Technical field The present invention relates to the field of cleaning and/or debridement of medical implant surfaces, in particular dental implant surfaces, as well as cleaning and/ or debridement of hard and/or soft tissue surfaces, e.g. in the oral cavity.

Background art

Dental implants are utilized in dental restoration procedures in patients having lost one or more of their teeth. A dental implant comprises a dental fixture, which is utilized as an artificial tooth root replacement. Thus, the dental fixture serves as a root for a new tooth. The dental fixture is typically a screw, i.e. it has an external helical thread which enables the fixture to be screwed into the bone, although some fixtures can instead be press fit into the bone. The fixture is surgically implanted into the jawbone, where after bone tissue ceils (osteoblasts) grow on and into the surface of the implanted fixture such that the implant is fixated in the bone with the bone in direct contact with the implant surface. This process is called osseointegration. By means of the osseointegration, a rigid installation of the implant is obtained.

Osseointegrated implants are also used in other areas of surgery, particularly in craniomaxillofacial (CMF) areas, usually in relation to reconstructive surgery. Examples of metal materials commonly utilized for constructing medical implants are steel, titanium, zirconium, tantalum, niobium, hafnium and alloys thereof. In particular, titanium and titanium alloys have proved to be suitable to utilize for constructing dental and other implants. This is due to the fact that titanium is biocompatible, it has excellent corrosion resistance in body fluids, it resists adherence of bacteria, and it is light and strong. Also, titanium shows very good osseointegration behavior. Today, the majority of available dental implants on the market are made of titanium, titanium-zirconium or zirconium oxide/ceramics.

In numerous situations a need exists for cleaning and/or debridement of hard and/or soft tissue surfaces, such as in the oral cavity, as well as cleaning and/or debridement of medical implant surfaces. However, currently available methods are challenging to handle for the practitioner, do not always produce satisfactory results and/or have problems with damaging of tissues and/or implants, or include the use of toxic or otherwise harmful agents.

Periodontal diseases are caused by bacteria and toxins in dental plaque, a sticky colorless film constantly forming on the surfaces of the teeth. It is caused by bacteria! deposits accumulating on tooth surfaces along the gingival margins and results in the destruction of tooth-supporting tissues. The destruction of tooth-supporting tissues results in a deepening of the space (periodontal pocket) between the root of the tooth and the gum tissue. Second to tooth decay, periodontal diseases are the most frequent oral diseases and may lead to partial or complete tooth loss, it has been estimated that they affect as much as between 70-90% of the world population, and they are the major cause of tooth loss in people over 35 years of age. The most common forms of periodontal diseases are gingivitis and periodontitis. Gingivitis is the mildest form of periodontal disease, causing the gingiva to become red, swollen, and bleed easily. Gingivitis, if untreated, may develop into periodontitis. In periodontitis the infection has progressed to involve the oral tissues which retain the teeth in the jawbone. If untreated, periodontitis ultimately leads to loss of the affected tooth. Chronic periodontitis, the most frequently occurring form of periodontitis, results in inflammation within the supporting tissues of the teeth, progressive loss of attachment as well as progressive alveolar bone resorption. This form of periodontitis is characterized by pocket formation and/or recession of the gingiva. As the destruction advances, the mobility and movement of teeth increase, finally causing spontaneous loss of a tooth or a necessity of tooth extraction.

Treatment of periodontal disease usually involves the removal of bacterial deposits and dental calculus. This is commonly performed by scraping the teeth with a curette to remove bacterial deposits and dental calculus, including deposits in the gingival margin. However, it is difficult to have full access for treating deeper periodontal pockets, resulting in remaining bacteria that may re-infect the tissue. This is of course also the case for other bacteria!ly infected tissues, where an incomplete removal of bacteria or dead or damaged tissue may cause problems for healing and give rise to re-infection. Therefore, this treatment is often combined with surgical procedures to open the tooth pocket to expose the tooth. The roots are then scraped or otherwise mechanically freed from bacterial deposits and calculus but also granulation tissue and bacterial toxin. In addition it is often advantageous to debride surgically exposed hard tissue surfaces in other situations. For example, debriding of surgically exposed hard tissue surfaces may be advantageous or necessary to perform before regenerative treatment, i.e. in order to prepare the hard tissue surfaces for regenerative treatment. Examples of such conditions are: periodontitis lesions, marginal periodontitis, apical periodontitis, furcation defects, resection or revision of implants, resection or revision of fractures, and removal of temporary bone implants. Such debridement can also be useful more generally during various treatments of healthy and malign tissue. Patients with denial implants are susceptible to developing conditions similar to the above described periodontal diseases but which instead attack the tissues surrounding the implant. One such disease is periimplant mucositis. This condition involves the presence of inflammation in the mucosa at an implant but with no signs of loss of supporting bone. Patients with implants can also suffer from a condition called peri-implantitis, which is caused by the colonization of bacteria of the implant's surface. The infection may be caused by bacteria introduced during surgery or post-surgically by insufficient oral hygiene. Inflammation in the bone surrounding the implant then causes loss of bone which ultimately may lead to failure of the implant. Peri-implantitis can stem from an existing periodontitis infection or patients can develop peri-implantitis without a previous history of periodontitis.

