WO2007028857A1

WO2007028857A1 - A dentist’s hand instrument, tip of a dentist’s hand instrument and a dental care arrangement, and a method for curing a fibre bundle on the surface of an object

Info

Publication number: WO2007028857A1
Application number: PCT/FI2006/000299
Authority: WO
Inventors: Ilppo Sandberg; Tiina Varrela; Mikko Salminen
Original assignee: Stick Tech Oy
Priority date: 2005-09-09
Filing date: 2006-09-08
Publication date: 2007-03-15
Also published as: FIU20050288U0; FI6975U1

Abstract

The invention relates to a dentist's hand instrument, its tip and a dental care arrangement as well as a method for curing a fibre bundle on the surface of an object, such as a tooth. In the dentist's hand instrument according to the invention, there is a tip (1), which comprises at least a fixing part (2) for fixing the tip to the instrument (3) and a tool part (6), which is in connection with the fixing part (2). The tool part (6) comprises a working surface (4) meant to be pressed against a tooth. In the working surface (4) of the tool part there is an elongated recess (5) for the material to be pressed against the tooth.

Description

A dentist's hand instrument, tip of a dentist's hand instrument and a dental care arrangement, and a method for curing a fibre bundle on the surface of an object

FIELD OF THE INVENTION

The invention is directed to a dentist's hand instrument, its tip and a dental care arrangement, as well as a method for curing a fibre bundle on the surface of an object, as defined below in the preambles of the independent claims. The invention relates especially to a new device and way of placing fibre bundles in a patient's teeth.

PRIOR ART

Fibre products such as fibre fabrics and fibre bundles are commonly used in dentistry for splinting teeth and for reinforcing and repairing various dental prosthetic appliances such as crowns, fixed bridges, removable dentures and so- called surface attachable bridges and facades. Such fibre reinforcing products may either solely comprise fibres, or be fibre-reinforcing products preimpregnated with a polymer or a monomer. Fibre products having the desired shape are obtained by curing the polymers and/or monomers present in the products for instance with blue light. Fibre products remain in the final products as reinforcements and accordingly, they should be shaped precisely to conform to the final location (e.g. a supporting tooth) before curing and constructing a desired structure thereon (a bridge, removable denture or the like). Placing fibre bundles into the patient's mouth has traditionally been done by hand or with hand instruments. Usually, a suitable combination of instruments is used so that the fibres would not need to be handled with fingers.

Better tools for taking the fibre bundles to the patient's mouth and for holding the fibres than those presently available have for long been wanted. In the known solutions, the problem has been for instance that the fibre bundle stay in the desired form during the treatment, e.g. as round as possible. One problem has been that parts of the fibre bundle fray easily to unwanted areas on the surface of the tooth. It has been difficult to press the fibre bundles against the teeth with appropriate force.

PURPOSE AND A BRIEF DESCRIPTION OF THE INVENTION An object of the invention is to reduce and even to eliminate the said problems present in the solutions of the prior art.

An object of the invention is to obtain an easy and good way to lay a fibre composite on the surface of a tooth or another object.

In order to realize i.a. the above-mentioned objects, the method, the dentist's instrument, its tip and the dental care arrangement according to the invention are characterized by what is disclosed in the characterizing parts of the appended independent claims.

The objects, exemplary embodiments and advantages mentioned in this text relate, when applicable, to the method, the dentist's instrument, its tip as well as to the dental care arrangement of the invention, even though it is not always specifically mentioned.

A typical tip of a dentist's instrument of the invention comprises at least

- a fixing part for fixing the tip to the instrument, and

- tool part which is in connection with the fixing part and which comprises a working surface meant to be pressed against an object, such as a tooth. A typical tool part according to the invention comprises an elongated recess arranged in the working surface for the material to be pressed against the object.

An object according to the invention onto which a fibre or a fibre bundle is attached, can for instance be one or several teeth, a dental prosthetic appliance or a partial prosthesis.

The fixing part can for instance be a fitting or another part that can be connected for instance to a hand instrument's arm or to a hand instrument's fixing part. A tip according to the invention can be detachably connectable to a hand instrument. The tip according to the invention can, for the working period, be fixed for instance to lock tweezers or to a hand instrument specifically made for the tip.

