Expansion-type root canal filling medical instrument combination based on tooth root tip biological sealing, and use

Abstract

An expansion-type root canal filling medical instrument combination based on tooth root tip biological sealing, and a use. The medical instrument comprises a sealant composition and a titanium material root canal obturating point; the sealant composition is composed of a liquid agent, component-A powder, and component-B powder that are isolated from each other before use, the component-A powder comprises 75%-95% of tricalcium silicate and 5%-25% of β-tricalcium phosphate, and the component-B powder is composed of 45%-55% of nano zirconium dioxide, 44.7%-52% of calcium hydroxide, and 0.3%-3% of calcium oxide; the surface of a root canal section (1) of the titanium material root canal obturating point is provided with a thread (102) tending to be horizontal, and a thread groove of the root canal obturating point is used for being filled with a prepared sealant; the surface of a dental crown section (2) is provided with a retention groove section. The medical instrument combination solves the problems of root canal treatment failure or poor long-term effect and the like caused by volume shrinkage after existing sealants and gutta percha points are filled, and can realize high-safety, high-biocompability, high-quality and high-density root canal filling.

Description

Expandable root canal filling medical device combination and its application based on biological sealing of tooth root apex

[0001] This application claims priority from two Chinese patent applications, the entire contents of which are incorporated herein by reference. The two prior Chinese patent applications are:

[0002] 1. Application number: 202310643104.3, application date: June 1, 2023;

[0003] 2. Application number: 202310794572.0. Application date: June 30, 2023. Technical Field

[0004] The present application relates to dental medical devices, and in particular to a root canal filling device based on biological sealing of tooth root apex and its application. Background Art

[0005] Root canal therapy is the primary treatment for endodontic and periapical lesions. After completing the initial root canal preparation and disinfection, the key challenge remains ensuring that each root canal is safely and tightly filled, effectively sealing the apical foramen. Furthermore, defects in root canal filling devices have become a major pain point in the dental endodontic treatment industry.

[0006] The existing root canal filling technology uses a combination of root canal sealer and gutta-percha tips. However, almost all root canal sealers and gutta-percha tips shrink to varying degrees after the filling solidifies. To address the volume shrinkage problem after root canal filling with sealer and gutta-percha tips, the industry has adopted the concept of "filling with as little root canal sealer as possible and as much gutta-percha as possible." This is a root canal filling method that uses gutta-percha tips as the main method and gutta-percha tips as the auxiliary method. This has led to the formation of two major root canal filling technology systems currently used in clinical practice, namely, cold gutta-percha lateral extrusion filling technology and hot gutta-percha vertical pressure filling technology. In recent years, the injectable bioceramic and gutta-percha tip single-point root canal filling technology has emerged. However, the problem of root canal material volume shrinkage has not been completely solved. A document titled "Difficulties and Misconceptions in Root Canal Filling" (Zhang Chen, West China Journal of Stomatology, Vol. 35, No. 3) reports that gutta-percha tips shrink by 7% after heating and cooling, resulting in microgaps, microleakage, incomplete apical sealing, and secondary infection in the apical sealing area after root canal filling, ultimately leading to root canal treatment failure.

[0007] In summary, the volume shrinkage of root canal sealers and gutta-percha fillings leads to incomplete apical sealing, microgaps, and microleakage. This is a difficult problem that needs to be solved urgently in the industry and is also one of the main reasons for the failure of root canal treatment.

[0008] In addition, the potential harm that the toxic and harmful components contained in root canal sealers and gutta-percha tips themselves may bring to patients is also an important issue that needs to be addressed urgently.

[0009] Gutta-percha points have been used for nearly 180 years, and the current mainstream root canal filling technology still relies on ideas related to gutta-percha points, resulting in many of its existing problems remaining unresolved.

[0010] The following is a brief analysis of the composition and characteristics of several commonly used root canal sealers and gutta-percha tips, some of which are quoted from "Progress in Research on Root Canal Sealers" (Yang Xueying et al., Electronic Journal of General Stomatology, 2019).

[0011] 1. Clove oil / zinc oxide root canal sealer

[0012] Clove oil / zinc oxide is a traditional root canal filling agent, mainly composed of zinc oxide, rosin and eugenol. It is characterized by strong disinfection effect and can promote the regeneration of granulation tissue. However, its disadvantage is that after solidification, the volume shrinkage causes it to peel off from the root canal wall and create microgaps, making it impossible to achieve complete root canal sealing. Its cytotoxicity is also controversial, and it is now mostly used as a control group in new material testing.

[0013] 2. Resin root filling materials

[0014] Resin-based root canal filling pastes have the advantages of good fluidity, stable volume, and strong adhesion to root canal dentin. However, they contain toxic and harmful ingredients such as formaldehyde and resorcinol.

[0015] 3. Calcium hydroxide root canal sealers

[0016] Calcium hydroxide provides a strongly alkaline environment (pH up to 12.5), destroying bacterial cell membranes and protein structures, thereby inhibiting bacterial growth. It also promotes the activation of calcium-mediated ATPase during hard tissue formation, boosting dentinoid and cementum formation, inducing healing of periapical lesions, and enhancing root apical adhesion. However, its disadvantage is that calcium hydroxide paste shrinks in volume after solidification and has a certain solubility and absorbability in contact with tissue fluid. This absorption comes from the continuous consumption of calcium ions during bone tissue reconstruction, and the long-term efficacy stability of calcium hydroxide alone is poor.

[0017] 4. Glass ionomer root canal sealer

[0018] Glass ionomers are a mixture of polyacrylic acid aqueous solution and aluminum silicate glass powder. They have physical properties very similar to those of dentin and can bond to the dentin surface through a chain reaction of ultrastructure. The polyacrylate ions therein can undergo an irreversible replacement reaction with the phosphate groups in hydroxyapatite, and have long-lasting adhesion to dentin even in humid conditions. They also have certain biocompatibility and can release fluoride ions to prevent caries.

[0019] The main disadvantage of glass ionomer is that it still shrinks significantly after solidification. Studies have shown that its apical sealing performance is significantly worse than the first three types of root filling agents, and it is not easy to remove after solidification, making secondary treatment very difficult.

[0020] 5. Calcium silicate bioceramic root canal sealer

[0021] Calcium silicate bioceramics have the advantages of good biocompatibility, low cytotoxicity, and long-term stability. They maintain a high pH during and after setting, inhibiting bacterial growth. While bioceramic materials should be the future of root canal filling materials, existing bioceramic sealers also have many shortcomings that need to be addressed. For example, some brands of bioceramics contain harmful ingredients such as bismuth oxide, and some injectable bioceramic sealers contain resin thickeners. These resin thickeners can produce carcinogens in the high-temperature environment of gutta-percha filling. During root filling, the sealer is inevitably squeezed out of the root apex and into the apical physiological environment, potentially posing a risk to the human body. Furthermore, the thickeners in injectable calcium silicate root fillings keep the silicon and calcium ions in a "suspended" state, hindering their precipitation and penetration into the micro-interstices of the root canal and dentinal tubules. Furthermore, like all other types of root canal sealers, existing calcium silicate root canal sealers must be used in conjunction with gutta-percha tips. Once overfilled, the harmful substances in the gutta-percha tips can also harm the human body.

[0022] Composition and characteristics of gutta-percha tips:

[0023] The main components of gutta-percha tips are gutta-percha, zinc oxide, barium sulfate, and various pigments such as ultramarine, chromium oxide, and dye yellow. Among them, barium sulfate and chromium oxide contain toxic ingredients, and zinc oxide has also been reported to be cytotoxic. If the operation is not careful, the gutta-percha tip may extend beyond the apical end point of the tooth root and enter the physiological environment zone. Long-term contact with blood and bone tissue will cause chronic inflammation in the apical area, apical cysts, bone absorption, necrosis and other hazards. Overfilling of gutta-percha tips is not uncommon in clinical practice.

[0024] Summary of the Invention

[0025] In order to solve the problem that the existing root canal sealers and gutta-percha fillings affect the apical sealing due to volume shrinkage, leading to root canal treatment failure, and the toxic and harmful components they contain cause potential harm to patients, the present application proposes an expandable root canal filling medical device combination and application based on apical biological sealing.

