DE102007046879A1 - Two-piece dental implant for providing anodont jaw in mouth of patient, has implant shaft provided with external thread with inclination to axis of implant shaft, and abutment shaft comprising external thread corresponding to inner thread - Google Patents

Abstract

The implant has a two-piece structure comprising an implant body (1) made of ceramic materials provided in a tooth root region of the implant. An abutment (2) is connectable with the implant body, where the implant body comprises an implant upper part (3) and an implant shaft (4). The implant shaft is provided with an external thread (5) with an inclination to an axis of the implant shaft. An abutment shaft (8) has an external thread corresponding to an inner thread of the implant shaft, where the external thread forms a connecting region (9) together with the inner thread.

Description

The The invention relates to a dental implant, which consists of a two-part Implant body and an abutment connected to this constructed and modified so that the implant body very has good osseointegrative properties.

Dental implants are used to treat edentulous or partially edentulous jaws for years successfully used in practice.

in the The state of the art, in addition to titanium implants, is also a series of implants made of ceramic materials known and in use. Generally there is a requirement for dental implants that implants in the tooth root area as uncomplicated as possible in the Jawbone introduced and kept there long-term stable should. For this it is desirable that the implant in grows the jawbone and osteoblasts on the surface adhere to the implant.

Increasingly become zirconia and similar high strength mixed ceramics used in dental implantology. These ceramic materials have best aesthetic properties, because their tooth color prevents the show-through of the implant body or the visualization of the head, as is common in titanium implants by occurring soft tissue reactions is the case. Continue to own high-strength mixed ceramics in principle a better tissue compatibility as metallic implants and are also chemical stable and have a resistance to the oral environment. Also is in the State of the art and science known that the ceramic Implants already good compared to metal implants Have osseointegration properties.

The Osseointegration depends on dental implants the possibility of adhesion, ie attachment of the cells at the implant surface in the tooth root area in the first hours after implantation.

outgoing from this finding is proposed in the prior art, by mechanically modified surfaces osseointegration to improve.

From the DE 10 2004 017 344 A1 For example, a titanium-based external thread dental implant is known which attempts to solve the problem of stable fixation and osseointegration improvement by providing two functionally different threads. It is proposed, on the one hand, to provide a holding thread for holding the implant in the bone, and, on the other hand, to provide a contact thread with smaller dimensions arranged between the turns of the holding thread with the same orientation for better ingrowth of the implant into the bone.

adversely At this state of the art is that the smaller contact thread of its disclosed dimensions is not effective in osseointegration because the geometric dimensions of the osteoblasts, which are embedded in structures of the surface of the implant material are supposed to differ by orders of magnitude from those through the contact thread on the surface of the implant to provide.

Building In this problem are in the art further solutions for improving surface structuring and osseointegration known.

In the prior art, for example, from the EP 1 609 436 A1 a ceramic dental implant is known, which is constructed in one piece from an anchoring part for anchoring in the bone and a body part for receiving a prosthetic superstructure. The anchoring part and the mounting part are formed integrally from a material based on zirconium oxide, wherein at least the anchoring part on its outer surface partially pretreated by a subtractive, erosive method or provided with a coating by which an ossification is supported.

Furthermore, from the WO 01/58374 A2 an implant with microgeometric surface structures is known, which has structures in a range of 2 microns to 25 microns on the surface of the implant, which serve for the attachment of osteoblasts and thus the ingrowth of the implant into the bone.

One associated with the ingrowth of ceramic implants in the jaw Problem area is the need of wearing protective rails for the newly implanted dental implant. With the protective rails the abutment is damaged during impairments the growth of the implant and protected from the application of the secondary structure. Particularly detrimental to the use of temporary guard rails is that this sometimes intolerance symptoms cause the patients and also felt uncomfortable become.

It is an object of the invention to provide ceramic dental implants with improved osseointegration available and also disadvantages by the use of protection seemed to prevent during implant ingrowth as well as to allow greater flexibility in the formation of secondary structures in the further processing of the implants.

The The object of the invention is achieved by a dental implant with a two-part Structure solved, which is an implant body the base of ceramics in the dental root area of the dental implant and having an abutment connectable to the implant body. The implant body has an implant top and a Implant shaft on. The abutment is divided into an abutment upper part and an abutment shaft.

Farther It is advantageous that the abutment shaft one with an internal thread has the external thread corresponding to the implant shaft, the internal thread of the implant body and the external thread of Abutmentschaftes together a connection area between Forming abutment shaft and implant shaft.