It is also possible that the tip according to the invention is formed as an integral part of a hand instrument. In this case, by fixing part is meant the part between the tip and the instrument, connecting them.

The entire tip can be manufactured as one and the same piece of one material. It is also possible to manufacture the fixing part and the tool part as separate pieces and to join them. The tool part can also be manufactured of one or more parts.

A tip according to the invention can be manufactured for instance by injection moulding from a suitable plastic. Possible production materials are for instance polypropylene, polyethylene, polycarbonate, polyamide, particularly amorphous polyamide. A suitable additive or coating that reduces the clinging of the tip according to the invention to the fibres can be used in the manufacture. Various organic and/or synthetic substances, such as waxes, are suitable as an additive and/or a coating. For instance, in the manufacture of the tip according to the invention TEFLON™ can be used as an additive.

A tip according to the invention is usually used as a part of a dentist's hand instrument that, in addition to the tip, comprises at least a gripping part for the dentist's hand. It is also possible to use the tip according to the invention as a part of another instrument than an instrument meant to be held in a dentist's hand.

In a typical dental care arrangement according to the invention, a fibre bundle has readily been placed in the recess of the tip of the hand instrument according to the invention. This kind of combination is immediately ready to be used by a dentist.

The tip according to the invention is usually used in such a way that the uncured fibre is placed to the recess of the tip, the fibre or the fibre bundle in the recess is taken onto the desired target, and the fibre is cured onto the object, such as the surface of a tooth, with a dentist's light-curing machine.

In a typical method according to the invention for curing a fibre bundle onto the object,

- an uncured fibre or fibre bundle is placed into an elongated recess arranged in the working surface of the tool part of the hand instrument's tip,

- the fibre or the fibre bundle present on the working surface is taken onto the desired object, typically to an intimate contact with the object, - the fibre or fibre bundle is cured with a light-curing machine onto the surface of the object.

In a typical embodiment of the method according to the invention, the tip and thus also the fibre or fibre bundle is pressed by hand against the object during curing.

Light-curing machines are previously known. A light-curing machine can for instance comprise a source of light that produces a suitable wavelength for the light curable fibre bundle, e.g. 470 nm or UV radiation. The source of light can for instance be plasma, a halogen or a LED, from which the light is lead to its object for instance by means of an optical fibre.

It is possible to make the surface and the edges of the recess according to the invention to support the fibre bundle during different stages of the method according to the invention, that is when the fibre bundle is taken to its object, when the fibre bundle is pressed against the object and during curing of the fibre bundle. In this way, it is possible to facilitate a dentist's work.

An advantage of the invention is that in the recess or groove according to the invention, the fibre bundle stays as round as possible, when so desired, and parts of it will not fray away to unwanted areas on the surface of a tooth or another object. An advantage of the invention is that by means of a recess in the tip according to the invention, it is possible to attach the fibres firmly to the tool part of the tip. In this way, the fibre can be taken onto its object safely and easily.

By fibre bundle, in this application is meant a fibre bundle or a fibre bundle in which the fibres are mainly unidirectional. The material of the fibre bundle can be fibre composite, glass fibre, polyethylene fibre, carbon fibre, metal wire or some other elongated support or clamp to be attached onto the surface of an object, such as a tooth. Glass fibre, carbon fibre or polyethylene or more generally polyolefin fibre can be used as such without a ready impregnation, or it can be pre- treated so that it contains some light curing compound in it.

By a dentist it is meant any ones working in the field of dentistry, such as dentists, dental technicians and students.

The instrument, the tip and the arrangement according to the invention can be used, in addition to real patients, also when practising the operations to be performed for instance with dummies.

The invention can be used for dental care of both humans and animals.

By using the method according to the invention, a fibre or a fibre bundle can be cured to its object either inside the mouth or outside the mouth.

The instrument, the tip and the arrangement according to the invention can be used for instance for placing a fibre composite as a fixation on the surface of the tooth. The fixation can be for instance an orthodontic anchorage, segmentation or a fixation to be placed for retention purposes, parodontological fixation for immobilization purpose of wobbly teeth or a fixation to be placed for prosthetic purposes, e.g. a bridge frame. It is also possible to make the hand instrument disposable. Such instrument can advantageously be manufactured for instance of a suitable plastic by injection moulding. The advantage of such a disposable tool is for instance the hygiene.

