CH709868B1 - Dental implant with a short post and a ring element at the free end of the post. - Google Patents

Abstract

The invention relates to a dental implant made of ceramic, in particular zirconium oxide, comprising a dental implant body (2) and an external thread (4) arranged apically thereon for screwing into a jawbone and a post (3) arranged on its coronal end for receiving an abutment (10 ), the post (3) having a height (L) and being formed in one piece with the dental implant body (2). According to the invention, the height (L) is in a range from 2 mm to 4 mm, the post (3) at least has an undercut (8), this undercut (8) being created in that the free end (7) has a ring element (9), the ring element (9) having a larger diameter in plan view than the part of the post (3) which adjoins the ring element (9) and extends in the direction of the dental implant body (2), wherein the ring element (9) is a retention element (as a male), which with a m can interact with another retention element of the abutment (1) as (matrix). In addition, a dental implant system is provided that consists of the abutment and the dental implant.

Description

Technical field

The invention relates to a dental implant for a dental implant system according to the features of the preamble of claim 1 and an abutment according to claim 5 and a dental implant system according to claim 7.

State of the art

Dental implants are introduced into the jawbone in such a way that their upper edge is flush with the bone or ends above it in the area of the covering gums.

The tooth crown anchored on the dental implant is usually screwed to the dental implant by an intermediate piece or structural element, the so-called abutment, in the sense of a dowel-screw connection (dowel = implant, screw = abutment).

In the area of this transition there is a reduction in the jaw bone of about 1 mm in the first months after loading the dental implant. This is attributed, among other things, to the fact that there is a gap in the transition area between the dental implant and the abutment in which bacteria can multiply (Zipprich et al., 2007). Likewise, numerous studies (including Atieh et al., 2010) have shown that if the abutment has a smaller diameter than the dental implant, it has a positive effect on the preservation of the bone, i.e. the abutment does not touch the outer edge of the dental implant, but is shifted towards the center and thus lies further inside. As a result, the dental implant-abutment interface moves further away from the bone boundary, which enables better bone development and better gum attachment.

A basic distinction is made between one and two-part dental implants. The one-piece dental implants are constructed in such a way that the apical end and the cervical end of the dental implant, namely the coronal part, are connected to one another in one piece. In contrast, in the case of two-part dental implants, both a dental implant body and an abutment element are provided, which can be connected to one another.

The dental implant body of the two-part dental implant is first used with appropriate application in the jawbone of the patient. This time has to heal there, since the dental implant can wax in without any strain. In a further work step, the abutment is applied by connecting the abutment to the dental implant body by means of a connecting element.

To set an artificial tooth, it is necessary to completely remove the defective tooth, including its roots. A hole is then drilled in the jaw or a thread is cut into it. The dental implant is then screwed into this hole. After inserting the dental implant, which usually comprises at least the dental implant and a possibly arranged abutment or a post, it must wax in for at least three but up to six months until it is firmly connected to the jaw. During this healing phase, the part of the dental implant that protrudes from the gums must not be exposed to any or only slight mechanical loads, since otherwise the healing phase can be extended considerably or even lead to it not connecting to the bone at all.

After healing, the abutment is usually screwed and glued to the dental implant or connected with cement and then the attached structure such as a crown or bridge is applied to the abutment. The abutment is a type of post that is used to mechanically attach the abutment to the abutment.

[0009] However, this has some disadvantages. In the area of the transition from dental implant to abutment, there is an unavoidable micro-gap, which represents a retention niche for bacteria. By placing this micro-gap directly above the bone, there is constant contamination and bacterial contamination. As a result, in the course of the natural remodeling processes after the insertion of a dental implant in the area of the dental implant shoulder (= upper edge), a resorption process can be observed, which is due, among other things, to the bacterial load emanating from the gap. In particular, there are gaps between the abutment and the dental implant, which are bacterially problematic, especially if they are at the bone level and are made of flexible materials (titanium). As a result of the load, the saliva-bacteria mixture in the gap is pumped out and pumped into the gap.

In addition, the posts must be of a certain size so that bridges or crowns can be firmly attached to them at a later point in time so that they do not come loose under loads. Because the bigger the post, the better the neck of the crown. However, this also leads to a considerable risk that the dental implants are loaded during the healing phase and therefore do not heal. This in turn means that the dental implants that are screwed in fail or at least have to be removed. This problem occurs in particular in one-piece dental implants in which the post is an integral part of the dental implant.

