Implant restoration screw channel sealing material and preparation method thereof

Abstract

The invention belongs to the technical field of medical supplies, and particularly relates to an implant restoration screw channel sealing material and a preparation method thereof.The preparation method comprises the following steps that S1, a polytetrafluoroethylene belt is prepared, and an expanded polytetrafluoroethylene film is obtained; s2, sodium-naphthalene complex surface modification: soaking the expanded polytetrafluoroethylene film in a sodium-naphthalene complex treatment solution to defluorinate the surface and form a carbonized layer, and then cleaning with ethanol and deionized water; s3, chitosan-chlorhexidine acetate modification: spraying a chitosan / chlorhexidine acetate stable solution on the surface of the expanded polytetrafluoroethylene film treated in S2 to form a chitosan-chlorhexidine acetate modified coating; and S4, preparing the expanded polytetrafluoroethylene film treated in S3 into a columnar solid, and performing high-temperature steam sterilization to obtain the implant restoration screw channel sealing material.

Description

Technical Field

[0001] This invention belongs to the field of medical supplies technology, specifically relating to a screw channel sealing material for implant prostheses and its preparation method. Background Technology

[0002] With the development of the times and the advancement of technology, implant restorations are becoming increasingly widely used. The main methods of implant restoration retention are adhesive fixation and screw fixation. Compared with adhesive-fixed restorations, screw-fixed implant restorations have the advantage of being removable for maintenance, such as component replacement and cleaning. However, microleakage often exists at the implant-abutment interface, and bacteria may seep into the implant through the screw channels, causing peri-implantitis. Therefore, sealing the screw channels has become an important means of reducing bacterial invasion.

[0003] Currently, common sealing materials in clinical practice include cotton balls, gutta-percha, and polytetrafluoroethylene (PTFE) combined with resin restorations. These materials need to protect the central retention screw, isolate the oral cavity from the implant-abutment interface, and bear a certain amount of occlusal force. Cotton balls, due to their fluffy and soft nature, often cannot completely isolate bacteria and can affect resin adhesion. Gutta-percha requires heating before use, and volume shrinkage during cooling and curing can lead to bacterial leakage. PTFE lacks adhesive properties, biocompatibility, and antibacterial properties.

[0004] Therefore, how to overcome the shortcomings of existing polytetrafluoroethylene (PTFE) in terms of insufficient adhesion and inability to prevent bacterial invasion is a technical problem that urgently needs to be solved in this field.

[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Summary of the Invention

[0006] This disclosure provides at least one embodiment of a screw channel sealing material for implant restorations and its preparation method.

[0007] In a first aspect, the present disclosure provides a method for preparing a screw channel sealing material for implant restorations, comprising the following steps: S1, preparing a polytetrafluoroethylene (PTFE) tape to obtain an expanded PTFE film; S2, surface modification with a sodium-naphthalene complex, immersing the expanded PTFE film in a sodium-naphthalene complex treatment solution to defluorinate the surface and form a carbonized layer, followed by washing with ethanol and deionized water; S3, modification with chitosan and chlorhexidine acetate, spraying a chitosan / chlorhexidine acetate stabilizing solution onto the surface of the expanded PTFE film treated in S2 to form a chitosan-chlorhexidine acetate modified coating; S4, forming the expanded PTFE film treated in S3 into a columnar solid, sterilizing it with high-temperature steam to obtain the screw channel sealing material for implant restorations.

[0008] In one optional embodiment, the expanded polytetrafluoroethylene film has a thickness of 70–80 μm and a bubble point pressure of 220–280 kPa.

[0009] In one optional embodiment, the method for preparing the sodium-naphthalene complex treatment solution includes: dissolving or complexing equal amounts of sodium and naphthalene in an active ether; the active ether includes either tetrahydrofuran or ethylene glycol dimethyl ether.

[0010] In one optional embodiment, the method for preparing the chitosan / chlorhexidine acetate stable solution includes: dissolving chitosan powder in acetic acid solution and stirring until completely dissolved to obtain a transparent and viscous chitosan solution; adding chlorhexidine acetate to the chitosan solution and stirring evenly, adding an emulsifier and stirring evenly, then adding glutaraldehyde toluene solution dropwise for crosslinking and curing at room temperature, centrifuging and washing, dispersing in acetone and drying at room temperature, and finally adding vinyl acetate-ethylene copolymer emulsion to form the chitosan / chlorhexidine acetate stable solution.

