| Two-part implant with a hydroxylated soft tissue contact surface -> Monitor Keywords |
|
|
 
Two-part implant with a hydroxylated soft tissue contact surfaceTwo-part implant with a hydroxylated soft tissue contact surface description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070202466, Two-part implant with a hydroxylated soft tissue contact surface. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001]The present invention relates to a two-stage implant comprising a base body having a bone contact surface and a tissue contact surface and to a method for preparing such an implant. BACKGROUND [0002]Implants which are used for insertion into bone, for example for attachment of artificial teeth, are known per se. Different types of implant systems are known, for example two-part implant systems. Said two-part implant systems comprise first an anchoring part for anchoring within the bone and second a mounting part. Onto the mounting part prosthesis elements, such as bridges or crowns, are screwed or cemented usually using intermediate so-called abutments. [0003]A central property of said implants is their osteointegration time, that is to say the time that passes before the bone substance has become connected with sufficient strength and permanently to the bone contact surface, that is to say it has become integrated with it. [0004]Therefore, much effort has been made in order to improve the osteointegration of said implants, such as described in EP 1 150 620. It was shown that the osteointegration time was significantly shorter if the bone contact surface of the implant is roughened, hydroxylated and hydrophilic. [0005]US 2004/0049287 discloses an endosseous implant, said implant having a surface made from metal or ceramic. The surface has a smooth or rough texture and has been treated with at least one pharmaceutically acceptable organic compound carrying at least one phosphonic acid group. Said implants showed an improved bone bonding strength. [0006]U.S. Pat. No. 5,397,362 discloses an implant prosthesis comprising a substrate of a ceramic material, a glass layer coated over the adhering interface of the substrate and a thermally sprayed layer of calcium phosphate based material formed over the glass layer. [0007]WO 2005/120386 discloses a dental implant comprising an anchoring element for anchoring the dental implant in the bone and an abutment for fastening a crown or the like suprastructure. The anchoring element and the abutment are produced from zirconium oxide. [0008]However, there is considerable evidence supporting the view that the supracrestal connective tissue plays a fundamental role in establishing an effective seal between the oral environment and the endosseous part of a dental implant. Indeed, the presence of bacteria on the implant surface may lead to an inflammation of the peri-implant mucosa, and, if left untreated, the inflammation spreads apically and results in bone resorption. As a consequence of the fact that rough surfaces accumulate and retain more plaque than smooth surfaces, nowadays, the soft tissue contact surface of the implants is highly polished (see Oral Implantology, Thieme Verlag, 1996, page 438). [0009]Various experiments have been carried out to investigate the difference of early inflammatory response to mucosa-penetrating implants prepared with varying surface roughness. Despite the fact that a rough surface may accumulate greater amounts of plaque than a smooth surface, no relation was found between inflammatory response and implant surface roughness (Wennerberg et al, J. Clin. Periodontol 2003: 30: 88-94; Quirynen et al, The International Journal of Oral and Maxillofacial Implants, 11, No. 2, 1996). [0010]It is the problem of the present invention to provide an implant with improved soft tissue integration. SUMMARY OF THE INVENTION [0011]An implant according to the invention comprises a base body having a bone contact surface and a soft tissue contact surface, wherein the soft tissue contact surface is at least partially hydroxylated or silanated. Said soft tissue contact surface has the potential to promote formation of soft tissue attachment. In contrast to conventional implants having a roughened, in same cases also hydroxylated bone contact surface and a smooth unhydroxylated tissue contact surface, the implant according to the present invention leads to the formation of new connective tissue adjacent to the soft tissue contact surface of the implant and the new connective tissue tends to be in close contact with the soft tissue contact surface of the implant. The loose connective tissue seems to become organized and replaced be newly formed collagen fibers, originating from its outer zone. These fibers tend to be organized in a perpendicular way