provided with a narrow groove 15, running along the whole length of the holder and extending into the centre of the holder from said one side thereof and serving to receive dental floss piece 11 in a position located at the bottom of said grocve. Dental floss piece 11, which extends along the whole length of holder 10, is permanently fixed to each holder portion 12 and 13, respectively, at a place located near the outer end of the holder portion.

In the drawings, said fixation of the dental floss

piece to each holder pcrtion has been illustrated as obtained by means of a generally cylindrical plug 17, inserted into and secured in a bottom hole 16 in the holder portion. However, said fixation may be obtained also in many other ways. Thus, in practice, the end por- tions of dental floss piece 11 may preferably be fixed to the holder portions by glue joints or melt joints.

Holder 10 may preferably consist of an injection moulded integral member consisting of a rigid plastic material. In this case, connection portion 14 may serve as an easily breakable weakened connection between the two holder portions 12 and 13, while each holder por- tion simultaneously may form a rigid elongate general- ly rod-like member. One suitable material for the pro- duction of holder 10 is styrene acrylonitrile plastic.

The dental floss piece 11 may suitably consist of a multifilament thread of a polyamide plastic.

When the dental floss device above described is to be used, dental floss piece 11, which previously has been located protected in groove 15, may be un- covered by swinging the outer ends of holder portions 12 and 13 towards each other in a manner indicated by arrows A in Figure 1. Hereby, ccnnection portion 14 is broken and the two holder portions 12 and 13 are sepa- rated from each other so as to form two separated mem- bers which may be handled individually and which are connected each to one end portion of dental floss piece 11. The user may then conveniently handle dental floss 11 in any desired manner while holding the two holder portions 12 and 13 in different hands.

In order to make it possible for a user to put the end of the dental floss connected to one holder portion into a lingual position in his mouth without simultaneously having to put the fingers by which he is holding said holder portion into a corresponding

position, the holder portion should have a length of at least about 3 centimetres. However, a larger length may be advantageous. If, as shown in the drawings, the two holder portions have mutually different lengths, the shorter holder portion may suitably have a length of at least 3 centimetres and preferably 3,5-4 centi- metres, while the longer holder portion may have a length of at least 4 centimetres and preferably 5-6 centimetres.

The cross-sectional dimensions of the two holder portions should amc, unt to at least about 3 millimetres but may just as well be slightly larger, for instance about 4 millimetres.

The invention is not restricted to the embodiment above described and shown in the drawings. Instead, many other embodiments are feasible within the scope of the invention. For instance, it could be mentioned that the two holder portions need not have the shape of absolutely straight rod-like members but may also consist of suitably curved such members.