In an embodiment of the invention, the tip is made of transparent, translucent or curing light permeable material. Thus, the curing light can be directed to the fibre through the tip according to the invention. In this way, the fibres can be kept in their place on the tip according to the invention during curing. If the fibres are cured with blue light, the tip according to the invention advantageously has to permeate at least some light, especially blue light.

In an embodiment of the invention, when placing the fibres, a spatula or another tool is used to cover those parts of the fibre that are not desired to be cured. Curing light is not generally wanted cure the fibre bundle elsewhere than below the tool according to the invention or in the immediate vicinity of the tool. Otherwise there is a danger that the prematurely cured fibre no longer is usable. For instance, with a spatula that is bent to a suitable shape, a temporary wall can be created between two teeth so that a fibre running across several teeth can be cured gradually, tooth by tooth. In this way, with the aid of the tip according to the invention, the fibre can be placed to the optimal position at the level of each tooth.

In an embodiment of the invention, the tip or at least its tool part or at least the edges of the elongated recess have been made of a substantially inelastic material. By substantially inelastic, it is meant that when pressing the tool part by hand against the object, for instance teeth, the material of the tip or the recess does not bend much. Then, when placing the fibre on the surface of the tooth, the instrument or its tip can be tilted a little from one side to the other so that the fibres can suitably be pressed against the curvy or uneven surface of the tooth.

In an embodiment of the invention, the tip or at least its tool part or at least the edges of the elongated recess are made of substantially elastic material. Then, when pressing the tip by hand against the object, such as one or several teeth, the tip bends at least a little according to the curvature of the object's surface. In this way, it is possible to place the fibre to be placed with the tip against the surface of the object for the entire width of the tip without a particular tilting of the tip. For instance, the tool part can be arranged to bend in the longitudinal direction of the elongated recess. The fibres do not generally need to reach the tooth gaps, but it is preferable to get the fibres in contact with the tooth on a sufficiently long range so that the sufficient fixing surface in the tooth is obtained.

If, when using a groove made of an elastic material, a slight pressure is set, a so- called contouring is obtained, whereby the fibre can be made to follow the curvature of the surface of the tooth. If the pressure is added, the groove will flatten and at the same time the groove will set flatter on the surface of the tooth.

In an embodiment of the invention, at least the edges of the elongated recess have been formed of a substantially elastic material so that, when pressing the working surface by hand against an object, such as a tooth, said edges are arranged to bend substantially away from each other. In this way, the edges will not turn between the fibre bundle and the object.

In an embodiment of the invention, the tool part has been formed of said substantially elastic material so that when pressing the working surface by hand against an object, the tool part is arranged to bend substantially in the longitudinal direction of the elongated recess.

In an embodiment of the invention, the form of the elongated recess is mainly straight and symmetrical with respect to an imaginary level arranged to the centre point of the bottom of the recess. By means of a symmetrical tool part, positioning the fibres in the object of use is easy. Then the dentist does not need to think about in which direction the tool part needs to be placed against a tooth or another object.

In an embodiment of the invention, the tool part and/or its working surface have an elongated form in the direction of the elongated recess. Thus, when the shape of the tool part and/or its working surface corresponds to the shape of the recess, this shape will indicate the position of the fibres to the dentist.

In an embodiment of the invention, the elongated recess has the length of at least mainly the entire working surface. Advantageously, said elongated recess has open ends. In this way, fibres having the length of the entire working surface, and even longer, can be placed to the recess.

In an embodiment of the invention, the cross-section perpendicular to the longitudinal direction of the elongated recess has a curvy and streamlined surface. Thus, it is easy to place the fibres or a fibre bundle to the tip and the fibres detach from the tip easily. In an embodiment, said cross-section of the surface is a part of the arch of a circle. Preferably, the cross-section forms 120-225°, more preferably 150-180° of a full arch of the circle. Thus, the fibres are easy to place to the recess. In addition, in this way, when pressing the tip against a tooth or another object, the edges of the recess do not bend between the fibres in the recess and the object. The edges of the recess can of course be made longer for instance so that the bottom of the recess forms a part of the arch of a circle, but from a certain point onwards, the edges continue as straight forward. In an embodiment of the invention, the fibres being in the recess according to the invention, the surface and the edges of the recess support the fibre or the fibre bundle from various different directions.

