Dental implant

Abstract

The invention relates to a zirconium dioxide-based dental implant comprising a mucophilic section for the growth of soft tissue, said mucophilic section having a roughened surface with an average roughness value (Ra) of approx. 0.3 µm to approx. 2 µm.

Description

[0001] dental implant

[0002] Description

[0003] The invention relates to a dental implant and a method for manufacturing a dental implant. Furthermore, the invention relates to the use of a dental implant according to the invention.

[0004] Titanium-based implants are well-known (e.g., Straumann® Standard Plus). These preferably have a smooth surface. Therefore, it was assumed that a smooth surface would also be advantageous for zirconia-based implants.

[0005] WO 2005 / 120386 Al describes a zirconia-based dental implant with a roughened surface. WO 2019 / 228713 Al describes a method for sandblasting a surface section of a zirconia-based dental implant to improve osteogenesis.

[0006] A common problem with dental implants is slow and / or incomplete osseointegration. This process occurs when soft tissue (gingiva) and hard tissue (bone) grow around the implant. A problem with slow and / or incomplete osseointegration is that contaminants, such as plaque, and bacteria can become trapped between the implant and the surrounding tissue. Even if complete osseointegration eventually occurs, these contaminants and bacteria can lead to inflammation and implant failure in the long term. Such inflammation often begins as a reversible soft tissue inflammation (peri-mucositis). However, this can develop into irreversible peri-implantitis, which affects the bone and is diagnosable as a loss of supporting tissue. Some of today's dental implants require approximately four weeks for osseointegration, and the failure rate after 10 years is between 20% and 30%.In cases of inflammation that may lead to implant failure, the soft tissue and the body are subjected to constant inflammatory stress for years. One object of the present invention is to further improve existing dental implants. In particular, the invention aims to provide a dental implant that heals quickly, exhibits a low failure rate even after extended periods, and ideally does not cause constant inflammatory stress. A further object is to describe a manufacturing process for such a dental implant.

[0007] At least one of the tasks is solved by a zirconia-based dental implant, wherein the dental implant comprises a mucophilic section for soft tissue ingrowth, wherein the mucophilic section for soft tissue ingrowth has a roughened surface, wherein the roughened surface of the mucophilic section has a mean roughness (Ra) of about 0.3 pm to about 2 pm.

[0008] The mucophilic section, with its roughened surface, promotes the ingrowth of soft tissue. An advantage of the implant according to the invention is that gingival epithelium grows into it within four hours. In the prior art, this often takes 14-21 days. This rapid ingrowth prevents contaminants and bacteria from penetrating between the new implant and the hard tissue (bone) and soft tissue (gingiva). This can reduce the failure rate.

[0009] The dental implant is a zirconium dioxide-based dental implant. A zirconium dioxide-based dental implant means that the dental implant consists essentially of zirconium dioxide, preferably modified zirconium dioxide. In a preferred embodiment, the dental implant contains at least 85% or 95% zirconium dioxide by weight. Preferably, the zirconium dioxide is stabilized zirconium dioxide, for example, yttrium-stabilized zirconium dioxide.

[0010] The mean roughness (Ra) of the roughened surface of the mucophilic section is from about 0.3 pm to about 2 pm, preferably from about 1 pm to about 2 pm, more preferably about 1 pm, and most preferably about 0.7 pm.

[0011] The range from approximately 0.3 pm or approximately 1 pm to approximately 2 pm, for example, consists of the range from > 0.5 pm or > 0.50 pm to < 2.4 pm or < 2.49 pm. The specification of approximately 1 gm, for example, consists of the range from > 0.5 pm or > 0.50 pm to < 1.4 pm or < 1.49 pm.

[0012] In a preferred embodiment, the mean roughness (Ra) of the roughened surface of the mucophilic section is > 0.50 pm to < 2.49 pm, more preferably > 0.50 pm to < 1.49 pm, and most preferably 0.7 pm.

