The scope of the present invention is a file for use in dental applications. The file according to the invention can be used in orthodontics, in aesthetic rehabilitation, in prophylaxis, in conservative dentistry and in similar dental applications. Preferably, the file according to the invention can be used for processing the interproximal space in orthodontics and/or in conservative dentistry. The file in accordance with the invention can be of a manually operated type. Alternatively, a file in accordance with the invention can be of a type suitable for being used with mechanical driving devices, referred to as "handpieces" or the like.

Files are known for processing the interproximal space in orthodontics and/or in conservative dentistry. Such files comprise an abrasive sheet which allows to process the teeth in correspondence with the interproximal space.

Files are known which can be connected to a handling device for being operated automatically, and also files that can be operated manually.

The known manually operated files have some drawbacks.

First of all, they are uncomfortable to use and to handle.

In addition, the known files are not sufficiently sturdy and consequently there is a risk that, in operating conditions, they possibly deform and flex. A deformed or flexed file can lead to deforming the abrasive sheet, which would jeopardize the correct operation of the sheet itself.

In addition, the known files are not so structured as to allow a homogeneous distribution of the force applied by a user in manually operating the file.

The files suitable for being used with mechanical driving devices also have a number of similar drawbacks, among which a not sufficiently sturdy structure and the use of abrasive sheets having non-optimum characteristics for all applications of interest. In the light of the foregoing, the main object of the present invention is to solve one or several problems encountered in the known art.

An object of the present invention is to provide a file that is structurally firm and sturdy.

A further object of the present invention is to provide a file that can be operated manually in an easy and comfortable manner.

- l - A further object of the invention is to implement a file structured in such a way as to prevent points featuring an excessive mechanical stress from being present in the file.

A further object is to provide a file equipped with an abrasive sheet having strength and effectiveness characteristics greater than those known.

A further object of the present invention is to simplify and make the use of files easier.

The Applicant realized a file that overcomes the drawbacks of the known files. These objects and others, which will be more apparent from the following description, are substantially achieved by a file in accordance with the provisions of one or more of the attached claims and/or the following aspects, taken alone or in a combination whatsoever between them or in combination with anyone of the attached claims and/or in combination with anyone of the further aspects or characteristics described below.

In one aspect there is provided a file for processing the interproximal space in orthodontics and/or in conservative dentistry comprising a substantially arc-shaped tool-holder structure defining an internal space of the file, the tool-holder structure comprising a first and second side portions and a central portion, transversal to the first and second side portions and interposed between said side portions, the file also comprising an abrasive sheet tool engaging the side portions of the tool-holder structure and developing in correspondence with the internal space of the file. In one aspect, the file also comprises a first and second handle portions having an at least partially curvilinear development, the first and second handle portions engaging the tool-holder structure and being configured for providing a firm manual holding of the file.

In one aspect, the tool-holder structure features a substantially "C-shaped" or "ΙΓ- shaped configuration.

In one aspect, the first and second handle portions engage the first and second side portions respectively.

In one aspect, said side portions comprise a respective free end and a respective junction end joining the central portion, the junction end and the free end being reciprocally opposed, the abrasive sheet tool engaging the tool-holder structure in correspondence with or in proximity to the free ends of the side portions.

In one aspect, said handle portions are shaped and configured so that, under operating conditions of the file, the application point of the force due to the manual operation of the file is spaced away from the free ends of the side portions and is arranged in proximity to the junction ends of the side portions.

In one aspect, the first and second handle portions are made so as to overhang with respect to the tool-holder structure.

In one aspect, the first and second handle portions are one-piece with the tool- holder structure.

In one aspect, the tool-holder structure is a one-piece one, in particular made from a plastic material.

In one aspect, the tool-holder structure and the handle portions form one piece, in particular made from a plastic material.

In one aspect, the tool-holder structure and the handle portions are obtained by molding.

In one aspect, the first and second handle portions are substantially concave, the concavity of said handle portions facing the outside with respect to said side portions so as to simplify and make it possible an easy manual holding of the file.

In one aspect, the handle portions have a width greater than a characteristic dimension of the cross-section of the tool-holder structure, for instance with respect to a width of the cross-section, preferably the maximum width of the handle portions being at least equal to twice said characteristic dimension of the cross-section of the tool-holder structure.

