Abstract:
An implant is provided that can be implanted into a hole of a jaw bone. The implant comprises inner and outer parts. The inner part is sized and configured to be inserted into the hole of the jaw bone. The outer part is sized and configured to support a dental prosthesis. The inner part at least partially comprises compressed biocompatible metal powder. The outer part at least partially comprises compressed biocompatible ceramic powder. The compressed biocompatible ceramic and metal powders of the respective ones of the inner and outer parts can be collectively compressed to form the body of the implant. Further, a method and system for producing the implant are also provided. The implant can eliminate the need to conceal dark coloring caused by the metal powder where the implant emerges from the hole in the jaw bone.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. National Phase of International Application No. PCT/SE2005/001201, International Publication No. WO 2006/025777, filed Aug. 11, 2005, which claims priority to Swedish Patent Application No. 0402108-5, filed Sep. 1, 2004, each of which is hereby incorporated by reference in its entirety. 
     
     BACKGROUND 
       [0002]    1. Field of the Inventions 
         [0003]    The present inventions relate generally to dental implants, and more specifically to a dental implant having a uniquely configured body shape that is implantable into a jaw bone by means of an inner part and being operative to support a dental prosthesis by means of an outer part. The inventions also relate to a method and a system for producing such an implant. 
         [0004]    2. Description of the Related Art 
         [0005]    It is known in the art that implants and other prosthetic constructions can be produced from compressed (i.e. sinterable) metal powder. In many instances, the implants and other prosthetic constructions have preferably been made of titanium powder, and if appropriate, in the form of an alloy. For example, see PCT International Patent Publication No. WO 00/15137, entitled “METHOD AND DEVICE FOR, AND USE OF, A DENTAL PRODUCT OR OTHER PRODUCT FOR THE HUMAN BODY,” and PCT International Patent Publication No. WO 03/061509, entitled “ARRANGEMENT, DEVICE, METHOD, PRODUCT AND USE IN CONNECTION WITH A BLANK MADE PREFERABLY OF TITANIUM POWDER,” the entireties of both of which are incorporated herein by reference. 
         [0006]    It is also already known in the art that crowns and other prosthetic parts can be produced from compressed (i.e. sinterable) ceramic powder. For example, see PCT International Patent Publication No. WO 97/01408, entitled “METHOD AND MEANS FOR PRODUCING A CERAMIC OR METALLIC PRODUCT FOR SINTERING,” the entirety of which is incorporated herein by reference. 
         [0007]    Further, it is also already known in the art to provide fully automatic production systems for the production of dental products. For example, see European Patent Application Publication No. EP 490848, entitled “A PROCEDURE AND APPARATUS FOR PRODUCING INDIVIDUALLY DESIGNED, THREE-DIMENSIONAL BODIES USABLE AS TOOTH REPLACEMENTS, PROSTHESES, ETC., and European Patent Application Publication No. EP 634150, entitled “PROCESS AND DEVICE IN CONNECTION WITH THE PRODUCTION OF A TOOTH, BRIDGE, ETC.,” the entireties of both of which are incorporated herein by reference. 
       SUMMARY 
       [0008]    Implants made of titanium or alloyed titanium now represent a well proven and satisfactory product which has great biocompatibility with the human body. Therefore, these products can constitute a very advantageous basis, from the medical point of view, for a prosthetic fixture. 
         [0009]    However, titanium or alloyed titanium both have a serious disadvantage in that they have a relatively dark color, which may be visually undesirable. In particular, the portion of the implant, which is situated at an upper part of the hole in which the implant is fitted and near the gum, is difficult to conceal. The dark color can show through and prevent a completely satisfactory result from an aesthetic point of view. Various embodiments disclosed herein are directed to solving these and other problems. 
         [0010]    According to an aspect of at least one of the embodiments disclosed herein is the realization that it is important that a biocompatible and effective material can be retained in all parts of the implant, and that well proven application and production methods can be used without the need for substantial changes that greatly increase costs. Embodiments disclosed herein are directed at solving this problem as well. 
