Appliance combination for expanding root canal filling based on apical biological sealing and application thereof

Abstract

The application discloses an expanding root canal filling medical device combination based on a dental root tip biological seal and application. The medical device combination comprises a sealant combination and a titanium material root canal plug tip, the sealant combination is composed of liquid agent, A component powder and B component powder which are mutually isolated before use, the A component powder comprises 75-95% of tricalcium silicate and 5-25% of beta tricalcium phosphate, the B component powder comprises 45-55% of nano zirconium dioxide, 44.7-52% of calcium hydroxide and 0.3-3% of calcium oxide; a root canal section surface of the root canal plug tip is provided with a horizontal screw thread, a screw thread groove of the screw thread is used for filling the prepared sealant, and a crown section surface is provided with a retaining groove section. The medical device combination solves the problems of root canal treatment failure or poor long-term curative effect caused by volume shrinkage after filling of the existing sealant and gutta-percha tip, and can realize high safety, high biocompatibility, high quality and high density root canal filling.

Description

Technical Field

[0001] This application relates to dental medical devices, specifically to a root canal filling medical device and its application based on root apex biological sealing. Background Technology

[0002] Root canal treatment is the primary treatment for pulp and periapical diseases. After the initial root canal preparation and disinfection, the key and challenging aspect of root canal treatment is how to safely and tightly fill each root canal and perfectly seal the apical foramen. The deficiencies of root canal filling instruments have become the biggest pain point in the dental root canal treatment industry.

[0003] Current root canal filling techniques involve the use of a combination of root canal sealant and gutta-percha points. However, almost all root canal sealants experience varying degrees of volume shrinkage after solidification. To address this issue, the industry has developed the concept of "filling with as little root canal sealant as possible and as much gutta-percha as possible," which is a root canal filling method that primarily uses gutta-percha points and secondarily uses root canal sealant. This has led to the two major root canal filling techniques currently used in clinical practice: cold gutta-percha lateral compression filling and hot gutta-percha vertical condensation filling.

[0004] However, the problem of shrinkage of root canal filling materials has not been completely solved. A literature article, "Difficulties and Misconceptions in Root Canal Filling" (Zhang Chen, West China Journal of Stomatology, Vol. 35, No. 3), reported that gutta-percha points have a 7% shrinkage rate after heating and cooling, which leads to micro-gaps, microleakage, incomplete apical sealing, and secondary infection in the apical sealing area after root canal filling, ultimately resulting in root canal treatment failure.

[0005] In summary, volume shrinkage after root canal filling with sealant and gutta-percha points leads to incomplete apical sealing, resulting in microgaps and microleakage. This is a pressing problem that the industry urgently needs to solve and is one of the main reasons for root canal treatment failure.

[0006] In addition, the potential harm to patients caused by the toxic and harmful components contained in root canal sealants and gutta-percha points is also an important issue that urgently needs to be addressed.

[0007] The following is a brief analysis of the composition and characteristics of several commonly used root canal sealants and gutta-percha points, partially quoted from "Research Progress of Root Canal Seals" (Yang Xueying et al., Electronic Journal of General Dentistry, 2019).

[0008] 1. Clove oil / zinc oxide root canal sealant

[0009] Eugenol / zinc oxide is a traditional root canal filling agent, mainly composed of zinc oxide, rosin and eugenol. Its characteristics include strong disinfection and the ability to promote granulation tissue regeneration. However, its disadvantage is that the volume shrinkage after curing causes it to peel off from the root canal wall, creating micro-gaps and failing to achieve complete root canal sealing. Its cytotoxicity is also controversial. It is now mostly used as a control group in the testing of new materials.

[0010] 2. Resin-based root filling materials

[0011] Resin-based root canal filling materials are characterized by good flowability, volume stability, and strong adhesion to root canal dentin. However, they contain toxic and harmful components such as formaldehyde and resorcinol.

[0012] 3. Calcium hydroxide-based root canal sealants

[0013] Calcium hydroxide provides a strongly alkaline environment (pH up to 12.5), which disrupts bacterial cell membranes and protein structures, thereby inhibiting bacterial growth. It also promotes the activation of calcium-mediated adenosine triphosphate (ATPase) during hard tissue formation, stimulating the formation of dentin and cementum, inducing the healing of periapical lesions, and enhancing apical occlusion. However, its drawbacks include volume shrinkage after curing, certain solubility and absorption in tissue fluid (due to the continuous consumption of calcium ions during bone remodeling), and poor long-term therapeutic stability of calcium hydroxide alone.

[0014] 4. Glass ionomer root canal sealant

[0015] Glass ionomer is a mixture of aqueous polyacrylic acid and aluminum silicate glass powder. It has physical properties very similar to dentin and can bond to the dentin surface through the interlocking effect of ultrastructure. The polyacrylate ions in it can undergo an irreversible replacement reaction with the phosphate ions in hydroxyapatite. It has long-lasting adhesion to dentin even under humid conditions. It also has a certain degree of biocompatibility and can release fluoride ions, which have anti-caries function.

[0016] The main drawback of glass ionomer is that it still shrinks significantly after solidification. Studies have shown that its root tip sealing performance is significantly worse than the previous three types of root filling agents, and it is not easy to remove after solidification, making secondary treatment very difficult.

[0017] 5. Calcium silicate-based bioceramic root canal sealant

[0018] The advantages of calcium silicate bioceramics include good biocompatibility, low cytotoxicity, and good long-term stability. They maintain a high pH value for a period after solidification, inhibiting bacterial growth. Bioceramic materials should be the future direction of root canal filling materials. However, existing bioceramic sealants also have many shortcomings that need to be addressed. For example, some brands of bioceramics contain harmful components such as bismuth oxide, and some injectable bioceramic sealants contain resin thickeners. These resin thickeners may produce carcinogens in the high-temperature environment of hot gutta-percha filling. During root canal filling, the sealant is inevitably squeezed out of the apical foramen and enters the apical physiological environment, potentially posing a risk to the human body. Furthermore, like all other types of root canal sealants, existing calcium silicate root canal sealants still need to be used in combination with gutta-percha points. If overfilling occurs, the harmful substances in the gutta-percha points may also cause harm to the human body.