[0026] In order to achieve the above objectives, this application provides the following technical solutions:

[0027] An expandable root canal filling medical device combination based on biological sealing of tooth root apex, comprising a sealant combination and a titanium root canal plug tip;

[0028] The sealing agent combination consists of a liquid, a component A powder, and a component B powder, which are isolated from each other before use. The liquid is used to mix the component A powder into a paste when in use. The component A powder contains: 75%-95% tricalcium silicate, 5-25% beta tricalcium phosphate, and the component B powder contains: 45%-55% nano zirconium dioxide, 44.7%-52% calcium hydroxide, and 0.3%-3% calcium oxide.

[0029] The titanium root canal plug tip is an integrated structure, including a root canal segment and a crown segment coaxially arranged from bottom to top; the root canal segment is a cone, the surface of the root canal segment body is provided with an external thread, and the surface of the root canal segment close to the crown segment is provided with multiple circles of horizontal blades, which are respectively recorded as the root canal thread segment and the root canal horizontal blade segment. The grooves of the root canal thread segment and the root canal horizontal blade segment are used to fill the prepared sealant; the crown segment is a cylinder, and a retention groove segment is provided on the surface.

[0030] Optionally, the liquid is distilled water or chitosan oligosaccharide aqueous solution.

[0031] Optionally, the component B powder is replaced with an antibacterial enhanced powder comprising 45% nano zirconium dioxide, 42%-44.7% calcium hydroxide, 0.3%-3% calcium oxide, and 10% iodoform.

[0032] Optionally, the physical axial taper of the root canal segment is smaller than the taper of the outer contour of the root canal segment.

[0033] Optionally, the physical axis of the root canal segment is narrowed near the crown segment to form a frustum portion, and a thinner cone portion (serving as the main body of the physical axis of the root canal segment) is formed below the frustum portion, and the taper of the cone portion is smaller than that of the frustum portion.

[0034] Optionally, the taper of the outer contour of the root canal segment and the physical axis refers to the taper specification of the machine expansion needle used for dental root canal preparation, wherein the taper of the outer contour of the root canal segment is 04 taper, 06 taper or 08 taper, and the taper of the physical axis of the root canal segment is 01 taper, 02 taper or 03 taper.

[0035] Optionally, for titanium root canal plug tips with a root canal segment outer contour taper of 04 or 06, the maximum end diameter of the root canal segment outer contour is equal to the diameter of the crown segment outer contour; for titanium root canal plug tips with a root canal segment outer contour taper of 08 or above, the crown segment outer contour is radially indented relative to the root canal segment outer contour, so that a shoulder is formed between the root canal segment and the crown segment.

[0036] Optionally, the crown segment retention groove section is in the form of a thread or multiple circles of horizontal blades or horizontal grooves.

[0037] A self-expanding sealant combination for biological sealing of tooth root apex comprises a liquid, a component A powder, and a component B powder, which are isolated from each other before use. The liquid is used to mix the component A powder into a paste when in use. The component A powder contains: 75%-95% tricalcium silicate, 5-25% beta tricalcium phosphate, and the component B powder contains: 45%-55% nano zirconium dioxide, 44.7%-52% calcium hydroxide, and 0.3%-3% calcium oxide.

[0038] An application of a bioceramic root canal sealer combination, the bioceramic root canal sealer combination comprising a liquid, a component A powder, and a component B powder that are isolated from each other before use, wherein the liquid is used to mix the component A powder into a paste when used;

[0039] The A component powder comprises: tricalcium silicate 75%-95%, beta tricalcium phosphate 5-25%;

[0040] The B component powder comprises: 45%-55% nano zirconium dioxide, 44.7%-52% calcium hydroxide, and 0.3%-3% calcium oxide; or, the B component powder comprises 45% nano zirconium dioxide, 42%-44.7% calcium hydroxide, 0.3%-3% calcium oxide, and 10% iodoform;

[0041] The application is specifically a two-layer root canal filling method: the first layer filling: first, the A component paste is introduced into the entire root canal with a titanium root canal plug tip and ultrasonically vibrated for a few seconds. During the introduction process, a small amount of A component paste will inevitably enter the physiological environment area outside the apical end point. The bioactive ceramic components of A component will promote the proliferation of bone cells and apical mineralization in the apical area to form a biological apical seal; the second layer filling: the titanium root canal plug tip root canal segment with the A component paste remaining is placed in the B component dry powder and rotated to make its surface covered with the B component dry powder. At this time, the titanium material The root canal plug tip is a shaped drug stent with expandable bioceramic powder coated on the surface. It is quickly inserted into the root canal to form an AB component mixture. The calcium oxide contained in the B component will undergo a chemical expansion reaction with the water in the A component paste, and serve as the second layer of filling material to densely fill the non-physiological environment area of ​​the root canal. The self-expansion force of the second layer of AB component mixture filling material and the spiral propulsion compression force of the conical root canal section of the titanium root canal plug tip will further squeeze the first layer of A component paste into all micro gaps on the inner wall of the tooth root canal and the physiological environment area of ​​the root apex.

[0042] A titanium root canal plug tip adopts an integrated structure, including a root canal segment and a crown segment coaxially arranged in sequence from bottom to top; the root canal segment is a cone, the surface of the root canal segment body is provided with an external thread, and the surface of the area of ​​the root canal segment close to the crown segment is provided with multiple circles of horizontal blades, respectively recorded as a root canal thread segment and a root canal horizontal blade segment, and the grooves of the root canal thread segment and the root canal horizontal blade segment are used to fill with a prepared sealant; the crown segment is a cylinder, a rectangular parallelepiped or a triangular prism, and the surface is provided with a retention groove segment.

[0043] A new root canal filling mode uses a titanium root canal plug tip as a root canal metal support. The chemical expansion reaction of the self-expanding bioceramic root canal sealer is rapidly delivered and controlled in the root canal. The self-expanding force of the bioceramic material and the spiral compression force of the titanium root canal plug tip advancing in the root canal are combined to form a new uniform and dense root canal filling mode.

[0044] Compared with the prior art, this application has at least the following beneficial effects:

[0045] 1. This application is based on the concept of biological apical sealing. The sealant does not contain any thickeners or other harmful substances. The root canal plug tip is made of medical titanium material with excellent biocompatibility, which is used for partitioning, layering and material filling: the first layer is filled with component A paste, which ensures the high purity and high safety of the bioactive ceramic entering the physiological environment of the tooth, avoiding the damage caused by harmful components contained in existing sealants entering the physiological environment of the tooth. In addition, after entering the physiological environment of the root apex, component A paste can also stimulate the proliferation of new bone cells and root apex mineralization, achieving ideal biological apical sealing; The second layer of filling is in the non-physiological environment area within the apical base point of the tooth root canal, and is filled with a mixed sealer of components A and B. Component B contains calcium oxide, which will react chemically with the moisture in the previous component A paste and expand rapidly. When used in combination with the titanium material root canal plug tip of the present application, the expansion process of the sealer can be accurately and quickly controlled in the root canal, and the micro-gaps of the root canal cavity are filled with expansion and extrusion, which solves the problems of root canal treatment failure or poor long-term efficacy caused by volume shrinkage after filling with existing sealers and gutta-percha tips, and ultimately achieves high safety, high biocompatibility, high quality and high density root canal filling.

[0046] 2. The titanium root canal plug tip in the present application enables the effective implementation of zoned and layered filling with bioceramic sealants: after the first layer of component A paste completes the root canal filling, the titanium root canal plug tip with the surface of the root canal segment coated with component B dry powder sealant is equivalent to a drug stent with both plasticity and a certain elasticity. The conical thread structure of the titanium root canal plug tip rotates and advances in the conical root canal cavity. The sealant is evenly divided, compressed and filled in the root canal cavity by each circle of the thread of the root canal segment of the titanium root canal plug tip. The filling density is much greater than the filling density of the existing root canal sealing paste plus gutta-percha tip, providing a strong guarantee for stable long-term therapeutic effects.