         [0011]    According to an embodiment of the implant, an inner part of the implant can be made completely or partially of compressed (i.e. sintered) powder of biocompatible metal, and is preferably made at least partially of titanium or alloyed titanium. Further, an outer part of the implant can be made completely or partially of compressed powder of biocompatible ceramic, is preferably made at least partially of zirconium dioxide. The metal and/or ceramic powders can be compressed or pressed together to form a body shape of the implant in a single piece. 
         [0012]    In a preferred embodiment, the inner part can be fitted in a hole in the jaw bone. In this regard, the inner part can be sized and configured to be able to cooperate substantially with the jaw bone. Additionally, the outer part can extend through an upper part of the hole and through the gum and out into the oral cavity. In some embodiments, the compressed ceramic powder can be pressed together with the compressed metal powder, and can have a light color or shade or can be substantially white. The metal powder can comprise alloyed titanium of grade four, and it can comprise approximately 6% aluminum and approximately 4% vanadium. 
         [0013]    In some embodiments, particle size or grain size can be selected according to user needs. The implant can be made up of a plurality of parts, such as two or more, which can be arranged in different or layered powder types with or without specific transition layers between respective part pairs. The term “layered” is intended to signify layers which are of the same type of material, but which are not located next to one another, and are instead separated by another powder type. Some of the features of certain embodiments are set forth in the dependent claims relating back to the main implant claim. 
         [0014]    According to another embodiment, a method is provided for production of the implant. In some embodiments, the method comprises utilizing metal powder for complete or partial formation of the inner part and ceramic powder for complete or partial formation of the outer part. These powders can be applied, compressed and pressed together under vacuum, and preferably in a pressing tool, for formation of the body shape. The compression and pressing together can take place in a single step. 
         [0015]    In a preferred embodiment, the metal powder used can be an alloyed titanium powder and the ceramic powder used can be zirconium dioxide. The particle and/or grain sizes can be chosen to optimize the strength of the compressed or sintered powder types. The pressing together of the powders can yield very high temperatures, such as approximately 1100° C. Therefore, the tool and its components should be made of appropriate materials, such as graphite, for such an application. The pressing tool can be designed with one or more mold cavities having smooth mold cavity walls. 
         [0016]    In accordance with yet another embodiment, a system is provided for producing the implant. The system can include identification members for determining the inner and outer parts&#39; shapes and relationships to one another. Further, depending on the powder types and particle and/or grain sizes required, the members of the system can determine the powder quantities for the inner and outer parts, as well as determine whether a possible transition layer is needed between the parts, and if so, what its parameters should be. In some embodiments, the application members can apply the metal and ceramic powders in a pressing tool. The members can set a compression pressure and duration of the compression pressure depending on the chosen or desired temperature during the compression and pressing together (and sintering, if applicable). 
         [0017]    In some embodiments of the system, the tool can be designed with a number of mold cavities. The mold cavities can extend in parallel relative to each other. Further, the mold cavities can be oriented such that at their first ends, they are arranged opposite a common piston or counterstay member and at their other ends, they are arranged opposite individual counterstay or piston members. The tool can be configured such that at the common piston and/or counterstay member, the tool can have funnel-shaped or cone-shaped portions. In one embodiment, the system can be a substantially fully automated production system, for example, the Procera® type developed by NOBEL BIOCARE. 
         [0018]    Through implementation of the embodiments disclosed herein, the implant can be formed to have a color or shade in common with the prosthesis. In particular, the color of upper parts of the implant or those parts which emerge from the hole via the gum can be selectively controlled. In many embodiments, conventional powder compositions can be used for the implant. The pressing together of the different powder types can function extremely well to provide excellent properties, such as strength in the transition layer between different types of powders. If so desired, the implant can be made up of more than two parts, with different or layered powder types in the different parts. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0019]    The abovementioned and other features of the inventions disclosed herein are described below with reference to the drawings of the preferred embodiments. The illustrated embodiments are intended to illustrate, but not to limit the inventions. The drawings contain the following figures: 
           [0020]      FIG. 1  is a side partial cross-sectional view of an implant applied to a jaw bone and gum of a human, and as well as a dental prosthesis connected to the implant, in accordance with an embodiment of the present inventions. 