Of the Implant stem is for fixing the implant body with an external thread with a slope to the axis of Implantschaftschaftes provided. In addition, due to laser structuring in the area of the cylindrical implant shaft in the direction of the generatrices of the cylinder, a line or groove structure arranged, the between the threads of the external thread in Threaded portion of the implant shaft extends. The line or Groove structures are considered more uniform spaced apart grooves each having a depth of one micron and a width of five microns.

In particularly advantageously corresponds to a line or groove structure the specified dimensioning of the natural geometry of the bone tissue, resulting in efficient natural attachment allows osteoblasts.

From particular advantage of the two-part embodiment of the ceramic Implant continues to be that serious disadvantages in implantation of one-piece implants for the patient avoided become. By the separation of implant body and abutment For the patient, the lengthy carrying is eliminated a protective rail, which in the implantation of one-piece Implants must be worn by the patient for up to three months. In order to is in the two-part embodiment of the dental implant of the Healing process favored over a one-piece implant. This is primarily due to the fact that that no foreign body made of plastic with this intrinsic Incompatibility symptoms must be used. The Protective rail is necessary for one-piece implants to achieve this one-piece ceramic implant from damage during Protecting the waxing process. This is in the two-part embodiment according to the invention of the ceramic implant superfluous, since the Abutment only after ingrowth of the implant body can be used in the jaw.

• • die normale Mundflora des Patienten erhalten bleibt,
• • die Mundhygiene verbessert wird,
• • die sonst bei einteiligen Implantaten überschienten Nachbarzähne geschont werden,
• • die rasch wiedereinsetzende Belastung des Implantatkörpers durch Kauen dessen Verwachsen im Kiefer begünstigt,
• • eine Beeinträchtigung des Patienten bei der Nahrungsaufnahme ohne Schiene weniger groß ist und
• • die Sekundärkonstruktion an das Abutment einfacher und individueller anpassbar ist, was zu ästhetischen und ökonomischen Vorteilen führt.

The advantages of the two-part embodiment of the implant of the implant body and the abutment connectable therewith consist in the fact that

• • the normal oral flora of the patient is preserved,
• • the oral hygiene is improved,
• • the neighboring teeth, which are otherwise covered with one-piece implants, are spared,
• • favors the rapid re-loading of the implant body by chewing its ingrowth in the jaw,
• • Patients are less susceptible to eating without a splint and
• • The secondary construction to the abutment is simpler and more customizable, resulting in aesthetic and economic benefits.

To An advantageous embodiment of the invention are the line structures by grooves with a distance of 12 microns parallel to each other arranged.

Especially It is advantageous if, in addition to the implant body also the abutment is formed of a ceramic material.

To a preferred alternative embodiment of the invention is the Abutment in two parts from an abutment shell and a separate connection means executed abutment shaft formed.

constructive that is relatively easy and inexpensive perform separate connection means as a screw whose Screw head the abutment top into the conical seat of the implant body shell presses and whose thread is screwed into the implant shaft.

Especially advantageous in this case is that the screw cost can be made of metal, thereby increasing the connection of abutment shell and implant shaft can be realized low. The dental implant is according to this embodiment of the invention in three parts from an implant body, an abutment shell and executed a screw connecting these two parts. The use of a metal screw leads to a reduction the cost and improved handling of the multipart Dental implant.

According to another advantageous Ausgestal tion of the invention, the abutment is formed with a predetermined breaking point such that at a mechanical stress of the abutment in the strength of the jaw bone Abutmentoberteil breaks at the predetermined breaking point and thus protects the implant body or the jaw from breaking stress. In particular, in accidents is prevented by jaw bone injuries caused by excessive stress on the secondary structures and the abutments by the abutment breaks away before the introduction of destructive force into the implant body at the predetermined breaking point.

It has proven to be particularly advantageous as a ceramic material Use zirconium dioxide.

To a particularly advantageous embodiment of the invention are the Implant upper part and the abutment upper part correspondingly frusto-conical formed with a conical seat of the abutment shell in the implant shell. It is already in the insertion of the abutment in the Implant body through the cone seat a guide generated. According to an advantageous embodiment of the invention the conical seat is formed at an angle of 18 °.

to Connection of abutment and implant body is additional for positive engagement or alternatively in the connection area an adhesive system as composite cement provided for traction, of course also an adhesive system such as glass ionomer cement alone for non-positive Connection of abutment and implant body can be applied can.