[0013] The term "center roughness" (Ra) used in this document can also be referred to as arithmetic mean roughness, AA (arithmetic average), and CLA (center line average). The arithmetic mean roughness is the arithmetic mean of all ordinate values ​​within a single measurement section (e.g., along a substantially horizontal surface). The single measurement section can be, for example, 0.8 mm. The cut-off wavelength c can be 0.8 mm or 2.5 mm. The center roughness (Ra) can be measured, for example, with a Keyence VR-5000 3D profilometer. The results comply with the specifications of DIN EN ISO 4287:2010-07. DIN EN ISO 4287:2010-07 also contains designations, definitions, and parameters of surface finish, such as the center roughness (Ra). Rules and procedures for assessing surface quality can be found in DIN EN ISO 4288: 1998-04.Accordingly, the determination of the mean roughness (Ra) and / or the roughness depth (Rz) can be carried out in accordance with DIN EN ISO 4288: 1998-04.

[0014] A surface can be considered a roughened surface if the surface has a mean roughness value (Ra) of > 0.3 pm, preferably > 0.7 pm.

[0015] Preferred embodiments are also described in the claims.

[0016] Preferably, the dental implant comprises an ossophilic section with an external thread for anchoring the dental implant in bone, wherein the ossophilic section has a roughened surface to promote bone ingrowth. Preferably, the roughness of the roughened surface of the ossophilic section differs from the roughness of the roughened surface of the mucophilic section. The different roughness of the roughened surfaces can be reflected in a different mean roughness (Ra). Particularly preferably, the roughened surface of the ossophilic section has a greater roughness (especially a greater mean roughness) than the roughened surface of the mucophilic section. For example, the roughened surface of the ossophilic section can have a mean roughness (Ra) of approximately > 2 pm, for example, from approximately 3 pm to approximately 13 pm, or for example, from approximately > 2.50 pm to < 13.49 pm.

[0017] The mean roughness (Ra) of the roughened surface of the ossophilic section ranges, for example, from approximately 3 pm to approximately 13 pm. The range from approximately 3 pm to approximately 13 pm consists, for example, of values ​​> 2.5 pm or > 2.50 pm to < 13.4 pm or < 13.49 pm. The specification "approximately > 2 pm" describes, for example, a value of > 2.5 pm or > 2.50 pm.

[0018] A corresponding ossophilic section promotes rapid and permanent bone growth, thereby reducing the rate of bone loss.

[0019] Preferably, the mucophilic section and the ossophilic section are formed from the same material, preferably from stabilized zirconium dioxide.

[0020] In a preferred embodiment, the roughened surface of the mucophilic section has a roughness depth (Rz) of about 2 pm to about 8 pm, preferably of about 4 pm.

[0021] The range for the preferred roughness depth (Rz) of the roughened surface of the mucophilic section from approximately 2 pm to approximately 8 pm consists, for example, of the range from > 1.5 pm or > 1.50 pm to < 8.4 pm or < 8.49 pm. The specification for the preferred roughness depth (Rz) of the roughened surface of the mucophilic section from approximately 4 pm consists, for example, of the range from > 3.5 pm or > 3.50 pm to < 4.4 pm or < 4.49 pm.

[0022] In a particularly preferred embodiment, the roughened surface of the mucophilic section has a roughness depth (Rz) of > 1.50 pm to < 8.49 pm, preferably of > 3.50 pm to < 4.49 pm.

[0023] A corresponding mucophilic area promotes the rapid and permanent ingrowth of soft tissue, thereby reducing the rate of tissue loss. The term surface roughness (Rz) used in this document can also be referred to as averaged roughness and describes the arithmetic mean of the individual roughness depths of several measurement sections. An individual roughness depth is the greatest vertical distance from the lowest to the highest profile point within the individual measurement section. The roughness depth (Rz) can be determined according to DIN EN ISO 4288: 1998-04.

[0024] Preferably, the roughened surface of the mucophilic section is roughened with an abrasive before the final sintering of the green body by sandblasting. Preferably, the roughened surface of the ossophilic section is also roughened with the abrasive before the final sintering of the green body by sandblasting. The abrasive can comprise a powder selected from calcium phosphate powder, hydroxyapatite powder, and corundum powder. For example, an abrasive comprising calcium phosphate powder and / or hydroxyapatite powder and / or corundum powder is used. Furthermore, it is possible for the abrasive to consist of calcium phosphate powder and / or hydroxyapatite powder and / or corundum powder. Particularly preferably, the abrasive contains corundum.

[0025] Sandblasting the green body, especially with corundum, can roughen the surface, which later shapes the roughened surface of the mucophilic section as well as the roughened surface of the ossophilic section.