The surface of dental implants, or the vicinity thereof, has thus sometimes to be cleaned after placing, for example, when an infection or contamination occurs, causing

periimplantitis. In these cases, the surface of the ailing implant has to be cleaned of microbes and other contaminants to stop the progression of the disease. Failure to clean the implant surface will eventually lead to loss of bone and implant, and make further alternative treatments difficult and sometimes even impossible. Traditionally, dentists and surgeons utilize the same cleaning tools that are used in relation to treatment of periodontitis, for example a curette. Such instruments are relatively hard, and hence are considered to provide a thorough cleaning of the implant. Such hard cleaning tools may, for example, be made of stainless steel, hard metal alloys or hard polymers. However, such hard cleaning tools are not suitable to utilize for cleaning all implant materials, in particular those having a surface of a soft metal or metal alloy, such as e.g. titanium, a titanium alloy, zirconium or a zirconium alloy. The use of hard cleaning tools on such surfaces leads to a risk of damaging the implant and also forms scratches. Also, when a cleaning tool is used for cleaning a hard tissue or implant surface, there is always a risk that parts of the cleaning tool will detach from the tool and be left in the body, in addition, cleaning and/or debridement using a curette is a time consuming and labour intensive process, resulting in a long surgical procedure and the attendant risks. Further, the curette is an all purpose tool comprising at its tip a single point, hook or scoop. This geometry is not ideally suited to accessing a bone defect, and ensuring a thorough cleaning of implant threads can be particularly challenging.

Other implant cleaning methods include use of abrasive blasting, chemical cleaning agents and lasers. Each of these methods has drawbacks; for example, although a laser can be used to kill bacteria, this method in isolation does not necessarily remove the bacteria, and thus a biofiim can remain on the implant which can hinder osseointegration and may act as a source of later infection. Care must also be taken not to damage surrounding healthy tissue due to heat dissipation. Any chemical cleaning agent used must of course be biocompatible and not cause damage to the surrounding hard and soft tissues, while still acting to kill and/or remove bacteria. This limits the number of suitable cleaning agents available, and it can be a difficult and time consuming task to identify suitable agents. Further, there is some doubt that the use of chemical cleaning agents in isolation would be able to diffuse through a thick biofiim and thus enable its removal from the implant. Known abrasive blasting methods include the use of glycin particles in pressurised air. Such methods however carry a risk of emphysema, namely an abnormal distension of the surrounding tissues with gas.

The total treatment outcome of peri-implantitis diseases depends to some extent on the degree of damage to the anatomical structure, and/or the implant by the debridement tool during the debridement procedure. Furthermore, the total treatment outcome may also depend on the amount of contaminating material residues that is left on the treated surface by the debridement tool. Contaminating material residues may e.g. trigger a foreign body response. It is also known that the morbidity and frequency of adverse effects, such as e.g. post-surgery effects, are directly related to, and often proportional to, the time used for the debridement of surgically exposed implant or tissue surfaces. Thus, rapid debridement treatment ensures a better total treatment outcome

Medical implants placed in other regions of the body, such as the CMF area, are also susceptible to infection either during or post surgery. The problems discussed above are also faced when attempting to clean the surface of such implants. In order to mitigate some of the above problems, and improve total treatment outcome, in WO 2009/083281 , a new cleaning tool was presented in the form of a twisted-in-wire brush. The brush has bristles of titanium or titanium alloy leading to a reduced risk of damaging the implant surface, due to the suitable hardness of such bristles in view of the material of the surface to be cleaned.

The device of WO 2009/083281 may be used with a motor-driven unit, such as a conventional drill motor. This system provides more efficient, effective cleaning and lesser damage to the surface to be cleaned or debrided than using a curette. It has however recently been found that when the brush of WO 2009/083281 is used with a conventional motor-driven unit, which has a rotational movement, hereinafter referred to as a "rotational handpiece", the bristles are liable to be flattened around the rotational axis of the brush if the dentist applies too high a pressure during use. When this occurs the brush cannot clean as effectively, as the bristle sides will clean the surface instead of the tips of the bristles. Using the brush of WO 2009/083281 with a rotational handpiece can therefore, under certain operating conditions, influence the bristles in a way leading to reduced cleaning ability of the brush and potentially reduce the lifetime of the tool. If the treatment at the time of flattening of the bristles is not finished, the brush has to be replaced, causing an unnecessary use of material and leading to higher treatment costs, as well as unduly prolonging the time of treatment and thus affecting the outcome of the treatment negatively. What is more, the rotational movement of the brush inevitably leads to a translational movement, thus causing the spatial position of the brush to change in a manner not directly controllable by the user. Hence the rotating brush "runs away" from the user, reducing the ease of handling. In a worst case scenario, when a twisted in wire brush such as that disclosed in WO2009/083281 is used and becomes jammed, the shaft of said brush could be unwound by the rotational movement of the motor driven unit, resulting in the bristles coming loose from the brush and being discarded in the tissue to be cleaned. The object of the present invention is to overcome or at least mitigate some of the problems associated with the prior art.

Summary of invention According to one aspect the present invention provides a brush for cleaning and/or debriding a medical implant in combination with a handpiece capable of effecting a rotationally oscillating movement. The implant is preferably a dental implant and can comprise or consist of a metallic, or a non-metallic material, such as a ceramic. The brush comprises a cleaning section comprising titanium and/or titanium alloy bristle(s) for cleaning and/or debriding the medical implant and a linking component enabling the brush to be operatively connected to the handpiece.