In ceramic dental implants, the structure on the post is usually always made of ceramic or zirconium oxide. In the case of one-piece dental implants in particular, however, the dentist is bound to cement the abutment or the crown / denture directly on the post. It is no longer possible for him to remove the crown or denture and to make any changes. This is because, regardless of which cement is used per se, the connection zirconium oxide to zirconium oxide is no longer soluble.

[0012] Implantologists and dentists are accustomed to being able to build up on dental implants which are at least partially removable. Losing weight is important, for example, if appropriate adjustments have to be made after the trial period, but also if the ceramic breaks, but the aesthetics also have to be revised. For this reason, the previous two-part titanium dental implants are provided with screwed solutions.

[0013] Two-part dental implants with a removable abutment are also known from the prior art. They are used particularly when the final restoration of tooth replacement cannot be predicted over a long period of time. This is especially true if there is bone substance that brings with it the probability that the dental implants only partially heal well. For example, a so-called Locator® push button on the dental implant is known. However, one-piece dental implants do not provide such solutions. Above all, because the partially removable construction with a push button or locator in titanium brings with it a high degree of wear due to abrasion, which means that the push button and locator abutments made of titanium usually have to be replaced after 3 to 5 years. With a one-piece push-button or locator ring, this would mean that the entire dental implant would have to be removed from the bone.

[0014] Two-part titanium dental implants have so-called insertion aids which can be screwed firmly onto the dental implant. As a result, they can be held firmly and firmly during the screwing-in process, even when they are being guided from the sterile packaging to the hole in the jaw. However, one-piece dental implants, in particular those made of zirconium oxide, generally do not provide such insertion tools, since the post protrudes and no tools are provided to grip and fix the dental implant differently. If the dental implant accidentally falls out of the holder, it is unusable because it must not be re-sterilized (Medical Devices Act).

Object of the invention

The object of the invention is to provide a one-piece dental implant made of ceramic, in particular zirconium oxide, with which at least some of the disadvantages that have been listed above can be avoided.

Solution of the task

The solution of the problem is solved by the features of claim 1.

Advantages of the invention

According to the invention it is provided to form a dental implant made of ceramic with a dental implant body and with a post in one piece, but the post has only a small height. The post attaches to a dental implant body in the coronal direction and extends in the cervical direction. This post is preferably rotationally symmetrical and its axis is identical to the axis of the likewise rotationally symmetrical dental implant body. The diameter of the post is less than the diameter of the dental implant body in the area in which the post attaches.

A small height is understood to mean a size range between 2 mm and 4 mm, the height being measured from the front attachment of the dental implant body to the free end of the post. A preferred embodiment provides for a post height of 3 mm. In comparison to the prior art, the posts known hitherto for one-piece zirconium oxide dental implants are at least 4 mm in size or even larger. The post size is so extremely small that the dental implant can always remain in the healing phase without protective measures. If the patient wears a prosthesis, it can simply be ground out, since the small post takes up little space.

The post has an enveloping contour, which is preferably conical and preferably has a 6 to 10 degree inclination with respect to its vertical, the post tapering towards the free end with respect to its diameter.

An embodiment advantageously has a functional element with a plurality of surfaces, preferably four surfaces, which are preferably located directly at the base of the post, i.e. are arranged at the transition from the dental implant body to the post.

In a preferred embodiment, the functional element comprises projections or undercuts arranged on the circumference of the post. With a suitable screwing tool, a positive and non-positive connection can be made between the screwing tool and the post. This enables simple screwing in with a screwing tool.

These surfaces of the functional element preferably offer a double function, which can be seen on the one hand in that a screwing tool acts on the functional element in order to screw in the dental implant body and, on the other hand, to interact with a crown or the abutment.

Subsequent to the functional element - in the coronal direction - an undercut is provided. This means that first a reduction in diameter and then an increase in diameter in the coronal direction is formed. This results in a ring element. The size is dimensioned such that it also fits on a small diameter of 4mm on reduced-diameter dental implants.

In contrast to the prior art, the dental implant thus has a very extremely short post which, due to its technical design, namely the provision of a corresponding undercut with a ring element arranged at the free end, permits many possibilities.

One possibility is to provide a secure holder for the attending physician with a gripping and screwing tool which is clicked over the post like a push button. This makes it possible for the one-piece ceramic dental implant to be guided from its storage unit to the patient without losing the patient, regardless of the corresponding movement. After screwing in, the screwing tool is simply pulled off the "push-button connection". One embodiment provides that the ring element is symmetrical and thus round. Another embodiment provides that the ring element is “cut off” when viewed from above, so that the ring element can also be used as a screwing tool.