[0026] Preferably, the roughened surface of the mucophilic section is formed from native tetragonal zirconium dioxide, particularly preferably from native polycrystalline tetragonal zirconium dioxide. In a preferred embodiment, the roughened surface of the mucophilic section is free of calcium phosphate particles, hydroxyapatite particles, and corundum particles (aluminum oxide particles).

[0027] A roughened surface of native tetragonal zirconium dioxide has proven particularly advantageous for the rapid growth of soft and hard tissues. Such a surface can be obtained if no further surface treatment is performed after sintering, especially if no mechanical processing (e.g., roughening) is carried out after sintering. Such mechanical processing can destroy the native tetragonal zirconium dioxide structure. In other words, the roughened surface of the mucophilic section is preferably formed from pure or undamaged tetragonal zirconium dioxide.

[0028] Preferably, soft tissue grows into the roughened surface of the mucophilic section within one to seven days, more preferably within one to three days. This preferably creates a seal between the soft tissue and the implant.

[0029] In the prior art, this often takes 14-21 days. The dental implant according to the invention quickly prevents contaminants and bacteria from penetrating between the new implant and hard or soft tissue. This reduces the failure rate, particularly the long-term failure rate associated with years of inflammation.

[0030] In a preferred embodiment, the mucophilic section for the growth of soft tissue is arranged on a conical part of the dental implant.

[0031] In a preferred embodiment, the mucophilic section for soft tissue growth is arranged on a part of the dental implant that connects an abutment to a part of the dental implant on which the ossophilic section with external thread for anchoring the dental implant in a bone is arranged.

[0032] In a preferred embodiment, the mucophilic section for soft tissue growth is arranged on a part of the dental implant that has a larger diameter than a part of the dental implant on which the ossophilic section with external thread for anchoring the dental implant in a bone is arranged.

[0033] In a preferred embodiment, the mucophilic section for the growth of soft tissue after implantation of the dental implant is not in direct contact with bone.

[0034] Another object of the present invention is to provide a manufacturing process for an improved dental implant.The problem is solved by a method for manufacturing a dental implant, preferably a dental implant according to the invention, comprising the steps of: a) providing a zirconium dioxide-based green body in implant form, b) at least partially sandblasting the green body with an abrasive, wherein the sandblasting at least partially roughens the surface of the green body, resulting in a sandblasted green body, wherein the abrasive preferably contains corundum, c) sintering the sandblasted green body, resulting in a dental implant comprising a mucophilic section for soft tissue ingrowth, wherein the mucophilic section for soft tissue ingrowth has a roughened surface, wherein the roughened surface of the mucophilic section has a mean roughness (Ra) of about 0.3 pm to about 2 pm, preferably of about 1 pm to about 2 pm, more preferably of about 1 pm, and particularly preferably of about 0.7 pm.

[0035] In a preferred embodiment, the roughened surface of the mucophilic section has a mean roughness value (Ra) of > 0.50 pm to < 2.49 pm, more preferably of > 0.50 pm to < 1.49 pm, and most preferably of 0.7 pm.

[0036] The method makes it possible to obtain a dental implant according to the invention with the described properties and advantages.

[0037] The process parameters described below as preferred can, especially in combination with the other described process parameters, result in a dental implant with a particularly advantageous roughened surface and particularly advantageous properties.

[0038] In a preferred embodiment, step a) provides a green body that has been pre-sintered / pre-fired. Step a) may also include pre-sintering / pre-firing the green body.

[0039] In a preferred embodiment, the green body is pre-sintered / pre-fired at a temperature of 600 °C to 1100 °C, particularly 700 °C to 1050 °C. These are low pre-sintering temperatures, resulting in a relatively soft green body. This allows the abrasive or abrasive particles to act more easily on the green body. In other words, a relatively soft green body is easier to roughen, allowing for less intensive sandblasting and thus less abrasive contamination.

[0040] The abrasive is preferably applied to the surface of the green body during sandblasting at a pressure of 0.1 bar to 10.0 bar, particularly 1.0 bar to 5.0 bar. The pressure at which the abrasive is applied to the surface of the green body in step b) must be selected based on the provided green body. The softer the surface to be blasted, the lower the pressure or blasting pressure can be. The surface hardness is related to the selected pre-sintering temperature. For example, at a pre-sintering temperature of 800 °C, a blasting pressure of approximately 1.0 bar can be selected. At a pre-sintering temperature of 1,000 °C, a blasting pressure of approximately 2.0 bar can be selected.

