Abstract:
The invention relates to a capsule for producing a composition, particularly for dental care, comprising an enclosure provided with at least two compartments, the number of compartments corresponding to the number of components to be mixed, and at least one wall for isolating the components, said wall being provided to isolate the components from each other in storage mode, and to allow fluidic communication between the compartments in mixing mode, said capsule also comprising a shank for removable attachment to a hand-held part.

Description:
[0001]    This application is a continuation of PCT Application No. PCT/IB2016/050284 filed Jan. 21, 2016, pending, and claims priority of Switzerland Appln No. 00145/15 filed Feb. 4, 2015. The contents of each of these applications are incorporated herein by reference in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a capsule for preparing a mixture, in particular for dental treatment, said capsule being connectable in a standard way to an instrument by virtue of its specific connector piece. The present invention also relates to a method for preparing dental material. 
       BACKGROUND 
       [0003]    Faced with the realities of the oral and dental health needs of individuals, a dental surgeon needs to master a wide variety of treatments to be provided to patients. 
         [0004]    For example, many treatments require the application of dental materials, in particular dental cements, clay, polymers, resins, composites, etc., for example in order to fix a dental prosthesis, to fill prepared dental cavities, to replace missing parts of teeth, to provide mechanical support, a protective base of a cavity, etc. For certain operations, the patient&#39;s blood has to be mixed with bone graft material. Many dental materials have to be prepared a short time before the operation by mixing two components. For example, water-based cements have to be prepared by mixing the cement and the water just before application of the cement, in order to prevent the latter from hardening. This mixing is traditionally carried out manually by the dentist or the dental assistant, using various tools such as glass plates and spatulas. Although such an approach allows the treatment to be adapted to the patient, it nevertheless has some disadvantages. 
         [0005]    For example, manual preparation of paste or cement for dental treatment presents recurrent difficulties, such as controlling the precise dose of the mixture necessary for the specific oral and dental problem of the patient. For the person preparing the mixture, it is thus difficult to perfectly and reproducibly control the quantity of water added to a water-based cement. The quality of the cement obtained therefore varies from one occasion to another and from one practitioner to another. 
         [0006]    Such a preparation, when obtained by traditional means, can dry out relatively quickly, thus forcing the practitioner to apply the preparation very quickly. 
         [0007]    Moreover, the preparation for dental treatment obtained by traditional mixing has the disadvantage of not being homogeneous. In fact, the mixture obtained by traditional means cannot be perfectly smooth. It can therefore contain lumps, which make the application of the paste difficult. This can result in a quality of treatment that is not equal. 
         [0008]    Some dentists use a vibrator to mix the different components of the dental material. However, with the gradual move away from dental amalgams made of mercury, such vibrators tend not to be available anymore in dental practice, and dentists do not wish to acquire such appliances that are rather noisy and cumbersome or space consuming. 
         [0009]    Another drawback may arise in the case of a traditional preparation for dental treatment. Manual mixing requires the use of various components that are intended to be combined in order to constitute mixtures. The various steps involved in the preparation of the mixtures also involve the use of different tools and instruments making it possible to mix and work the paste or the cement. Under such conditions, it is difficult to observe strict hygiene requirements. Therefore, various risks of contamination are constantly present, despite the fact that the treatments are carried out in a sterile environment. 
         [0010]    The document U.S. Pat. No. 3,814,387 proposes an appliance for dentists, making it possible to measure and mix metal filings for preparing the amalgam paste, with a capsule containing pre-measured components for the preparation of dental cements and dental synthetic resins, the mixing being carried out in a single capsule. Such an architecture takes up a lot of space and is expensive, and it requires specific tools for this operation. 
         [0011]    The application U.S. Pat. No. 3,640,510 relates to a mixing machine for materials used in dentistry. Since the elimination of air or of air bubbles is necessary in order to ensure a perfect result upon setting of the component, the appliance comprises a closed mixing vessel, a rotary stirring device, and a vacuum pump for the rotary stirring device which is driven by a motor via a magnetic clutch. A time switch is provided so that, after a predetermined time, the operation of the mixing apparatus is interrupted, but the vacuum pump continues to operate. Such a concept is unwieldy and expensive and involves considerable operating costs. 