Thus, there is the possibility for the attending physician to directly adapt and apply the crown or the bridge to the one-piece dental implant. This is possible with appropriate connecting elements such as cement or plastic.

On the other hand, there is also the possibility of applying an abutment which is constructed in such a way that it closes tightly on the edge of the dental implant or dental implant body. This abutment rests on the short post, the outer diameter of which is preferably larger than the dental implant body in the area of the attachment of the post. The post offers a first retention element (male) which interacts with a further retention element (female) arranged within the abutment, so that there is a usable connection. Since the dental implant and thus also the post consist of zirconium oxide, the ring element together with the undercut can be designed as a male part, for example as a locator <®> ring, and can be dimensioned such that corresponding clamping ring elements as a male part, for example Novaloc <®> female part , can be added to create a detachable connection.

The abutment is also made of zirconium oxide and has a sufficient wall thickness. Sufficient is to be understood in the order of magnitude of approximately 0.5 mm to 2 mm. The abutment can be screwed onto the post of the dental implant body with a screw, for example M1.5 or M1.6. For this purpose, a threaded hole is provided on the front end of the free end of the post. With regard to the screwing with the insertion tool, the temporary restoration and the definitive denture, this threaded hole offers a variety of options for efficiently and effectively supplying the dental implant with dentures. To date, no designs of one-piece dental implants are known from the prior art which have a threaded bore on the end face. Due to the choice of material (ceramic), a particularly stable design of this threaded hole is possible. This threaded connection can only be activated or used when high forces act on the abutment.

The abutment 10 itself also has a thread on the side facing the dental implant. This thread is usually larger, for example it has an order of magnitude of M2.5. This thread is preferably formed in a chimney-like construction pointing away from the abutment. This in turn brings with it the possibility that a further “restoration”, such as a crown or bridge-supporting bar construction, can be screwed onto the abutment.

To ensure the hold between the abutment and the dental implant, the retention elements are provided. These retention elements enable the abutment to lie tightly against the posts of the dental implant with a defined force, since these retention inserts are available in different variants with regard to the defined withdrawal force. A preferred embodiment provides that a clamping ring element (matrix) engages around the undercut on the post within the abutment and thus forms a fixation. The abutment is placed on the post like a push button and pressed until the clamping ring element inside the abutment passes over the ring element (male) on the post and snaps into the undercut (clicks). This means that the abutment can also be removed. Novaloc <®> matrices and retention inserts, for example, can be used as clamping ring elements. The clamping ring elements have a defined pull-off force, which is preferably in the ranges from 6N to 25N.

Such training for one-piece dental implants made of titanium would not make sense, since this retention element would wear out and the dental implant would have to be replaced approximately every 3 to 5 years. Training in zirconium oxide makes sense because there is no wear and flexibility is gained. For example, you can start with e.g. provisionally supply four locator-based dental implants. Even over a longer period of time, the flexibility is retained to form the abutment initially releasably and possibly later firmly.

As an alternative, a cement lock can also be used with the same abutment and the same post.

The final crown shape can be fired directly onto the abutment. Then this crown can be cemented directly - no retention element is used. As a result, the cement flows into the undercut below the ring element and into the recess of the retention element in the abutment. A cement ring forms around the post in the area of the undercut, which in the sense of a “cement lock” prevents the crown from detaching from the post in spite of the small post size. Alternatively, however, a second abutment without a recess can be used for the retention element - this contains an annular recess to form the cement ring. But there is also the possibility of screwing the crown directly onto the post with the screw. Furthermore, by inserting the retention element, as described above, there is also the possibility of “clicking” the crown on the post and thus giving the patient the opportunity to remove the dentures daily for cleaning and to clean dentures and posts.

Due to the design of the post and the interaction of the abutment with the retention element and possibly the screw which can be screwed into the end face of the post, any denture or temporary can be clicked, screwed and cemented. This allows abutments to be placed on this post as a mesostructure (by screwing, clicking or cementing).

Because of the design and design of the dental implant system, it is no longer necessary to technically process the dental implant in the mouth (for example, to grind it). Based on the modeling of the abutment structure, this can be done outside the mouth, for example by the dental technician.

So-called disangulations can now be compensated by the dental technician by grinding the abutment, which is also made of ceramic, since the abutment, in contrast to the far-reaching state of the art, has sufficient wall thickness.

Since the post contains the ring element, in the event of loss of dental implants or if not enough dental implants can be inserted, the dentures can be provided with a removable solution immediately by inserting retention inserts (for example Novaloc <®>) into a prosthesis. Conversely, a planned and existing removable solution when inserting further dental implants can be easily converted into a fixed or conditionally fixed restoration by the options mentioned above.