towards the soft tissue contact surface, similarly to the naturally occurring fibers most responsible for compensation forces on the tooth. [0012]An implant in terms of the present invention is intended to mean the anchor part of a two-part implant system, that is that part which becomes integrated with the bone. The anchoring part of said two-part implant system may be inserted in a one-stage or a two-stage procedure. Said anchoring part is sunk in up to about 1.5-3 mm above the bone ridge at mucosal level. Said anchor part has a bone contact surface meaning the part which is in contact with the bone. The top of the anchoring part which is in contact with the soft tissue is defined as the soft tissue contact surface. After implantation the wound edges can be directly adapted to the soft tissue contact surface thereby effecting a primary soft tissue closure to the implant. [0013]Hydroxylated" in terms of the present invention means hydroxyl groups which are present in the outermost atomic layer of the implant surface. If the implant comprises titanium, zirconium, tantalum, niobium, hafnium or alloys thereof as well as chemically similarly reacting alloys, it is assumed that the surface of metal oxidizes spontaneously in air and water and that a reaction then takes place with water on the surface to form hydroxyl groups. This surface containing hydroxyl groups is referred to in the literature as a "hydroxylated" surface; cf. H. P. Boehm, Acidic and Basic Properties of Hydroxylated Metal Oxide Surfaces, Discussions Faraday Society, vol. 52, 1971, pp. 264-275. The same applies to ceramic surfaces (either on a ceramic implant or a metallic implant with a ceramic coating). A metal surface whose hydroxyl groups are covalently blocked, e.g. because of chemical modification, is not a "hydroxylated" surface in terms of the present invention. [0014]Silanated in terms of the present invention means that the implant surface is covered by a silanole or by an organo silane compound which has at least one free hydroxyl group. Examples of such organo silane compounds are X.sub.nSiR.sub.4-n, wherein X is selected from the group consisting of Cl, Br, I, F or OR, and R is selected from the group of lower alkyl groups, such as methyl, ethyl, propyl etc. Implants made of metal are preferably covered by a silanole, whereas implants made of ceramic are preferably covered by an organo silane compound. Implants made of metal can also be covered by an organo silan compound, and implants made of ceramic can also be covered by silanole. [0015]In a preferred embodiment of the present invention the soft tissue contact surface is completely hydroxylated. Such an implant showed good results in vivo and said implants are economically interesting and can be produced in a controlled process. In addition it has been shown that with the implants according to the present invention the healing process is improved, that is a good osteointegration as well as an excellent soft tissue integration is achieved. Therefore, the implants comprise a reduced risk of periimplantitis and as a consequence fewer implants will have to be replaced. Due to their purity, meaning that the soft tissue contact surface is free of organic compounds, the surface charge is better available. Therefore, the surface is hydrophilic, which results in an improved soft tissue integration. Therefore, they do not bear the risk of autoimmune reactions and other unwanted side effects. [0016]In a further embodiment of the present invention the soft tissue contact surface is roughened and hydroxylated. A roughened surface in terms of the present invention means a macroscopic texture of the surface which is obtained for example by sandblasting the soft tissue contact surface. It has been found that if the soft tissue contact surface is roughened and hydroxylated the blood coagulum is stabilized which accelerates the healing procedure. [0017]In a further embodiment of the present invention the soft tissue contact surface is smooth but hydroxylated. A smooth surface in terms of the present invention means a macroscopic texture of the surface which is obtained for example by machining or additional polishing, preferably by electropolishing the soft tissue contact surface. With a smooth surface the accumulation of plaque can be prevented or at least minimized, and such a soft tissue contact surface has outstanding wettability properties which is highly preferred. [0018]In a further embodiment of the present invention the bone contact surface and the soft tissue surface of the implant are both roughened, hydroxylated and hydrophilic or alternatively both smooth, hydroxylated and hydrophilic. Such implants are particularly easy to produce since the entire implant can be treated in the same way. This