         [0012]    U.S. Pat. No. 1,665,260 describes a capsule for a dental product that is to be mixed. The capsule has a single compartment and, consequently, is not suitable for mixtures of two components. 
         [0013]    U.S. Pat. No. 3,715,806 describes a capsule for a dental amalgam. The construction is adapted to straight handpieces. The very elongate shape of the capsules may allow the mixture to be applied directly in the mouth, but it makes them difficult to store. The components in the different compartments mix together with difficulty. In addition, the rate of penetration of the first component in the second component is poorly controlled; this capsule may be suitable for mixing amalgams, but not for mixing dental cement, since it would immediately cause lumps to form, and these lumps are very difficult to resorb subsequently. 
         [0014]    To overcome these various disadvantages, the invention proposes various technical means. 
       SUMMARY 
       [0015]    Firstly, it is a purpose of the invention to solve at least some of the problems of the prior art that have been mentioned above. 
         [0016]    Another goal is to provide a system which makes it possible for mixtures of dental materials to be produced with optimal and reproducible quality. 
         [0017]    Another goal is to provide a system for preparation of a dental mixture which can ensure high levels of hygiene. 
         [0018]    Another goal of the invention is to design a container that facilitates the storage of the various components before they are mixed. 
         [0019]    To do this, the invention proposes a capsule for preparing dental or surgical material obtained by mixing components prior to use, comprising an enclosure provided with at least two compartments, which are intended to receive the same number of components to be mixed, and at least one wall or membrane for isolating the components. The wall for isolating the components is intended to isolate the components from each other in storage mode and to allow fluidic communication between the compartments in mixing mode. The capsule further comprises a drive rod adapted to a dental handpiece, for example a handpiece of which one end is in accordance with the standard ISO 1797 for removable attachment to a handpiece or contra-angle. The capsule is additionally closed in a hermetic manner such that moisture cannot penetrate from outside. 
         [0020]    The invention proceeds in particular from the knowledge that the practice of modern dentistry often entails the use of various instruments such as the contra-angle or the handpiece (collectively referred to hereinbelow as “handpiece”). This handpiece comprises a motor (the turbine) for driving a removable tool at high speed, for example a dental burr, a drill bit, etc. The tool is fixed to the handpiece by means of a connection that accords with standards, for example the standards ISO 1797-1 (for the shanks made of metals) and ISO 1797-2 (shanks made of plastic), collectively designated by “standard ISO 1797”. 
         [0021]    According to one aspect of the invention, such a handpiece provided with a connection according to the standard ISO 1797 is used in a novel manner in order to mix the various components of a dental material. 
         [0022]    The invention also makes it possible to improve the storage of the components before they are mixed, by storing them in a single capsule provided with different compartments. 
         [0023]    The capsule can contain various components for the preparation of different mixtures; for example, different types of cement, variable proportions of water and of cement, or other components. The number of components can be equal to two or greater than two. 
         [0024]    Sets of capsules containing different components may be provided, allowing the dentist to choose a particular mixture simply by selecting a capsule. 
         [0025]    The invention thus permits simple, quick and clean use. 
         [0026]    The capsule has compartments arranged concentrically. 
         [0027]    The isolating wall between the compartments can be a disk positioned and dimensioned in such a way as to cover the surface occupied by all of the concentric compartments. 
         [0028]    According to an advantageous embodiment, the compartments of the capsule can also be arranged side by side, the isolating wall between the compartments being a removable, tearable or deformable membrane. 
         [0029]    According to another embodiment of the invention, the capsule comprises a plurality of mixer arms which are arranged to plunge into the mixture to be mixed when the capsule is in mixing mode. 
         [0030]    According to an advantageous variant, the capsule comprises an Archimedes screw in fluidic communication with the base of one of the compartments and arranged in such a way as to transport the component present in this compartment during rotation of the drive rod. 