Rotational handpieces, such as a contra-angle handpiece for dental drilling, are standard devices that are used in many steps of standard dental implantation treatment, and other aspects of dental work, for example drilling, smoothing, implant insertion etc. Such rotational handpieces are thus the "go to" tool for most dentists and dental surgeons, and are an essential tool within all dental practices. Despite the familiarity of this tool, and its suitability for other aspects of dental implantology, it has been found that this type of handpiece has significant disadvantages when used with a medical implant cleaning and/or debridement brush, as discussed above. It has now surprisingly been found that, when a brush is instead operated using a handpiece effecting a rotationaliy oscillating movement, rather than a rotational movement in a single direction, the above discussed problems are solved, or at least significantly reduced. As the bristles are not continuously rotated in a single direction, the bending of the bristles about the rotational axis is reduced, and thus they are less liable to be flattened out. Further, any flattening of the bristles which does occur when the brush rotates in one direction is cancelled out when the brush is rotated in the other direction. This enables the dentist to apply an increased pressure to the brush, without fear that the cleaning ability will be reduced. Ease of handling is therefore increased. In addition, when an oscillating movement is used, the brush remains in a stationary spatial position and thus a better handling and control of the brush is achieved.

The present invention thus, for the first time, discloses the use of a medical implant cleaning and/or debridement brush in combination with a handpiece arranged to provide a rotationaliy oscillating movement, hereinafter referred to as a "rotationaliy oscillating handpiece" or an "oscillating handpiece". Such a use effects an improved handling of the brush, leading to a minimization of damage to the implant and/or surrounding tissue, a longer lifespan of the bristles of the brush, more efficient and effective cleaning and/or debridement treatment as well as handling without risking an unwanted unwinding of a twisted-in wire brush, if such a brush is used. In addition, said operation of a medical implant cleaning and/or debridement brush in combination with an oscillating handpiece facilitates a minimization of the risk of spreading debris and/or cleaning agents outside of the area to be cleaned and/or debrided. Furthermore, a relatively rapid debridement of surfaces, which are otherwise hard to dean by hand instrumentation, may be performed by means of the brush of the present invention when operated in a rotationally oscillating manner. The present invention therefore provides a combination or a kit comprising at least one medical implant cleaning and/or debridement brush comprising a cleaning section comprising titanium and/or titanium alloy bristle(s) for cleaning and/or debriding the surface of a medical implant, and a linking component suitable for connecting the brush to a motor driven unit; and a rotationally oscillating handpiece capable of connection to said linking component to effect a rotationally oscillating movement of the brush. In accordance with a further aspect, the present invention provides a kit comprising at least one medical implant cleaning and/or debridement brush comprising a cleaning section comprising titanium and/or titanium alloy bristle(s) for cleaning and/or debriding the surface of a medical implant and a linking component suitable for connecting the brush to a motor driven unit, and an instruction leaflet describing the use of said brush together with a rotationally oscillating handpiece for cleaning and/or debriding a medical implant surface, and/or a hard and/or a soft tissue surface through rotationally oscillating movement of the brush. The brush in accordance with the present invention must be suitable for cleaning and/or debriding the surface of a medical implant. In the context of the present invention this means that the brush can be utilized for removing contaminants e.g. bacterial biofilm, debris, calculus, fibrous tissue, concrements, microbes, unwanted tissue, cells and cell residues, scar tissue, and/or necrotic tissue from the implant. The brush may also be utilized as a medical cleaning and/or debridement brush for human tissues, in particular hard and soft tissues in the oral cavity. Hard tissues are, for example, bone, cementum, dentin, enamel, cartilage and ligaments. Soft tissue includes granulation tissue and dead and/or decaying tissues. The term "debridement" includes cleaning of a tissue surface in order to remove, for example, biofilm, concrements, microbes, unwanted tissue, cells and ceil residues, scar tissue, and/or necrotic tissue. Debridement may, for example, be performed in order to control local infections, inflammations, foreign body reactions, pathological conditions and degenerative processes (e.g. periodontitis, periimplantitis).

Any brush designed for cleaning and/or debriding medical implants can also be used by the dentist or surgeon to clean and/or debride both hard and soft tissue, should this be considered necessary. Therefore, any brush which can clean and/or debride the surface of an implant will also be capable of cleaning/debriding tissue. The material(s) and dimensions of the brush and its different parts are selected so as to enable the brush's use with a medical implant, such as a dental implant or an implant for CMF applications. This means that the length and diameter of the brush must be selected to enable cleaning of the desired implant. For example, when the brush is designed for use with a dental implant it cannot be too long or its diameter too wide that it cannot comfortably be manipulated within the patient's mouth and fit within the bone cavity around the implant. Further, the materials used for the bristles as well as for other parts of the brush are typically biocompatible and have properties which exert limited damage to the surfaces that are contacted by the brush.

The linking component can be any shape which enables the brush to be axially retained relative to a motor driven unit and for a rotationally oscillating driving force to be transmitted to the brush. The linking component can be arranged for direct or indirect connection to the rotationally oscillating handpiece, for example, the connection might occur through an intermediate adaptor piece. Preferably however, the linking component enables direct connection between the brush and the rotationally oscillating handpiece. For example, the linking component could comprise a section having an octagonal or other polygonal cross-section and a resilient retention ring, such as a PEEK o-ring. In a particularly preferred embodiment the linking component has a standard ISO latch configuration. This enables the brush to be directly connected to a large number of commercially available handpieces.