[0047] 3. The existing gutta-percha tips contain harmful ingredients such as barium sulfate, chromium oxide, and dye yellow. Once overfilled, these toxic chemical components will come into contact with blood in the physiological environment of the root apex, causing toxic side effects such as inflammation, cysts, and bone resorption. Titanium root canal plug tips have excellent biocompatibility. The excess titanium tip will guide new bone cells to adhere and deposit on its surface, forming a biological closure of the apical foramen.

[0048] 4. This titanium root canal plug tip replaces existing gutta-percha tips, fiber posts, and root canal nails. It eliminates the need for secondary root canal insertion after root filling, thus avoiding unnecessary secondary root canal preparation damage and root fracture caused by stress concentration in the middle of the root canal caused by root canal nails. Furthermore, the presence of one or more titanium tips within the tooth, extending from the root apex to the occlusal surface of the crown, significantly enhances the tooth's overall fracture resistance.

[0049] To more intuitively illustrate the prior art and the present application, several exemplary drawings are provided below. It should be understood that the specific shapes and structures shown in the drawings should not generally be considered as limiting conditions for implementing the present application; for example, based on the technical concepts disclosed in the present application and the exemplary drawings, those skilled in the art are capable of easily making routine adjustments or further optimizations to the addition / reduction / attribution division, specific shapes, positional relationships, connection methods, dimensional ratios, etc. of certain units (components).

[0050] FIG1 is a schematic structural diagram of a titanium root canal plug tip used in one embodiment of the present application;

[0051] FIG2 is a schematic diagram of the root canal plug tip being introduced into the root canal;

[0052] FIG3 is a schematic structural diagram of a titanium root canal plug tip (with a shoulder) used in another embodiment of the present application.

[0053] FIG4 is a modification of the embodiment shown in FIG3 .

[0054] FIG5 is an axonometric view of the sample of the first embodiment of the present application.

[0055] FIG6 is an axonometric view of a sample of the second embodiment of the present application.

[0056] FIG7 is an axonometric view of a sample of the third embodiment of the present application.

[0057] Explanation of the accompanying reference numerals: 1. root canal segment; 101. physical axis of the root canal segment; 102. external thread of the root canal segment; 103. horizontal blade of the root canal segment; 2. crown segment; 201. physical axis of the crown segment; 202. external thread of the crown segment. DETAILED DESCRIPTION

[0058] The present application will be further described below in detail through specific embodiments in conjunction with the accompanying drawings.

[0059] In the description of this application, the terms "first," "second," etc. are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (for example, they should not be understood as emphasizing the degree of importance or order, etc.). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0060] Terms such as "upper," "lower," "left," "right," and "center" used in this application are generally intended to facilitate intuitive understanding when compared with the accompanying drawings and are not intended to be absolute limitations on positional relationships in actual products. Changes to these relative positional relationships are considered within the scope of this application without departing from the technical concepts disclosed herein.

[0061] This application is the first in the dental root canal treatment industry to propose a division of the dental physiological environment zone and non-physiological environment zone based on the concept of biological sealing of the root apex, and adopts a root canal treatment approach of filling in sections, layers, and materials in sequence.

[0062] The high-purity bioactive ceramic of component A enters the physiological environment area and serves as the first layer of filling: in the physiological environment areas such as the micro-flared apical foramen area, the periapical area, and the accessory root canals on each side and the micro-channels on the root surface outside the narrowest part of the root canal apex (apical base point) where there is blood circulation and metabolism, what is squeezed in or filled is the high-purity, degradable, and bone cell-stimulating silicon / calcium phosphate bioactive ceramic hydrated gel of component A, which induces apical mineralization and closure, and induces osteoblasts to proliferate, differentiate, deposit and grow into the apical physiological area and apical foramen in the apical area to form a good biological apical closure.

[0063] The bioceramic mixture of components A and B enters the non-physiological environment, forming the second layer of filling. Within the narrow, non-physiological apical region, where there's no vital pulp and no metabolism, the pulp cavity and root canal area are filled with nano-zirconium dioxide, calcium hydroxide, and calcium oxide. Calcium hydroxide is a strong alkaline substance that acts as a sterilizer, while calcium oxide's chemical expansion reaction upon contact with water forms an effective physical seal. Calcium oxide and calcium hydroxide maintain a dry and sterile root canal environment. Nano-zirconium dioxide, a bioinert ceramic, is inherently non-degradable. In this dry and sterile root canal environment, all filling materials in the AB mixture remain intact, forming a stable chemical seal.

[0064] In particular, in combination with the titanium root canal plug tip proposed in this application (the titanium material can specifically be medical pure titanium or titanium alloy), its circles of thread grooves can cleverly and quickly and evenly bring the B component composite bioceramic containing calcium oxide into the root canal filled with the A component silicon / calcium phosphate hydrate gel, and quickly and accurately transport and control the chemical reaction process of the composite bioceramic expansion in the root canal.

[0065] Taking tooth 6 as an example, this embodiment applies a two-layer filling method, specifically: after conventional root canal preparation is completed, a post channel about 3 mm deep is prepared by grinding at the root canal orifice, and the inner diameter of the post channel is larger than the maximum outer diameter of the horizontal blade of the root canal segment of the root canal plug tip. The first layer of filling: first, the A component paste is introduced into the entire root canal using a titanium root canal plug tip and ultrasonically vibrated. The introduction and vibration process will inevitably cause a small amount of A component paste to enter the physiological environment area outside the apical end point. The bioactive ceramic component of A component will promote the proliferation of bone cells in the apical area and apical mineralization to form a biological apical seal; the second layer of filling The titanium root canal plug tip, with residual Component A paste, is placed in Component B dry powder and rotated until its surface is completely coated with Component B dry powder. The Component B mixture is then inserted into the root canal to form the Component A / B mixture. The calcium oxide contained in Component B chemically expands with the water in Component A paste, forming a second layer of filling material that densely fills the non-physiological environment of the root canal. The self-expansion of the second Component AB filling material and the spiral compression force of the titanium root canal plug tip push the first layer of Component A paste further into all micro-interstices within the root canal wall and the physiological environment of the root apex. Finally, the root canal orifice post is quickly flushed with a three-way gun, the excess filling material is blown dry, and then a light-curing fluid resin or glass ionomer is injected to complete the filling.

[0066] The root canal sealer combination in the present application can be divided into a basic formulation and an antibacterial enhanced formulation, and both of these two sealer combinations are composed of a liquid and a powder.

[0067] Basic dosage form:

[0068] Liquid preparation: distilled water or chitosan oligosaccharide / distilled water (500 mg / L mass concentration) solution;

[0069] The powder is divided into component A powder and component B powder; the composition of component A is (by mass fraction): tricalcium silicate 75%-95%, beta tricalcium phosphate 5-25%; the composition of component B is (by mass fraction): nano zirconium dioxide 45%-55%, calcium hydroxide 44.7%-52%, calcium oxide 0.3%-3%;

[0070] Enhanced antibacterial type:

[0071] Liquid preparation: distilled water or chitosan oligosaccharide / distilled water (500 mg / L mass concentration) solution;

[0072] The powder is divided into component A powder and component B powder; wherein the composition of component A is (by mass fraction): tricalcium silicate 75%-95%, beta tricalcium phosphate 5-25%; the composition of component B is (by mass fraction): nano zirconium dioxide 45%, calcium hydroxide 42%-44.7%, calcium oxide 0.3%-3%, iodoform 10%;

[0073] The basic dosage form is suitable for the vast majority of cases, and the enhanced antibacterial dosage form is suitable for a small number of root canal cases with chronic exudative inflammation and some difficult-to-treat cases.

[0074] The specific experimental groups are shown in Table 1.

[0075] Table 1

[0076] The above experimental groups were able to achieve the effects expected by the inventors, and the specific analysis is detailed below.