The Osseointegration can be applied to the implant body additionally by a coating of a mixture of Improve hydroxyapatite and tricalcium phosphate. Becomes advantageous the coating by electrophoresis and subsequent Sintering of the layer reaches the implant body. alternative The coating can be done by plasma spraying and subsequent Sintering done on the implant body.

When a particularly advantageous mixture of hydroxyapatite and tricalcium phosphate the ratio of 60 to 40 mass% is given.

Further Details, features and advantages of the invention will become apparent the following description of exemplary embodiments with reference to the accompanying drawings. Show it:

1 : two-piece dental implant and

2 : three piece dental implant.

In 1 a two-part dental implant is shown. The two-part dental implant consists of an implant body 1 which is inserted directly into the jaw, and further from an abutment 2 , Also referred to as a body part element, which in the implant body 1 is fixed.

The implant body 1 in turn consists of an implant shell 3 and an implant shaft 4 , wherein the implant top 3 and the implant shaft 4 are integrally formed. The implant shaft 4 is designed cylindrically according to the illustrated embodiment, whereas the implant top 3 also has a cylindrical or frusto-conical shape. The implant shaft 4 has at its outer periphery a threaded portion 6 on which directly serves the anchoring in the jaw, whereas the implant top 3 mostly in the gums.

The abutment 2 , Also referred to as body part, alternatively consists of titanium or other metals or preferably also of ceramic material such as the implant body 1 , In the latter implementation, problems with tooth coloration as the abutment passes through the secondary structure are avoided. Under the secondary structure, the tooth structure on the abutment 2 Understood. The abutment 2 is similar to the implant body 1 from two areas, but in the embodiment according to 1 only one piece, trained. The abutment 2 consists of an abutment shell 7 , which one with the inside frusto-conical implant top 3 corresponding outer frusto-conical shape and from an abutment shaft 8th which likewise corresponds to the implant shaft 4 is cylindrical.

The conical outer contour of the abutment shell 7 facilitates the insertion and fixation of the abutment 2 in the implant body 1 , The implant shaft 4 has inside a recess into which the abutment shaft 8th can be introduced, wherein between the implant shaft 4 and the abutment shaft 8th a connection area 9 is trained. According to the illustrated embodiment of the invention is the connection area 9 designed as a thread.

Due to the positive connection of the abutment 2 in the implant body 1 about that in the connection area 9 Trained thread is the abutment 2 in the implant body 1 fixed reversibly. The connection of abutment 2 and implant body 1 may additionally or alternatively be prepared or improved by the use of adhesive systems, such as composite cements. The composite cement used is preferably glass ionomer cement (GIZ). The surface of the implant shaft 4 is to the jaw with a Gewindebe rich 6 with an external thread 5 Mistake. The slope of the external thread 5 is carried out according to customary, known in the prior art parameters. In addition to the external thread 5 on the implant shaft 4 is in the threaded area 6 introduced a line structure by means of laser structuring. The linear structure is used as parallel generatrices of the cylindrical implant shaft 4 between the threads of the external thread 5 on the implant shaft 4 arranged. The individual lines of the line structure are one micron deep and have a width of five microns. It has been found that this dimensioning of the lines or grooves of the line structure leads to a particularly outstanding osseointegration of the dental implant in the jaw. The grooves of the line structures themselves are parallel to each other at a distance of approximately 12 μm as generatrices of the cylindrical implant shaft 4 arranged on the surface. The ingrowth of the bone tissue over the osteoblasts with the line structure on the implant shaft 4 , which is arranged in the direction of the generatrices, leads to a particularly firm connection of the implant body 1 in the jaw, as a turning out of the implant body over the external thread 5 by the staggered perpendicular introduced in the generatrix line structure of a movement by rotation of the implant body is opposed to the axis thereof. This results in the excellent strength of the connection of implant body 1 and pine.

According to a preferred embodiment of the invention is in the embodiment according to 1 between the abutment shaft 8th and abutment shell 7 a breaking point 10 arranged, for example, in case of accidental force on the secondary structure and the abutment 2 and the implant body 1 in the jaw to rupture the abutment 2 leads and thus the implant body 1 and protects the pine from destruction.