In one aspect, the handle portions have a length substantially equal to a length of the side portions of the tool-holder structure, the length of the handle portions being defined parallel to the length of the side portions.

In one aspect, the first and second handle portions include a respective appendage to engage the central portion of the tool-holder structure, the appendages firmly binding said handle portions to the central portion of the tool-holder structure.

In one aspect, the first and second handle portions make it possible a firm and stable handling of the file and at the same time they are suitable for making it possible to proportionate the handling force of the file applied in correspondence with said handle portions.

In one aspect, the first and second handle portions make it possible a firm handling of the file between a user's thumb and forefinger.

In one aspect, the tool-holder structure also comprises a stiffening rib developing at least in correspondence with the central portion and emerging from the central portion in correspondence with the internal space of the file, under operating conditions of the file the stiffening rib being configured for discharging the force exerted onto the handle portions by a user.

In one aspect, the stiffening rib comprises coupling portions configured for engaging the stiffening rib to the side portions of the tool-holder structure.

In one aspect, the coupling portions feature a cross-section having a surface area that decreases as moving from one side portion of the tool-holder structure toward a center line of the central portion of the tool-holder structure.

In one aspect, the stiffening rib is symmetrical with respect to a center line of the central portion of the tool-holder structure.

In one aspect, the stiffening rib develops along a longitudinal extension substantially equal to an extension of the central portion, the stiffening rib being configured so as to prevent the tool-holder structure from flexing and/or bending under operating conditions of the file.

In one aspect, the tool-holder structure also comprises at least one stiffening ridge, said stiffening ridge developing in correspondence with said central portion and along at least a length in correspondence with said side portions and being configured for stiffening the tool-holder structure.

In one aspect, the stiffening ridge features a substantially "C"- or "U"-shaped configuration.

In one aspect, the tool-holder structure comprises two stiffening ridges, one stiffening ridge being arranged in correspondence with a front portion of the tool- holder structure and the other stiffening ridge being arranged in correspondence with a rear portion of the tool-holder structure.

In one aspect, the abrasive sheet tool comprises an abrasive material applied onto one surface only of the abrasive sheet tool. In one aspect, the abrasive sheet tool comprises an abrasive material applied onto at least one surface of the abrasive sheet tool.

In one aspect, the abrasive material comprises a material treated according to a treatment suitable for making it more abrasive.

In one aspect, the abrasive material comprises a diamond-tooled material.

In one aspect, the abrasive material comprises a material treated or coated with silicon carbide.

In one aspect, the abrasive material comprises a material treated or coated with aluminium oxide.

In one aspect, the diamond-tooled material features a granulometry suitable for removing materials from dental surfaces by abrasion.

In one aspect, the granulometry of the diamond-tooled material ranges from 1 to 70 microns or from 5 to 65 microns or substantially equals 9 microns or 15 microns or 30 microns or 45 microns or 60 microns.

In one aspect, the abrasive material is applied onto the two opposed main work surfaces of the abrasive sheet tool.

In one aspect, the abrasive sheet tool is made from a plastic material, preferably polyester.

In one aspect, the abrasive sheet tool is made from diamond-tooled polyester. In one aspect, the abrasive sheet tool is made from diamond-tooled polyester in the form a polyester sheet, a preferably synthetic resin coating, and a preferably synthetic diamond-tooled coating.

In one aspect, the abrasive sheet tool is made from a metallic material.

In one aspect, the file is provided with a mount portion suitable for selectively engaging a device for mechanically operating the file or handpiece, to make it possible to operate the file mechanically.

In one aspect, there is provided a use of the file in accordance with one or several of the previous aspects and/or with one or several of the attached claims in orthodontics and/or in conservative dentistry and/or in aesthetic rehabilitation and/or in prophylaxis and/or in conservative or in similar dental applications.

In one aspect, when using the file in aesthetic rehabilitation, the abrasive sheet tool has an abrasive material on one main development surface only of the abrasive sheet. In one aspect, when using the file in orthodontics, the abrasive sheet tool has an abrasive material on the two opposed main development surfaces of the abrasive sheet tool.