[0041] In sandblasting, the abrasive is preferably applied via at least one nozzle. The at least one nozzle is particularly preferably made of zirconium-containing material, preferably zirconium dioxide or zirconium.

[0042] The use of zirconium-containing nozzles can reduce contamination of the green body with other elements, resulting in a more homogeneous product with the desired roughness.

[0043] Preferably, the at least one nozzle is located at a distance of 10 cm to 20 cm from the green object during sandblasting. Preferably, the at least one nozzle has a nozzle diameter of 0.6 mm to 1.5 mm, more preferably of 0.7 mm to 1.0 mm.

[0044] In combination with the other described process parameters, these process parameters have resulted in dental implants with a particularly advantageous roughened surface and particularly advantageous properties.

[0045] In a preferred embodiment, the green body rotates during sandblasting. Preferably, the green body rotates at a speed of 200 to 300 revolutions per minute during sandblasting. The rotation results in a more uniform product. Furthermore, the amount of abrasive remaining on the green body is reduced when the green body rotates at a certain speed.

[0046] The blasting abrasive can comprise a powder selected from calcium phosphate powder, hydroxyapatite powder, and corundum powder. For example, a blasting abrasive comprising calcium phosphate powder and / or hydroxyapatite powder and / or corundum powder is used. Furthermore, it is possible for the blasting abrasive to consist of calcium phosphate powder and / or hydroxyapatite powder and / or corundum powder. Particularly preferably, the blasting abrasive contains corundum.

[0047] Corundum has proven particularly effective in combination with the other process parameters to produce a dental implant with a particularly advantageous roughened and clean surface and particularly advantageous properties.

[0048] Preferably the particle size of the blasting medium, in particular the corundum powder, is 70 pm to 150 pm.

[0049] This particle size has proven particularly effective in combination with the other process parameters to produce a dental implant with a particularly advantageous roughened and clean surface and particularly advantageous properties.

[0050] Preferably, the roughening of the green body is not uniform, so that at least two sections with differently roughened surfaces are present, which later form the roughened surface of the mucophilic section and the roughened surface of the ossophilic section. This uneven roughening of the green body can be achieved by partially covering a portion of it during sandblasting. It can also be achieved by adjusting the distance between the nozzle and the green body and / or their positions. For example, the particle velocity and quantity of the abrasive decrease from the center of the jet to its edge. In this way, the dental implant is optimally adapted, allowing soft and hard tissue to integrate quickly and permanently.

[0051] Preferably, the sandblasted green body is freed from blasting media before sintering, preferably using compressed air and / or ultrasound.

[0052] Thus, during sintering, a roughened surface made of native tetragonal zirconium dioxide, preferably of native polycrystalline tetragonal zirconium dioxide, can be formed.

[0053] Sintering can take place, for example, at a temperature of 1300 °C to 1700 °C, preferably 1400 °C to 1600 °C. A slow temperature increase is preferably used initially in a sintering furnace. Preferably, the temperature increase is approximately 100 °C per hour. Once the final temperature is reached, this temperature should be maintained for approximately 0.5 to 4.0 hours, particularly for 1.0 to 3.0 hours, and most preferably for approximately 2.0 hours. The heat supply can then be switched off, and the dental implant should remain in the sintering furnace until it has completely cooled down. Alternatively, the temperature in the sintering furnace can be allowed to decrease slowly. In this step, the final sintering or firing of the dental implant component takes place. A usable dental implant is then available.

[0054] Preferably, a roughened surface made of native tetragonal zirconium dioxide, preferably of native polycrystalline tetragonal zirconium dioxide, is formed during sintering.

[0055] A roughened surface of native (polycrystalline) tetragonal zirconium dioxide has proven particularly advantageous for the rapid growth of soft and hard tissues. Such a surface can be obtained especially if no further surface treatment is performed after sintering, particularly if no mechanical processing (e.g., roughening) is carried out after sintering. Such mechanical processing can destroy the native tetragonal zirconium dioxide structure. In other words, the roughened surface of the mucophilic section is preferably formed from pure (polycrystalline) tetragonal zirconium dioxide or undamaged (polycrystalline) tetragonal zirconium dioxide.

