AT14617U1 - Dental implant with a micro and a macro thread - Google Patents

Abstract

The invention relates to a dental implant in one or two-part design, consisting of a base body and an abutment which can be arranged on the base body by means of posts or connecting elements, wherein the base body is provided with a micro- and a macro-thread. According to the invention, it is provided that the micro-thread (6) is designed such that it has two regions, namely a. a region with a large core diameter located in the cervical area of the implant (1) and b. In addition, it should be noted that a ratio of the macro-thread relative to the largest thread depth to the micro-thread is present in the order of magnitude of 13 to 20 with respect to the smallest thread depth.

Description

description

DENTAL IMPLANT WITH A MICROWAVE AND MACRO THREAT ENGINEERING AREA

The present invention relates to a dental implant for a fixed dental prosthesis, namely a dental implant, which consists of a base body.

STATE OF THE ART

Dental implants are anchored as a substitute for the natural tooth roots in the human jawbone for receiving abutments or crowns, bridges and general her¬ausnehmbaren dentures.

The dental implant consists of a main body with an apical and cervical end. In the region of the apical end, a thread is arranged, which is suitable for screwing into the jawbone. The basic body in the apical region is designed such that it serves for the fixed primary anchoring of the dental implant in the jawbone. Cervical imkoronalen area is usually provided either a post for receiving an abutment or a connection plane or a connection area for receiving an abutment zusam¬men with a connecting element.

In the case of dental implants, a distinction is made between one-part and two-part dental implants. In a one-piece dental implant, the main body is made with the post in one piece. In the case of a two-part implant, the abutment can be applied to the base body with corresponding connecting elements such as, for example, screws or pins.

Natural teeth as well as dental implants are subject to bone or gum decline as a function of time biological factors. This decline manifests itself in a subjective, longer-lasting tooth root and, analogously, in a titanium dental implant in a visible, darker, roughened metal surface of the main body. Such exposure inevitably leads to the necessity of an implant removal with new implantation and preparation of a new dental prosthesis or for attaching a removable dental prosthesis which covers the dark metal surface with the aid of gum-colored plastic for optical reasons.

Furthermore, there is a demand for an implant because of the increasing aesthetic demands of the patient relationship as a result of time, which, in addition to a very good hold, also results in a visually appealing image even with different bones of morphological formations.

However, since many patients are allergic to metal, implants of titanium or comparable metallic elements can only be used after previous metal compatibility testing. As an alternative, ceramic implants may be provided which, for example, consist of zirconium oxide.

A variety of two-part implants are made of metallic materials, such as titanium. The reason for this is that, in particular, the connection between the coronal part and the implant body is simple in design, since undercuts can be provided in the connection region, which prevent the coronal part of the structural element from rotating relative to the implant body. In addition, screws can be provided as connecting elements that extend far into the implant body.

Despite the small wall thickness caused by the inner bore for receiving the connecting element in the implant body, the necessary breaking strength according to EN ISO 14801: 2007 (D) must be observed.

[0010] According to EN ISO 14801: 2007 (D), the implant must be clamped in a holder at a defined angle to a vertical impact load such that the clamping site is spaced 3mm apically from the defined nominal bone level. In the following, this position is described as a test point, test site or test level. The nominal bone level - or as it is defined in the regulation as a nominal bone margin - is usually specified by the manufacturers in each case. If the nominal bone level is not specified by the manufacturer, then according to EN ISO 14801: 2007 (D) the most unfavorable case is to be assumed. In many dental implants, it is known that the bone margin regresses apically to a static level after implantation of the implant. The distance 3 mm was therefore set to represent a typical case of bone loss and an extreme load on the implant.

In addition, sufficient strength or resilience of the dental implant must be ensured.

An approach to meet the above-described requirements is a in the document WO 2004/096075 A1 described full zirconia dental implant. In the described dental implant, however, has the disadvantage in the one-piece body and post. This means that the part of the implant protruding from the bone and the gums has to be ground intraoperatively with rotating instruments which generate heat, so that they can be adapted to a preoperative protective splint. This splint must be worn for protection against mishandling during the 3 month healing phase. In addition, the disadvantage of this one-piece design is that for mounting the overlying dentures, which can extend over several adjacent teeth, a sufficient parallelism of the posts must be ensured. A compensation of the axial deviations over the posts is not possible with this dental implant.

