Method for hydrophilizing surface of dental implant body

Abstract

To provide a simple method for hydrophilizing a surface of a dental implant body.SOLUTION: A method for hydrophilizing a surface of a dental implant body includes drying the implant body after immersing it in ozone nanobubble water. Even when the implant body is exposed to atmosphere before being immersed in the ozone nano-bubble water and a surface thereof becomes contaminated and hydrophobized by organic substances such as hydrocarbons in the atmosphere, the surface contaminants are decomposed by drying the implant body after immersion in the ozone nano-bubble water, to clean the surface as well as making the surface hydrophilic, thereby facilitating acquisition of osteointegration.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for hydrophilizing the surface of a dental implant body (hereinafter, sometimes simply referred to as "implant body"). [Background technology]

[0002] It is well known that dental implant treatment has been gaining attention in recent years when the roots of permanent teeth are lost for some reason. Dental implant treatment is performed using implants configured to attach an artificial crown to an implant body (fixture) via an abutment (connecting part) or to attach an artificial crown to the implant body without an abutment. Regardless of the implant configuration used, it is essential that the implant body firmly bond with the bone over a long period of time (osteointegration). For this reason, implant bodies are made of highly biocompatible materials such as titanium or titanium alloys and have a male screw shape. Furthermore, to shorten the time required for osteointegration, the surface of the implant body is subjected to treatments such as blasting and acid etching.

[0003] However, even implants with these improvements can be exposed to the atmosphere between the time they are manufactured by the manufacturer and when they are delivered to a dental clinic and implanted into the patient's alveolar bone. This can lead to surface contamination and hydrophobicity due to organic substances such as hydrocarbons in the air, adversely affecting osteointegration. Various solutions to this problem have already been proposed, including Patent Document 1, which proposes irradiating the contaminated surface of a contaminated implant with ultraviolet (UV) light. This method not only cleans the surface by decomposing contaminants on the implant's surface, but also makes the surface hydrophilic, facilitating osteointegration. However, UV irradiation equipment is large and expensive, making it difficult for all dental clinics to adopt this method. Furthermore, if UV-irradiated implants are not immediately implanted into the patient's alveolar bone, their surface will become contaminated and hydrophobic again before implantation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2005-505352 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a simple method for hydrophilizing the surface of a dental implant body. [Means for solving the problem]

[0006] The present inventors have conducted extensive research in light of the above points and have found that even if the surface of an implant body has become hydrophobic due to exposure to the atmosphere, the surface of the implant body in a dry state can be made hydrophilic by immersing it in ozone nanobubble water and then drying it.

[0007] The method for hydrophilizing the surface of a dental implant body of the present invention, which was made based on the above findings, involves immersing the dental implant body in ozone nanobubble water and then drying it, as described in claim 1. Furthermore, the method of producing a dental implant body having a hydrophilized surface of the present invention comprises, as set forth in claim 2, immersing the dental implant body in ozone nanobubble water and then drying it. [Effects of the Invention]

[0008] According to the present invention, a simple method for hydrophilizing the surface of a dental implant body can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] This photograph shows that in Experiment 4 of the Example, the hydrophilized surface of the implant body was maintained even 137 days after it was immersed in ozone nanobubble water and then dried, and tap water was rising from the tip of the implant body. DETAILED DESCRIPTION OF THE INVENTION

[0010] The method for hydrophilizing the surface of a dental implant according to the present invention involves immersing the dental implant in ozone nanobubble water and then drying it. In the present invention, "hydrophilization" is understood to mean modifying the surface of a dental implant in a dry state to improve wettability.

[0011] The implant body to which the present invention can be applied may be made of any material, including titanium or a titanium alloy (an alloy of titanium with at least one metal selected from the group consisting of aluminum, tin, zirconium, molybdenum, nickel, palladium, tantalum, niobium, vanadium, and platinum), which have high biocompatibility, and may be subjected to a surface treatment known per se, such as a blast treatment or an acid etching treatment. The shape of the implant body is also not particularly limited, and may be any shape, including a male screw shape.