[0077] The titanium root canal plug tip is an integrated structure, as shown in Figures 1, 3, and 4, and includes a root canal segment 1 and a crown segment 2 coaxially arranged from bottom to top. The root canal segment 1 is a cone, and the external taper of the root canal segment is consistent with the taper specification of the dental root canal preparation machine expansion needle (configurable models include 04 taper, 06 taper, and 08 taper). The root canal segment surface is provided with a root canal segment external thread 102, and its thread groove is used to fill the prepared sealant. Therefore, a horizontal thread form is preferred, for example, a thread lead angle of 0 to 30 degrees. The crown segment 2 is a cylinder, and the surface is provided with a crown segment external thread 202. The thread here mainly serves as a retention function and can also be changed to a horizontal blade form. After the root canal plug tip is filled in place, the crown segment is located in the cavity within the crown. After filling with fluid resin or glass ionomer adhesive, it is used to fix the root canal plug tip in the tooth body.

[0078] In one embodiment, a titanium root canal plug with an integrated structure has a conical root canal segment 1. The external taper of the root canal segment is consistent with the standard taper of a dental root canal preparation machine expansion needle (configurable models include 04 taper, 06 taper, and 08 taper). The root canal segment surface is provided with an external root canal segment thread 102. The thread groove is used to fill the prepared sealant. Therefore, a horizontal thin blade non-standard thread form is preferred, for example, with a thread lead angle of 0 to 30 degrees. To further improve the filling effect of the agent, it is recommended that the thread profile angle of the root canal thread segment be no greater than 60 degrees, for example, 15 to 45 degrees. The crown segment 2 is cylindrical (the cylinder here refers to the main body of the crown segment being cylindrical, and a more convenient shape for clamping can be machined locally based on the cylinder as needed). The surface is provided with an external crown segment thread 202, which primarily serves as a retaining thread and can also be modified to a horizontal blade form. After the root canal plug tip is filled in place, the crown segment is positioned within the crown cavity and is filled with fluid resin or glass ionomer adhesive to secure the root canal plug tip within the tooth. In addition to being cylindrical, the crown segment can also be designed as a rectangular parallelepiped or a triangular prism, and the specific form of the retention groove section provided on the surface is not limited to a thread, but can also be a horizontal blade or a horizontal annular groove.

[0079] The state of the titanium root canal plug tip being introduced into the root canal is shown in FIG2 .

[0080] A root canal segment horizontal blade 103 is also provided in the area near the crown segment on the upper surface of the root canal segment. The purpose of providing the root canal segment horizontal blade 103 is: 1. To form a blind groove in the root canal segment thread groove, so that the sealant in the thread groove will not overflow from the groove when rotating into the root canal, ensuring that there is a sufficient amount of sealant in the root canal and that it is compressed and compacted in the groove between the root canal cavity and the thread groove. 2. The groove of the horizontal blade can be filled with either sealant or filling materials such as fluid resin adhesive or glass ionomer, serving as a boundary marker between the sealant and the filling material. 3. To prevent the water flow from washing away the sealant in the root canal segment thread groove when rinsing the crown after the root canal is filled. The grooves in each circle of the thread groove are connected, and the sealant will be washed away by the water flow. However, the grooves in each circle of the horizontal blade are not connected to each other. Each circle is an independently closed groove and will not be washed away by the water flow, thus protecting the sealant in the root canal from being washed away, diluted, or contaminated by saliva.

[0081] The root canal segment physical axis 101 (the metal physical axis at the bottom of the root canal threaded segment and the horizontal blade segment groove) and the crown segment physical axis 201 (the metal physical axis at the bottom of the crown threaded segment groove) have a smooth transition, but the root canal segment physical axis 101 may not be a standard cone. The thread of the crown segment 2 only serves to fix the root canal plug tip in the tooth body after filling with fluid resin or glass ionomer adhesive. Therefore, the crown segment physical axis 201 can be thicker; further, as shown in Figures 1 and 3, the part of the root canal segment physical axis 101 close to the crown segment (specifically, it can be the upper part of the physical axis at the bottom of the root canal horizontal blade segment groove) can be significantly narrowed, so that the main body of the root canal segment physical axis 101 is relatively thinner.

[0082] The taper of the root canal segment's solid axis 101 includes 01 taper, 02 taper, and 03 taper. Reducing the taper of the solid axis can increase its flexibility to better adapt to small and curved root canals.

[0083] For titanium root canal plug tips with a taper of 08 or above, they can also be modified as follows: the outer contour of the crown segment is radially indented relative to the outer contour of the root canal segment, so that a shoulder is formed between the root canal segment and the crown segment, as shown in Figures 3 and 4. Specifically, the maximum diameter of the largest end of the external thread of the root canal segment (i.e., the connection with the crown segment) is larger than the diameter of the external thread of the crown segment, and the diameter of the external thread of the crown segment is narrower than the maximum diameter of the largest end of the external thread of the root canal segment by about half the width of the thread, that is, a narrow shoulder is provided between the root canal segment and the crown segment. The narrow shoulder is provided to reserve a larger gap at the root canal orifice after the root canal is filled to facilitate flushing and drying of excess sealant, to facilitate better flow of fluid resin or glass ionomer adhesive into the root canal orifice, and to better fix the root canal plug tip to the crown.

[0084] To more intuitively illustrate the various embodiments of this application, Figures 5, 6, and 7 provide axonometric views of three examples. Figure 6, compared to Figure 5, primarily changes the radial dimensions of the crown segment. Figure 7 shows the retention grooves on the crown segment surface, specifically in the form of graduated grooves, and the horizontal blades of the root canal segment are slightly thicker in the center. Of course, the details of these sample drawings should not be construed as limiting the products claimed in this application.

[0085] The specific steps for performing two-layer root canal filling using the titanium root canal plug are as follows:

[0086] Step 1: Select a basic or antibacterial enhanced root canal sealer according to the indication of the affected tooth, select a titanium root canal plug tip that matches the taper and length of the root canal to be filled, mix the sealer component A with the liquid agent to form a paste, scrape the paste into the thread groove of the root canal segment (1), and introduce the paste into the root canal through the root canal plug tip, continuously and quickly press several times, and repeat the above action 1-2 times (after exiting, hang the paste again and introduce it into the root canal), complete the sealing and filling of the physiological environment area of ​​the root apex and the first layer of high-purity bioactive ceramic coating and filling of the inner wall of the root canal under the action of the vertical component force and the horizontal component force of the cone of the root canal segment of the root canal plug tip, and then rotate and exit in the opposite direction of the thread entry;

[0087] Step 2: Place the root canal segment of the root canal plug tip in the dry powder of the sealant component B and rotate it so that the surface of the residual paste in the thread groove is covered with the dry powder of the bioceramic component B containing calcium oxide. At this time, the titanium root canal plug tip is an arbitrarily shaped drug stent, and the surface is coated with expandable bioceramic powder (this is similar to the spraying of hydroxyapatite bioceramics on the surface of the titanium implant of the dental implant, except that the hydroxyapatite must be sintered at high temperature on the titanium surface, while in this embodiment, only the bioceramics need to be coated in the thread groove of the titanium root canal plug tip); after light rolling for preliminary compaction, rotate it along the thread entry direction and insert it into the preset position of the root canal; because the prepared root canal cavity and the root canal plug tip are both round The titanium root canal plug has a conical shape, so the component B bioceramic powder in the thread groove of the root canal plug tip will be further compressed and compacted in the root canal cavity. By utilizing the principle that calcium oxide will expand rapidly when it comes into contact with water, the calcium oxide in the component B powder in the thread groove of the titanium root canal plug tip and the water in the component A paste in the root canal cavity will undergo a chemical expansion reaction. At this time, a small part of the nano zirconium dioxide in the component B will enter the micro-gaps of the root canal cavity, the lateral root canals, and the dentinal tubules under the extrusion of the expansion force, completing the secondary second-layer bioceramic root canal filling. The second layer of bioceramic will further squeeze the first layer of hydrated calcium silicate / calcium phosphate gel coated on the inner wall surface of the root canal cavity into the physiological environment area of ​​the tooth and the micro-gaps and dentinal tubules adjacent to the physiological environment area.

[0088] During the root canal filling process, the titanium root canal plug tip can also be directly electrically connected to the dental root gauge, allowing the root canal length to be accurately measured while filling. There is no need to measure the root canal in advance or take X-rays to confirm the tooth length, and there is no need to pre-set the working length of the root canal plug tip. Filling and measuring are performed simultaneously with digital operations, allowing ultra-precise root canal filling to be completed in seconds.