[0011] In one optional embodiment, the preparation method of the emulsifier includes: taking liquid paraffin as the oil phase, adding surfactants Span 80 and Tween, stirring evenly at an environment not higher than 40°C, and a rotation speed not lower than 600 r / min.

[0012] In one alternative embodiment, the centrifugal washing includes washing several times with anhydrous ethanol and petroleum ether.

[0013] In one optional embodiment, the thickness of the chitosan-chlorhexidine modified coating is 30–50 μm.

[0014] In an optional embodiment, S3 further includes irradiating the chitosan-chlorhexidine modified coating with ultraviolet light to promote intermolecular crosslinking of chitosan.

[0015] Secondly, this disclosure also provides a screw channel sealing material for implant restorations, which is prepared using the method described above.

[0016] Thirdly, this disclosure also provides a method for using the implant prosthesis screw channel sealing material as described above, including the following steps: cleaning the screw hole with 2% chlorhexidine and drying it; inserting the implant prosthesis screw channel sealing material into the screw channel and filling it tightly, leaving a 1mm gap below the screw opening for resin filling; and sealing the screw channel with light-cured resin.

[0017] The beneficial effects of this invention are that the preparation method of the screw channel sealing material for implant restorations enhances the adhesion of polytetrafluoroethylene (PTFE) by using a sodium-naphthalene complex to hydrophilically modify the surface, providing biocompatibility. Simultaneously, chlorhexidine acetate, which is easily soluble in water, is selected as the antibacterial functional molecule to achieve long-term antibacterial properties. Chlorhexidine acetate is loaded into chitosan nanospheres via emulsification and then cross-linked to obtain a stable solution. This allows for the stable and long-lasting release of chlorhexidine acetate within the material, effectively reducing microbial leakage from the abutment screw channel and improving the implantation success rate.

[0018] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a graph showing the antibacterial rate test results provided in an embodiment of this disclosure; Figure 2 The graph shows the antibacterial rate test results provided in the embodiments of this disclosure. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0024] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0025] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0026] Existing domestic products: The "Dentist Park" Teflon tape has the registration number Ji Tang Xie Bei 20170008. This product is not sterile and still needs to be disinfected before use. It also lacks antibacterial modification.

[0027] "Zhongke Anchi" abutment screw channel filling column: individually packaged and sterile, but lacks antibacterial modification.

[0028] Existing foreign products: 35NEWTONS FirstPlug is a product for sealing screw holes. This product is made of medical-grade PTFE material, and its production and assembly strictly adhere to the quality control system for medical devices. However, it is still provided in a non-sterile state and requires sterilization before use.

[0029] The shortcomings of the above solutions are the result of the inventor's practical experience and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure below should be considered as the inventor's contribution to this disclosure.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0032] This disclosure provides a method for preparing a screw channel sealing material for implant restorations, comprising the following steps: S1, preparing a polytetrafluoroethylene (PTFE) tape to obtain an expanded PTFE film; S2, surface modification with a sodium-naphthalene complex, immersing the expanded PTFE film in a sodium-naphthalene complex treatment solution to defluorinate the surface and form a carbonized layer, followed by washing with ethanol and deionized water; S3, chitosan-chlorhexidine modification, spraying a chitosan / chlorhexidine stabilizing solution onto the surface of the expanded PTFE film treated in S2 to form a chitosan-chlorhexidine modified coating; S4, forming the expanded PTFE film treated in S3 into a columnar solid, sterilizing it with high-temperature steam to obtain the screw channel sealing material for implant restorations.

[0033] In some embodiments, specifically, the thickness of the expanded polytetrafluoroethylene film is 70–80 μm, and the bubble point pressure is 220–280 kPa.

[0034] In some embodiments, specifically, the preparation method of the sodium-naphthalene complex treatment solution includes: dissolving or complexing equal amounts of sodium and naphthalene in an active ether; the active ether includes either tetrahydrofuran or ethylene glycol dimethyl ether.