[0019] Composition and properties of gutta-percha points:

[0020] The main components of gutta-percha points 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 components, and zinc oxide has also been reported to have cytotoxicity. If handled improperly, gutta-percha points may extend beyond the root apex and enter the physiological environment zone. Long-term contact with blood and bone tissue can cause chronic inflammation in the periapical region, periapical cysts, bone resorption, necrosis, and other harms. However, in clinical practice, cases of incomplete filling, overfilling, or underfilling with gutta-percha points are not uncommon. Summary of the Invention

[0021] To address the problems of root canal treatment failure caused by the volume shrinkage of existing root canal sealants and gutta-percha points affecting apical sealing, as well as the potential harm to patients caused by their toxic and harmful components, this application proposes an expandable root canal filling medical device combination and its application based on apical biological sealing.

[0022] To achieve the above objectives, this application provides the following technical solution:

[0023] An expandable root canal filling medical device assembly based on root apex bio-sealing includes a sealant assembly and a titanium root canal plug tip;

[0024] The sealing agent combination consists of a liquid, component A powder, and component B powder that are isolated from each other before use. The liquid is used to mix and stir the component A powder into a paste during use. The component A powder contains 75%-95% tricalcium silicate and 5-25% β-tricalcium phosphate. The component B powder contains 45%-55% nano-zirconium dioxide, 44.7%-52% calcium hydroxide, and 0.3%-3% calcium oxide.

[0025] The titanium root canal plug tip is an integral structure comprising a root canal segment and a crown segment arranged coaxially from bottom to top. The root canal segment is a cone, with external threads on its main surface. The area of ​​the root canal segment near the crown segment has multiple horizontal blades, referred to as the root canal thread segment and the root canal horizontal blade segment, respectively. 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, with retention grooves on its surface.

[0026] Optionally, the liquid is distilled water or an aqueous solution of chitosan oligosaccharide.

[0027] Optionally, the B component powder can be replaced with an antibacterial enhanced powder, which contains 45% nano-zirconia, 42%-44.7% calcium hydroxide, 0.3%-3% calcium oxide, and 10% iodoform.

[0028] Optionally, the solid axial taper of the root canal segment is smaller than the outer contour taper of the root canal segment.

[0029] Optionally, the portion of the solid axis of the root canal segment near the crown segment narrows to form a frustum portion, and a finer cone portion (which is the main body of the solid axis of the root canal segment) is formed below the frustum portion, wherein the taper of the cone portion is smaller than that of the frustum portion.

[0030] Optionally, the taper of the outer contour of the root canal segment and the solid axis refers to the taper specification of the dental root canal preparation reamer, 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 solid axis of the root canal segment is 01 taper, 02 taper or 03 taper.

[0031] Optionally, for titanium root canal tips with a taper of 0.4 or 0.6 on the outer contour of the root canal segment, the maximum diameter of the outer contour of the root canal segment is equal to the diameter of the outer contour of the crown segment; for titanium root canal tips with a taper of 0.8 or higher on the outer contour of the root canal segment, the outer contour of the crown segment is radially recessed 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.

[0032] Optionally, the crown segment retention groove segment is in the form of a thread or multiple horizontal blades or horizontal grooves.

[0033] A self-expanding sealant assembly for apical biosealing of teeth 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 and prepare the component A powder into a paste during use. The component A powder contains 75%-95% tricalcium silicate and 5-25% β-tricalcium phosphate. The component B powder contains 45%-55% nano-zirconia, 44.7%-52% calcium hydroxide, and 0.3%-3% calcium oxide.

[0034] Application of a bioceramic root canal sealant combination, the bioceramic root canal sealant combination consisting 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 and stir the component A powder into a paste during use;

[0035] The A component powder contains: 75%-95% tricalcium silicate and 5-25% β-tricalcium phosphate;

[0036] 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.

[0037] The specific application is a two-layer root canal filling method: First layer filling: The A-component paste is first introduced into the entire root canal using a titanium root canal plug tip. During the introduction process, a small amount of the A-component paste inevitably enters the physiological environment zone outside the apical stop. The bioactive ceramic component of the A-component promotes osteocyte proliferation and apical mineralization in the apical region, forming a biological seal at the apex. Second layer filling: The root canal segment of the titanium root canal plug tip with residual A-component paste is placed in the B-component dry powder and rotated to coat its surface with the B-component dry powder. It is then inserted into the root canal to form an A / B mixture. The calcium oxide contained in the B-component reacts chemically with the water in the A-component paste, densely filling the non-physiological environment zone of the root canal as the second filling material. The self-expansion force of the second A / B mixture filling material and the spiral compression force of the titanium root canal plug tip conical root canal segment further compress the first A-component paste into all micro-spaces of the root canal wall and the apical physiological environment zone.

[0038] Compared with the prior art, this application has at least the following beneficial effects:

[0039] 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 is made of medical titanium material with excellent biocompatibility. It is used to fill the canal in different zones and layers: The first layer of filling uses component A paste, which ensures the high purity and high safety of the bioactive ceramic entering the physiological environment of the tooth. This avoids the damage caused by the harmful components contained in existing sealants entering the physiological environment of the tooth. Furthermore, after component A paste enters the physiological environment of the root apex, it can also stimulate the proliferation of new bone cells and root apical mineralization, achieving ideal biological apical sealing. The second layer of filling is done in the non-physiological environment area within the apical abutment of the root canal. A mixture of components A and B sealant is used, with component B containing calcium oxide, which reacts chemically with the moisture in the previous component A paste to expand rapidly. When used in combination with the titanium root canal plug tip of this application, the expansion process of the sealant can be precisely and quickly controlled within the root canal. This allows for expansion and compression filling of the micro-spaces in the root canal cavity, solving the problems of root canal treatment failure or poor long-term efficacy caused by volume shrinkage after filling with existing sealant and gutta-percha points. Ultimately, this achieves high safety, high biocompatibility, high quality, and high density root canal filling.

[0040] 2. The titanium root canal plug tip in this application enables the effective implementation of zonal and layered filling with bioceramic sealant: After the first layer of component A paste is used to fill the root canal, the titanium root canal plug tip, coated with and adhered to component B dry powder sealant, acts as a drug-elastic scaffold with both plasticity and a certain degree of elasticity. Its conical thread structure rotates and advances within the conical root canal cavity. The sealant is evenly separated, compressed, and filled within the root canal cavity by each turn of the thread of the titanium root canal plug tip. The filling density is much greater than that of existing root canal sealant paste plus gutta-percha filling, providing a strong guarantee for stable long-term efficacy. Attached Figure Description

[0041] To more intuitively illustrate the prior art and this application, several exemplary figures are provided below. It should be understood that the specific shapes and structures shown in the figures should not generally be regarded as limiting conditions for implementing this application; for example, based on the technical concept disclosed in this application and the exemplary figures, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, size ratios, etc. of certain units (components).