[0089] Finally, rinse and dry the excess bioceramics in the root canal orifice, crown cavity and the thread groove of the crown segment of the root canal plug, inject light-curing fluid resin into the root canal orifice and crown cavity for light curing or natural curing of glass ionomer adhesive to quickly complete a high-quality root canal treatment.

[0090] In the above embodiments, using conventional tools such as root canal enlargement needles, smooth probes, and gutta-percha tips would likely make it difficult to uniformly and proportionally fill the root apex with the dry powder of component B and the hydrated gel of component A, quickly and efficiently before the chemical expansion reaction. However, using the titanium root canal plug tip described above allows the chemical expansion reaction of the composite bioceramic to be precisely delivered and controlled within the root canal.

[0091] Chemical composition analysis of the bioceramics in the root canal sealer of this medical device combination:

[0092] 1. Tricalcium silicate:

[0093] Tricalcium silicate has excellent biological activity and the ability to induce the deposition of bone-like hydroxyapatite, and it has the ability to promote the formation of chemical bonds with soft and hard tissues. Tricalcium silicate reacts with water at room temperature to form hydrated calcium silicate gel (CSH) and calcium hydroxide. CSH biomaterials have a significant effect on stimulating the proliferation and differentiation of osteoblasts, and on the proliferation and differentiation of dental pulp stem cells into odontoblast-like cells. Silicon ions play an important role in promoting metabolism, collagen synthesis, and bone tissue mineralization, and are an important factor in bone and blood vessel formation. The induced hydroxyapatite deposit can penetrate into the dentinal tubules and form chemical bonds with the dentin, thus having better root canal sealing properties.

[0094] In addition, the hydration reaction of calcium silicate also produces a small amount of calcium hydroxide, which has a certain antibacterial effect, while β-tricalcium phosphate does not have antibacterial properties.

[0095] Wang Xiaohong, Chang Jiang, Sun Hongchen and others reported in the academic paper "Experimental Study on Blocking of Dentin Tubules by Tricalcium Silicate" that the self-curing process of CSH biomaterials will generate amorphous calcium and phosphate ions of about 100nm-300nm on the dentin surface to block dentinal tubules, and induce dentin remineralization under physiological conditions.

[0096] Fei Lisha, Sun Jiao and others reported in the academic paper "Preliminary Study on the In Vitro Osteogenic Effect of Calcium Silicate Bioceramics with Different Contents" that calcium silicate (GS) has a significant ability to induce bone cell proliferation and differentiation in vitro. The osteogenic effect is proportional to the content of CS and is significantly better than β-tricalcium phosphate (β-TCP).

[0097] In the paper "Study on the Degradability of α-Calcium Silicate and β-Calcium Silicate in Vitro and In Vivo", Liu Yong et al. reported on an animal model of implanting α-calcium silicate, β-calcium silicate and β-tricalcium phosphate into rabbits. They discussed in detail the mechanism of α-calcium silicate, β-calcium silicate and β-tricalcium phosphate in vivo degradation and stimulation of osteoblast proliferation and differentiation, and demonstrated that the osteogenic activity and speed of calcium silicate are higher than those of β-tricalcium phosphate.

[0098] 2. β-tricalcium phosphate:

[0099] β-tricalcium phosphate has good biodegradability, osteoinductivity and conductivity, biocompatibility and biosafety. When it is implanted into the human body, the degraded Ca ions and P ions can enter the living body's circulatory system to form the basic substance of new bone and induce new bone regeneration. β-tricalcium phosphate alone can also achieve bone-cementum-dentin osseous fusion and achieve biological closure of the root apex.

[0100] The curing process of β-tricalcium phosphate does not generate heat, and its combination with calcium silicate has a positive effect on maintaining the normal physiological environment balance of the root apex.

[0101] The solidification strength of β-tricalcium phosphate is lower than that of calcium silicate after solidification. When used in combination with calcium silicate, it can reduce the strength of the root canal filling, which is conducive to the subsequent removal of the root canal filling for root canal retreatment.

[0102] The degradation rate of β-tricalcium phosphate in the physiological environment is lower than that of calcium silicate. For areas with large apical bone absorption, the proliferation rate of bone cells often cannot keep up with the degradation rate of calcium silicate materials. The combined use of calcium silicate and β-tricalcium phosphate will make the degradation rate of the material closer to the proliferation rate of bone cells.

[0103] The hydration reaction of tricalcium silicate generates calcium silicate hydrate gel and a small amount of calcium hydroxide, and the calcium hydroxide reacts with β-tricalcium phosphate to generate hydroxyapatite.

[0104] 3. Nano zirconium dioxide:

[0105] Nano-zirconium dioxide is an excellent bioinert material with high strength and good chemical stability. It does not react with other chemical components, does not cause hemolytic reactions, is non-degradable, non-cytotoxic, and has no rejection reaction when in contact with bone cells. It has a large specific surface area, strong oxygen storage capacity, and relatively high density. It has a radioblocking effect on X-rays and can be used as a developer, facilitating radiography after root canal filling. For reference, the paper "Effects of Nano-Zirconium Dioxide-Toughened Hydroxyapatite Biocomposite Ceramics on the Proliferation and Differentiation of Rabbit Bone Marrow Stromal Stem Cells" (Tang Yuejun, Wang Xinling, Zhou Zhonghua, and Lü Chuntang) can be used.

[0106] 4. Calcium hydroxide:

[0107] Calcium hydroxide, also known as slaked lime, is strongly alkaline with a pH value as high as 12.5. It can damage bacterial cell membranes and denature bacterial proteins. The released hydroxide ions cause bacterial DNA chains to break, thereby killing bacteria. It can also penetrate into dentinal tubules to kill bacteria.

[0108] Calcium hydroxide can neutralize the acidic substances produced during the inflammation process, eliminate lactic acid produced by osteoclasts, inhibit acid phosphatase, inhibit apical inflammatory absorption, and prevent further destruction of hard tissue. At the same time, it can activate alkaline phosphatase to promote the formation of hard tissue.

[0109] Calcium hydroxide has good biocompatibility, is non-irritating to the body and dental pulp tissue, and is non-toxic. It can promote and induce the formation of dentin bridges, promote the closure of the apical foramen, and promote the repair of periapical bone tissue.

[0110] 5. Calcium oxide:

[0111] Calcium oxide, also known as quicklime, is hygroscopic and reacts with water to form calcium hydroxide. The volume expansion rate after hydration reaction is about 200%.

[0112] Although calcium oxide only accounts for 0.3%-3% of component B in this embodiment, it undergoes a chemical reaction when exposed to water and moisture and expands rapidly, giving the bioceramic sealant the self-expanding property. It is the only, irreplaceable and important component in component B.

[0113] Analysis of the combined effects of the composite bioceramic root canal sealer and the root canal apical plugging device in this embodiment:

[0114] Chitosan oligosaccharides in the liquid can inhibit the resorption of osteoclasts, increase the activity of osteoblasts, and promote the synthesis of bone morphogenetic protein (BMP) by osteoblasts to repair bone damage or bone resorption caused by inflammation, trauma, etc. in the root apex.

[0115] When component A is mixed with chitosan oligosaccharide / distilled water solution, the calcium silicate therein reacts with water to generate calcium silicate hydrate gel (CSH) and a small amount of calcium hydroxide.

[0116] In the root canal, calcium silicate hydrate gel CSH can enter the micro-gaps such as dentinal tubules and lateral root canals to form an obstruction seal.

[0117] A small amount of calcium silicate hydrate gel (CSH) will be squeezed out of the narrow area of ​​the root canal apex and enter the apical physiological environment area, inducing cementum mineralization, stimulating the proliferation and differentiation of osteoblasts, inducing the deposition of bone-like hydroxyapatite to generate new bone to seal the apical foramen, and promoting the formation of chemical bonds with soft / hard tissues.

[0118] Calcium hydroxide generated by the hydration reaction of calcium silicate reacts with β-tricalcium phosphate to form hydroxyapatite.

[0119] Among them, β-tricalcium phosphate, after entering the physiological environment of the tooth root, the degraded Ca ions and P ions can enter the living body's circulatory system to form the basic substance of new bone and induce new bone regeneration to close the apical foramen.