In an embodiment of the invention, the fixing part has a certain fixing direction in which direction it is arranged to be fixed to the instrument. Then typically, the longitudinal direction of the elongated recess and said fixing direction form an angle with respect to each other, which angle is 30-90°, preferably 60-90°, more preferably 80-90° or 90°. The fixing part can contain one or more additional angles or folds in order to arrange the position of the tip to be suitable, for instance with respect to the direction of arm of the hand instrument.

In an embodiment of the invention, the tool part of the tip has in the direction of the elongated recess a length of 1-30 mm, preferably 2-20 mm, more preferably 3-10 mm or 4-6 mm. The tool part can thus be arranged to have the length of one or two teeth. By means of a suitably short tool part, it is easy to cure the fibre a short distance at a time.

In an embodiment of the invention, the elongated recess is perpendicular with respect to its longitudinal direction at the level of the working surface with a width of 0,5-5 mm, preferably 1-3 mm, more preferably 1 ,2-2 mm. In an embodiment of the invention, the elongated recess has in a perpendicular direction with respect to its longitudinal direction and the level of the working surface a depth of 0,5-5 mm, preferably 1-3 mm, more preferably 1 ,2-2 mm. A recess of this size is suitable for most fibre bundles being used.

SHORT DESCRIPTION OF THE FIGURES

The invention will be described in more detail below by referring to the appended schematical drawing, in which

Figure 1 shows a tip according to the invention from below,

Figure 2 shows the tip of Figure 1 from front,

Figure 3 shows the tip of Figure 1 from the side,

Figure 4 shows the tip of Figure 1 from above, Figure 5 shows the tip of Figure 1 as a perspective view, and

Figure 6 shows the tip of Figure 1 as fixed to a dentist's hand instrument.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE FIGURES Figures 1-5 show a tip 1 of a hand instrument according to the invention, in which tip there is a cylindrical fixing pin 2. The fixing pin 2 is meant to fit to a fitting of the hand instrument seen in Figure 6, which fitting is suitable for the fixing pin. An elongated tool part 6 is arranged in the fixing pin perpendicularly therewith.

In Figure 1 , the tip is depicted from the direction of the working surface 4. The working surface is a partly imaginary level meant to be pressed against a tooth, which level is shown by a dotted line in Figure 3. The tip has a recess 5 opening towards the working surface. The recess 5 has the cross-section of a part of an arch of a circle. The recess 5 is suitably sized in order to place therein a fibre bundle (not shown) needed in dental care. The recess 5 has the length of the entire working surface 4 and tool part 6.

To the hand instrument 3 shown in Figure 6 a fold 7 has been formed so that the tip 1 can be placed better to various positions in the patient's mouth. There could be more folds, for instance two or three, in order to enable more ergonomic and efficient working positions.

The Figures show only one advantageous embodiment according to the invention. The Figures do not show anything that is inessential to the main idea of the invention, known perse or obvious to the man skilled in the art, such as fibre bundles or teeth. It is clear to the man skilled in the art that the invention is not limited solely to the embodiments presented, but that the invention may vary within the scope of the appended claims below. In the dependant claims, some possible embodiments are presented, and they should not be construed to limit the scope of protection of the invention.

Claims

1. A tip (1 ) of a dentist's hand instrument, which tip comprises at least

- a fixing part (2) for fixing the tip to the instrument (3), - a tool part (6), which is in connection with the fixing part (2) and which comprises a working surface (4) meant to be pressed against an object, such as a tooth, characterized in that

- the tool part comprises an elongated recess (5) arranged on the working surface for the material to be pressed against the object.

2. The tip according to the claim 1 , characterized in that the tool part (6) is at least mainly made of a transparent material.

3. The tip according to the claim 1 or 2, characterized in that the tool part (6) is at least mainly made of a substantially elastic material.

4. The tip according to the claim 1 , 2 or 3, characterized in that the edges of the elongated recess (5) have been formed of substantially elastic material so that when pressing the working surface (4) by hand against the object, said edges are arranged to substantially bend away from each other.