           [0021]      FIG. 2  is a schematic view of a system including a module included in a substantially fully automatic production system, according to another embodiment. 
           [0022]      FIG. 3  is a perspective view of a tool for production of the implant illustrated to  FIG. 1 , according to another embodiment. 
           [0023]      FIG. 4  is a side cross-sectional view of the tool of  FIG. 3 . 
           [0024]      FIG. 5  is a side cross-sectional view of the tool of  FIG. 3  wherein the tool is being utilized for the formation of a second embodiment of an implant produced by the tool. 
           [0025]      FIG. 6  is a side cross-sectional view of a second embodiment of the tool wherein a plurality of implants can be produced simultaneously. 
           [0026]      FIG. 7  is a perspective view, obliquely from above, of the tool of  FIG. 6 . 
           [0027]      FIG. 8  is a perspective view of a structural embodiment of the tool. 
           [0028]      FIG. 9  is a perspective view of samples produced according to an embodiment of the method. 
           [0029]      FIG. 10  is a diagram illustrating, inter alia, an exemplary relationship of the temperature and time in connection with the use of the tool. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0030]    According to an embodiment of the present inventions, a dental implant is provided that can be formed to match a color or shade of a dental prosthesis in order to enhance the aesthetic qualities and appearance of the implant and prosthesis. The implant can be formed to include inner and outer parts whose physical and aesthetic properties can be determined utilizing the disclosure and teachings herein. The inner part can be fitted in a hole in the jaw bone and can cooperate substantially with the jaw bone to provide a desired fit. Additionally, the outer part can extend through an upper part of the hole, through the gum and into the oral cavity. 
         [0031]    The inner part of the implant can be made completely or partially of compressed powder of biocompatible metal. The inner part is preferably made at least partially of titanium or alloyed titanium. Further, the outer part of the implant can be made completely or partially of compressed powder of biocompatible ceramic. The outer part is preferably made at least partially of zirconium dioxide. The metal and/or ceramic powders can be compressed or pressed together, and can be sintered, to form a body shape of the implant in a single piece. 
         [0032]    In some embodiments, particle size or grain size of the powder can be modified. The implant can comprise a plurality of individual parts. These parts can be arranged in layered types of powder and can have transition layers between respective parts. 
         [0033]    In this manner, it is contemplated that the implant can be selectively manufactured utilizing a method disclosed and taught herein such that an upper part of the implant, which is adjacent gums of a wearer, is formed to have a desirable appearance. In addition, the compression of different types of powder can also provide excellent strength properties in the transition layer between different types of powders. If so desired, the implant can be made up of more than two parts, with different or layered powder types in the different parts. 
         [0034]    It is also noted that embodiments of the implant and the method disclosed herein can be utilized in conjunction with a production principle of the Arcam® type. Further, it is noted that “Rapid Prototyping” with stereolithography (“SLA”) can also be implemented in some embodiments. Additionally, other manufacturing processes which concerns use of powder material in plastic, such as selective laser sintering (“SLS”), can also be used. 
         [0035]    In accordance with an aspect of embodiments disclosed herein, metal, for example in the form of titanium or alloyed titanium in powder form, can be combined with ceramic, zirconium dioxide and can be used in the formation of such embodiments of the implant. In the illustrative embodiment, the particle size and grain size of the different powder types can be in the range from merely a few nanometers to approximately 200 nanometers. For example, a grade 4 titanium alloy can be used, cf. ASTM B 346, ASTM F 67, ASTM F 136. In the case of alloyed titanium, it is possible to include in the titanium: approximately between 4 to 8% and preferably, approximately 6% aluminum (Al); and approximately between 2 to 6%, and preferably approximately 4% vanadium (V). The implant or dental product can be formed from combined metal and ceramic materials which cannot be alloyed together. The implant can therefore include different types of material which can be optimized with respect to the tissue and jaw bone in terms of strength, appearance, etc. 