[0056] Accordingly, the surface of the dental implant is preferably not roughened after sintering.

[0057] The invention also relates to a dental implant obtainable by a method according to the invention.

[0058] The inventive method can produce a dental implant with an advantageous roughened surface made of native polycrystalline tetragonal zirconium dioxide with defined and matched roughness, to which soft and hard tissue grow quickly and densely.

[0059] The invention also relates to a dental implant according to the invention for use in the prophylaxis and / or treatment of inflammation selected from reversible soft tissue inflammation (peri-mucositis) and irreversible soft-hard tissue inflammation (peri-implantitis).

[0060] As described at the outset, an advantage of the implant according to the invention is that gingival epithelium grows into it within four hours. In the prior art, this often takes 14-21 days. The dental implant according to the invention prevents contaminants and bacteria from penetrating between the new implant and hard tissue (bone) or soft tissue (gingiva), thereby preventing or treating reversible soft tissue inflammation (peri-mucositis) and, if necessary, irreversible soft-hard tissue inflammation (peri-implantitis).

[0061] The invention also relates to the use of a dental implant according to the invention for creating a seal between soft tissue and the implant.

[0062] The invention also relates to a dental implant according to the invention for use in creating a seal between soft tissue and the implant. The invention also relates to a method for treating a patient, comprising the implantation of a dental implant according to the invention.

[0063] A further invention relates to a zirconia-based dental implant, wherein the dental implant comprises a mucophilic section for soft tissue ingrowth and an ossophilic section with an external thread for anchoring the dental implant in bone, wherein the mucophilic section for soft tissue ingrowth has a roughened surface, and wherein the ossophilic section for bone ingrowth has a roughened surface, the roughened surface of the ossophilic section having a greater roughness than the roughened surface of the mucophilic section. The above descriptions, explanations, and preferred embodiments also apply to this invention.

[0064] The invention is explained in more detail below with reference to two figures.

[0065] Figure 1 is a cross-sectional view of a part of an implanted dental implant according to the invention.

[0066] Figure 2 is a partial view of a dental implant according to the invention, showing a section with a magnification of 2500 and a section with a magnification of 10000.

[0067] Fig. 1 shows a dental implant 10 based on stabilized zirconium dioxide. The dental implant 10 comprises a mucophilic section 11 for the ingrowth of soft tissue 20, wherein the mucophilic section 11 for the ingrowth of the soft tissue 20 has a roughened surface, wherein the roughened surface of the mucophilic section 11 has a mean roughness (Ra) of about 1 pm (0.7 pm) and a roughness depth (Rz) of 4 pm.

[0068] The dental implant 10 further comprises an ossophilic section 12 with an external thread 13 for anchoring the dental implant in a bone 30, the ossophilic section 12 having a roughened surface to promote bone ingrowth. Fig. 2 shows the surface of the dental implant 10. The roughened surface of the ossophilic section 12 has a greater roughness than the surface of the mucophilic section 11.

[0069] The surface of the mucophilic section 11 and the surface of the ossophilic section 12 on the green body were roughened by sandblasting with corundum as the abrasive before the final sintering of the green body. After sintering, this surface was not significantly further treated.

[0070] The roughened surface of the mucophilic section 11 and the roughened surface of the ossophilic section 12 are formed from native polycrystalline tetragonal zirconium dioxide. Soft tissue 20 fuses with the roughened surface of the mucophilic section 11 within three days. This achieves rapid sealing between soft tissue 20 and dental implant 10, preventing contaminants and bacteria from penetrating between the new dental implant 10 and hard tissue 30 and soft tissue 20. As a result, the failure rate is low.

[0071] Therefore, the dental implant 10 is suitable for use in the prophylaxis and treatment of reversible soft tissue inflammation (peri-mucositis) and irreversible soft-hard tissue inflammation (peri-implantitis).

[0072] The dental implant 10 can be manufactured using the method according to the invention.