Document DE 10 2006 011 800 A1 describes a dental implant which has a head part, for example for receiving a crown, and a main body part for insertion into a bore in a jawbone, wherein the head part and the main body part are both made of zirconium oxide. The main body part and the head part are connected together by means of a screw.

The problem with this dental implant is that the screw is screwed into an internal thread in the basic body part. The provision of an internal thread in a component made of zirconium oxide is, in particular due to the hardness of the zirconium oxide, extremely expensive in terms of production technology. In addition, high torque tightening of a screw threaded into the female thread, due to the brittleness of the zirconia, regularly results in tearing of the threads.

An essential task of the dental implant is, on the one hand, to provide a high stability of the implant, but to minimize the peri-implantitis risk. In addition, it should be prevented that the Kompakta is also subject to corresponding compressions. Increased compression leads to bone loss and thus to relaxation of the dental implant.

From WO 2003/015654 A1, a dental implant is known, which has substantially an outer cylindrical contour, wherein in the coronal region a micro-thread and in the remaining area a macro-thread is provided. The core diameter of the Dentalimplant¬tats is almost constant over the entire longitudinal extent.

From PCT / EP2010 / 05113 a dental implant is known, which has this essentially Wesentli¬ an external cylindrical contour, wherein in the coronal area a Mikrogewin¬de and then in the apical direction a macro-thread is provided. The core diameter of the dental implant is almost constant over the entire longitudinal extent, a taper being formed exclusively in the apical region.

DISADVANTAGES OF THE PRIOR ART

Previous two-part implant systems consist primarily of titanium and are in a cylindrical or slightly conical implant with a relatively long screw, which came to lie somewhere in the middle region of the implant, screwed.

This resulted in a strong wall thickness reduction exactly in the range defined by EN ISO 14801: 2007 (D) as a weak point (fracture-prone area), 3mm below the nominal bone level. Due to the high elasticity of the titanium material, this procedure works very well except for small fractures. For ceramic implants this connection is not suitable because the wall thickness is too low and does not meet the purchasing power requirements. For this reason, implants made of ceramic have either been produced in one piece or have been connected by a glued-together ceramic pin which also grips deeply into the implant.

Both one- and two-part implants have a trough in the apical region and in the cervical region at least a roughened surface, which interacts with the Kom-pacta. However, the stabilities provided here are only suitable for bone class II. As an alternative to the roughened surface, a fine thread is also provided which cooperates with the compacta. However, the fine thread extends only over a short range and usually does not exceed the test point prescribed by EN ISO 14801: 2007 (D). Test site. The reason for this is that with the forms known from the prior art, it is not possible to further weaken the wall in the area specified by EN ISO 14801: 2007 (D) (3 mm apically below the nominal bone level) ¬chen.

OBJECT OF THE INVENTION

The object of the invention is to further improve a one- or two-part dental implant in terms of strength and applicability.

SOLUTION OF THE TASK

An essential basic idea of the invention consists in the development and creation of an implant, which creates a significantly increased inside diameter by the following two features: a) In the region defined on the basis of the nominal bone level in apical

Direction up to three millimeters below and another millimeter for safety beyond, so to one millimeter below (in the apical direction) the outlined by ENISO 14801: 2007 (D) test point addition) is given to a coarse thread ver¬zichtet; B) in this area (defined under point a)) a micro-thread of not more than 0.1 mm thread depth is created.

This implies that in the underlying part (in the apical direction) an extremely aggressi¬ves thread (macro thread) is added with large thread depth to the loss of Stabili¬tät in bone, the reduced surface in the critical, fracture-prone zone and compensate for the screw action of the implant.

The solution is provided by the features of claim 1.

ADVANTAGES OF THE INVENTION

The implant according to the invention, irrespective of whether it is now formed in one or two parts, thus has a macro-thread on the apical side and a micro-thread on the cervical side.

The micro-thread preferably has a thread depth of at most 0.1 mm (an advantageous embodiment has a thread depth of 0.04 mm), whereas the macro-thread has a thread depth of 0.2 to 2 mm depending on the apical direction. The micro-thread thus preferably has a constant thread depth, whereas the macro-thread varies in thread depth depending on the apical position.

Thus, there is a ratio of the macro-thread with respect to the largest thread depth to the micro-thread based on the smallest thread depth in the order of 10 to 20. An advantageous embodiment provides a ratio of 12 to 20 before, another preferred embodiment sees a ratio of 13 to 20 before. The mentioned ranges have the advantages that the implants formed in this way can be suitably used for all bone regions I-IV.