In 2 a three-part dental implant is shown, which in extension to the 1 Dental implant shown a screw 11 as an additional separate connecting element between the abutment 2 and implant body 1 having. The screw 11 forms the abutment shaft 8th that's about the connection area 9 with the implant shaft 4 connected is. The screw head is in a tapered recess in Abutmentoberteil 7 introduced and held in this form-fitting. The threaded area of the screw 11 extends through the abutment shell 7 through into the connection area 9 of the implant shaft 4 into it, so the screw 11 in the implant shaft 4 can be screwed into it while the abutment 2 in the conical seat with the implant upper part 3 pressed. The screw 11 is preferably made for manufacturing economic reasons of metal, in particular of titanium, which also for the efficient design of the connection of the abutment 2 and implant body 1 is advantageous.

Again, a predetermined breaking point is preferred 10 provided to the jaw and the implant body 1 to protect. The breaking point 10 is arranged directly on the screw head, so that in case of breakage of the screw 11 - In contrast to the embodiment according to 1 - also the abutment 2 , possibly even with the secondary structure, is reusable.

1

implant body

2

Abutment / body part

3

Implant shell

4

implant stem

5

external thread implant

6

threaded portion

7

Abutmentoberteil

8th

Abutmentschaft

9

connecting area

10

Breaking point

11

screw

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102004017344 A1 [0007]
• EP 1609436 A1 [0010]
• WO 01/58374 A2 [0011]

Claims (16)

Dental implant with a two-part construction, comprising an implant body ( 1 ) on the basis of ceramic in the tooth root area of the dental implant and having a with the implant body ( 1 ) connectable abutment ( 2 ), wherein the implant body ( 1 ) an implant top ( 3 ) and an implant shaft ( 4 ) and the abutment ( 2 ) an abutment top ( 7 ) and an abutment shaft ( 8th ) and that the implant shaft ( 4 ) with an external thread ( 5 ) with a slope to the axis of the implant shaft ( 4 ) and that the abutment shaft ( 8th ) with an internal thread of the implant shaft ( 4 ) has corresponding outer thread, which together form a connection region ( 9 ) form. Dental implant according to claim 1, characterized in that by laser structuring in the region of the cylindrical implant shaft ( 4 ) are arranged in the direction of the generatrices line structures which between the threads of the external thread ( 5 ) in the threaded area ( 6 ) are arranged, wherein the line structures are formed as grooves with a depth of one micron and a width of five microns. Dental implant according to claim 2, characterized in that that the line structures through grooves at a distance of twelve microns are arranged to each other. Dental implant according to one of claims 1 to 3, characterized in that the abutment ( 2 ) is formed of ceramic material. Dental implant according to one of claims 1 to 3, characterized in that the abutment ( 2 ) in two parts from an abutment shell ( 7 ) and an abutment shaft designed as a separate connecting means ( 8th ) is trained. Dental implant according to claim 5, characterized in that the separate connection means of Abutmentoberteil ( 7 ) and implant shaft ( 4 ) as a screw ( 11 ) is executed. Dental implant according to one of claims 1 to 6, characterized in that the abutment ( 2 ) with a predetermined breaking point ( 10 ) is designed such that when a mechanical stress of the abutment ( 2 ) in the area of the strength of the jawbone the Abutmentoberteil ( 7 ) breaks at the predetermined breaking point. Dental implant according to one of the claims 1 to 7, characterized in that the ceramic material as zirconia is trained. Dental implant according to one of claims 1 to 8, characterized in that the implant upper part ( 3 ) and the abutment top ( 7 ) correspondingly frusto-conical with a conical seat of the abutment upper part ( 7 ) in the implant upper part ( 3 ) are formed. Dental implant according to claim 9, characterized in that that the conical seat is formed at an angle of 18 ° is. Dental implant according to one of claims 1 to 10, characterized in that in addition to the positive connection between the implant body ( 1 ) and abutment ( 2 ) in the connection area ( 9 ) An adhesive system is arranged for adhesion. Dental implant according to claim 11, characterized in that that the adhesive system is formed as Glasionomerzement. Dental implant according to one of claims 1 to 12, characterized in that on the outside of the implant body ( 1 ) a coating of a mixture of hydroxylapatite and tricalcium phosphate is arranged. Dental implant according to claim 13, characterized in that the coating by electrophoresis and subsequent sintering on the implant body ( 1 ) is applied. Dental implant according to claim 13, characterized in that the coating by plasma spraying and subsequent sintering on the implant body ( 1 ) is applied. Dental implant according to one of the claims 1 to 15, characterized in that the coating of hydroxylaphatite and tricalcium phosphate in a ratio of 60 to 40 Mass% is formed.