5. The tip according to any of the previous claims, characterized in that the tool part (6) is formed of said substantially elastic material so that when pressing the working surface (4) by hand against the object, the tool part (6) is arranged to substantially bend in the longitudinal direction of the elongated recess (5).

6. The tip according to any of the previous claims, characterized in that the form of the elongated recess (5) is mainly straight and symmetrical with respect to an imaginary level arranged to the centre point of the bottom of the recess.

7. The tip according to any of the previous claims, characterized in that the tool part (6) and/or its working surface (4) has an elongated form in the direction of the elongated recess (5).

8. The tip according to any of the previous claims, characterized in that the elongated recess (5) has the length of at least mainly the entire working surface (4).

9. The tip according to any of the previous claims, characterized in that the elongated recess (5) has open ends.

10. The tip according to any of the previous claims, characterized in that the cross-section perpendicular to the longitudinal direction of the elongated recess (5) is curved and streamlined.

11. The tip according to claim 10, characterized in that the said cross-section is an incomplete arch of a circle, preferably 120-225°, more preferably 150-180° of a full arch of a circle.

12. The tip according to any of the previous claims, characterized in that the fixing part (2) has a certain fixing direction, in which direction it is arranged to be fixed to the instrument (3), and that the longitudinal direction of the elongated recess (5) and said fixing direction form an angle with respect to each other, which angle is 30-90°, preferably 60-90°, more preferably 80-90° or 90°.

13. The tip according to any of the previous claims, characterized in that in the elongated recess (5), there is a fibre bundle in the direction of the recess.

14. The tip according to any of the previous claims, characterized in that the tool part (6) has in the direction of the elongated recess (5) a length of 1-30 mm, preferably 2-20 mm, more preferably 3-10 mm or 4-6 mm.

15. The tip according to any of the previous claims, characterized in that the elongated recess (5) has in a perpendicular direction with respect to its longitudinal direction on the level of the working surface (4) a width of 0,5-5 mm, preferably 1-3 mm, more preferably 1 ,2-2 mm.

16.The tip according to any of the previous claims, characterized in that elongated recess (5) has in a perpendicular direction with respect to its longitudinal direction and the level of the working surface (4) a depth of 0,5-5 mm, preferably 1-3 mm, more preferably 1 ,2-2 mm.

17. The tip according to any of the previous claims, characterized in that the tool part (6) is at least mainly made of a substantially inelastic material.

18. A dentist's hand instrument (3), which comprises at least - a gripping part for the dentist's hand,

- a tip (1 ) which contains a tool part (6), and

- a fixing means (2) for fixing the tip to the gripping part, characterized in that the tip is in accordance with any of the claims 1-16.

19. The hand instrument according to claim 18, characterized in that the tip (1) is detachably attached to the fixing means and thus replaceable.

20. A dental care arrangement that comprises

- a fibre bundle, - a hand instrument (3) for placing a fibre bundle onto a patient's tooth, characterized in that the hand instrument (3) is in accordance with claim 18 or 19.

21. Method for curing a fibre bundle on the surface of an object, in which method

- an uncured fibre or fibre bundle is placed on a working surface (4) of a tool part (6) of a hand instrument's tip (1 ),

- the fibre or the fibre bundle present on the working surface (4) is taken onto the desired object, - the fibre or fibre bundle is cured onto the surface of the object by a light- curing machine, characterized in that the uncured fibre or fibre bundle is placed in an elongated recess (5) arranged on the working surface (4).

22. The method according to claim 21 , characterized in that the object is one or several teeth, a dental prosthetic appliance or a partial prosthesis.

23. The method according to claim 21 or 22, characterized in that the tip (1) is pressed against the object, whereby the tool part (6) bends at least a little according to curvature of the object's surface.

24. The method according to any of the claims 21-23, characterized in that the edges of the elongated recess (5) are of substantially elastic material, whereby when pressing the working surface (4) of the tip against the object said edges bend substantially away from each other.

25. The method according to any of the claims 21-24, characterized in that the tool part (6) is of substantially elastic material, whereby when pressing the working surface (4) of the tip against the object, the tool part (6) bends substantially in the longitudinal direction of the elongated recess (5).