         [0031]    Advantageously, the drive rod is made of an injected polymer. 
         [0032]    Also advantageously, the cover and the chamber are made of injected SBS. Other materials may also be considered. 
         [0033]    According to an advantageous embodiment, the capsule comprises a bayonet arranged to position the cover in three positions, chosen from:
       a closed position;   a mixing position;   a position in which the cover is withdrawn.       
 
         [0037]    According to another embodiment, the cover is maintained on the chamber without a bayonet, for example by means of adhesive tape. 
         [0038]    Advantageously, the capsule is specifically adapted for the storage and the preparation of dental cement. 
         [0039]    In a variant, the capsule is specifically adapted for the storage and the preparation of a composition for plastic surgery. 
         [0040]    According to another alternative embodiment, the capsule is specifically adapted for the storage and the preparation of a pedicure composition. 
         [0041]    According to another alternative embodiment, the capsule is specifically adapted for the storage and the preparation of a composition for orthopedic operations. 
         [0042]    The present invention also relates to a method for preparing dental material with the aid of such a capsule. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0043]    All the embodiment details are set out in the following description with reference to  FIGS. 1A to 10  which are given solely as non-limiting examples and in which: 
           [0044]      FIG. 1A  is a side view of the handpiece connected to the preparation capsule for dental treatment; 
           [0045]      FIG. 1B  is a perspective view of the handpiece connected to the preparation capsule for dental treatment; 
           [0046]      FIG. 2A  is an exploded perspective view of the constituent elements of the capsule; 
           [0047]      FIG. 2B  is a side view of the constituent elements of the capsule prior to assembly; 
           [0048]      FIG. 2C  is a perspective view of the capsule after assembly, which capsule is connected to the shank of a handpiece prior to use; 
           [0049]      FIG. 3A  is a perspective view of a cover; 
           [0050]      FIG. 3B  is a side view of the same cover; 
           [0051]      FIG. 4A  is a perspective view of the cover seen from below, with a plurality of mixer arms; 
           [0052]      FIG. 4B  is a bottom view of the cover with a plurality of mixer arms; 
           [0053]      FIG. 4C  is a side view of the cover with a plurality of mixer arms; 
           [0054]      FIG. 5A  shows a side view of the chamber in which the mixing is carried out; 
           [0055]      FIG. 5B  shows the same mixing chamber in a perspective view; 
           [0056]      FIG. 6A  is another perspective view of the cover with a plurality of mixer arms; 
           [0057]      FIG. 6B  is a perspective view of the cover of the capsule connected to the standard shank of the handpiece; 
           [0058]      FIG. 7  is a sectional view of a detail of the cover, of the chamber and of the mixer arms; 
           [0059]      FIG. 8  is a sectional view of a detail of the chamber and of the mixer arms; 
           [0060]      FIG. 9  is a side view of a capsule closed by an adhesive tape. 
           [0061]      FIG. 10  is a side view of forecepts for rotary mixing of a capsule 
       
    
    
     DETAILED DESCRIPTION 
       [0062]    The capsule  3  for dental treatment illustrated in the figures is intended to accommodate various components in order to mix them at the time of use, with the aim of obtaining a dental material, for example a paste, specifically adapted to the oral and dental health of each of the patients. 
         [0063]      FIGS. 1A and 1B  show the capsule  3 , for storage and preparation of components for dental treatment, when it is connected to a handpiece (here a contra-angle)  1  by a standard shank  2 . 
         [0064]      FIGS. 2A and 2B  are exploded views showing the various components of the capsule  3 . The capsule  3  is thus formed of a chamber  6  within which the mixing will be able to be carried out. The chamber  6  is subdivided into two compartments  8  separated from each other. One is intended to contain a first component, for example a powdered component, and the other is intended to receive a second component, for example a liquid component. Such an arrangement of compartments allows the components to be dosed very precisely in the desired quantities in order to obtain a preparation adapted to a specific problem. These components are isolated from each other in storage mode, until the capsule  3  is used by the dentist. The components will then be brought into contact with each other in mixing mode, when the capsule  3  is driven by the rotation of the shank  2  by way of the handpiece  1 . 