[0042] Figure 1 This is a schematic diagram of the structure of a titanium root canal plug tip used in one embodiment of this application;

[0043] Figure 2 A schematic diagram of inserting a root canal plug into the root canal;

[0044] Figure 3This is a schematic diagram of the structure of a titanium root canal plug tip (with a shoulder) used in another embodiment of this application.

[0045] Figure 4 for Figure 3 A modification of the illustrated embodiment.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1. Root canal segment; 101. Solid axis of root canal segment; 102. External thread of root canal segment; 103. Horizontal blade of root canal segment;

[0048] 2. Crown segment; 201. Solid axis of crown segment; 202. External thread of crown segment. Detailed Implementation

[0049] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] In the description of this application: the terms "first," "second," etc., are intended to distinguish the objects they refer to, and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0051] The terms used in this application, such as "upper," "lower," "left," "right," and "middle," are generally used to facilitate intuitive understanding by referring to the accompanying drawings, and are not absolute limitations on the positional relationships in the actual product. Changes in these relative positional relationships, without departing from the technical concept disclosed in this application, should also be considered within the scope of this application.

[0052] This application is the first in the dental root canal treatment industry to propose a root canal treatment approach that divides the tooth into physiological and non-physiological environmental zones based on the concept of biological sealing at the root apex, and uses a zoned, layered, and material-component-based filling method.

[0053] The first layer of filling is high-purity bioactive ceramic component A, which enters the physiological environment zone. In the physiological environment zone outside the narrowest part of the root canal (apical base) where blood circulation and metabolism are involved, such as the micro-flare apical foramen, periapical zone, and the micro-channels on the surface of each lateral accessory root canal and tooth root, high-purity, biodegradable, and bone cell-stimulating bioactive ceramic hydration gel component A is squeezed or filled. This induces root apical mineralization and closure, and induces osteoblasts to proliferate, differentiate, deposit, and grow into the physiological zone and apical foramen of the root apex to form a good biological root apical seal.

[0054] Entering the non-physiological environment zone, a mixture of A and B components of bioceramic forms the second filling layer. Within the apical constriction of the non-physiological environment zone, devoid of viable pulp and metabolism, the pulp canal is filled with nano-zirconia, calcium hydroxide, and calcium oxide. Calcium hydroxide, being strongly alkaline, acts as a bactericide and disinfectant. Calcium oxide's chemical expansion upon contact with water creates a good physical seal. Calcium oxide and calcium hydroxide maintain a dry and sterile root canal environment. Nano-zirconia, as a bio-inert ceramic, is itself non-degradable. In this dry and sterile root canal environment, all filling materials in the A and B component mixture remain non-degradable, forming a stable chemical root canal seal.

[0055] In particular, combined with the titanium root canal tip proposed in this application (the titanium material can be medical pure titanium or titanium alloy), its spiral grooves can cleverly and quickly and evenly introduce the B-component composite bioceramic containing calcium oxide into the root canal filled with the A-component silicon / calcium phosphate hydration gel, so as to quickly and accurately deliver and control the chemical reaction process of the composite bioceramic expansion in the root canal.

[0056] Specifically:

[0057] The root canal sealant combination in this application can be divided into a basic formulation and an antibacterial enhancement formulation, both of which consist of liquid and powder.

[0058] Basic dosage form:

[0059] The liquid preparation is: a solution of distilled water or chitosan oligosaccharide / distilled water (500 mg / L mass concentration);

[0060] The powder is divided into component A powder and component B powder; the composition of component A (mass fraction) is: tricalcium silicate 75%-95%, β-tricalcium phosphate 5-25%; the composition of component B (mass fraction) is: nano-zirconium dioxide 45%-55%, calcium hydroxide 44.7%-52%, calcium oxide 0.3%-3%;

[0061] Enhanced antibacterial formula:

[0062] The liquid preparation is: a solution of distilled water or chitosan oligosaccharide / distilled water (500 mg / L mass concentration);

[0063] The powder is divided into component A powder and component B powder; the composition of component A (mass fraction) is: tricalcium silicate 75%-95%, β-tricalcium phosphate 5-25%; the composition of component B (mass fraction) is: nano zirconium dioxide 45%, calcium hydroxide 42%-44.7%, calcium oxide 0.3%-3%, iodoform 10%;

[0064] The basic formulation is suitable for most cases, while the antibacterial enhanced formulation is suitable for a small number of root canal cases with chronic exudative inflammation and some refractory root canal cases.

[0065] See Table 1 for the specific experimental groups.

[0066] Table 1

[0067]

[0068]

[0069] All of the above experimental groups achieved satisfactory results, as detailed below.

[0070] Titanium root canal plugs are integrally structured, such as... Figure 1 , Figure 3 , Figure 4 As shown, the structure includes a root canal segment 1 and a crown segment 2 arranged coaxially from bottom to top. Root canal segment 1 is a cone, and its outer taper matches the taper of a dental reamer (configurable models include 04 taper, 06 taper, and 08 taper). The surface of the root canal segment has an external thread 102, whose grooves are used to fill with prepared sealant. Therefore, a horizontal thread type is preferred, for example, a thread helix angle of 0–30 degrees. Crown segment 2 is a cylinder with an external thread 202 on its surface. This thread primarily serves a retention function and can also be modified to a horizontal blade type. After the root canal plug is filled, the crown segment is located in the cavity within the crown. After filling with fluid resin or glass ionomer cement, it is used to fix the root canal plug within the tooth body.

[0071] In one embodiment, a one-piece titanium root canal plug tip, such as Figure 1 , Figure 3 , Figure 4As shown, the device includes a root canal segment 1 and a crown segment 2 arranged coaxially from bottom to top. The root canal segment 1 is a cone, and the outer taper of the root canal segment is consistent with the taper of the dental root canal preparation reamer (configurable models include, for example, 04 taper, 06 taper, and 08 taper). The surface of the root canal segment is provided with an external thread 102, and its thread groove is used for filling with the prepared sealant. Therefore, a horizontal, thin-bladed non-standard thread form is preferred, for example, a thread helix angle of 0 to 30 degrees. To further improve the filling effect of the sealant, it is recommended that the thread profile angle of the root canal thread segment not exceed 60 degrees, for example, 15 to 45 degrees. The crown segment 2 is cylindrical (here, "cylinder" refers to the main body of the crown segment being cylindrical; depending on actual needs, a shape more conducive to clamping can be machined locally based on the cylindrical shape). Its surface is provided with external threads 202, which primarily serve a retention function; these threads can also be modified to a horizontal blade shape. After the root canal plug tip is properly filled, the crown segment is located in the cavity within the crown. After filling with fluid resin or glass ionomer cement, it is used to fix the root canal plug tip within the tooth body. Besides being cylindrical, the crown segment can also be designed as a cuboid or triangular prism, and the specific shape of the retention grooves on the surface is not limited to threads; they can also be horizontal blades or horizontal annular grooves, etc.