Further advantageous refinements emerge from the following description, the drawings and the claims.

drawings

[0039] The figures show: <tb> Fig. 1 <SEP> a three-dimensional view of the one-piece dental implant with the specially designed post; <tb> Fig. 2 <SEP> a further view of the post of the dental implant according to FIG. 1; <tb> Fig. 3 <SEP> a three-dimensional view of the dental implant system consisting of the specially designed dental implant with the corresponding post and an abutment; <tb> Fig. 4 <SEP> a section through the abutment according to FIG. 3; <tb> Fig. 5 <SEP> a section through the abutment with a retention element; <tb> Fig. 6 <SEP> a section through the abutment with a cement lock provided.

Description of an embodiment

1 and 2, part of the dental implant system is shown. The dental implant 1 consists of the dental implant body 2 and the post 3 which is integrally connected to the dental implant body 2.

Both dental implant body 2 and post 3 consist of a ceramic material, for example zirconium oxide.

The dental implant body 2 has an external thread 4 at its apical end, which extends in the cervical direction. The largest diameter of the dental implant body 2 in the embodiment shown here is preferably up to 3.8 mm, but can also vary up to 4.6 or 5.4 mm.

The dental implant body 2 has the post 3 on the front side in the cervical (coronal) direction. This post 3 is rotationally symmetrical about an axis A3. The axis A3 is congruent with the axis A2 of the dental implant body 2.

Starting from the approach of the post 3, a functional element 5 is initially provided in the embodiment shown here in the figures. This functional element 5 has the function of interacting with a tool in order to exert a rotational movement in the direction of arrow 6 on the dental implant 1 in order to be able to use it properly. In this context, the functional element 5 represents an insertion aid (for an insertion tool).

Then the post 3 tapers to its free end 7 and forms an undercut 8 before it changes into a ring element 9 with a larger diameter with respect to the undercut 8. The ring element 9, which has a width B, can be regarded as a locator <®> ring. This ring element 9 forms a first retention element and is referred to as a male.

The post 3 has a length L, this length is extremely short. Extremely short here means that the post has a maximum length of approx. 2mm to 4mm.

The dental implant 1 is now used so that a supply can either be applied directly to the post 3. By supply is meant, for example, a crown or a bridge. It is also conceivable that a corresponding positive and non-positive connection between the post and crown can be achieved with a cement lock. A plastic-like design and a firm connection therewith are also conceivable. As an alternative or in addition to this, a screw connection is also provided.

The complete dental implant system Z is shown in FIG. 3. It consists of the dental implant 1 and the abutment 10. The abutment 10, which is shown in section in FIG. 4, has a sufficient wall thickness W (preferably 1-3 mm) compared to the prior art. This has the advantage that the outer contour can be adjusted according to the needs.

In addition, two bores are provided in the area of the abutment 10, namely a first bore 11 and a further bore 12. The first bore 11 corresponds, as can also be seen in the sectional view in FIGS. 5 and 6, with the post 3. By introducing a further retention element 13 - referred to as a matrix - (FIG. 5), a positive and non-positive connection between the abutment 10 and the dental implant body 2 is achieved, which corresponds to a threaded bore 15b inside the post 3.

In this case, a cavity is formed within the abutment 10, which is designed such that a retention insert 13 can be inserted. When the abutment 10 is fitted, the retention element 13 engages in the undercut 8 and interacts with it. The abutment 10 is now arranged on the post 3 with a defined pull-out force. Male and female are joined together.

Alternatively, a cement lock 14 can be introduced into the area in which the retention element 13 is provided. Cement flows into the area of the undercut 8 below the ring element 9 and into the recess for the retention element 13 in the abutment. This forms a cement ring around the post, which in the sense of a cement lock 14 prevents the crown from detaching from the post in spite of the small post size.

An additional screw connection 15 (M1.4 to M1.8 - length 1.0 to 3 mm) ensures that the connection can withstand extreme loads. The screw connection 15 consists of a screw 15a and a threaded bore 15b. This screw 15a is guided through the bore 12 of the abutment 10 and interacts with the threaded bore 15b, which is arranged on the end face at the free end 7 of the post 3. The further bore 12 is designed such that it additionally has a seat 16 for a screw head of a screw 15a. The screw 15a is seated on a seat 16 within the abutment 10, so that the screw 15a holds the abutment 10 on the post 3.