[0012] The ozone nanobubble water used in the present invention refers to water containing ozone bubbles (gas bubbles) with nanometer-order particle sizes, and may be produced by a method known per se. A specific example of a method for producing ozone nanobubble water is described in JP 2005-245817 A, which involves generating ozone bubbles with micrometer-order particle sizes in water containing electrolyte ions such as magnesium ions, calcium ions, potassium ions, and sodium ions, and then applying physical stimuli (such as discharge using a discharge generator, ultrasonic irradiation using an ultrasonic transmitter, or utilizing the compression, expansion, or vortex flow that occurs when water is flowed) to rapidly shrink the ozone bubbles. This method produces water containing ozone bubbles with a peak particle size of 100 nm or less (e.g., 10 to 50 nm) and an ozone concentration of, for example, 0.1 to 20 mg / L, but the method for producing ozone nanobubble water is not limited to this method.

[0013] The method of using ozone nanobubble water to hydrophilize the surface of an implant body is extremely simple. Ozone nanobubble water is highly stable and can be prepared in advance (even one year after production, the ozone concentration decreases, but does not disappear). It can be stored in containers such as plastic bottles. Such containerized ozone nanobubble water is also commercially available. For example, simply purchase containerized ozone nanobubble water, pour the required amount into a container for immersing the implant body, immerse the implant body in it, close the lid, and leave it in a dark place where the stability of the ozone nanobubble water will not be adversely affected. The immersion time is preferably at least 6 hours, and more preferably at least 12 hours. If the immersion time is too short, the surface of the implant body after drying may not be sufficiently hydrophilized, or it may be difficult to maintain the hydrophilized surface of the implant body for a long period of time. The upper limit of the immersion time is not limited, and it may be, for example, more than 100 days. Even when implants are immersed in ozone nanobubble water for such long periods of time, the ozone nanobubble water is highly stable, so there is no need to periodically replace the ozone nanobubble water in which the implants are immersed (although this does not mean that it should not be replaced).

[0014] The method for drying the implant body after immersion in the ozone nanobubble water is not particularly limited. For example, the implant body may be removed from the container containing the ozone nanobubble water and allowed to dry naturally in the atmosphere or may be blown with air (at room temperature).

[0015] The implant body, whose surface has been hydrophilized by immersion in ozone nanobubble water and then drying, can maintain its hydrophilized surface for a long period of time by sealing it in a container known per se and keeping it isolated from the outside air. While the longer the immersion time in ozone nanobubble water, the longer the hydrophilized surface of the implant body will be maintained, by immersing it in ozone nanobubble water for, for example, 10 days or more, the hydrophilized surface can be maintained for, for example, 10 days or more (even for more than 100 days). To maintain the hydrophilized surface of the implant body for a longer period, the immersion time in ozone nanobubble water is preferably 30 days or more, more preferably 50 days or more, and even more preferably 70 days or more.

[0016] When the method for hydrophilizing the surface of a dental implant body of the present invention is used by an implant body manufacturer, for example, a step of immersing the implant body in ozone nanobubble water and then drying it can be added as a step preceding the step of sealing and packaging an implant body produced by a predetermined process in a container by a predetermined method. If the implant body whose surface has been hydrophilized by the method of the present invention is sealed and packaged in a container by a predetermined method, and then shipped after being sterilized by gamma radiation, the hydrophilized surface of the shipped implant body will be maintained until it is delivered to a dental clinic. Therefore, after delivery to the dental clinic, it can be immediately implanted into the patient's alveolar bone by a predetermined procedure, facilitating osteointegration.

[0017] The method for hydrophilizing the surface of a dental implant of the present invention may also be used in dental clinics. Even implants delivered to dental clinics in the conventional form (implants whose surfaces are not hydrophilized) can be hydrophilized by immersing them in ozone nanobubble water and then drying them at the dental clinic, and then implanted into the patient's alveolar bone using a predetermined procedure. [Example]

[0018] The present invention will be described in detail below with reference to examples, but the present invention should not be construed as being limited to the following description.