[0072] The state of the titanium root canal plug after insertion into the root canal is as follows: Figure 2 As shown.

[0073] A horizontal blade 103 is also placed on the upper surface of the root canal segment near the crown segment. The functions of the horizontal blade 103 are: 1. To create a blind groove in the root canal's threaded groove, preventing the sealant in the threaded groove from overflowing when it rotates into the root canal, ensuring sufficient sealant is compressed and compacted within the groove between the root canal lumen and the threaded groove. 2. The groove of the horizontal blade can be filled with sealant, as well as fluid resin adhesive or glass ionomer filling materials, serving as a boundary marker between the sealant and the filling material. 3. To prevent the sealant in the root canal's threaded groove from being washed away by the water flow when rinsing the crown after root canal filling. While the grooves in the threaded groove are interconnected and the sealant is washed away by the water flow, the grooves in the horizontal blade are independent and closed, protecting the sealant from being washed away, diluted, or contaminated by saliva.

[0074] The root canal segment solid axis 101 (the metal solid axis of the root canal threaded segment and the bottom of the horizontal leaf segment groove) and the crown segment solid axis 201 (the metal solid axis of the crown threaded segment groove) transition smoothly, but the root canal segment solid axis 101 does not have to be a standard tapered shape. The threads of the crown segment 2 only serve to fix the root canal plug tip in the tooth body after filling with fluid resin or glass ionomer cement. Therefore, the crown segment solid axis 201 can be thicker; furthermore, such as Figure 1 , Figure 3As shown, the portion of the root canal segment solid axis 101 near the crown segment (specifically, the upper part of the solid axis at the bottom of the root canal horizontal leaf segment groove) can be significantly narrowed, making the main body of the root canal segment solid axis 101 relatively thinner.

[0075] The taper of the root canal segment solid axis 101 is 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.

[0076] For titanium root canal tips with a taper of 0.8 or higher, the design can be modified such that the outer contour of the crown segment is radially recessed relative to the outer contour of the root canal segment, creating a shoulder between the root canal segment and the crown segment. Figure 3 , Figure 4 As shown. 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 greater than the diameter of the external thread of the crown segment. The diameter of the external thread of the crown segment is about half the width of the thread compared to the maximum diameter of the largest end of the external thread of the root canal segment. In other words, a narrower shoulder is provided between the root canal segment and the crown segment. The purpose of providing a narrow shoulder is to leave a larger gap at the root canal orifice after root canal filling, so as to facilitate the flushing and drying of excess sealant, and to allow fluid resin or glass ionomer cement to flow better into the root canal orifice, and to better fix the root canal plug tip in the crown.

[0077] The specific steps for performing two-layer root canal filling using the aforementioned titanium root canal plug tip are as follows:

[0078] Step 1: Select a basic or antibacterial enhanced root canal sealant according to the indications of the affected tooth. Select a titanium root canal tip that matches the taper and length of the root canal to be filled. Mix the sealant component A with the liquid to form a paste. Scrape the paste into the threaded groove of the root canal segment (1). Introduce the paste into the root canal through the root canal tip. Apply pressure quickly several times and repeat the above actions 1-2 times (after exiting, apply the paste again and introduce it into the root canal). Under the action of the vertical and horizontal components of the root canal tip and the cone of the root canal segment, complete the sealing and filling of the physiological environment zone of the root apex and the first layer of high-purity bioactive ceramic coating filling of the inner wall of the root canal. Then rotate out in the reverse threading direction.

[0079] Step two: Place the root canal tip in the dry powder of component B of the sealant and rotate it. This allows the surface of the remaining paste in the threaded grooves to be coated with the dry powder of component B bioceramic containing calcium oxide. At this point, the titanium root canal tip acts like a shaped drug-eluting scaffold, its surface coated with expandable bioceramic powder (similar to the application of hydroxyapatite bioceramic to the surface of titanium implants, except that implants require high-temperature sintering of hydroxyapatite onto the titanium surface, while this embodiment only requires coating the bioceramic into the threaded grooves of the titanium root canal tip). After initial compaction by gentle rolling, rotate it in the direction of thread insertion and insert it into the pre-set position in the root canal. Because both the prepared root canal cavity and the root canal tip are round... Because of its conical shape, the B-component bioceramic powder in the threaded groove of the root canal plug is further compressed and compacted within the root canal cavity. Utilizing the principle that calcium oxide expands rapidly when it comes into contact with water and moisture, the calcium oxide in the B-component powder in the threaded groove of the titanium root canal plug undergoes a chemical expansion reaction with the moisture in the A-component paste in the root canal cavity. At this time, under the pressure of the expansion force, a small portion of the nano-zirconia in the B-component also enters the micro-spaces, lateral canals, and dentinal tubules of the root canal cavity, completing the secondary bioceramic root canal filling. The second layer of bioceramic further compresses 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-spaces and dentinal tubules adjacent to the physiological environment area.

[0080] During root canal filling, titanium root canal tips can be directly electrically connected to a dental endodontic instrument to accurately measure the root canal length while filling. There is no need to predict the root canal length in advance or take radiographs to confirm the tooth length, and there is no need to preset the working length of the root canal tip. The filling and measurement are performed digitally simultaneously, and ultra-precise root canal filling can be completed in seconds.

[0081] Finally, rinse and dry the root canal orifice, crown cavity, and the threaded groove of the canal plug crown segment to remove excess bioceramic. Then, inject light-curing fluid resin into the root canal orifice and crown cavity and cure it by light curing or glass ionomer cement curing naturally. This will quickly complete a high-quality dental root canal treatment.

[0082] In the above embodiments, if ordinary tools such as root canal reamers, smooth probes, and gutta-percha points are used, it may be difficult to ideally and uniformly fill the root apex region with the dry powder of component B and the hydrated gel of component A in proportion and quickly before the chemical expansion reaction. However, by using the aforementioned titanium root canal plug, the chemical reaction process of composite bioceramic expansion can be precisely delivered and controlled within the root canal.