The area defined on the basis of the nominal bone level in an apical direction up to three millimeters below it is also defined as a critical zone or zone susceptible to fracture. In this critical zone and another millimeter for safety, ie up to one millimeter below the test point specified in EN ISO 14801: 2007 (D), a coarse thread is dispensed with; This means that in the critical zone a micro-thread is vorgese¬hen. The micro-thread preferably has a simple thread with a constant thread depth. However, this can be designed such that a 2, a 3, a 4 or even a 5 or 6-fold thread is provided.

The micro-thread interacts with the macroscopic thread provided in the apical region. Macro thread is called the thread because thread depth at the apical tip starts with a low value then increases, then decreases again. Thus, the macro-thread in the apical region has an extremely high thread depth (up to 2 mm), which then decreases in the cervical direction due to the preferably conical or comparable design of the main body. A sheath overlying the flanks of the macro-thread preferably has a parabolic shape. This parabolic shape has a very flat configuration at the apical tip, such that the distance from the sheath to the base body in the region of the tip is low but then initially very large in the cervical direction - up to an extremum - and as a result the thread depth is also large. In the cervical direction, the distance between the sheath and the main body subsequently decreases and thus the depth of the thread in the cervical direction decreases starting from the extremum, arranged immediately after the apical tip. Immediately here means that after a quarter, half or full turn or two or three turns or more, the thread depth already reaches an extremum.

The macro-thread serves to provide the compression necessary to compress the bone. As a result, the corresponding primary stability of the implant is ensured. Due to the thread depth creates a very large surface, especially in the first threads when screwing, so there is already felt here appropriate primary stability.

In the cervical direction, any compression of the compact should be avoided per se. Therefore, only a micro-thread is provided, which has a low to almost no longer detectable primary stability. As a result, the compression of the compact is minimized or even completely avoided. Another advantage is that the peri-implantitis risk is thereby at least reduced. This is because there is low bone compression in this area. This in turn means that bone loss and gum decline in this area is avoided. However, since the core diameter of the micro-thread is greater than that of the macro-thread, a stability is also ensured in relation to the high core diameter of the implant in this area.

The high primary stability in turn means that a rapid osseointegration is possible.

Exactly the interaction between the defined micro-thread that extends beyond the test point or test level defined per EN ISO 14801: 2007 (D) and the interaction with a macro-thread that provides a high primary stability is an implant, that applies equally to all bone categories (I to IV).

Due to the core diameter at the test limit or test level defined by ENISO 14801: 2007 (D) is given a high breaking strength, since this is preferably greater than 3.5mm. 3 mm in this area. The core diameter can according to the invention, however, be designed to be so large, inter alia, only because a macro-thread is provided which assumes the primary stability.

The micro-thread is designed in such a way that it has two areas per se, namely a region with a large core diameter, which is located in the cervical region of the implant, and a region with a small core diameter compared to the mentioned core diameter. The latter is characterized by the arrangement in the fracture-prone area (defined by EN ISO 14801: 2007 (D)).

Further advantageous embodiments will become apparent from the following description, the drawings and the claims.

DRAWINGS

FIG. 1 shows a section through a two-part implant, with a micro-thread and a macro-thread; FIG. FIG. 2 shows a section through a one-part implant with a macro-thread and a micro-thread; FIG. FIG. 3 is a side view of a one-piece implant according to FIG. 2; FIG. FIG. 4 shows a perspective view of the one-piece implant according to FIG. 2; FIG.

DESCRIPTION OF THE EMBODIMENTS

In Fig. 1, a two-part implant 1 is shown. FIGS. 2 to 4 show a one-piece implant 1. All of the following refers to Figures 1 to 4, unless otherwise indicated.

The implant 1 consists of a base body 2 and an abutment 3 which can be coupled to the base body 2. In order to establish the connection between the base body 2 and the abutment 3, a connecting element 4 is provided, which is designed as a screw in the embodiment shown here ,

The basic body 2 is essentially divided into two regions A and B.