[0120] Component A is a biodegradable bioactive ceramic material that can induce the mineralization of dentin and cementum in the apical area, induce the differentiation and proliferation of cementoblasts and osteoblasts, form bone-cementum-dentin osseous fusion, and achieve the most ideal root canal treatment effect of biological sealing of the root apex.

[0121] The nano-zirconium dioxide in component B is a non-degradable, bioinert ceramic material that can directly penetrate into micro-gaps such as dentinal tubules (diameter approximately 2-4 microns) and lateral root canals to form a blockage seal. Within the root canal, the nano-zirconium dioxide acts as a transmission medium for the internal expansion force and the external rotational compression force of the titanium threads. This pushes the first layer of tricalcium silicate / tricalcium phosphate hydrated gel coated on the inner wall of the root canal deeper into the dentinal tubules and other micro-gaps, achieving a better sealing effect.

[0122] The pH value of calcium hydroxide is as high as 12.5, which can maintain a strong alkaline environment in the root canal and play a role in sterilization and disinfection.

[0123] Calcium oxide reacts with the water in component A to form calcium hydroxide, which expands by 200%. Utilizing its rapid expansion upon chemical reaction in contact with water and moisture, this bioactive ceramic sealant expands upon filling, forming a dense root canal filling and ensuring the physical sealing advantage of the root canal. Combined with titanium root canal plug tips, it can address the industry's problem of volume shrinkage after root canal filling.

[0124] Calcium oxide also has a drying effect. After the chemical reaction, it will consume excess water in the root canal. After the A and B components are mixed, they can maintain a dry and sterile root canal environment for a long time. The mixed bioceramics of the A and B components will not degrade in a dry and sterile non-physiological environment, and can maintain the long-term stable density of the filling in the root canal and good long-term therapeutic effects.

[0125] Calcium oxide generates calcium hydroxide after hydration reaction, which works together with the original calcium hydroxide component in component B to keep the root canal dry and sterile, ensuring the advantage of chemical sealing of the root canal.

[0126] The titanium root canal plug tip compresses a mixture of tricalcium silicate, calcium hydroxide, and zirconium dioxide into the root canal, forming "reinforced concrete" of the tooth.

[0127] Quantitative analysis of the expansion rate and heat generation rate of this medical device combination:

[0128] During use of the medical-device combination of this embodiment, after the B component material is brought into the root canal by the titanium root canal plug tip, the volumes of the A and B component materials each account for about 50% (the specific usage ratio can be controlled at A:B=1:0.8~1.2), and the calcium oxide content in the B component accounts for about 0.3%-3%. The volume expansion rate of the calcium oxide hydration reaction is about 200%. It can be calculated that the expansion rate of the root canal apical sealer is approximately: 1*50%*0.3%*200%=0.3%, 1*50%*3%*200%=3%, and the volume expansion rate of the root canal apical sealer is about 0.3%-3%, which should meet clinical application requirements (the calcium oxide content ratio can be increased or decreased according to clinical needs).

[0129] Furthermore, in self-expanding composite bioceramics, calcium oxide has the side effect of generating heat during the hydration reaction. After the composite bioceramic root filling is mixed, the volume of component B, which is carried into the root canal by the thread groove of the root canal plug tip, accounts for approximately 50%. The calcium oxide content of component B is 0.3%-3%. Calculations show that the calcium oxide content in the root canal is 1*50%*0.3%=0.15%, and 1*50%*3%=1.5%. The calcium oxide content in the root canal is approximately 0.15%-1.5%, generating much less heat than the heat generated in the root canal by traditional hot gutta-percha filling methods.

[0130] Compared with existing bioceramic sealants, the sealant combination of this embodiment has the following advantages:

[0131] During root canal filling, a portion of the sealant will inevitably be squeezed out of the apical narrow area into the physiological environment area with blood circulation and metabolism, including the apical foramen and the periapical area outside it.

[0132] Some existing brands of bioceramic sealers contain harmful ingredients such as bismuth oxide. Some injectable bioceramics contain resin thickeners, which can produce carcinogens in the high-temperature environment of gutta-percha fillings. Since the tooth cannot be zoned and layered during filling, these harmful substances inevitably extend beyond the root apex and into the physiological environment, posing a potential hazard to the human body. Existing calcium silicate root canal sealers used in combination with gutta-percha tips still face safety concerns, including significant gutta-percha tip shrinkage and the presence of toxic components in the gutta-percha tips after overfilling. Furthermore, the thickeners in injectable calcium silicate root canal sealants keep the silicon and calcium ions in suspension, hindering their precipitation and penetration into the micro-interstices of the root canal and dentinal tubules.

[0133] Component A of the sealant in this embodiment is mixed with distilled water to produce a calcium silicate hydrate gel-calcium hydroxide paste. This paste combines the fineness of a gel with a "wet sand"-like sedimentation. This "wet sand" sedimentation facilitates ultrasonic vibration after filling, allowing it to penetrate into the dentinal tubules and micro-interstices in the root apex. After filling, excess water can be absorbed with a dry cotton ball to increase the concentration of tricalcium silicate and the root filling density, achieving an ideal biological apical seal and dense root canal filling.

[0134] The sealer of this embodiment does not contain any thickeners or other harmful substances. The root canal plug tip is made of highly biocompatible medical titanium. It is used in a combination of zones, layers, and groups, each filled with a biodegradable, high-purity, and highly active bioceramic, along with a non-degradable bioceramic. This ensures the purity of the bioactive ceramic within the tooth's physiological environment, while preventing the harmful effects of traditional sealants. Specifically, a layer of high-purity, biodegradable bioactive ceramic, Component A, is applied to the tooth's physiological environment and adjacent physiological zones, as well as micro-gaps within the root canal wall and dentinal tubules. Component A consists of 75%-95% tricalcium silicate and 5%-25% tricalcium phosphate, mixed with distilled water or a chitosan oligosaccharide / distilled water solution. It does not contain any other ingredients that are unhelpful or detrimental to bone cell growth, such as thickeners, radiopaque contrast agents, or other inorganic fillers. Upon entering the root canal, it forms the first layer of high-purity, bioactive ceramic sealing barrier.

[0135] When component A is mixed with distilled water or chitosan oligosaccharide / distilled water to form a fluid paste, the tricalcium silicate hydrates to form calcium silicate hydrate gel (CSH) and calcium hydroxide. Once introduced into the root canal, a small portion of this paste squeezes out of the narrow apical zone and enters the physiological environment of the tooth, where it participates in metabolism and induces the differentiation and proliferation of cementoblasts and osteoblasts. CSH induces the deposition of bone-like hydroxyapatite to form new bone, repairing bone resorption and bone defects in the apical region caused by apical periodontitis. It also induces mineralization of cementum and dentin in the apical region, achieving biological sealing of the apical foramen, consistent with our proposed concept of biological apical sealing.

[0136] β-tricalcium phosphate (CTP) is similar to the inorganic components of dentin and bone matrix, exhibiting excellent osteogenic activity and osteoconductivity, guiding bone cell growth into the root apex. Degraded calcium and phosphate ions become essential substances for bone cell growth. β-TCP reacts with calcium hydroxide to form hydroxyapatite, which deposits and forms a biological apical sealant with bone-cementum osseointegration, consistent with our proposed concept of biological apical sealing.

[0137] The non-physiological environment area within the narrow area of ​​the root apex of the tooth is filled with expandable, non-degradable AB component mixed bioceramics (the component nano zirconium dioxide in the B component is a bioinert ceramic that itself does not degrade. In the dry and sterile root canal in a non-physiological environment, all components of the AB component do not degrade. The advantage of non-degradation is that it can maintain long-term stable filling density in the root canal and good long-term therapeutic effects).

[0138] In addition, the sealing agent combination of this embodiment is also the result of continuous optimization by the inventors. The previously attempted formula is:

[0139] Liquid: distilled water or normal saline;

[0140] Component A powder: tricalcium silicate 55-75%, β-tricalcium phosphate 25-45%;

[0141] Component B powder: calcium hydroxide 35-40%, nano-hydroxyapatite 21-26%, nano-zirconium dioxide 20-25%, nano-tantalum oxide 10-15%, calcium oxide 3-5%.