[0083] Chemical composition analysis of the various bioceramics used in the root canal sealant in this medical device combination:

[0084] 1. Tricalcium silicate:

[0085] Tricalcium silicate possesses excellent bioactivity and the ability to induce the deposition of bone-like hydroxyapatite, and it promotes the formation of chemical bonds with soft and hard tissues. At room temperature, tricalcium silicate reacts with water to form hydrated calcium silicate gel (CSH) and calcium hydroxide. CSH biomaterials significantly stimulate osteoblast proliferation and differentiation, and promote the proliferation and differentiation of dental pulp stem cells into odontoblast-like cells. Silicon ions play a crucial role in promoting metabolism, collagen synthesis, and bone mineralization, and are important factors in bone and blood vessel formation. The induced hydroxyapatite deposits can penetrate into the dentinal tubules and form chemical bonds with dentin, thus exhibiting good root canal sealing properties.

[0086] 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.

[0087] In their academic paper "Experimental Study on Tricalcium Silicate Blocking Dentin Tubules", Wang Xiaohong, Chang Jiang, Sun Hongchen, and others reported that the self-curing process of CSH biomaterials generates amorphous calcium and phosphorus ions of about 100nm-300nm on the dentin surface to block dentinal tubules, and induces dentin remineralization under physiological conditions.

[0088] In their academic paper, "Preliminary Study on the Osteogenic Effect of Bioceramics with Different Calcium Silicate Contents in Vitro," Fei Lisha, Sun Jiao, and others reported that calcium silicate (GS) has a significant ability to induce osteoblast proliferation and differentiation in vitro. The osteogenic effect is proportional to the CS content and is significantly better than that of β-tricalcium phosphate (β-TCP).

[0089] In their paper "In Vitro and In Vivo Degradation of α-Calcium Silicate and β-Calcium Silicate", Liu Yong et al. reported that by implanting α-calcium silicate, β-calcium silicate and β-tricalcium phosphate into rabbits, they discussed in detail the mechanism by which α-calcium silicate, β-calcium silicate and β-tricalcium phosphate degrade in vivo and stimulate osteoblast proliferation and differentiation, demonstrating that the osteogenic activity and rate of calcium silicate are higher than those of β-tricalcium phosphate.

[0090] 2. Tricalcium β-phosphate:

[0091] β-tricalcium phosphate has good biodegradability, osteoinductive and conductive properties, biocompatibility and biosafety. When implanted in the human body, the degraded Ca and P ions can enter the living circulatory system to form the basic substances for new bone formation and induce new bone regeneration. β-tricalcium phosphate alone can also achieve osseointegration of bone, cementum and dentin, and achieve biological closure of the root apex.

[0092] 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 balance of the root apex.

[0093] The hardening strength of β-tricalcium phosphate is lower than that of calcium silicate after hardening. When used in combination with calcium silicate, it can reduce the strength of the root canal filling, which is beneficial for removing the root canal filling later for root canal retreatment.

[0094] β-tricalcium phosphate degrades at a slower rate than calcium silicate in physiological environments. In areas with significant bone resorption at the root apex, the proliferation rate of bone cells often cannot keep up with the degradation rate of calcium silicate materials. However, the combined use of calcium silicate and β-tricalcium phosphate can make the degradation rate of the material closer to the proliferation rate of bone cells.

[0095] Tricalcium silicate hydration reaction produces calcium silicate hydration gel and a small amount of calcium hydroxide. Calcium hydroxide reacts with β-tricalcium phosphate to produce hydroxyapatite.

[0096] 3. Nano-zirconia:

[0097] Nano-zirconia is an excellent bio-inert material with high strength, good chemical stability, and does not react with other chemical components, does not cause hemolysis, is non-degradable, non-cytotoxic, and does not repel bone cells upon contact. It has a large specific surface area, strong oxygen storage capacity, relatively high density, and X-ray blocking effect, making it suitable as a contrast agent for radiographic examination after root canal filling. See the paper "The Influence 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, Lü Chuntang).

[0098] 4. Calcium hydroxide:

[0099] 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, denature bacterial proteins, and release hydroxide ions that cause bacterial DNA strand breaks, thereby killing bacteria. It can also penetrate into dentinal tubules to kill bacteria.

[0100] Calcium hydroxide can neutralize acidic substances produced during inflammation, eliminate lactic acid produced by osteoclasts, inhibit acid phosphatase, inhibit inflammatory absorption at the root tip, prevent further destruction of hard tissue, and at the same time activate alkaline phosphatase, thereby promoting the formation of hard tissue.

[0101] Calcium hydroxide has good biocompatibility, is non-irritating and non-toxic to the body and dental pulp tissue, and can promote and induce the formation of dentin bridges, promote the closure of the apical foramen, and promote the repair of periapical bone tissue.

[0102] 5. Calcium oxide:

[0103] Calcium oxide, also known as quicklime, is hygroscopic and reacts with water to form calcium hydroxide. After hydration, its volume expands by approximately 200%.

[0104] Although calcium oxide accounts for only 0.3%-3% of component B in this embodiment, it undergoes a chemical reaction upon contact with water and moisture, causing it to expand rapidly. This gives the bioceramic sealant its self-expanding properties, making it the unique and irreplaceable important component in component B.

[0105] Analysis of the combined effects of the composite bioceramic root canal sealant and root canal tip in this embodiment:

[0106] The chitosan oligosaccharide in the liquid can inhibit osteoclast resorption, promote osteoblast activity, and promote osteoblast synthesis of bone morphogenetic protein (BMP), thereby repairing bone damage or bone resorption in the root apex region caused by inflammation, trauma, etc.

[0107] When component A is mixed with chitosan oligosaccharide / distilled aqueous solution, the calcium silicate reacts with water to form hydrated calcium silicate gel (CSH) and a small amount of calcium hydroxide.

[0108] Within the root canal, calcium silicate hydrated gel (CSH) can enter the micro-spaces such as dentinal tubules and lateral root canals to form a blockage and seal.

[0109] A small portion of calcium silicate hydrate gel (CSH) is squeezed out of the apical constriction of the root canal and enters the apical physiological environment, inducing cementum mineralization, stimulating osteoblast proliferation and differentiation, inducing the deposition of osteoid hydroxyapatite to form new bone and close the apical foramen, and promoting the formation of chemical bonds with soft / hard tissues.

[0110] The calcium hydroxide produced by the hydration reaction of calcium silicate reacts with β-tricalcium phosphate to form hydroxyapatite.

[0111] Among them, β-tricalcium phosphate, after entering the physiological environment zone of the tooth root, degrades Ca and P ions, which can enter the living circulatory system to form the basic substances for new bone formation and induce new bone regeneration to close the apical foramen.