The brush preferably comprises an elongated base member having a longitudinal axis whereby said cleaning section is positioned at a first end of said base member. The cleaning section may be an integral part of the base member, or may be a separate part attached to the base member. Similarly the bristles may be an integral part of the cleaning section or may be separately attached to the cleaning section. Preferably the cleaning section is co-axial with the elongated base member. The linking component is preferably located at the opposite end of the elongated base member from the cleaning section. In some embodiments the linking component is an integral part of the base member. Preferably however the linking component is fixedly connected to the base member, for example through clamping, bonding, moulding or force fit. Clamping is a particularly preferred fixing method. Preferably the linking component is co-axial with the elongated base member. Thus, in a particularly preferred embodiment the linking component, elongated base member and cleaning section are all coaxial and extend along the longitudinal axis. The elongated base member can be formed by at least two wires being twisted with each other, and wherein said bristle(s) are fixed between said twisted wires. Thus in such embodiments the cleaning section is an integral part of the base member.

WO2009/083281 discloses a brush according to this embodiment. In a preferred embodiment the at least two wires are formed by a single wire bent at an angle of 180° about an axis perpendicular to its longitudinal axis such that the wire is folded back over itself to form two parallel wires. This is beneficial as it prevents separation of the wires at the distal tip of the brush and in addition simplifies manufacturing by ensuring axial alignment of the two wires.

Alternatively the base member can be a solid or hollow member and said bristie(s) can be in the form of a cut strip wound around said elongated base member. WO2011/ 52789 discloses such a base member.

Alternative brush configurations are also possible. For example, the base member and the bristles may be integrally formed, or the base member may comprise a plurality of holes or slots, into or through which one or more bristles are attached via gluing, welding, compression, screwing etc. The base member may be solid, however preferably this comprises a through passage extending along the longitudinal axis in order to enable a flow of fluid through the brush.

The elongated base member can comprise any suitable material, such as e.g. a metal, a metal alloy, or a polymeric material. In certain embodiments the base member can be flexible or resilientiy deformable. Preferably the base member consists of steel, titanium and/or titanium alloy. When the base member consists of titanium or titanium alloy this may be made from the same or a different material than the bristle(s). Further, the base member may comprise different materials, i.e. the base member may be assembled from different parts being made of different materials or comprising a mixture of materials. In one particularly preferred embodiment, the elongated base member consists of steel. When the cleaning section and/or linking component are not an integral part of the base member, these may be made of different material(s) to the base member. However, preferably at least the base member and the linking component are formed from the same material. Thus, in a preferred embodiment the linking component consists of steel. The cleaning section is defined as the section of the brush comprising bristles. Usually the cleaning section will comprise bristles along the entire longitudinal length of the cleaning section, however in some embodiments there may be some axial locations of the cleaning section which do not comprise bristles, e.g. the bristles may be placed in bands, sections or bunches along the longitudinal length of the cleaning section. All of said bristle(s) can have essentially the same length, or alternatively the bristles may have differing lengths. When different lengths of bristles are provided, these can be located on the cleaning section in accordance with their length, such that the overall shape of the cleaning section, as defined by the tips of the bristles, tapers or otherwise varies along the longitudinal length of the cleaning section. The cleaning section may thus alternatively adopt a conical shape (V-shape), a diamond-like shape wherein the length of the bristles increases in a direction from a first end of the cleaning section to an intermediate point where after the length of the bristles decreases again toward the second end of the cleaning section, a ball-shaped configuration, or "zig zag" shape.

By varying the shape of the cleaning section, e.g. by varying the length of the bristle(s) in different parts of the cleaning section, the size and shape of the brush may be adapted to a particular implant design, i.e. the size and shape of the brush may be adapted such that it is suited for cleaning a particular type and shape of surface.

Alternatively the differing bristle lengths can be unordered such that the shape of the cleaning section is undefined and bristles of varying length are found throughout the length of the cleaning section.

Typically, the bristle(s) extend 360° around the longitudinal axis of the cleaning section, so that bristles are found on all sides of the brush. Nonetheless, alternative ways to distribute the bristles are envisioned as well.

At each axial location of the cleaning section the bristles can be located over 360° or only at one or more angular locations. For example, as shown in WO201 1/152789 the bristles may extend in a helical pattern about the longitudinal axis. In W02009/08328 the bristles extend in a double helix.

It is preferable that the bristle length is chosen such that the bristles can reach into any grooves, threads or other indentations on the surface of the implant. The preferred bristle length will therefore vary depending on the design of medical implant with which it is intended to use the brush. For example, when a dental implant has threads having a depth of, say, 0.35mm, a brush for cleaning such an implant preferably has bristles with a greater length, e.g. at least 0.4mm.

In one embodiment, the protruding length of the bristie(s), as measured from the core diameter of the cleaning section (i.e. the diameter of the cleaning section, excluding the bristles, at the axial location of the bristle to be measured), is between 0.2 to 5 mm, such as between 0.35 to 1.5 mm. In another embodiment, the protruding length of the bristle(s) is no more than 1 mm and preferably no less than 0.5 mm. The number of bristle(s) will also vary depending on the medical implant to be cleaned, how long the cleaning section needs to be and depending on the spacing between the individual bristles as well as their size and shape. For a twisted-in-wire brush the twist of the wires also affects the number of bristie(s) per brush, a closer twist requiring a higher number of bristles per length unit.