In one aspect, a use of the file is provided for processing the interproximal space in orthodontics and/or in conservative dentistry.

In one aspect, the use of the file supports a manual handling or operation of the file.

A detailed description of one or more preferred embodiments of the invention is given below for explanatory non-limitative purposes, wherein:

figure 1 shows a perspective view of a manual file in accordance with a first embodiment;

figure 2 shows a frontal view of the file of figure 1 ;

figure 3 shows a perspective view of a file suitable for use with a mechanically operated device, implemented in accordance with a second embodiment.

With reference to the figures, the reference numeral 1 identifies a file as a whole. The file 1 can be used in orthodontics, in aesthetic rehabilitation, in prophylaxis, in conservative dentistry, and in similar dental applications. In particular, the file 1 is configured for processing the interproximal space in orthodontics and/or in conservative dentistry.

The file 1 comprises a substantially arc-shaped tool-holder structure 2, so as to define an internal space of the file 1 . As shown in the attached figures, the tool- holder structure 2 can have a substantially "C" or substantially "U"-shaped configuration or similar configurations defining an internal space of the file 1 .

The tool-holder structure 2 comprises a first and second side portions 3, 4, which are interconnected by a central portion 5 which develops transversally to the side portions 3, 4 and is interposed therebetween. The central portion 5 features a greater extension as compared to the extension of the side portions 3, 4. An internal space of the file 1 is defined between the side portions 3, 4.

The first and second side portions 3, 4 substantially develop parallel to each other and have one and the same extension.

The file 1 also comprises a first and second handle portions 6, 7 featuring an at least partially curvilinear configuration. The first and second handle portions 6, 7 are engaged and defined externally to their respective side portions 3, 4, as shown in the attached figures. The first handle portion 6 develops in continuity with the first side portion 3 and the second handle portion 7 develops in continuity with the second side portion 4. The first and second handle portions 6, 7 are made so as to overhang with respect to the tool-holder structure 2 and form one piece with the tool- holder structure 2. Preferably are the tool-holder structure 2 and the handle portions 6, 7 one piece made from a plastic material, for instance by molding.

The handle portions 6, 7 are substantially identical and symmetrical and make it possible a firm and stable holding of the file 1 . The handle portions 6, 7 are substantially concave and, just because of their concave configuration, they are suitable for making it possible a stable seizure or manual holding of the file 1 and for making it possible to proportionate the handling force of the file 1 . The manual seizure of the file 1 is particularly ergonomical, simple, and simultaneously firm because the first and second handle portions 6, 7 make it possible to hold the file 1 between a user's thumb and forefinger. Such seizure makes it possible an optimum manual handling of the file 1 and consequently an effective manual use of the file 1 . The handle portions 6, 7 feature a main longitudinal extension, or length M, substantially parallel to the longitudinal extension of the side portions 3, 4, and dimensionally comparable (or substantially equal) thereto, and a maximum width L greater than a characteristic dimension of the cross-section (such as the width or height or diameter of the cross-section) of the tool-holder structure 2. Said cross- section can be taken in correspondence with either side portions 3 or 4 or with the central portion 5 of the tool-holder structure 2. Preferably, in order to make it easier to seize the file 1 , the maximum width L of the handle portions 6, 7 at least equals twice said characteristic dimension of the cross-section of the tool-holder structure 2.

Each side portion 3, 4 comprises a free end 3a, 4a and a junction end 3b, 4b to connect to the central portion 5 developing one opposite to the other.

The file 1 also comprises an abrasive sheet tool 8, arranged in correspondence with the internal space of the file 1 and supported by the tool-holder structure 2. The abrasive sheet tool 8 engages the tool-holder structure 2 in correspondence with the free ends 3b, 4b of the side portions 3, 4. The abrasive sheet tool 8 is substantially shaped like a strip (see figure 2). Onto at least one surface of the abrasive sheet tool 8 an abrasive material can be applied, as schematically shown in the attached figures as a dotted area. The abrasive material can be any type of material suitable for use in processing the interproximal space of teeth and/or in conservative dentistry and can be configured for removing materials from a dental surface by abrasion. The abrasive material is preferably a diamond-tooled material featuring a predetermined granulometry. The granulometry of the diamond-tooled material preferably ranges from 1 to 70 microns (pm) and can equal to 9 microns or 15 microns or 30 microns or 45 microns or 60 microns. The diamond-tooled material can be applied onto one surface only of the abrasive sheet tool 8 or onto both surfaces of the abrasive sheet tool 8, depending on the use that the file 1 is intended for. For example, files intended for use in orthodontics can have the abrasive material on both surfaces of the abrasive sheet tool 8, whereas files intended for use in rehabilitation might have an abrasive material on one surface only of the abrasive sheet tool 8.