         [0065]      FIG. 2C  is a perspective view of the capsule  3  when it is ready to be used. In this view, the standard shank  2  for a handpiece is inserted into the capsule, so as to be able to actuate it with the handpiece. 
         [0066]      FIGS. 3A and 3B  show the outer part  4  of the cover of the capsule  4 . This allows the components to be kept in the capsule during mixing, but it also preserves the sterile nature of the stored components. The edge of the cover has two flat portions allowing it to be held by a tool, for example an open-ended wrench, in order to open the cover and gain access to the mixture. This figure also shows openings, in this example three radial openings, which make it possible to lift the inner part  5  of the cover and to apply pressure to this inner part. 
         [0067]      FIGS. 4A, 4B, 4C and 6A  show the inner part  5  of the cover from below, when it is integrated with the outer part  4 . It will be see from these views that this part forms a helix and has two mixer arms  5  which penetrate into one of the compartments and allow the various components to be mixed when these arms are set in rotation with respect to the chamber  6  of the capsule by way of the handpiece. The lower face of the cover additionally serves as an isolating wall between the compartments  8 , making it possible to avoid component transfer during the transport or storage of the capsule. 
         [0068]      FIGS. 7 and 8  show how the inner part  5  of the cover closes in a leaktight manner on the chamber  6 , avoiding the risk of liquid or powder passing from one compartment to the other or between one compartment and the outside of the capsule. 
         [0069]      FIG. 7  shows how the leaktightness is obtained between the lower face of the inner part  5  of the cover and the outer edge of the chamber  6 . In this embodiment, an annular shoulder  50  under the inner part  5  of the cover  4 ,  5  engages against an annular face  60  on the outer shoulder of the chamber  6  in such a way as to prevent exchange of liquid or of powder between the outside of the capsule and the outer compartment. At least one of the faces  50  or  60  is made of plastic or of another elastically deformable material in such a way as to provide the leaktightness. An annular seal can be provided in order to improve this leaktightness. 
         [0070]      FIG. 8  shows how the cover  4  ensures leaktightness between the two compartments of the chamber  6 . In this embodiment, the shoulder  61  between the two compartments will bear elastically against a portion  51  of the lower face of the inner part of the cover  5 , in such a way as to prevent infiltration of water or of powder from one compartment of the chamber to the other. The shoulder  61  and/or the lower face  51  can be ribbed in order to ensure leaktight engagement. The shoulder  61  and/or the lower face  51  can be made of an elastically deformable material in order to provide the leaktightness. An annular seal can be provided in order to improve this leaktightness. 
         [0071]    A scraper could also be provided so as to be driven by the handpiece in order to scrape the cover clean during the mixing. 
         [0072]      FIGS. 5A and 5B  show the chamber  6  of the capsule, inside which the different compartments  8  are arranged. In storage mode, the compartments  8  are isolated from each other by the inner part of the cover  4 , as is described below. 
         [0073]    To implement the various phases in the preparation and in the application of the prepared mixture, the cover  4 ,  5  of the capsule is advantageously formed in two parts. The inner part  5  carries the mixer arms. With the outer part  4 , it is possible to close the assembly and adjust the relative position of the different elements depending on the phase in progress. Thus, in the example shown, a bayonet makes it possible to select three positions, namely:
       a closed position, in which the different compartments are isolated from each other;   a mixing position, in which the components combine and mix;   a position in which the cover is withdrawn in order to allow the practitioner access to the prepared dental material subsequent to the mixing.       
 
         [0077]    The change from one position to another is effected by turning the outer portion of the cover  4  with respect to the chamber  6 , for example by hand. 
         [0078]    In another embodiment, the outer part of the cover  4  does not have to be pivoted to lift the helix and to allow liquid or powder to pass from one compartment to the other. In this case, the inner part  5  of the cover (the helix) lifts by turning against the inclined shoulder of the chamber  6  when set in rotation, in such a way as to detach the inner face of the cover  4 ,  5  from the chamber  6  and permit mixing. In this case, the change from the closed position to the mixing position is effected automatically during the driving of the drive rod by the handpiece, which produces a displacement and possibly a deformation of the isolating wall. 