Typically, the number of bristle(s) is between 1-1000, more preferably 10-500 bristles, such as 10-100 bristles or 5-50 bristles. In one embodiment it is preferred that the cleaning section comprises 150-250 bristles. In any event, the cleaning section comprises no less than 1 bristle, preferably a plurality of bristles, preferably no less than 5, 10, 50, 100, 150 or 200 bristles.

Additionally or aiternatively, the cleaning section preferably comprises about 20-30 bristles per millimetre, such as 20-27, or 25-30 bristles per millimetre. This range of bristle density is considered particularly beneficial for a twisted-in-wire brush.

The tips of the bristle(s) may be manufactured with sharp edges that provide a good "cutting edge" that assists in effectively cleaning away inflamed/infected soft tissue and calculus or other contaminants from the implant and/or tissue defect. Rounded tips may alternatively be beneficial when a gentler cleaning and/or debridement action is desired.

The bristle(s) consist of titanium and/or a titanium alloy. The term "alloy" is herein intended to mean a metallic material containing a base metal and at least one alloying component. The term "base metal" is herein intended to mean the metal being the primary constituent of the alloy and the term "alloying component" is intended to mean a component added to the base metal in order to form the alloy. Thus, the term "titanium alloy" is intended to mean an alloy comprising titanium as base metal and at least one alloying component. Thus, the bristle(s) may consist of pure, i.e. unalloyed, titanium. For example, the bristle(s) may consist of titanium selected from the group consisting of: titanium of grade 1 , titanium of grade 2, titanium of grade 3 and titanium of grade 4 according to AST F67. These types of titanium are sometimes also denoted as "commercially pure" titanium.

At least some of the bristle(s) however preferably consist of a titanium alloy, whereby the titanium alloy comprises titanium as base metaf and at least one alloying component selected from the group consisting of nickel, zirconium, tantalum, hafnium, niobium, aluminium, vanadium, molybdenum, chrome, cobalt, magnesium, iron, gold, silver, copper, mercury, tin and zinc.

In preferred embodiment, the bristie(s) may consist of a titanium alloy, whereby the titanium alloy comprises titanium as base metal, and aluminum and vanadium as alloying components. One preferred example of such a titanium al!oy comprises about 94.5% titanium, about 3% aluminum and about 2.5% vanadium.

Another example of a titanium alloy, which the bristle(s) may consist of, is a Titanium-6 A!uminium-4 Vanadium (Ti6AI4V) alloy. For example, the bristle(s) may consist of a Titanium-6 Aluminium-4 Vanadium (Ti6AI4V) alloy selected from the group consisting of a Titanium-6 Aiuminium-4 Vanadium (Ti6AI4V) alloy according to ASTM F136 and a Titanium-6 Aluminium-4 Vanadium (Ti6AI4V) alloy according to ASTM F1472.

Alternatively, the bristle(s) may consist of a titanium alloy selected from the group consisting of a Titanium-6 Aiumtnium-7 Niobium (Ti6AI7Nb) alloy according to ASTM F1295, a Titanium-13 Niobium-13 Zirconium (Ti13Nb13Zr) alloy according to ASTM F1713 and a Titanium-12 Molybdenum-6 Zirconium-2 Iron (Tt12Mo6Zr2Fe) alloy according to ASTM F1813.

The bristles may comprise different materials, in other words, individual bristles may comprise different materials in the same brush. In some embodiments not all of the bristles will consist of titanium or titanium alloy. For example, some nylon or polymer bristles may also be included in the brush. However, preferably all the bristles consist of titanium or titanium alloy; more preferably all of the bristles are formed of the same material, e.g. one of the above titanium alloys.

A brush suitable for use as the brush in the present invention is the twisted-in-wire brush disclosed in WO 2009/083281 , to which reference is herewith made. Another type of brush suitable for use in the present invention comprises a first main part which is a handle that is stiff, plastically deformable or elastically deformable and a second main part that is at least one cleaning element comprising a base part and one or several bristle(s), which can be in the form of loops, or a cam of spikes. The bristle loops in such a brush may be seen as a grooved strip that is wound around the base member. An example of such a brush is disclosed in WO 201 1/152789, to which reference is herewith made. The present invention concerns the use of brushes of the type hereinbefore described in combination with rotationally oscillating handpieces, that is, handpieces which are arranged to provide a rotationally oscillating movement. A handpiece is a motor driven unit that can drive an instrument connected to it while its position and orientation are manually manipulated by a user. Rotationally oscillating movement is defined as alternate clockwise and anti-ciockwise rotation about an axis. Some rotationally oscillating handpieces also provide axial oscillation, namely forwards and backwards motion along an axis, however such axial oscillation is not an essential requirement of the handpiece of the present invention. In the context of the present invention therefore an "oscillating handpiece" must simply provide for rotational oscillation about an axis; axial oscillation is not necessary.

Although rotationally oscillating handpieces are known in the dental field, their use has so far been limited to specialist fields remote from implantology. For example, rotationally oscillating handpieces are occasionally used during root canal surgery, which necessarily concerns much smaller tools than those used in relation to dental implants. Even in this field however, rotating handpieces are the norm. Oscillating handpieces have, to the knowledge of the present inventors, never previously been used in relation to dental implant work. Examples of handpieces that can be used in the present invention are the Ti-MAX X (models X35L REF C620X35 and X35 REF C624) from NSK, certain handpieces from KaVo and BienAir handpiece REF 1600051-001.