[0019] Experiment 1: Hydrophilic surface treatment of pure titanium dishes treated with SLA (part 1) (Experimental Method) One side of a commercially available 15 mm diameter x 1 mm thick pure titanium dish was treated with SLA (Sand-blasted Large-grit Acid-etched Surface) (see, for example, Daniel Buser et al., "Interface shear strength of titanium implants with a sandblasted and acid-etched surface: A biomechanical study in the maxilla of miniature pigs," J Biomed Mater Res, 45, 75-83, 1999, if necessary) to mimic the surface shape of an SLA-treated implant. The pure titanium dish (hereinafter referred to as the "sample dish") with one side treated with SLA was placed in a pathology container (made of synthetic resin; the same applies hereinafter) with sterile tweezers and left uncovered for 30 days in a dark room. After 30 days, the sample dish was removed from the pathology container with sterile tweezers and immersed in another pathology container containing test water. The lid was then closed and the dish was left in a dark room for 90 days. After 90 days, the sample dishes were removed from the pathology container with sterile tweezers and dried by blowing high-pressure air onto them using an air syringe from a dental unit. Immediately after drying, a drop of tap water was placed in a syringe onto the SLA-treated surface of the sample dish, and the way the water spread was observed. The following four types of water were used as test water. (1) Ozone nanobubble water (product name "NANO DENTAL α" sold by Nippon Vitely Co., Ltd., water containing ozone nanobubbles with a peak particle size of 40-50 nm, ozone concentration 1-3 mg / L) (2) Sterile saline (3) Sterile purified water (4) Ozone water generated using a commercially available ozone water generator (ozone concentration immediately after generation is 1-3 mg / L)

[0020] (Experimental results) When the sample was immersed in ozone nanobubble water and then dried, the water droplets spread to the maximum extent, and the contact angle of the water droplet with the surface was 0°, indicating superhydrophilicity. In contrast, when the sample was immersed in sterile saline, sterile purified water, or ozone water and then dried, the contact angle of the water droplet with the surface was 30-40°, indicating some hydrophilicity but not superhydrophilicity. Furthermore, when a drop of tap water in a syringe was dropped from the syringe needle onto the SLA-treated surface of the sample dish immediately before immersion in the test water, the contact angle of the water droplet with the surface was 90-110°, indicating hydrophobicity.

[0021] Experiment 2: Hydrophilic surface treatment of pure titanium dishes treated with SLA (part 2) In Experiment 1, we observed the wetting and spreading of water droplets on the SLA-treated surface. Sample dishes were immersed in ozone nanobubble water and then dried. They were then dried using a high-pressure air syringe from a dental unit, sealed in a glass ampoule with sterile tweezers, and stored indoors. After seven days, the sample dishes were removed from the glass ampoule with sterile tweezers, and the wetting and spreading of water droplets on the SLA-treated surface was observed in the same manner as in Experiment 1. After the observations were completed, the sample dishes were dried using a high-pressure air syringe from a dental unit, sealed in a glass ampoule with sterile tweezers, and stored indoors. Similar observations were then repeated every six to seven days to evaluate the degree to which the hydrophilic SLA-treated surface of the sample dishes remained. As a result, even 189 days after the SLA surface-treated surface of the sample dish was hydrophilized by immersing it in ozone nanobubble water and then drying in Experiment 1, the water droplets spread to the maximum extent, and the contact angle of the water droplets with the surface was 0°, which indicates superhydrophilicity, confirming that the hydrophilic SLA surface-treated surface of the sample dish was maintained.