[0073] First, a green body based on stabilized zirconium dioxide is prepared. The green body was pre-fired at approximately 1000 °C. Then, the green body is sandblasted with corundum as the abrasive. The corundum particles have a size of approximately 100 pm. The abrasive is applied from a distance of 15 cm at a pressure of approximately 2.0 bar through a nozzle made of zirconium-containing material with a nozzle diameter of 0.8 mm. During this process, the green body rotates at 250 revolutions per minute. The sandblasting roughens the surface of the green body. This roughening is not uniform across the green body, but rather, by positioning the nozzle and green body in such a way that two differently roughened sections are created. These sections later represent the roughened surface of the mucophilic section 11 and the roughened surface of the ossophilic section 12.After sandblasting, the sandblasted green body is cleaned of any adhering abrasive using compressed air and ultrasound. The processed green body is then sintered at a temperature of approximately 1500 °C for two hours, resulting in the dental implant 10. The surface of the dental implant 10 is not significantly roughened after sintering to preserve the surface of native tetragonal zirconium dioxide.

[0074] Reference symbol list

[0075] 10 dental implants

[0076] 11 mucophilic section

[0077] 12 ossophilic section

[0078] 13 external threads

[0079] 20 Soft tissue

[0080] 30 bones

Claims

Claims 1. Zirconium dioxide-based dental implant comprising a mucophilic section for soft tissue ingrowth, wherein the mucophilic section for soft tissue ingrowth has a roughened surface, wherein the roughened surface of the mucophilic section has a mean roughness (Ra) of about 0.3 pm to about 2 pm.

2. Dental implant at least according to claim 1, characterized by the fact that the dental implant comprises an ossophilic section with an external thread for anchoring the dental implant in a bone, wherein the ossophilic section has a roughened surface for bone growth, wherein the roughened surface of the ossophilic section has a greater roughness than the surface of the mucophilic section.

3. Dental implant at least according to one of the preceding claims, characterized by the fact that the roughened surface of the mucophilic section has a mean roughness value (Ra) of > 0.5 pm to < 1.4 pm.

4. Dental implant at least according to one of the preceding claims, characterized by the fact that the roughened surface of the mucophilic section has a roughness depth (Rz) of about 2 pm to about 8 pm, preferably of about 4 pm.

5. Dental implant according to at least one of the preceding claims, characterized by the fact that the zirconium dioxide is stabilized zirconium dioxide.

6. Dental implant at least according to one of the preceding claims, characterized by the fact that the roughened surface of the mucophilic section and optionally the roughened surface of the ossophilic section on the green body is sandblasted before a final sintering of the green body. is roughened by an abrasive material, wherein the abrasive material preferably contains corundum.

7. Dental implant at least according to one of the preceding claims, characterized by the fact that the roughened surface of the mucophilic section is formed from native tetragonal zirconium dioxide, preferably from native polycrystalline tetragonal zirconium dioxide.

8. Dental implant at least according to one of the preceding claims, that is indicated by a sign that Soft tissue grows together with the roughened surface of the mucophilic section within one to seven days, preferably within one to three days.

9. A method for manufacturing a dental implant, preferably a dental implant according to any of the preceding claims, comprising the steps of: a) providing a zirconium dioxide-based green body in implant form, b) at least partially sandblasting the green body with an abrasive, wherein the sandblasting at least partially roughens the surface of the green body, yielding a sandblasted green body, c) sintering the sandblasted green body, yielding the dental implant, wherein the dental implant comprises a mucophilic section for soft tissue ingrowth, wherein the mucophilic section for soft tissue ingrowth has a roughened surface, wherein the roughened surface of the mucophilic section has a mean roughness (Ra) of about 0.3 pm to about 2 pm.

10. Method at least according to the preceding claim, characterized by the fact that the blasting medium is applied via a nozzle made of zirconium-containing material.

11. Method at least according to one of the preceding claims, characterized by the fact that the blasting medium contains corundum.

12. Method at least according to one of the preceding claims, characterized by the fact that the surface of the dental implant is not roughened after sintering.

13. Method at least according to one of the preceding claims, characterized by the fact that the sandblasted green body is freed from abrasive before sintering, preferably using compressed air and / or ultrasound.

14. Dental implant according to at least one of claims 1-8 for use in the prophylaxis and / or treatment of inflammation selected from reversible soft tissue inflammation (peri-mucositis) and irreversible soft-hard tissue inflammation (peri-implantitis).

15. Use of a dental implant according to at least one of claims 1-8 for creating a seal between soft tissue and the implant.

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