The further bore 12, which lies opposite the first bore 11, is intended to be able to accommodate further connections, for example a crown or a bridge can be screwed over this. In the drawing, a screw 17 is shown, which is suitable for screwing the crown or bar to the abutment 10. If this screw 17 is not required for screwing, a plug element, as shown in FIGS. 3 to 6, is provided). This screw 17 thus has no function.

The abutment 10 serves to receive the supply accordingly. Due to the sufficient wall thicknesses - which, among other things, are also possible due to the short post - disangulation is also possible. In particular, because the abutment 10 consists of zirconium oxide (ceramic) and can be ground in the laboratory by the dental technician. This enables parallelism to be created between two actually non-parallel dental implants. However, it can also be fired directly onto this zirconium oxide abutment and a crown can be made.

The inventive dental implant system is characterized by the extremely short post size of the dental implant. This advantageously means that the dental implant can always remain in the healing phase without any protective measure. If the patient wears a prosthesis, it can simply be ground out, since the small post takes up little space.

In this healing phase, a so-called healing cap could also be clicked onto the post in order to prevent the threaded bore 15b from becoming dirty and to not present any angular edges on the tongue.

Due to the provided push button geometry on the surface of the post, a restoration can be attached to the post by inserting a retention element into the abutment by means of a click connection, which is easily removable again. This makes it easy to test the structure.

However, the final crown shape can also be fired directly onto the abutment. This crown can also be cemented directly so that no retention element or screw has to be used. This causes the cement to flow into the undercut of the abutment. A cement ring forms around the post, which, in the sense of a cement lock, prevents the crown from detaching from the post in spite of the small post size.

Alternatively, a second abutment without a cutout for the retention element can also be used. This contains an annular recess for forming the cement ring. However, there is also the possibility of screwing the crown directly onto the post with a screw, for example in the order of M1.6.

An advantageous further embodiment provides that by inserting a retention element, the crown can only be clicked on the post and thus permanently gives the patient the opportunity to remove the dentures daily for cleaning and to clean dentures and dental implants. In addition, a bar construction on the abutment can also be achieved via the larger threaded connection. The abutment is then used as a so-called mesostructure.

REFERENCE SIGN LIST

1 dental implant 2 dental implant body 3 post 4 external thread 5 functional element 6 arrow direction 7 free end 8 undercut 9 ring element 10 abutment 11 first hole 12 further hole 13 retention element 14 cement lock 15 screw connection 15a screw 15b threaded hole 16 seat 17 screw A2 axis A3 axis B width L length W wall thickness Z dental implant system

Claims (7)

1. Dental implant (1) made of ceramic, in particular zirconium oxide, comprising a dental implant body (2) and an external thread (4) arranged apically thereon for screwing into a jawbone and a post (3) arranged on its coronal end for receiving an abutment (10) , wherein the post (3) has a height (L) and is formed in one piece with the dental implant body (2), characterized in that the height (L) is in a range from 2 mm to 4 mm, the post (3) having at least one undercut (8), this undercut (8) arises from the fact that the free end (7) has a ring element (9), the ring element (9) having a larger diameter in plan view than the part of the post (3) attached to the ring element (9 ) connects and extends in the direction of the dental implant body (2), wherein the ring element (9) is a retention element as a male, which can interact with a retention element of the abutment (10) as a female. 2. Dental implant (1) according to claim 1, characterized in that the post (3) has a threaded bore (15b) at its free end (7). 3. Dental implant (1) according to one of the preceding claims, characterized in that the post (3) has an envelope contour which is essentially conical and has a 6 to 10 degree inclination with respect to its perpendicular and the post (3) is therefore tapered to its free end (7). 4. Dental implant according to one of the preceding claims, characterized in that a functional element (5) is provided on the circumference of the post (3) in the formation of projections and undercuts, that on the one hand a positive and non-positive connection is made with an insertion tool and on the other hand can interact with the abutment (10). 5. Abutment for interaction with a dental implant according to one of claims 2 to 4, characterized in that the abutment (10) has two bores, namely a first bore (11) and a further bore (12), which lie opposite one another on an axis, wherein this first bore (11) corresponds to the post (3), the abutment (10) having an inserted retention element (13) as a matrix in order to establish a positive and non-positive connection between the abutment (8) by engaging in the undercut (8). 10) and the dental implant body (2), and wherein the further bore (12) has a seat for the screw head of a screw (15a) which can cooperate with a threaded bore (15b) to produce a screw connection (15). Abutment according to claim 5, characterized in that the abutment (10) consists of zirconium oxide. 7. Dental implant system with a dental implant (1) according to one of claims 2 to 4 and an abutment (10) according to one of claims 5 or 6.