Preferably the handpiece is arranged to operate at a speed of 200-1500

oscillations/minute. The most preferred oscillation speed will be in part determined depending on the surface to be cleaned. An oscillation of between 600-1200

oscillations/minute is particularly preferred, in particular between 800 and 1000, such as 800, 850, 900, 950, or 1000. In one preferred embodiment the oscillating handpiece of the present invention is arranged to operate at a speed of approximately 900

oscillations/minute. It has been found that this speed provides effective cleaning without excessive heat generation, which would be harmful to the surrounding tissues. These preferred oscillation ranges have been found to be particularly beneficial for dental applications.

A single oscillation is defined as a reciprocal clockwise and anti-clockwise rotation, such that at the end of the oscillation the brush is in the same angular orientation as at the start. The angle of oscillation is defined as the amount of rotation provided by the handpiece about the rotational axis in a single direction (which will be the same in both clockwise and anti-clockwise directions). The angle of oscillation can vary. In some embodiments it is possible that the handpiece is arranged to rotate the brush by over 360° in each direction, for example, the handpiece may rotate the brush by two complete turns in one direction, followed by two complete turns in the other direction.

This is however not preferred, as the further the brush is rotated in a single direction the greater the possibility that the bristles will bend around the rotational axis and not provide the most effective cleaning. In addition, if a twisted in wire brush is used and becomes jammed, a rotation of over 360° could result in the unwinding of the base member.

Preferably therefore the oscillation angle is less than 360°. More preferably the angle of oscillation is between 30° and 90°. Most preferably the angle of oscillation is

approximately 60°. As discussed above the handpiece may be capable of direct or indirect connection to the linking component. Preferably the handpiece and linking component are capable of direct connection. Preferably, the rotationally oscillating handpiece is capable of (direct or indirect) connection to the brush so as to effect a rotationally oscillating movement of the brush about the longitudinal axis of the elongated base member. More generally, the handpiece and brush are preferably arranged such that in use the handpiece effects a rotationally oscillating movement of the brush about the longitudinal axis of the cleaning section.

The dental handpiece is an instrument used daily by dental practitioners throughout the world. To permit the interchange of instruments from various manufacturing sources in different countries, agreement on the dimensions for the coupling units is necessary.

Standards have been developed to specify the nominal dimensions and tolerances of the coupling used between the dental handpieces and their driving mechanisms. The linking component of the present invention comprises at its proximal end a means to connect the brush to a handpiece in the form of a standard ISO latch, however other coupling means are possible. Specifically, this coupling mechanism is defined in ISO 3964:1982 "Dental handpieces - Coupling dimensions".

The present invention for the first time describes the use of a kit or a combination comprising at least one medical implant cleaning and/or debridement brush comprising a cleaning section comprising titanium and/or titanium alloy bristle(s) for cleaning and/or debriding the surface of a medical implant, and a finking component suitable for connecting the brush to a motor driven unit and a rotationally oscillating handpiece and/or a leaflet for cleaning and/or debriding a medical implant surface, and/or a hard and/or soft tissue surface in a rotationally oscillating manner. Viewed from a further aspect the present invention provides the use of a medical implant cleaning and/or debridement brush comprising a cleaning section, comprising titanium and/or titanium alloy bristle(s) for cleaning and/or debriding the surface of a medical implant, and a linking component suitable for connecting the brush to a motor driven unit, in combination with a rotationally oscillating handpiece capable of connection to said linking component for cleaning and/or debriding a medical implant surface, and/or a hard and/or soft tissue surface with a rotationally oscillating movement.

What is more, viewed from another aspect the present invention comprises a method for cleaning and/or debriding a medical implant surface, and/or a hard and/or a soft tissue surface, comprising the steps of contacting a medical implant surface, and/or a hard and/or a soft tissue surface to be cleaned and/or debrided with medical implant cleaning and/or debridement brush comprising a cleaning section comprising titanium and/or titanium alloy brist!e(s) for cleaning andfor debriding the surface of a medical implant, and effecting the brush to move in a rotationally oscillating manner, such as by the use of a rotationally oscillating handpiece.

A procedure involving use of the brush of the present invention may, for example, involve the steps of: surgically exposing a hard tissue and/or implant surface to be treated;

removal of inflamed soft tissue; cleaning and/or debriding the surface by means of the above method; applying (regenerative) treatment as needed; replacing soft tissue;

suturing for good primary closure and wound stability; and allowing the wound to heal. Said method can e.g. be used for preventing and/or treating an oral and/or dental condition. Preferably the method is used to treat periimplantitis. Other conditions and situations which may be treated using the above method include periodontitis lesions, marginal periodontitis, apical periodontitis, furcation defects, resection or revision of implants, resection or revision of fractures, and removal of temporary bone implants, such as orthopaedic bone plates, retainers and screws, as well as other treatments for healthy and/ or malign tissues.