         [0036]      FIG. 1  illustrates a human mouth  1 , a jaw bone  2 , and the gum  3  of the jaw bone  2 . Using known methods and medical procedures, a hole  4  can be formed through the gum  3  and in the jaw bone  2 . According to an aspect of embodiments disclosed herein, the hole  4  should be sized and configured to accommodate a dental implant  5 , which can facilitate the placement and anchoring of a dental prosthesis. 
         [0037]    As illustrated, some embodiments of the implant  5  can be formed to have an external thread  6  by means of which the implant  5  can be screwed into the hole  4  in a known manner. Alternately, other embodiments of the implant  5  can be formed such that the external thread  6  is omitted; in such embodiments, the implant  5  can be driven down into the hole  4  and retained therein by means of a precision fit between the implant  5  and the hole  4 . 
         [0038]    The partial cross-sectional view of  FIG. 1  illustrates that the implant  5  can be made up of an inner part  5   a  which can be inserted fully into the hole  4 . The implant  5  can also have an outer part  5   b  which can extend from the upper parts  6   a  of the hole  4  and through the gum  3 . At its outer parts  5   b , the implant supports a dental prosthesis which can be of various types. The design of the implant  5  and the application of the dental product to the implant  5  can be variously performed. A direction of viewing  8  is also indicated in  FIG. 1 . 
         [0039]    The inner part  5   a  can be made of metal powder. The metal powder is preferably of a type that has a substantial and well-proven stability function at the same time as a well-proven biocompatibility with respect to the jaw bone. The outer part  5   b  can be made of ceramic powder. In many embodiments, the outer part  5   b  can be configured to have a bright shade of color or to be substantially white. Thus, a dark color, typical of metal powder, will not tend to show through from the implant  5  and prosthesis structure in the direction of viewing  8 . Upper parts of the implant  5  and the prosthesis can thus merge naturally with the tooth color at the gum  3  and the upper parts  2   a  at the gum  3 . From the aesthetic point of view, this is a considerable advance in dental treatment techniques. In an illustrative embodiment, the implant  5  can include a transition zone  5   c  which comprises metal powder and ceramic powder in combination. 
         [0040]      FIG. 2  illustrates a substantially fully automatic production system  9  of Procera® type. In accordance with an embodiment, a module function  10  can be included for implementing the production method for the implant  5  in the exemplary system  9  shown in  FIG. 1 . In order to facilitate ordering and delivery of the implant, the system  9  comprises identification and ordering equipment (or orderer)  11  which, via connection  12 , can transmit information i 1  to the system  9 . The connection  12  can transfer the ordering information i 1 ′ to the system  9 . Correspondingly, the system  9  can communicate with the orderer  11  by means of information i 2  and i 2 ′. 
         [0041]    The system  9  can have an internal management and treatment function, and reference may be made here for example to International Publication No. WO 98/44865, entitled “ARRANGEMENT AND SYSTEM FOR PRODUCTION OF DENTAL PRODUCTS AND TRANSMISSION OF INFORMATION.” The system  9  can comprise a unit  14  for controlling and instructing the module  10 . As such, the module  10  can comprise identification members  15  which, depending on the information  16  from the unit  14 , can determine the shapes and relationships of the inner and outer parts  5   a  and  5   b  of the implant  5 . The module  10  can also comprise a member  17  which, depending on the powder type and particle and/or grain sizes, can determine the powder quantities for the inner and outer parts  5   a  and  5   b  of the implant  5  and can optionally serve to configure the transition layer  5   c  between the inner and outer parts  5   a  and  5   b . This determination can also be effected from the unit  14  by means of a control  18  in  FIG. 2 , according to another embodiment. 