[0112] Component A is a biodegradable bioactive ceramic material that can induce mineralization of dentin and cementum in the root apex region, induce differentiation and proliferation of cementoblasts and osteoblasts, and form a osseointegration of bone, cementum and dentin, achieving the most ideal root canal treatment effect of biological sealing of the root apex.

[0113] Component B contains nano-zirconia, a non-degradable bio-inert ceramic material that can directly penetrate dentinal tubules (approximately 2-4 micrometers in diameter) and lateral canals to form a sealing barrier. Within the root canal, nano-zirconia acts as a medium for transmitting internal expansion forces and external titanium thread rotational compression forces, further pushing 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-spaces, achieving a better sealing effect.

[0114] Calcium hydroxide has a pH value as high as 12.5, which can maintain a strongly alkaline environment in the root canal and play a role in sterilization and disinfection.

[0115] Calcium oxide reacts with water in component A to form calcium hydroxide, which expands by 200%. Utilizing its property of rapidly expanding upon contact with water and moisture, this bioactive ceramic sealant expands upon filling, forming a dense root canal filling. This ensures the physical sealing advantage of the root canal. When used in combination with titanium root canal tips, it can solve the industry problem of volume shrinkage after root canal filling.

[0116] Calcium oxide also has a drying effect. After the chemical reaction, it will consume excess water in the root canal, which can maintain a dry and sterile root canal environment for a long time. The bioceramic mixture of components A and B does not degrade in a dry and sterile non-physiological environment, which can maintain the long-term stable density of the filling material in the root canal and good long-term efficacy.

[0117] After the calcium oxide hydrates, it produces calcium hydroxide, which, together with the original calcium hydroxide component in component B, keeps the root canal dry and sterile, thus ensuring the chemical sealing advantage of the root canal.

[0118] Titanium root canal plugs are made by compressing a mixture of tricalcium silicate, calcium hydroxide, and zirconium dioxide into the root canal, forming a "reinforced concrete" structure for the tooth.

[0119] Quantitative analysis of the expansion rate and heat generation rate of this medical device combination:

[0120] In this embodiment, during the use of the medical device combination, after component B is introduced into the root canal by the titanium root canal plug tip, the volume of components A and B each accounts for approximately 50% (the specific ratio can be controlled at A:B = 1:0.8 to 1.2). The calcium oxide content in component B is approximately 0.3%-3%, and the volume expansion rate of calcium oxide hydration reaction is approximately 200%. The expansion rate of the root canal apical segment sealant can be calculated to be approximately: 1*50%*0.3%*200% = 0.3%, 1*50%*3%*200% = 3%. The volume expansion rate of the root canal apical segment sealant is approximately 0.3%-3%, which should meet the requirements for clinical application (the proportion of calcium oxide content can be adjusted according to clinical needs).

[0121] Furthermore, in self-expanding composite bioceramics, the side effect of calcium oxide is heat generation during the hydration reaction. After the composite bioceramic is mixed with the root canal filling material, the volume of component B, which is carried into the root canal by the threaded grooves of the root canal plug tip, accounts for approximately 50%. The calcium oxide content in 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%, respectively. The heat generated by calcium oxide in the root canal is approximately 0.15%-1.5%, which is far lower than the heat generated in the root canal by traditional thermoplastic gutta-percha filling methods.

[0122] Compared with existing bioceramic sealants, the advantages of the sealant combination in this embodiment are:

[0123] During root canal filling, some of the sealant will inevitably be squeezed out of the physiologically active areas outside the apical stenosis, including the apical foramen and surrounding periapical regions.

[0124] Some existing brands of bioceramic sealants contain harmful ingredients such as bismuth oxide, and some injectable bioceramics contain resin thickeners. These resin thickeners may produce carcinogenic substances in the high-temperature environment of hot gutta-percha filling. Because it's impossible to fill the tooth in sections and layers, harmful substances inevitably exceed the apical foramen and enter the physiological environment, potentially posing a risk to human health. The current combination of calcium silicate root canal sealants and gutta-percha points still faces safety concerns regarding significant shrinkage of the gutta-percha points and the potential safety hazards of overfilling due to the presence of toxic components in the gutta-percha points themselves.

[0125] The sealant in this embodiment contains no thickeners or other harmful substances. The root canal tip is made of medical-grade titanium material with excellent biocompatibility. It is used in combination for zoned, layered, and grouped filling with biodegradable, high-purity, highly active bioceramic and non-biodegradable bioceramic, ensuring the high purity of the bioactive ceramic entering the physiological environment of the tooth. This avoids the damage caused by harmful components in traditional sealants entering the physiological environment of the tooth, resulting in ideal apical bio-sealing and dense root canal filling. Specifically:

[0126] A layer of high-purity biodegradable bioactive ceramic component A is applied to the filling and coating of the dental physiological environment zone, adjacent physiological environment zone, and micro-spaces and dentinal tubules within the root canal. Component A consists of 75%-95% tricalcium silicate and 5%-25% tricalcium phosphate, mixed with chitosan oligosaccharide / distilled aqueous solution. It does not contain other components that are not conducive to or detrimental to bone cell growth, such as thickeners, X-ray radiopaque agents, or other inorganic fillers. After entering the root canal, it forms the first high-purity bioactive ceramic sealing barrier layer.

[0127] When component A is mixed with distilled water or chitosan oligosaccharide / distilled water to form a fluid paste, the tricalcium silicate undergoes a hydration reaction to generate calcium silicate hydrate gel (CSH) and calcium hydroxide. After being introduced into the root canal, a small portion is extruded from the apical constriction and enters the physiological environment of the tooth to participate in metabolism, inducing the differentiation and proliferation of cementoblasts and osteoblasts. CSH induces the deposition of osteogenic hydroxyapatite to generate new bone, repairing bone resorption and bone defects in the periapical region caused by apical periodontitis. Simultaneously, it induces mineralization of cementum and dentin in the periapical region to achieve biological closure of the apical foramen, consistent with our proposed concept of biological apical closure.

[0128] Beta-tricalcium phosphate (β-phosphate) is similar to the inorganic components of dentin and bone matrix, exhibiting good osteogenic activity and osteoconductivity. It can guide osteocytes to grow into the apical foramen, and the degraded calcium and phosphate ions become important substances for osteocyte growth. β-phosphate reacts with calcium hydroxide to form hydroxyapatite, which deposits to create a biological apical seal that integrates bone and cementum, consistent with our proposed concept of biological apical seal.