Such a method may be important to prepare the surface for regenerative treatment. In particular, it has been observed that the brush of the present invention in combination with an oscillating handpiece is an efficient tool for debridement of surgically exposed tooth root surfaces, furcation defects and bony defects before regenerative treatment (i.e. by means of, for example Straumann ^® Emdogain, bone graft materials, autologous bone, membranes, etc.). The brush is especially effective for removing granulation tissue, and for removing concrements of calcified biofilms (plaques) and subgingival calcus.

The kit, combination, use and method of the present invention can be used for cleaning and/or debriding all types of medical implants. Preferably the medical implant is a craniomaxillofacial (CMF) implant and most preferably a dental implant for insertion into a patient's jaw bone. Preferably the brush is a dental implant cleaning and/or debridement brush suitably dimensioned and designed to enable cleaning and/or debridement of a dental implant in situ within the human jaw bone. in such embodiments the cleaning section generally has a length between about 1-30 mm. The longest length of the cleaning section is in general terms about as long as the surface to be cleaned (brushed). Generally, the cleaning section may therefore have a shortest length of about 1 mm and a longest length of about 18 mm. The cleaning section may thus be e.g. about 1-18 mm, such as about 2-16 mm, such as about 2-10 mm, such as 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 mm.

The diameter of the bristle(s) may be e.g. between 0.03-1.0 mm, preferably between 0.05- 0.5 mm, such as 0.05, 0.1 , 0.2, 0.3, 0.4, 0.5mm. Bristle(s) with a thinner diameter may have a diameter of 0.03-0.09 mm, such as 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085 or 0.09 mm.

The brush preferably has a total longitudinal length of between 15-70 mm, more preferably between 20-50 mm, and most preferably between 30-40 mm. When a twisted- in-wire construction is used for the base member, the diameter of the respective wires may be about 0.1-2.0 mm or about 0.1 -1 mm, e.g. 0.5mm.

Other features and advantages of the invention will be apparent from the following detailed description, drawings, examples, and from the claims.

Preferred embodiments of the present invention shall now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure legend

FIG 1 shows a plan view of a medical implant cleaning and/or debridement brush for use in the kit, combination and method of the present invention;

FIG 2 shows a perspective view of the brush of FIG 1 ;

FiGs 3A-C show alternative embodiments of the cleaning section of the brush;

F!G 4 shows the brush of FIG 1 in a handpiece in accordance with the present invention. Detailed description of the invention FIGs 1 and 2 show a brush (1 ) for use in accordance with the present invention. Brush (1) comprises an elongated base member (2) extending along longitudinal axis (3). The elongated base member (2) comprises a cleaning section (5) at a first end and a linking component (7) at the opposing end, both of which are coaxial with the base member (2). The cleaning section (5) comprises a plurality of bristles (4) protruding radially from the longitudinal axis (3).

Base member (2) is formed by a pair of wires (6), (8) twisted round one another. Bristles (4) are held between the twisted wires (6), (8) and protrude radially outwards beyond the wires (6), (8). As can be seen most clearly from FIG 2, wires (6), (8) are, in this embodiment, formed by a single wire which is bent 180° about an axis perpendicular to the longitudinal axis (3) and folded back over itself, such that it effectively forms two parallel wires. These wires are then twisted about each other. Materials suitable for the bristle(s) (4), disclosed elsewhere herein, are also suitable for the base member (2), i.e. titanium or titanium a!!oy. Preferably however the base member (2) is made from steel. In some instances it may rather be desirable to use a brush which is deformable or elastically deformable.

The base member (2) may be solid or hollow to allow a fluid to be distributed. When, as in the present embodiment, the base member (2) comprises wires (6), (8) one or both of these can be hollow.

Cleaning section (5) is located at the distal end of the twisted wires (6), (8). The proximal end of these wires (6), (8) is attached to linking component (7). This can be achieved via gluing, welding, force fit etc. However in this embodiment the proximal end of wires (6), (8) is inserted into a blind bore extending into the distal end of the linking component (7). Two or more punches are then applied to the exterior of the linking component to compress and deform the walls of the blind bore in order to clamp wires (6), (8) in place. The indents (9) formed by this punching action can be seen in FIG 2. in other embodiments the cleaning section (5) may be separately provided and attached to the base member (2) in a similar manner, either before or after attachment of the bristles (4). Materials suitable for the cleaning section (5) if provided separately are the same as when it is an integral part of the base member.

The linking component (7) comprises at its proximal end a means to connect the brush (1) to a handpiece. In the present embodiment this means takes the form of a standard ISO latch (10), however other coupling means are possible. Specifically, this coupling mechanism is defined in ISO 3964: 1982 "Dental handpieces - Coupling dimensions".

The linking component (7) and twisted wires (6), (8) can be made of the same or different materials, for example steel.

The bristles (4) are made of titanium and/or titanium alloy in order to enable effective cleaning of implants made from soft metals without damaging the implant. When a twisted in wire brush is used each bristle protrudes at either end from the shaft. Thus each bristle (4) may have a length of about 0.1-50 mm, or about 0.1-10 mm. The bristles (4) are typically between 1 and 6 mm long, such as 1 to 5 mm, e.g. 1 , 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 mm. Once twisted between the wires (6), (8) the bristles (4) preferably protrude from the core diameter (D) of the cleaning section (5), which in this embodiment is the same as the base member (2), by no more than 1mm.

The bristles (4) of brush (1 ) all have essentially the same length, so that the said cleaning section (5) adopts a cylindrical shape. However, the bristles (4) may also have a varying length over the longitudinal length of the cleaning section (5).