         [0042]    Application members  19  can also be included in the module  10  for applying the metal and ceramic powders in a pressing tool which can operate with the vacuum cavity and is described in more detail below. The application members  19  can cooperate with or comprise members for setting the compression pressure and duration of the compression pressure as a function of the chosen temperature which is to be present during the compression and pressing together. The application member(s)  19 ,  20  can be controlled with control information  21  from the unit  14 . By means of the module  10 , the system  9  can produce other embodiments of the implant, such as the implant  5 ′ with inner part  5   a ′, outer part  5   b ′ and transition layer or transition zone  5   c ′, as shown in  FIG. 2 . Furthermore, the module  10  can also include a machining function, such as machining member  36 , which is described in greater detail below. 
         [0043]    Furthermore, in accordance with an aspect of some embodiments, the implant  5 ′ can be sent in a known manner, for example by post or parcel delivery, to the orderer or orderer function  1 . The order can be made over the public communications  12 , for example via the public telecommunications network, computer networks (Internet), etc. The system  9  can be configured to use different internal signals that are symbolized by  22 ,  23 ,  24 ,  25  and  26  in order to carry out various functions. 
         [0044]      FIGS. 3 and 4  illustrate an embodiment of a pressing tool  27  that can operate with a vacuum cavity. The pressing tool  27  can be made up of components  28 ,  29  and  30 , which are preferably made of graphite. In one implementation, the component  28  can include a cylindrical unit which has a through-hole. For example, the through-hole of the component  28  can be configured as a central hole  31  or cavity (vacuum cavity) in which pistons or counterstays  29 ,  30  can operate. 
         [0045]    In addition, the piston parts  29  and  30  can function as two pistons which can move toward and away from one another in the directions indicated by the double arrows  32  and  33 . For example, in order to place powder(s) in the cavity  31 , the piston part  29  can be removed so that the powder(s) can be inserted into the cavity  31 . In some embodiments, zirconium dioxide powder  34  can be introduced, followed by titanium powder  35 , or vice-versa. After inserting the powder(s), the piston part  29  can be repositioned in the cavity  31 . 
         [0046]    Thereafter, the piston parts  29  and  30  can be moved toward one another to compress the powder(s), and energy can thereby be transmitted to the powders, by which the arrangement can provide a vacuum function in the cavity  31 . The inner walls or the inner wall of the cavity  31  can be smooth so that the powders thus pressed together can be removed from the cavity  31  via either one of the piston parts  29  and  30 . The cavity  31  can be configured to have a rod shape that corresponds to the outer shape of the implant  5  (see  FIGS. 1 and 2 ). The rod-shaped unit (or implant  5 ) which is the result of the pressing under vacuum can then be subjected to machining through the machining member  36 , shown in exemplary system  9  of  FIG. 2 . The machining member  36  can serve to modify the rod-shaped unit such that it is formed to include, inter alia, the external thread  6 . Alternately, the function can be effected otherwise in the system  9 . This function can also be controlled, and the control information for the machining unit  36  has been indicated by  37  in  FIG. 2 . 
         [0047]      FIG. 5  shows an embodiment of a production method for the rod-shaped unit using titanium powder  35 ′ and zirconium dioxide powder  34 ′. In this embodiment, the above-mentioned layer  38  can be obtained in which the zirconium dioxide powder  34 ′ and the titanium powder  35 ′ have been mixed. This layer  38  can be given a thickness t, which can be approximately 1 to 3% of a total length L of the finished pressed rod. 
         [0048]      FIGS. 6 and 7  show a second embodiment of a pressing tool  27 ′ which effects the compression and pressing together of metal and ceramic powders to form a rod-shaped unit for making the implant. In particular, this embodiment can facilitate the joint production of a plurality of rod-shaped elements which can constitute the base of the implant. 
         [0049]    In the illustrative embodiment in  FIG. 6 , the tool  27 ′ can be configure to include three cavities  31 ′,  31 ″ and  31 ″′, which can be arranged in parallel. In this embodiment, a common piston  29 ′ can be used to provide compressive force from above for all of the cavities  31 ′,  31 ″ and  31 ″′. Additionally, the tool  27 ′ can also have individual pistons  30 ′,  30 ″ and  30 ″′ to provide compressive force from below for the respective ones of the cavities  31 ′,  31 ″ and  31 ″′. The tool  27 ′ can be configured such that the individual pistons  30 ′,  30 ″ and  30 ″′ can be actuated jointly by a common piston  39 . 