[0022] Experiment 3: Surface hydrophilization of implant bodies treated with SLA (part 1) An implant body (trade name: Ankylos A11, Dentsply Sirona) with an SLA surface treatment was removed from its packaging with sterile tweezers and placed in a glass screw cap vial (hereinafter the same). The implant was left uncapped and exposed to the atmosphere for 30 days at room temperature. After 30 days, the implant body was removed from the screw cap vial with sterile tweezers and held vertically. The tip of the implant was then exposed to tap water in a beaker. The tip repelled the tap water, confirming that the implant body's surface had become hydrophobic. The implant body with a hydrophobic surface was then immersed in a screw cap vial containing ozone nanobubble water (as in Experiment 1) with sterile tweezers, closed, and left in a dark room for 90 days. After 90 days, the implant body was removed from the screw cap vial with sterile tweezers and dried using high-pressure air from a dental unit air syringe. The behavior of the immediately dried implant body in tap water was observed after the tip was held vertically in a beaker. As a result, tap water rose from the tip of the implant to the platform, confirming that the surface of the implant had been made hydrophilic.

[0023] Experiment 4: Surface hydrophilization of implant bodies treated with SLA (part 2) In Experiment 3, the implant body, whose surface was confirmed to be hydrophilic by tap water rising from the tip to the platform, was dried by blowing high-pressure air from a dental unit air syringe, then sealed in a glass ampoule with sterile tweezers and stored indoors. Five days later, the implant body was removed from the glass ampoule with sterile tweezers, and the behavior of tap water in contact with the tip of the implant body was observed using the same method as in Experiment 3. After observation, the implant body was dried by blowing high-pressure air from a dental unit air syringe, then sealed in a glass ampoule with sterile tweezers and stored indoors. Similar observations were then repeated every four to five days to evaluate the extent to which the implant body's hydrophilic surface remained. As a result, even 137 days after the implant body's surface was hydrophilized by immersion in ozone nanobubble water and drying, tap water still rose from the tip to the platform, confirming that the implant body's hydrophilic surface remained intact. Figure 1 shows tap water rising from the tip of the implant body.

[0024] Experiment 5: Surface hydrophilization of implant bodies with anodized surface treatment An anodized surface-treated implant (product name: Replace Select Tapered, Nobel Biocare) was exposed to the atmosphere, then immersed in ozone nanobubble water (same as in Experiment 1) for 90 days and then dried, confirming that the surface was hydrophilized. The extent to which the hydrophilized surface of the implant was maintained was also evaluated in the same manner as in Experiment 4. As a result, even 76 days after the implant surface was hydrophilized by immersion in ozone nanobubble water and drying, tap water still rose from the tip of the implant to the platform, confirming that the hydrophilized surface of the implant was maintained.

[0025] (Consideration) From the above experimental results, it was found that even if the SLA surface-treated surface of the sample dish or the surface of an implant body that had been subjected to various surface treatments had been contaminated and hydrophobicized by organic substances such as hydrocarbons in the air, by immersing the surface in ozone nanobubble water and then drying it, the surface contaminants were broken down, not only cleaning the surface but also making it hydrophilic. At present, the inventors are not entirely clear as to why the SLA-treated surface of the sample dish and the surfaces of implant bodies that have been subjected to various surface treatments become hydrophilic when immersed in ozone nanobubble water and then dried. However, for example, in Experiment 3, the implant body that was immersed in ozone nanobubble water and then dried was indistinguishable in appearance from the implant body before immersion in ozone nanobubble water (no difference was observed even when compared under a microscope at 10x magnification). This suggests that the surface of the implant body that was immersed in ozone nanobubble water and then dried has the ozone nanobubbles themselves contained in the ozone nanobubble water or components derived from the ozone nanobubbles attached to it, and that the presence of these increases the number of hydroxyl groups on the surface of the implant body, and that this state is maintained for a long period of time. [Industrial Applicability]

[0026] INDUSTRIAL APPLICABILITY The present invention has industrial applicability in that it can provide a simple method for hydrophilizing the surface of a dental implant body.

Claims

1. A method for hydrophilizing the surface of a dental implant body by immersing it in ozone nanobubble water and then drying it.

2. A method for producing a dental implant body with a hydrophilic surface by immersing the dental implant body in ozone nanobubble water and then drying it.

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