FIGs 3A-C show some alternative brush embodiments. FIG 3A shows a dental brush (20), having a base member (2) which is identical to that of brush (1) of FIG 1. In this embodiment, bristles (24) have varying lengths, and are arranged within the cleaning section (25) according to their height, in FIG 3A the bristles (24) are arranged such that the length decreases with proximity to the distal end of the brush (20). This results in the cleaning section (25) having a conical shape. In an alternative embodiment the order of the bristles (24) could be reversed, such that the length increases with proximity to the distal end.

FIG 38 shows another twisted in wire brush (30), again having bristles (34) of differing lengths, in this embodiment the bristles (34) are arranged such that the cleaning section (35) has a "zig zag", or toothed shape.

FIG 3C shows a brush (40) having a solid elongated base member (42) that has been molded or machined. In this embodiment linking component (47) is integral with the base member (42), although it is possible that the linking component is provided separately from and fixedly attached to the solid base member (42). Bunches of bristles (44) are fixed into eveniy spaced holes within the cleaning section (45) of the brush (40). The holes are axially and angularly spaced such that the bristles extend along the longitudinal length of the cleaning section (45) and 360° about the axis (43). Other forms of brush are also possible, for example those disclosed in WO2009/083281 and WO201 1/152789.

Motor-driven units commonly used in the dental field, such as the contra-angle handpiece and orthopedic drills, operate in a single directional rotating manner.

The present inventors have however surprisingly found that rotational motion in one direction can lead to the flattening and bending of the bristles if a high pressure is applied to the brush during use. However, they have also surprisingly found that by effecting a rotationaily oscillating movement of the brush, the possibility of the bristles flattening out is significantly reduced, enabling the dentist to apply a greater pressure without reducing the cleaning effectiveness of the brush. They have further found that when a rotationaily oscillating movement of the brush is used, the brush does not "run away" from the practitioner. The use of an oscillating movement thus also results in a better handling and control of the procedure. The overall effect is a better cleaning and/or debridement of the surface, as well as a shorter treatment time.

FIG 4 shows the brush (1 ) of FIGs 1 and 2 connected to such a handpiece. Handpiece (50) comprises a gripping surface (51) at its proximal end which is sized and shaped to enable the handpiece to be held and manipulated with ease and comfort by the user. Gripping surface (51 ) comprises surface texturing to form an anti-slip surface which ensures a good grip can be achieved even when surgical gloves are worn and fluids are present on the handpiece (50). End surface (52) comprises connection means (not shown) to enable the handpiece to be connected to a power source, and in some instances a fluid source. St is also possible for the handpiece (50) to contain a battery chamber such that it can be operated without connection to an external power source. In a further embodiment the distal end of the handpiece could be articulated and attached to a wall or free standing unit, the articulation enabling the handpiece (50) to be freely manipulated by a medical practitioner.

At its distal end (53) the handpiece (50) comprises a blind bore (54) sized and shaped to enable the linking component (7) of the brush (1 ) to be axially retained within this. Once connected, the handpiece (50) can transmit a rotationaily oscillating movement to the brush (1 ) such that it rotates in an oscillating manner about its longitudinal axis (3). As discussed above such a movement improves the handing of the brush (1 ) and can improve its effectiveness and efficiency

Applications

The brush disclosed herein may be used in combination with a rotationaily oscillating device for a plethora of medical and dental applications in vivo and in vitro.

In vitro uses include, but are not limited to, the cleaning of parts of dental implants, such as abutments, before repositioning in a subject. The brush of the present invention may be utiiized during surgery for cleaning of the surface of a medical implant after infection and/or bone resorption. For example, it may be utilized for cleaning the surface of a dental implant. Alternatively, or in addition, the brush may be used in order to remove e.g. a bacterial biofilm, debris, calculus, fibrous tissue, concrements, microbes, unwanted tissue, cells and cell residues, scar tissue, and/or necrotic tissue from the vicinity of the dental fixture prior to, or after, implantation. The brush may also be utilized for cleaning the surface of an abutment.

It has surprisingly been found that the brush of the present invention in combination with a rotationally oscillating handpiece is advantageous to utilize for cleaning medical implants, in particular dental and/or C F implants, it is advantageous to utilize for cleaning both "hard" metallic implants having relatively hard surfaces, such as implants comprising or consisting of steel, and "soft" implants having delicate surfaces, such as e.g. titanium, a titanium alloy, zirconium or a zirconium alloy. In addition, the brush is as well suited for use in the cleaning of non metallic implants, such as those which comprise or consist of e.g. ceramic. The brush, when used with a rotationally oscillating handpiece, is particularly useful for cleaning and/or debridement of dental implants.

The titanium or titanium alloy of which the bristle(s) are made may be selected such that the hardness degree thereof exactly, or at least essentially, corresponds to the hardness degree of the implant surface to be cleaned. For example, in case the implant to be cleaned consists of pure titanium, pure titanium can be selected as the materia! of the bristle(s). Alternatively, the hardness of the bristles can be chosen to best match the hardness of the material from which the implant is made, e.g. zirconium or ceramics.

Other embodiments

It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims. For example, numerous brush designs can be combined with a rotationally oscillating handpiece. The handpiece itself can also take numerous forms, the only requirement is that this must be capable of transmitting a rotationally oscillating movement to the brush and be capable of manual manipulation.