[0142] The formula of the basic dosage form in this embodiment is:

[0143] Liquid: chitosan oligosaccharide / distilled water 500 mg / L solution;

[0144] Component A powder: tricalcium silicate 75%-95%, beta tricalcium phosphate 5-25%;

[0145] Component B powder: nano zirconium dioxide 45%-55%, calcium hydroxide 44.7%-52%, calcium oxide 0.3%-3%.

[0146] By consulting the latest research reports and conducting clinical verification, the inventors realized that calcium silicate is more effective in promoting bone cell proliferation than tricalcium phosphate, and there is a significant statistical difference. Therefore, the content of tricalcium silicate in component A was increased from 55-75% to 75%-95%, and the content of β-tricalcium phosphate was reduced from 25-45% to 5-25%, thereby achieving a better effect of promoting the proliferation of bone cells in the root apex.

[0147] In addition, the titanium root canal plug tip has also been improved. The handle of the root canal plug tip has been removed, and the length of the root canal plug tip has been reduced, making it easier for doctors to operate, especially for patients with limited mouth opening. The external thread taper of the root canal segment of the titanium root canal plug tip and the taper of the solid axis at the bottom of the thread groove have also been redesigned for differentiation. The taper and radial size of the solid axis are smaller and thinner, so that the root canal segment of the root canal plug tip has better flexibility and plasticity, which is more suitable for filling small and curved root canals, expanding the indications for the use of titanium root canal plug tips.

[0148] The tip of the root canal segment is arc-shaped, and the taper of the outer contour and the diameter of the tip of the root canal segment are consistent with the taper and the diameter of the tip of the dental root canal preparation machine expansion needle. The commonly used specifications of the 04 taper series are 04 / 025, 04 / 030, and 04 / 035, and the commonly used specifications of the 06 taper series are 06 / 025, 06 / 030, etc., and can be expanded up and down based on this series data.

[0149] The physical axis taper of the root canal segment can be designed as a single through-taper, with either a 0.1 taper, a 0.2 taper, or a 0.3 taper depending on actual clinical application scenarios. Any external taper data for the root canal plug tip can be combined with any physical axis internal taper data. To increase the flexibility and plasticity of the apical half of the root canal thread groove section at the root canal plug tip, while also increasing the strength of the horizontal root canal blade section, the physical axis taper of the root canal segment can also be designed as a variable taper depending on actual clinical application scenarios. Specifically, the lower half of the physical axis of the root canal thread groove section near the apex of the root canal plug tip has a 0.1 taper, the upper half of the physical axis of the root canal thread groove section has a 0.2 taper, and the physical axis of the horizontal root canal blade section has a 0.3 taper. Alternatively, other combinations of tapers can be designed, ranging from 0.1 to 0.3 tapers from the root canal plug tip's physical axis upward.

[0150] The commonly used length parameters of the root canal plug tip series are 13mm (root canal segment length 7.5mm, crown segment length 5.5mm), 15mm (root canal segment length 8.5mm, crown segment length 6.5mm), 17mm (root canal segment length 9.5mm, crown segment length 7.5mm), 19mm (root canal segment length 10.5mm, crown segment length 8.5mm), 21mm (root canal segment length 11.5mm, crown segment length 9.5mm), 23mm (root canal segment length 12.5mm, crown segment length 10.5mm), 25mm (root canal segment length 13.5mm, crown segment length 11.5mm), 27mm (root canal segment length 15.5mm, crown segment length 11.5mm), and 29mm (root canal segment length 17.5mm, crown segment length 11.5mm). Due to the large differences in tooth morphology, the data in this series can also be expanded up and down.

[0151] The overall advantages of this medical device combination:

[0152] 1. The composite bioceramic root canal sealer in this medical device combination has high safety, high biocompatibility, high quality and high density for root canal filling.

[0153] High safety means that the AB two-component bioceramics do not contain any ingredients harmful to the human body. The partitioned and layered filling method is adopted. The first layer is filled with high-purity bioactive ceramics of component A. This ensures the high purity and high safety of the bioactive ceramics entering the physiological environment of the tooth, and avoids the damage caused by harmful ingredients contained in existing sealants entering the physiological environment of the tooth.

[0154] Highly biocompatible, high-quality root canal fillings mean that the bioactive ceramic calcium silicate hydrate gel and β-tricalcium phosphate paste in Component A, which enter the physiological environment of the tooth, are degradable, stimulating the proliferation and differentiation of osteoblasts and cementoblasts, stimulating the deposition of new bone in the apical region and the growth of new bone into the apical foramen, or promoting the mineralization and closure of the apical foramen, resulting in the ideal biological apical seal. Existing root canal fillings with sealers and gutta-percha are merely physical apical seals.

[0155] High-density root canal filling means that the non-physiological environment area within the apical end point of the tooth root canal is filled with an expandable AB component mixed bioceramic root canal sealer. Component B contains calcium oxide. After the AB components are mixed, the calcium oxide will chemically react with the moisture in the A component paste to rapidly expand. When used in combination with the root canal plug tip, the expansion process of the sealer can be precisely controlled in the root canal, and the micro-gap of the root canal cavity is filled with a second layer of expansion and extrusion, which solves the problems of root canal treatment failure or poor long-term efficacy caused by volume shrinkage after filling with the existing root canal sealing paste plus gutta-percha tip.

[0156] Calcium oxide has a drying effect. After the expansion chemical reaction, it generates calcium hydroxide and consumes excess water in the root canal. Together with the calcium hydroxide in component B, it keeps the root canal dry and sterile. In the dry and sterile root canal environment, all components of the AB components do not degrade. The beneficial effect of non-degradation is that it can maintain a long-term stable filling density in the root canal and good long-term therapeutic effects.

[0157] 2. The titanium root canal plug tip in this medical device combination provides high safety, high biocompatibility, high quality and high density root canal filling.

[0158] 1. Medical pure titanium or titanium alloy and other titanium materials are non-toxic to the human body and have excellent safety and biocompatibility. They have been widely used in orthopedics, surgery and other fields. The root canal plug tip made of titanium material is allowed to extend beyond the root apex base point into the root apex physiological environment area. The surface of the titanium tip that extends beyond the tooth will form bone cells adhesion and deposition, forming a dense bone plate in the root apex area; the use of titanium root canal plug tips in combination with layered, partitioned and grouped fillings of high-purity bioceramics can induce the generation of new bone cells to grow into the root apex area and induce root apex mineralization to form a biological seal.

[0159] 2. The titanium root canal plug tip provided by this medical device combination enables the implementation of zoned, layered filling with bioceramic sealers: In addition to the sealer's own expansion, the titanium root canal plug tip's tapered threads compress the sealer as it rotates and advances within the tapered root canal cavity. After the first layer of Component A paste completes the root canal filling, the titanium root canal plug tip, coated with Component B dry powder sealer, acts as a drug stent, both plastic and elastic. The tapered threads of the root canal segment rotate and advance within the conical root canal cavity, evenly dividing, compressing, and filling the root canal cavity with each turn of the root canal plug tip's threads. This results in a filling density far greater than that achieved with existing sealers and gutta-percha tips, providing a strong guarantee for stable, long-term efficacy.

[0160] 3. Titanium root canal plug tip greatly improves the anti-fracture ability of the affected tooth and extends the service life of the affected tooth.

[0161] The titanium root canal plug tip in this medical device combination has a certain degree of softness and hardness. During the early stage of root canal preparation, compared with the amount of tooth preparation using gutta-percha tips, the use of titanium root canal plug tips can effectively reduce unnecessary preparation and cutting damage to the healthy tooth root canal, thereby improving the anti-fracture ability of the affected tooth.

[0162] After the traditional sealer + gutta-percha tip root filling is completed, a second root canal nail or fiber post is required for reinforcement. The titanium material root canal plug tip in this medical device combination adopts an integrated design of the apical section and the crown section. The crown section can replace the root canal nail or fiber post in the crown cavity, eliminating the need for a second root canal nail or fiber post. This reduces the unnecessary damaging cutting preparation to the healthy root canal tissue when the root canal post is driven after the root canal filling, retains more healthy tooth tissue, and improves the fracture resistance of the affected tooth.