[0035] Specifically, sodium first transfers its outermost electron to the empty orbital of naphthalene, forming an anionic radical, which then forms an ion pair with Na₂. The naphthyl anion transfers to PTFE, causing it to lose fluoride ions and generate a neutral group. These groups then re-form C-C bonds and cross-link; or the group accepts another electron to form a carbocation, which then reacts with a protic solvent to form a C-H bond; or it loses fluoride ions to form a C=C double bond. Therefore, sodium in the treatment solution can break the C-F bonds on the PTFE surface (or a few micrometers away from the surface), abstracting F atoms, causing surface defluorination and the formation of a carbonized layer. The modified PTFE surface contains active groups such as hydroxyl, carbonyl, and carboxyl groups, thereby improving the adhesive properties of the PTFE surface.

[0036] In some embodiments, the specific method for preparing the chitosan / chlorhexidine stable solution includes: dissolving chitosan powder in acetic acid solution and stirring until completely dissolved to obtain a transparent and viscous chitosan solution; adding chlorhexidine acetate to the chitosan solution and stirring evenly, adding an emulsifier and stirring evenly, then adding glutaraldehyde toluene solution dropwise for crosslinking and curing at room temperature, centrifuging and washing, dispersing in acetone and drying at room temperature, and finally adding vinyl acetate-ethylene copolymer emulsion to form the chitosan / chlorhexidine stable solution.

[0037] In some embodiments, specifically, the preparation method of the emulsifier includes: taking liquid paraffin as the oil phase, adding surfactants Span 80 and Tween, stirring evenly at an environment not higher than 40°C, and a rotation speed not lower than 600 r / min.

[0038] In some embodiments, specifically, the centrifugal washing includes washing several times with anhydrous ethanol and petroleum ether.

[0039] In some embodiments, specifically, the thickness of the chitosan-chlorhexidine modified coating is 30–50 μm.

[0040] In some embodiments, specifically, S3 further includes irradiating the chitosan-chlorhexidine modified coating with ultraviolet light to promote cross-linking between chitosan molecules.

[0041] This disclosure also provides a screw channel sealing material for implant restorations, which is prepared using the method described above.

[0042] This disclosure also provides a method for using the implant prosthesis screw channel sealing material as described above, including the following steps: cleaning the screw hole with 2% chlorhexidine and drying it; inserting the implant prosthesis screw channel sealing material into the screw channel and filling it tightly, leaving a 1mm gap below the screw opening for resin filling; and sealing the screw channel with light-cured resin.

[0043] Example S1: Prepare polytetrafluoroethylene tape to obtain expanded polytetrafluoroethylene film; S2, use a 0.4mol / L finished sodium naphthalene solution (Dongguan Fangguan Industrial Materials Co., Ltd., HJ-001, sodium + naphthalene + tetrahydrofuran), or 0.5mol / L, and soak the polytetrafluoroethylene film for 30s, 5min, or 10min. Then rinse thoroughly with ethanol and deionized water. The preferred soaking time is 5min. S3, take a certain amount of liquid paraffin in a beaker as the oil phase, add surfactant Span 80 and Tween (mass ratio 5:2) as emulsifiers (composite type), stir evenly at 40℃ and speed 600 r / min; chitosan can only be dissolved in acidic aqueous solutions with pH=6.5 or lower, dissolve chitosan powder (MW=205 kD) in a 2% acetic acid solution, stir until completely dissolved to form a chitosan solution, forming a transparent viscous solution; add 98% chlorhexidine acetate to the chitosan solution and stir evenly. Chitosan / chlorhexidine solution was added to emulsifier and stirred evenly to form a stable chitosan / chlorhexidine emulsion. Saturated glutaraldehyde-toluene solution was added dropwise to the emulsion in two portions. After crosslinking and curing for a certain period of time, the product was separated by centrifugation, washed once with anhydrous ethanol, and repeatedly washed three times with petroleum ether. Finally, it was dispersed in acetone and dried at room temperature. After drying, vinyl acetate-ethylene copolymer emulsion was added to form the final stable chitosan / chlorhexidine solution. The solution was evenly sprayed onto the PTFE surface using a sprayer, repeated three times to increase the coating thickness (30, 40, 50 micrometers). After drying, ultraviolet light irradiation (365 nm) for 30 minutes was used to promote crosslinking between chitosan molecules. The preferred coating thickness was 50 μm. S4, the expanded polytetrafluoroethylene film treated in S3 is formed into a columnar solid, which includes the following steps in sequence: Mixing: Polytetrafluoroethylene dispersion resin is selected and mixed evenly with extrusion aid at a certain mass ratio. This ratio is between 35%, 40%, 45%, and 50%. Preforming: A certain amount of the mixed material is added to a cylindrical preforming mold with a diameter slightly smaller than the extrusion die cavity. After the mold is closed, it is placed in a press, and then the pressure is slowly increased. The most suitable pressure is 20 MPa, and the pressing time is 30s, 1min, 90s, and 2min. The preform is pressed into a shape suitable for subsequent processing equipment. Calendering: The pre-formed rods are calendered using a double-roll calender. The temperature of the rolls is controlled at 50-60°C during calendering, and the calendering speed is 0.5, 1, 2.5, or 5 m / min to produce a film with a thickness of 0.2 mm, which further improves the material strength and produces a certain amount of oriented fibers in the material. Drying: The calendered strip is heated and dried for 10 hours to remove the extrusion aid on the strip and obtain a polytetrafluoroethylene film; Stretching: The polytetrafluoroethylene film is stretched at a temperature below the melting point of polytetrafluoroethylene. The stretching temperature needs to be controlled at 220, 270, and 320°C, with stretch ratios of 4, 6, and 8 times, and stretching rates of 3000% and 40,000% per second, respectively. Shaping: Place the expanded polytetrafluoroethylene film on a template, then put it into a mold, heat it to 327°C at a certain heating rate for 2 minutes to fix the mesh structure formed after stretching, and finally slowly cool it to room temperature to obtain expanded polytetrafluoroethylene. The preferred ratio of polytetrafluoroethylene dispersion resin to extrusion aid is 50%, the preferred preforming pressing time is 2 min, the preferred calendering temperature is 60℃, the preferred calendering speed is 2.5 m / min, the preferred stretching temperature is 320℃, the stretching ratio is 4 times, and the stretching rate is 3000% per second.