[0129] In the non-physiological environment area within the apical constriction of the root canal, an expandable, non-degradable AB component mixed bioceramic is used (the nano-zirconia component in component B is a bio-inert ceramic that is itself non-degradable; in the dry, sterile root canal in a non-physiological environment, all components of component AB are non-degradable, and the advantage of non-degradability is that it can maintain a long-term stable filling density in the root canal and a good long-term therapeutic effect).

[0130] Furthermore, the sealing agent combination in this embodiment is the result of continuous optimization by the inventors. Previous formulations attempted included:

[0131] Liquid: distilled water or physiological saline;

[0132] Component A powder: Tricalcium silicate 55-75%, Tricalcium β-phosphate 25-45%;

[0133] Component B powder: 35-40% calcium hydroxide, 21-26% nano hydroxyapatite, 20-25% nano zirconium dioxide, 10-15% nano tantalum oxide, and 3-5% calcium oxide.

[0134] In this embodiment, the formulation of the basic dosage form is as follows:

[0135] Liquid: Chitosan oligosaccharide / distilled water 500mg / L solution;

[0136] Component A powder: Tricalcium silicate 75%-95%, Tricalcium β-phosphate 5-25%;

[0137] Component B powder: 45%-55% nano-zirconium dioxide, 44.7%-52% calcium hydroxide, and 0.3%-3% calcium oxide.

[0138] Through consulting the latest research reports and conducting clinical verification, the inventors recognized that calcium silicate is superior to tricalcium phosphate in promoting bone cell proliferation, and that there is a significant statistical difference. Therefore, they increased the content of tricalcium silicate in component A from 55-75% to 75%-95% and reduced the content of β-tricalcium phosphate from 25-45% to 5-25%, thereby achieving a better effect in promoting the proliferation of bone cells in the root apex region.

[0139] In addition, the titanium root canal tips have been improved by removing the handle and reducing the length of the tip, making it easier for doctors to operate, especially for patients with limited mouth opening. The taper of the external thread of the root canal segment and the taper of the solid axis at the bottom of the thread groove have also been redesigned to be differentiable. The taper and radial dimension of the solid axis are smaller and finer, resulting in better flexibility and plasticity of the root canal segment, making it more suitable for filling small and curved root canals and expanding the indications for the use of titanium root canal tips.

[0140] The tip of the root canal segment is arc-shaped. The taper of the outer contour of the root canal segment and the diameter of the tip are consistent with the taper and diameter of the tip of the dental root canal preparation reamer. Specifically, the commonly used specifications for the 04 taper are 04 / 025, 04 / 030, and 04 / 035. The commonly used specifications for the 06 taper are 06 / 025 and 06 / 030, etc., and can be expanded up or down based on this series of data.

[0141] The solid axis taper of the root canal segment can be designed as a single through taper, with tapers of 0.1, 0.2, or 0.3, depending on the actual clinical application. Any external contour taper data for the root canal tip can be combined with any internal solid axis taper data. To increase the flexibility and plasticity of the apical half of the root canal thread groove segment of the root canal tip, and also to increase the strength of the horizontal leaf segment, the solid axis taper of the root canal segment can also be designed as a variable taper, depending on the actual clinical application. That is, the lower half of the solid axis of the root canal thread groove segment near the apex of the root canal tip has a taper of 0.1, the upper half has a taper of 0.2, and the solid axis of the horizontal leaf segment has a taper of 0.3. Alternatively, other combinations of tapers from 0.1 to 0.3 from bottom to top of the solid axis of the root canal tip can be used.

[0142] Commonly used length parameters for root canal plugs include 13mm (root canal segment 7.5mm, crown segment 5.5mm), 15mm (root canal segment 8.5mm, crown segment 6.5mm), 17mm (root canal segment 9.5mm, crown segment 7.5mm), 19mm (root canal segment 10.5mm, crown segment 8.5mm), 21mm (root canal segment 11.5mm, crown segment 9.5mm), 23mm (root canal segment 12.5mm, crown segment 10.5mm), 25mm (root canal segment 13.5mm, crown segment 11.5mm), 27mm (root canal segment 15.5mm, crown segment 11.5mm), and 29mm (root canal segment 17.5mm, crown segment 11.5mm). Due to the significant differences in tooth morphology, these parameters can be extended upwards and downwards.

[0143] The overall advantages of this medical device combination:

[0144] I. The composite bioceramic root canal sealant in this medical device combination offers high safety, high biocompatibility, high quality, and high density root canal filling.

[0145] High safety means that neither of the AB two-component bioceramics contains any components harmful to the human body. It adopts a zoned and layered filling method. The first layer is filled with high-purity bioactive ceramic of component A. This 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.

[0146] Highly biocompatible, high-quality root canal filling refers to the optimal biological apical foramen sealing achieved by the biodegradable bioactive ceramic calcium silicate hydrate gel and β-tricalcium phosphate paste (component A) that enter the physiological environment of the tooth. This hydration stimulates the proliferation and differentiation of osteoblasts and cementoblasts, promoting new bone deposition and ingrowth into the apical foramen or facilitating mineralization and closure of the apical foramen. In contrast, existing root canal fillings using sealants and gutta-percha points only provide physical apical sealing.

[0147] High-density root canal filling refers to filling the non-physiological environment area within the apical stop of the tooth root canal with an expandable AB component mixed bioceramic root canal sealant. Component B contains calcium oxide. After the AB components are mixed, the calcium oxide reacts chemically with the water in the A component paste and expands rapidly. When used in combination with root canal plugs, the expansion process of the sealant can be precisely controlled within the root canal. This allows for a second layer of expansion and compression filling of the micro-spaces in the root canal cavity, solving the problems of root canal treatment failure or poor long-term efficacy caused by volume shrinkage after filling with existing root canal sealant paste and gutta-percha points.

[0148] 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 components A and B do not degrade. The beneficial effect of non-degradation is that it can maintain a stable filling density in the root canal for a long time and a good long-term therapeutic effect.

[0149] II. The titanium root canal plugs in this medical device combination provide high safety, high biocompatibility, and high-quality, high-density root canal filling.

[0150] 1. Medical-grade pure titanium or titanium alloys are non-toxic to the human body and have excellent safety and biocompatibility. They have been widely used in orthopedics, surgery and other fields. Root canal plugs made of titanium materials are allowed to extend beyond the root apex and enter the physiological environment of the root apex. Bone cells will adhere and deposit on the surface of the titanium tip that extends beyond the root apex, forming a dense bone plate in the root apex region. The use of titanium root canal plugs in combination with the layered, zoned and grouped filling of high-purity bioceramics can induce the generation of new bone cells to grow into the root apex region and induce root apical mineralization to form a biological seal.