[0163] In the treatment solution provided by this embodiment, one to three titanium root canal plugs are placed inside the affected tooth, extending from the apex to the crown, eliminating stress concentration. This significantly improves the tooth's resistance to fracture and overall strength, avoiding the stress concentration at the halfway point of a traditional root canal nail that can cause root fracture. This treatment solution significantly outperforms existing sealant, gutta-percha, and root canal nail solutions, effectively extending the lifespan of the affected tooth.

[0164] 3. New filling mode brought by this medical device combination

[0165] The current concept of sealer + gutta-percha root canal filling is to use the gutta-percha tip as the primary method, supplemented by the sealer. The filling method involves compressing and deforming the gutta-percha tip to fill the root canal in response to postoperative sealer shrinkage. This involves applying lateral pressure with cold gutta-percha and vertical pressure with hot gutta-percha to seal the apical foramen and other micro-gaps. This increases the doctor's time, difficulty, and risk of failure. The current sealer + gutta-percha root canal filling method requires measuring the root length, testing the tip, taking an X-ray, testing the tip again, and taking another X-ray, repeatedly confirming the working length of the gutta-percha tip. Despite this, overfilling or underfilling of the gutta-percha tip with the root canal is still a common occurrence in clinical practice.

[0166] The root canal filling method of this embodiment's medical-device combination utilizes the titanium root canal plug tip as a drug support during root canal filling, allowing the sealer to chemically react and expand to fill the root canal. Furthermore, the conical design of the titanium root canal plug tip also compresses the sealer secondary to its insertion into the tapered root canal. This filling method significantly simplifies the existing root canal treatment process and improves root canal filling quality.

[0167] In addition, the titanium root canal plug tip is conductive and can be directly connected to the electronic root length measuring instrument, so that the root canal length can be directly measured while filling. The accuracy required for the insertion length of the root canal can be controlled to 0.1mm at one time, realizing digital and precise root canal filling.

[0168] The technical features of the above embodiments can be combined arbitrarily (as long as there is no contradiction in the combination of these technical features). In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described; these embodiments that are not explicitly written should also be considered to be within the scope of this specification.

Claims

1. Expandable root canal filling medical device combination based on biological sealing of tooth apex, It is characterized in that Includes sealer combination and titanium root canal plug tip; The sealing agent combination is composed of a liquid, a component A powder and a component B powder which are isolated from each other before use, wherein the liquid is used to mix the component A powder into a paste when in use; the component A powder contains: 75%-95% tricalcium silicate, 5-25% beta tricalcium phosphate, and the component B powder contains: 45%-55% nano zirconium dioxide, 44.7%-52% calcium hydroxide, and 0.3%-3% calcium oxide; The titanium root canal plug tip is an integrated structure, including a root canal segment and a crown segment coaxially arranged in sequence from bottom to top; the root canal segment is a cone, the surface of the root canal segment body is provided with an external thread, and the surface of the root canal segment close to the crown segment is provided with multiple circles of horizontal blades, which are respectively recorded as a root canal thread segment and a root canal horizontal blade segment, and the grooves of the root canal thread segment and the root canal horizontal blade segment are used to fill the prepared sealant; the crown segment is a cylinder, a rectangular parallelepiped or a triangular prism, and a retention groove segment is provided on the surface.

2. The expandable root canal filling medical-device combination based on biological closure of the tooth apex according to claim 1, It is characterized in that The liquid is distilled water or chitosan oligosaccharide aqueous solution.

3. The expandable root canal filling medical-device combination based on apical biological sealing according to claim 1, It is characterized in that The B component powder is replaced with an antibacterial enhanced powder, which contains 45% nano zirconium dioxide, 42%-44.7% calcium hydroxide, 0.3%-3% calcium oxide, and 10% iodoform.

4. The expandable root canal filling medical-device combination based on apical biological sealing according to claim 1, It is characterized in that The physical axial taper of the root canal segment is smaller than the taper of the outer contour of the root canal segment.

5. The expandable root canal filling medical-device combination based on apical biological sealing according to claim 4, It is characterized in that The part of the physical axis of the root canal segment close to the crown segment is narrowed to form a frustum portion, and a thinner cone portion is formed below the frustum portion, and the taper of the cone portion is smaller than that of the frustum portion.

6. The expandable root canal filling medical-device combination based on apical biological sealing according to claim 4, It is characterized in that The taper of the outer contour and the physical axis of the root canal segment refers to the taper specification of the machine expansion needle used for dental root canal preparation, wherein the taper of the outer contour of the root canal segment is 04 taper, 06 taper or 08 taper, and the taper of the physical axis of the root canal segment is 01 taper, 02 taper or 03 taper.

7. The expandable root canal filling medical-device combination based on apical biological sealing according to claim 6, It is characterized in that For titanium root canal plug tips with a root canal segment outer contour taper of 04 or 06, the maximum end diameter of the root canal segment outer contour is equal to the diameter of the crown segment outer contour; for titanium root canal plug tips with a root canal segment outer contour taper of 08 or above, the crown segment outer contour is radially indented relative to the root canal segment outer contour, so that a shoulder is formed between the root canal segment and the crown segment.

8. The expandable root canal filling medical-device combination based on apical biological sealing according to claim 1, It is characterized in that The retention groove section of the crown section is in the form of a thread or multiple circles of horizontal blades or a horizontal annular groove.

9. A self-expanding sealant combination for biological sealing of tooth root apex, It is characterized in that The invention is composed of a liquid, a component A powder and a component B powder which are isolated from each other before use, wherein the liquid is used to mix the component A powder into a paste when in use; the component A powder contains: 75%-95% tricalcium silicate and 5-25% beta tricalcium phosphate; the component B powder contains: 45%-55% nano zirconium dioxide, 44.7%-52% calcium hydroxide and 0.3%-3% calcium oxide.

10. Application of a bioceramic root canal sealer combination, Features: The bioceramic root canal sealer combination consists of a liquid, a component A powder, and a component B powder that are isolated from each other before use, wherein the liquid is used to mix the component A powder into a paste when in use; The A component powder comprises: 75%-95% tricalcium silicate and 5-25% beta tricalcium phosphate; The B component powder comprises: 45%-55% nano zirconium dioxide, 44.7%-52% calcium hydroxide, and 0.3%-3% calcium oxide; or, the B component powder comprises 45% nano zirconium dioxide, 42%-44.7% calcium hydroxide, 0.3%-3% calcium oxide, and 10% iodoform; The application is specifically a two-layer root canal filling method: the first layer filling: first, a paste made by mixing the liquid and component A is introduced into the entire root canal using a titanium root canal plug tip and ultrasonically vibrated for a few seconds; the second layer filling: the root canal segment of the titanium root canal plug tip with residual component A paste is placed in the component B dry powder and rotated so that its surface is coated with the component B dry powder, and then quickly inserted into the root canal and rotated and pushed into place to form a mixture of components A and B, so that the calcium oxide contained in the component B reacts chemically with the water in the component A paste.

11. A titanium root canal plug tip, It is characterized in that The titanium root canal plug tip adopts an integrated structure, including a root canal segment and a crown segment coaxially arranged in sequence from bottom to top; the root canal segment is a cone, the surface of the root canal segment body is provided with an external thread, and the surface of the root canal segment near the crown segment is provided with multiple circles of horizontal blades, which are respectively recorded as a root canal thread segment and a root canal horizontal blade segment, and the grooves of the root canal thread segment and the root canal horizontal blade segment are used to fill the prepared sealant; the crown segment is a cylinder, a cuboid or a triangular prism, and a retention groove segment is provided on the surface.

12. A root canal filling mode, It is characterized in that The titanium root canal plug tip is used as the root canal metal bracket, and the chemical expansion reaction process of the self-expanding bioceramic root canal sealer is quickly delivered and controlled in the root canal. The self-expanding force of the bioceramic material and the spiral compression force of the titanium root canal plug tip advancing in the root canal are combined to form a new uniform and dense root canal filling pattern.

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