[0044] Specifically, the antibacterial effect of the obtained screw channel sealing material was determined through antibacterial experiments.

[0045] Experimental bacterial strains: monoclonal E. coli (Escherichia coli, Gram-negative bacterium) and S. aureus (Staphylococcus aureus, Gram-positive bacterium); Experimental subjects: Ct-tape: chitosan-modified PTFE tape; Ct / ChD-tape: chitosan / chlorhexidine-modified PTFE tape; The preparation process for Ct / ChD-tape is as described above. The preparation process for Ct-tape is as follows: A certain amount of liquid paraffin was placed in a beaker as the oil phase, and surfactants Span 80 and Tween (mass ratio 5:2) were added as emulsifiers (composite type). The mixture was stirred evenly at 40°C and a speed of 600 r / min. Chitosan powder (MW=205 kD) was dissolved in a 2% acetic acid solution and stirred until completely dissolved to form a 4% chitosan solution, resulting in a transparent viscous solution.

[0046] A saturated glutaraldehyde-toluene solution was added dropwise to the emulsion in two portions. After cross-linking and curing for a certain period of time, the product was separated by centrifugation, washed once with anhydrous ethanol, washed three times repeatedly with petroleum ether, and finally dispersed in acetone and dried at room temperature.

[0047] After drying, vinyl acetate-ethylene copolymer emulsion is added to form the final chitosan stabilized solution.

[0048] Use a sprayer to evenly spray the solution onto the PTFE surface, repeating 3 times to increase the coating thickness.

[0049] After drying, the chitosan molecules are cross-linked by irradiation with ultraviolet light (365nm) for 30 minutes.

[0050] Experimental methods: 1. Antibacterial rate test, such as Figure 1 As shown, attach the tape to 10 ∧5 After co-incubating the bacterial solution for two hours, the bacteria were plated and counted 18 hours later.

[0051] 2. Inhibition zone test, such as Figure 2 As shown, attach the tape to 10 ∧3 The bacterial solution was spread on the plate together and incubated for 18 hours before the size of the inhibition zone was observed.

[0052] Experimental results: 1. Antibacterial rate test, such as Figure 1 As shown, Ct / ChD-tape (chitosan / chlorhexidine modified PTFE tape) is superior to Ct-tape (chitosan modified PTFE tape). The antibacterial rate is higher than 97% for both E. coli (Gram-negative bacteria) and S. aureus (Gram-positive bacteria). Overall, cationic antibacterial tape is more effective against Gram-negative bacteria than against Gram-positive bacteria.