is a very big advantage and is based on the surprising finding that a hydroxylated, hydrophilic and roughened soft tissue surface of the implant shows improved soft tissue integration. [0019]In a further preferred embodiment of the present invention the soft tissue contact surface is hydrophilic. In terms of the present invention, the soft tissue contact surface is referred to as "hydrophilic" if it is freely accessible to the body fluid and not covered with foreign substances, for example substances with a hydrophobic action. Various volatile hydrocarbons are conventionally present in non-purified air. These are rapidly adsorbed in a thin layer by hydroxylated and hydrophilic surfaces, whereby such surfaces are no longer hydrophilic. Likewise, such a hydroxylated and hydrophilic surface can become hydrophobic if the hydroxyl groups present on the surface associate or react chemically e.g. with carbon dioxide present in the air or with organic solvents, such as methanol or acetone, introduced via the cleaning process. The hydrophilic properties of the soft tissue contact surface may result in a higher wettability when compared to an untreated soft tissue contact surface, which promotes formation of the soft tissue. Further, the charge on the surface is better available which may accelerate the formation of soft tissue attachment as well. [0020]The implants according to the invention preferably comprise mainly a metal selected from the group consisting of titanium, zirconium, niobium, hafnium or tantalum, preferably titanium or zirconium. Alternatively the implants comprise an alloy of metals selected from the group consisting of titanium, zirconium, niobium, hafnium or tantalum, preferably a binary titanium/zirconium alloy. Such implants, their nature and the metal materials used to produce them are known per se and are described for example in J. Black, G. Hastings, Handbook of Biomaterials Properties, pages 135-200, published by Chapman & Hall, London, 1998. From an aesthetic point of view, in particular in the front visible region, the soft tissue contact surface is preferably covered with a ceramic coating. This is for example obtainable by thermally spraying a ceramic material on the surface of a metallic core material such as described in U.S. Pat. No. 4,746,532. Also EP 1 566 152 describes the coating of a dental implant with zirconia. Alternatively the implants may comprise a ceramic ring element, in particular in the soft tissue contact surface. Such ceramic coatings and ring elements comprise typically zirconia, aluminia, silica or mixtures thereof with possible further constituents, preferably they are made of zirconia. Alternatively the implant according to the present invention may be made of ceramic. [0021]In a most preferred embodiment the implant according to the present invention is made of ceramic comprising a zirconium oxide based material. The cubic structure of zirconium oxide (zirconia) may be stabilized by metallic oxides at room temperature. Preferred metallic oxides are magnesium oxide, calcium oxide, oxides of the lanthanide group, preferably yttrium oxide. Depending on the content of said metallic oxides the cubic high temperature phase of zirconia can be stabilized fully or partly at room temperature (cubic stabilized zirconium oxide). Preferably zirconia is stabilized by yttrium oxide. Continue reading about Two-part implant with a hydroxylated soft tissue contact surface... Full patent description for Two-part implant with a hydroxylated soft tissue contact surface Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Two-part implant with a hydroxylated soft tissue contact surface patent application. Patent Applications in related categories: 20090286202 - Polymeric dental implant assembly - A dental implant assembly (20) comprises an anchor (26, 126, 226) and a support ring (52, 152, 252) disposed about the anchor (26, 126, 226) and with a ring top end (54, 154, 254) engaging the bottom of the tooth-replicating device (24) to receive an impact force and to transfer ... ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Two-part implant with a hydroxylated soft tissue contact surface or other areas of interest. ### Previous Patent Application: Dental implant system and method for implantation and construction of the implant system Next Patent Application: Oral care implement Industry Class: Dentistry ### FreshPatents.com Support Thank you for viewing the Two-part implant with a hydroxylated soft tissue contact surface patent info. IP-related news and info Results in 0.15167 seconds Other interesting Feshpatents.com categories: Daimler Chrysler , DirecTV , Exxonmobil Chemical Company , Goodyear , Intel , Kyocera Wireless , 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