[0151] 2. The titanium root canal tips provided by this medical device combination enable the implementation of zonal and layered filling with bioceramic sealant: In addition to the expansion of the sealant itself, the conical thread design of the titanium root canal tip, rotating and advancing within the conical root canal cavity, also compresses the sealant. After the first layer of component A paste is completed for root canal filling, the titanium root canal tip, coated with and adhered to component B dry powder sealant, acts as a drug-elastic scaffold that is both malleable and elastic. Its conical thread structure rotates and advances within the conical root cavity, and the sealant is evenly divided, compressed, and filled within the root canal cavity by each turn of the tip's thread. The filling density is far greater than that of existing sealant plus gutta-percha fillings, providing a strong guarantee for stable long-term efficacy.

[0152] 3. Titanium root canal plugs greatly improve the fracture resistance of the affected tooth and extend its service life.

[0153] The titanium root canal plugs in this medical device kit have a certain degree of flexibility. In the early stage of root canal preparation, compared with the amount of tooth preparation required by using gutta-percha points, using titanium root canal plugs can effectively reduce unnecessary preparation and cutting damage to healthy tooth root canals, and improve the fracture resistance of the affected tooth.

[0154] Traditional root canal fillings with sealant and gutta-percha require a second root canal post or fiber post for reinforcement. The titanium root canal plug in this medical device kit features an integrated design of the apical and crown segments. The crown segment can replace root canal posts or fiber posts in the crown cavity, eliminating the need for a second root canal post or fiber post. This reduces unnecessary cutting and preparation of healthy root canal tissue during the second root canal post and post installation after root canal filling, preserving more healthy tooth structure and improving the fracture resistance of the affected tooth.

[0155] In the treatment plan provided in this embodiment, 1-3 titanium root canal plugs are inserted into the tooth structure from the root apex to the crown, providing support without stress concentration. This significantly improves the tooth's resistance to fracture and overall strength, avoiding root fracture caused by stress concentration at the midpoint of the root canal, as is common with traditional root canal post placement. The treatment plan provided in this embodiment is significantly superior to existing treatment plans using sealant + gutta-percha points + root canal post, effectively extending the lifespan of the affected tooth.

[0156] III. New Filling Modes Brought About by This Medical Device Combination

[0157] The current concept of sealant + gutta-percha root canal filling is: gutta-percha points as the primary component, and sealant as a secondary component. The filling method involves using external force to compress and deform the gutta-percha points to fill the root canal in order to cope with the shrinkage of the sealant after the procedure. This is achieved through methods such as cold gutta-percha lateral compaction and hot gutta-percha vertical compaction to seal the apical foramen and other micro-spaces. This increases the time cost for dentists, as well as the difficulty of the procedure and the risk of failure. In practice, the current sealant + gutta-percha root canal filling requires measuring the root length, trial filling, taking X-rays, trial filling again, and taking X-rays again, repeatedly confirming the working length of the gutta-percha points several times. Even so, overfilling or underfilling of gutta-percha root canals still occurs frequently in clinical practice.

[0158] In this embodiment, the root canal filling mode of the medical device combination simply allows the titanium root canal plug tip to act as a drug scaffold during filling, allowing the sealant to expand spontaneously through a chemical reaction to fill the root canal. Furthermore, the conical design of the titanium root canal plug tip's root canal segment also provides secondary compression of the sealant as it is advanced into the tapered root canal. This filling mode of the embodiment greatly simplifies existing root canal treatment procedures and improves the quality of root canal filling.

[0159] In addition, the titanium root canal plug tip is conductive and can be directly connected to an electronic root length measuring instrument, enabling the direct measurement of root canal length while filling the canal. It can control the required precision of the inserted root canal length to 0.1mm in one go, achieving digital precision root canal filling.

[0160] The technical features of the above embodiments can be combined in any way (as long as there is no contradiction in the combination of these technical features). For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written should also be considered to be within the scope of this specification.

Claims

1. A combination product of an expanding root canal filling medical device based on apical biological closure, characterized in that, The application relates to a root canal plug tip of titanium material and a sealing agent composition. The sealing agent composition is composed of a liquid agent, an A-component powder and a B-component powder which are mutually isolated before use, wherein the liquid agent is used to mix the A-component powder into a paste during use; the A-component powder contains 75-95% of tricalcium silicate and 5-25% of beta tricalcium phosphate; and the B-component powder contains 45-55% of nano-zirconium dioxide, 44.7-52% of calcium hydroxide and 0.3-3% of calcium oxide. The root canal plug tip of titanium material is an integrated structure and comprises a root canal section and a tooth crown section which are coaxially arranged in sequence from bottom to top; the root canal section is a cone body, the surface of the main body of the root canal section is provided with external threads, the surface of the area of the root canal section close to the tooth crown section is provided with multiple horizontal blades, and the root canal section and the tooth crown section are respectively denoted as a root canal threaded section and a root canal horizontal blade section; and the grooves of the root canal threaded section and the root canal horizontal blade section are used for filling the sealing agent which is mixed and prepared.

2. The apical-biocontainment-based, expansion-type root canal filling medical device combination product according to claim 1, characterized in that The liquid agent is distilled water or a chitosan oligosaccharide aqueous solution.

3. The apical-biocontainment-based, expansion-socket-filling medical device combination of claim 1, wherein, The B-component powder is replaced by a bacteriostatic reinforced powder which contains 45% of nano-zirconium dioxide, 42-44.7% of calcium hydroxide, 0.3-3% of calcium oxide and 10% of iodoform.

4. The apico-bioseal based, expansion root canal filling medical device combination product according to claim 1, characterized in that, The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section.

5. The apical-biocontainment-based, expansion-socket-filling medical device combination according to claim 4, characterized in that The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section.

6. The apico-bioseal based, expansion root canal filling medical device combination product according to claim 4, characterized in that, The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section.

7. The apico-bioseal based, expansion root canal filling medical device combination product according to claim 6, characterized in that, The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section.

8. The apico-bioseal based, expansion root canal filling medical device combination product according to claim 1, characterized in that, The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section.

9. A self-expanding sealant composition for apical biological closure of a dental root tip, characterized in that, The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section. The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section. The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section. The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section. The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section. The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section. The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section. The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section. The taper of the solid axial center of the root canal section is smaller than the taper of the outer contour of the root canal section. The taper of the solid axial center of the root canal section is smaller than the taper of the external contour of the root canal section. The taper of the solid axial center of the root canal section

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