Preferably is the abrasive sheet tool 8 made from polyester. In accordance with an alternative embodiment, the abrasive sheet tool 8 can be made from a metallic material.

Coming back to the handle portions 6, 7, it is worth saying that they are shaped and engage the side portions 3, 4 in such a way that the application point of the force due to the manual operation of the file 1 is spaced away from the free ends 3a, 4a of the side portions 3, 4 and is arranged in proximity to the junction ends 3b, 4b of the side portions 3, 4. Such arrangement prevents the abrasive sheet tool 8 from flexing under operating conditions, which might conversely occur if the application points of the force were arranged in proximity to the free ends of the side portions (as with the known files).

The first and second handle portions 6, 7 have a respective engagement appendage 6a, 7a configured in such a way as to firmly bind their respective handle portions 6, 7 to the central portion 5 of the tool-holder structure 2. The appendages 6a, 7a are arranged in proximity to, or in correspondence with, the junction ends 3b, 4b of the side portions 3, 4.

Structurally-wise, the tool-holder structure 2 also comprises a stiffening rib 9 developing at least in correspondence with the central portion 5 and emerging from the central portion 5 in correspondence with the internal space of the file 1 . The stiffening rib 9 develops parallel to the central portion 5 over a longitudinal extension substantially equal to an extension of the central portion 5 (see figures 1 , 2).

The stiffening rib 9 makes it possible to discharge the force exerted by a user onto the handle portions 6, 7 under operating conditions of the file and is configured to prevent the tool-holder structure 2 from flexing and/or bending. The stiffening rib 9 comprises coupling portions 10 configured for engaging the stiffening rib 9 to the side portions 3, 4 of the tool-holder structure 2. The coupling portions 10 feature a cross-section having a surface area that decreases as moving from a side portion 3, 4 of the tool-holder structure 2 toward a center line of the central portion 5 of the tool-holder structure 2 (see figure 2). The stiffening rib 9 is preferably symmetrical with respect to the center line of the central portion 5 of the tool-holder structure 2. The tool-holder structure 2 also comprises at least one stiffening ridge 1 1 which develops along the central portion 5 and along the side portions 3, 4. The stiffening ridge 1 1 is substantially "C"-shaped and is configured so as to stiffen the tool-holder structure 2, so as to prevent it from flexing or deforming in operating conditions of the file 1. The tool-holder structure 2 preferably features two stiffening ridges 1 1 , one arranged on a front portion of the tool-holder structure 2 and the other arranged on a rear portion of the tool-holder structure 2.

In accordance with a second embodiment shown in figure 3, the file is provided with a mount portion 12 suitable for selectively engaging a device for the mechanical operation of the file, or handpiece, to make it possible a mechanical operation of the file.

The present invention allows to obtain one or several of the following advantages and to solve one or several of the problems encountered in the known art.

First of all, the invention makes it possible to improve the known files under a number of aspects.

First of all, the invention provides a file easy to handle and featuring a sturdy structure.

The invention makes it possible to manually operate the file safely, thanks to it being held by the handle portions.

The file according to the invention is so structured as to obtain a homogeneous distribution of the force applied by a user in manually operating the file. The file in accordance with the invention is also structurally sturdy and is not subject to flexures under operating conditions.

The file in accordance with the invention features handle portions symmetrical to each other and consequently it can be advantageously seized from one side or from the other at will (being it possible to use the thumb and the forefinger in correspondence with the first and second handle portions respectively, or vice versa).

In addition, the invention is comfortable to use, easy to implement, and simple and cost-effective to manufacture.