         [0079]    In another embodiment, shown in  FIG. 9 , the cover is joined to the chamber by means of an adhesive tape  40  in the closed position. It can be changed to the mixing position and then to the withdrawal position by removing the adhesive and turning it with respect to the chamber. 
         [0080]    The adhesive tape  40 , or another adhesive, can also cover the openings formed in the cover, in order to prevent entry of dust. 
         [0081]    This architecture allows the practitioner to prepare specific compositions without getting dirty. For this, the dentist positions the bayonet in the mixing mode in order to displace the portion of the cover serving as isolating wall between the compartments. He then fixes the capsule  3  to the handpiece  1  and actuates the latter in order to obtain the mixed preparation. If necessary, the chamber  6  can be held while the mixer arms are being driven, by hand or by way of a tool such as an open-ended wrench, which allows the cover to be held via flat portions provided for this purpose on the chamber  6 . 
         [0082]    Once the mixing has been carried out, the dentist withdraws the cover and removes the preparation in order to apply the latter immediately. 
         [0083]      FIGS. 2B and 4C  show an Archimedes screw  9  provided under the inner part of the cover  4 . The Archimedes screw  9  permits a gradual rise of the component, for example a liquid, contained in the central compartment in order to facilitate its transfer to the peripheral compartment. The liquid then pours easily and gradually into the outer compartment containing, for example, cement, in order to obtain a mixture that is ready to be applied. 
         [0084]    In a variant not shown, several capsules  3  can be combined, for example superposed or juxtaposed, in order to permit the simultaneous preparation of several mixtures or to concoct complex mixtures from several capsules. 
         [0085]    After the capsule  3  has been fixed to the handpiece  1 , the pasty preparation can be obtained by then actuating the handpiece  1  while holding the outside of the chamber  6  in order to avoid any rotation of the latter. In this way, the handpiece causes only the mixer arms  5  to pivot. According to such an embodiment, the paste obtained from this mixing is very homogeneous. 
         [0086]    The capsules according to the invention allow the dentist to save time preparing the treatment and guarantee strict hygiene during the preparation by limiting the risks of contamination. Moreover, such an architecture does not necessitate the use of any tools other than the handpiece  1  and the shank  2  connected to the handpiece. 
         [0087]    In another version, the cover incorporates the shank  2 , which is inserted in the handpiece. A replaceable and/or reusable shank can be employed. 
         [0088]    The shank  2  can be integrated in the capsule or can be reusable. For example, it can be made of metal or advantageously of reinforced polymer, for example polymer reinforced with glass fiber or carbon fiber. The shank may also, for example, be molded, machined, or made by 3D printing. 
         [0089]    The components can be stored and protected in the capsule prior to being mixed. It is also possible to open the capsule prior to the mixing, in order to add components to it or to modify their proportions, and then to close the capsule, in order subsequently to obtain an individualized mixture. 
         [0090]    In another embodiment, after activating the rotary mixing capsule  3 , the mixed material inside the capsule may be extruded through a needle  11  that perforates the mixing capsule  3 . The material may be extruded through use of a forceps  12  shown, for example, in  FIG. 10 . The extruded material may be extruded directly into a patient&#39;s mouth or to an intermediate location depending on the length of the needle. The material may also be extruded through the needle via any other suitable method. The needle may be made of metal or reinforced polymer, for example polymer reinforced with glass fiber or carbon fiber. 
         [0091]    The system described above can advantageously be used in the field of dentistry since it has the advantage of rapidly preparing a preparation for dental treatment in a very hygienic manner. Another advantage also lies in the fact that very precise pre-dosages are carried out. This makes it possible to save considerable time during the phase of treatment preparation. 
         [0092]    The invention described above may be interpreted more widely, that is to say the capsules  3  can be used for purposes other than dentistry, for example in the field of surgery, cosmetic surgery, orthodontics, etc.