         [0050]    At their upper parts, said cavities  31 ′,  31 ″ and  31 ″′ can be formed to define funnel-shaped portions or extents  40 ,  41  and  42 . In the present embodiment, zirconium dioxide  34 ″ can be applied in the cavities  31 ′,  31 ″,  31 ″′, after which titanium powder  35 ″ or alloyed titanium powder can be applied in the cavities  31 ′,  31 ″ and  31 ″′ and in the funnel-shaped parts  40 ,  41  and  42 . In this way, an actuating force on the piston  29 ′ can be increased in the cavities  31 ′,  31 ″ and  31 ″′ such that sufficient energy is obtained during the compression and pressing together in the cavities. 
         [0051]      FIG. 7  is a perspective view of the tool  27 ′ illustrated in  FIG. 6  and shows how seven parallel cavities with funnel-shaped extents  40 ,  41  and  42  can be arranged in a cylindrical part  28 ′ of the tool  27 ′. In this case, only one individual piston  31 ″ is shown together with the symbolically indicated piston  39 ; however, it should be noted that as described above, each of the cavities can interact with respective pistons that can be cooperatively actuated by a common piston. It is also contemplated that the extent and number of the cavities can of varied as desired. 
         [0052]      FIG. 8  shows a practical and structural illustrative embodiment of the whole construction of the tool. The tool should be configured to provide sufficient energy for the compression and pressing together of the metal and ceramic powders in the cavity(ies). In this exemplary embodiment, the pistons  29  and  30  are arranged in the cylinder  28 . These pistons are acted upon respectively via first actuating members  43 ,  44  which have a diameter d well in excess of a diameter d′ of the respective piston  29 ,  30 . The actuating parts  43 ,  44  can be respectively acted upon by actuating parts  45  and  46  with diameters D which are well in excess of the diameters d for the parts  43  and  44 . In this way, an amount of energy obtained from actuating forces F and F′ on the units  45  and  46  can be selectively substantially increased during the actuation of the pistons  29  and  30 . The amounts of energy thus increased can result in the required compression and pressing pressure under which the metal powders form a rod-shaped integral unit. 
         [0053]      FIG. 9  is intended to show two examples of pressing together or compression to a common unit in accordance with another embodiment. The samples have been designated by  47  and  48 . The ceramic powder of the samples  47 ,  48  has been indicated respectively by  49  and  49 ′ and the titanium powder of sample  48  has been indicated by  50 . The sample  48  has been partially surface-treated, the lighter or white coloring  49 ′ for the ceramic powder being shown, and also the darker coloring for the titanium powder  50 . 
         [0054]      FIG. 10  is a graphic representation of how a temperature of 1100° C. is obtained for the above-described sintering, compression or pressing together of ceramic powder and titanium powder Ti/3Y-TZP, SPS. The sintering can, for example, take place for two minutes at a pressure of approximately 50 mPa after the temperature of approximately 1100° C. has been reached. In  FIG. 10 , reference number  51  shows the temperature of approximately 1100° C. can be reached after approximately 300 to 400 seconds by means of the above-described method and tool. A pressure of approximately 40 to 60 mPa, and preferably approximately 50 mPa, can be used for between 1 and 3 minutes, preferably 2 minutes. The right-hand vertical axis in the diagram shows the number of degrees and the horizontal axis shows the time in seconds. The left-hand vertical axis shows the movements of the powder particles in the ceramic powder, the displacements having been indicated in ΔZ. Said displacements as a function of time have been indicated by the curve  52 . In connection with the sintering or compression function, the pressure can be indicated in addition to the indication of the temperature during compression. This can be symbolized by the unit  36  and the control function  37 . 
         [0055]    Although these inventions have been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present inventions extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the inventions and obvious modifications and equivalents thereof. In addition, while several variations of the inventions have been shown and described in detail, other modifications, which are within the scope of these inventions, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combination or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of at least some of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above.