In the region A, a macro-thread 5 is provided at the apical end of the implant, with a micro-thread 6 closing in the further region B in the cervical direction. The micro-thread 6 extends from the nominal bone level KN L = 3mmin apical direction. The point reached thereby also corresponds to the test limit or the test point according to EN ISO 14801: 2007 (D), wherein preferably the thread additionally extends at least 1 mm apically beyond. As a result, a multiple of microwebs is provided in comparison with the prior art. This length of at least 4 mm of micro thread already leads to a slight stability with corresponding bone structures and thus to better implantability. In the cervical direction, the core diameter 7 of the main body 2 of the implant 1 increases in such a way that it is greater in the partial area of the micro-thread compared to the core diameter 8.

The implant 1 has a uniform insertion torque in all bone classes I to IV. This is about 35Ncm and results in the maxilla or mandible, regardless of the corresponding bone class to a constant healing time of about 8 weeks.

During the screwing-in process of the implant 1 into the bone K (FIG. 3), the macro-thread 5 is then inserted sufficiently soon after the corresponding pre-drilling until it engages in the bone region. At the same time, the micro-thread 6, which in the embodiment illustrated here represents a 4-fold thread, ensures the corresponding stability and guiding, however, without compression.

The macro-thread gives corresponding primary stability, since it has an extremely large surface and, in particular in the apical region, an extremely high thread depth G. This thread depth is preferably up to 2 mm. An envelope which lies over the flanks of the macro-thread 5 preferably has a parabolic shape. This parabolic shape has a very flat configuration at the apical tip, such that the distance from the sheath to the base body 2 in the area of the tip is low but then very long in the cervical direction - up to an extremum - and thus the distance Thread depth 5 is also large. In the cervical direction, the distance between the sheath and the base body subsequently becomes smaller and thus the thread depth decreases in the cervical direction starting from the extender, arranged immediately after the apical tip. Immediately here means that after a quarter, half or full turn or two or three turns the Gewindetie¬fe already reached an extreme. The thread depth G varies from the apical point in the cervical direction such that it increases, reaches an extremum and then passes into the micro-thread.

Especially the ratio of the corresponding thread depths in the micro thread area and in the macro thread area, which in one embodiment lies at the factor 10 to 20, ensures optimum stability and healing time regardless of the corresponding bone class. Even if the ratio is 12 to 20 or 13 to 20, the properties remain almost unchanged.

Even if the macro-thread does not engage, the micro-thread still serves to make a corresponding fixation in the bone area, especially in sinus lift, when the residual bone is only 2 to 5 mm.

In order to obtain an optimal interaction of the micro-thread with the bone, a counter-sink drill is used, which corresponds to the contour of the core diameter of the Mikroge¬windes (area B). Thus, due to the extremely aggressive macro-thread imapikale range on the compression in the upper area (micro-threaded area) waived. It is known that the compression in the upper region, in particular in the compacta, leads to bone necrosis or bone loss. However, this lack of compression must be compensated for by the compression in the lower part (apical region) and by the large surfaces in the region of the macro thread.

LIST OF REFERENCE NUMBERS

DENTAL IMPLANT WITH ONE MICRO AND ONE MACRO THREAD 1 implant 2 base 3 abutment 4 connecting element 5 macro thread 6 micro thread 7 core diameter 8 core diameter A first zone B second zone G thread depth CN nominal bone levelK bone length

Claims (4)

Claims 1. Dental implant in one or two-part design, consisting of a base body and an abutment which can be arranged on the base body by posts or connecting element, wherein the base body is provided with a micro and a macro thread, characterized in that the micro-thread (6) is formed in that it has two areas, namely a. a region of large core diameter located in the cervical area of the implant (1) and b. an area with a small core diameter, which is small compared to the mentioned core diameter, wherein the micro-thread (6) with a maximum thread depth of 0.01 mm extends 4 mm in the inapical direction, and here has a core diameter of greater than 3.5 mm, inside the arrangement of the micro-thread (6) in the apical direction is a conical cross-sectional tapering of the core diameter, followed by a cylindrical formation, which merges into the area with the macro-thread (5) and a ratio of the macro-thread with respect to the largest thread depth to the micro-thread based on the smallest thread depth in the order of 13 to 20 is present. 2. Dental implant according to claim 1, characterized in that the thread depth of the macro-thread (5) of apical tip begins with a low value, then rises extremely, and then decreases in the cervical direction. 3. Dental implant according to at least one of the preceding claims, characterized in that regions of the core diameter of the micro-thread (6) are larger than the core diameter of the macro-thread (5). For this 4 sheets drawings