[0053] 2. Inhibition zone test, such as Figure 2 As shown, by comparing the blank areas near the tape: for E. coli (Gram-negative bacteria) and S. aureus (Gram-positive bacteria), the inhibition zone area of ​​Ct / ChD-tape (chitosan / chlorhexidine modified PTFE tape) is larger than that of Ct-tape (chitosan modified PTFE tape).

[0054] In summary, the preparation method of this implant prosthesis screw channel sealing material enhances the adhesion and biocompatibility of polytetrafluoroethylene (PTFE) by using a sodium-naphthalene complex to hydrophilically modify the surface. Simultaneously, water-soluble chlorhexidine acetate is selected as the antibacterial functional molecule to achieve long-term antibacterial properties. Chlorhexidine acetate is loaded into chitosan nanospheres via emulsification and then cross-linked to obtain a stable solution. This allows for the stable and long-lasting release of chlorhexidine acetate within the material, effectively reducing microbial leakage from the abutment screw channel and improving implantation success rate.

[0055] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing a screw channel sealing material for implant restorations, characterized in that, Includes the following steps: S1, prepare polytetrafluoroethylene tape to obtain expanded polytetrafluoroethylene film; S2, Sodium-naphthalene complex surface modification: Expanded polytetrafluoroethylene film is immersed in sodium-naphthalene complex treatment solution to defluorinate the surface and form a carbonized layer, and then cleaned with ethanol and deionized water. S3, chitosan-chlorhexidine acetate modification: a chitosan / chlorhexidine acetate stabilizing solution is sprayed onto the surface of the expanded polytetrafluoroethylene film treated with S2 to form a chitosan-chlorhexidine acetate modified coating. S4. The expanded polytetrafluoroethylene film treated in S3 is made into a columnar solid and sterilized by high-temperature steam to obtain the screw channel sealing material for implant restorations.

2. The preparation method according to claim 1, characterized in that, The expanded polytetrafluoroethylene film has a thickness of 70–80 μm and a bubble point pressure of 220–280 kPa.

3. The preparation method according to claim 1, characterized in that, The preparation method of the sodium-naphthalene complex treatment solution includes: It is obtained by dissolving or complexing equal amounts of sodium and naphthalene in an active ether; The active ether includes either tetrahydrofuran or ethylene glycol dimethyl ether.

4. The preparation method according to claim 1, characterized in that, The preparation method of the chitosan / chlorhexidine stabilized solution includes: Chitosan powder was dissolved in acetic acid solution and stirred until completely dissolved to obtain a transparent, viscous chitosan solution. Chlorhexidine acetate was added to the chitosan solution and stirred until homogeneous. After adding the emulsifier and stirring until homogeneous, glutaraldehyde toluene solution was added dropwise for cross-linking and curing at room temperature. The mixture was then centrifuged, washed, dispersed in acetone, and dried at room temperature. Finally, vinyl acetate-ethylene copolymer emulsion was added to form a stable chitosan / chlorhexidine acetate solution.

5. The preparation method according to claim 4, characterized in that, The method for preparing the emulsifier includes: Take liquid paraffin as the oil phase, add surfactants Span 80 and Tween, and stir evenly at an environment not higher than 40°C and a speed not lower than 600 r / min.

6. The preparation method according to claim 4, characterized in that, The centrifugal washing includes washing several times with anhydrous ethanol and petroleum ether.

7. The preparation method according to claim 1, characterized in that, The thickness of the chitosan-chlorhexidine modified coating is 30–50 μm.

8. The preparation method according to claim 1, characterized in that, S3 further includes irradiating the chitosan-chlorhexidine modified coating with ultraviolet light to promote cross-linking between chitosan molecules.

9. A sealing material for screw channels in implant restorations, characterized in that, It is prepared by the method described in any one of claims 1-8.

10. A method of using the screw channel sealing material for implant restorations as described in claim 9, characterized in that, Includes the following steps: Clean the screw holes with a 2% chlorhexidine solution and blow them dry; The sealing material for the screw channel of the implanted prosthesis is inserted into the screw channel and filled tightly, leaving a 1mm gap below the screw opening for resin filling; UV-cured resin seals the screw channels.

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