A self-expanding root canal filling instrument assembly and method of use thereof

Abstract

The present application relates to the instrument and method of filling root canal, specifically relates to a kind of self-expanding root canal filling instrument combination based on the concept of root apex biological closure and its using method, for solving the volume shrinkage caused by the existing root canal sealant and gutta-percha point filling after filling, leading to root canal filling failure, and the toxic and harmful ingredients contained in root canal sealant and gutta-percha point itself can bring potential harm to the patient The deficiency, the self-expanding root canal filling instrument combination includes self-expanding composite bioceramic root canal sealant and root canal plug tip;The self-expanding composite bioceramic root canal sealant is composed of liquid agent, powder;The liquid agent is distilled water or physiological saline;The powder is divided into A component, B component;The material of the root canal plug tip is medical pure titanium or titanium alloy.

Description

TECHNICAL FIELD

[0001] The present application relates to a root canal filling instrument and method, in particular to a self-expanding root canal filling instrument based on the concept of apical biological sealing and its use method. BACKGROUND

[0002] The existing root canal filling technology is the combination of root canal sealant and gutta-percha point, but almost all root canal sealants have different degrees of volume shrinkage after filling and solidification. In order to solve the problem of volume shrinkage of root canal sealant, the industry has emerged the concept of "as little root filling paste as possible and as much gutta-percha filling as possible", that is, the root filling method with gutta-percha point as the main and sealant as the auxiliary, forming the current clinical mainstream root canal lateral extrusion cold gutta-percha filling technology and root canal vertical pressure hot gutta-percha filling technology.

[0003] However, the problem of volume shrinkage of root filling material has not been completely solved. Literature (《Root canal filling difficulties and misunderstandings》reported that gutta-percha point would have a shrinkage rate of 7% after heating and cooling (Zhang Chen. Root canal filling difficulties and misunderstandings [J]. West China Medical Journal, 2017, 35(3): 232-238. DOI: 10.7518 / hxkq.2017.03.002.), which leads to micro-gap, micro-leakage, incomplete apical sealing and secondary infection after root canal filling, and finally results in root canal filling failure. In summary, the volume shrinkage of root canal sealant and gutta-percha point after filling is one of the main reasons for the failure of root canal filling, which is an urgent problem to be solved in the industry.

[0004] On the other hand, the potential harm of toxic and harmful ingredients contained in root canal sealant and gutta-percha point to patients is also an important problem that needs to be solved urgently.

[0005] The following is a brief analysis of the composition characteristics of several commonly used root canal sealants:

[0006] 1. Eugenol / zinc oxide root canal sealant;

[0007] Eugenol / zinc oxide is a traditional root canal filling agent, mainly composed of zinc oxide, rosin and eugenol. Its characteristics are strong disinfection and can promote the regeneration of granulation tissue; but the disadvantage is that the volume shrinkage after solidification leads to micro-gap between the root canal wall and the root canal filling agent, which cannot achieve complete root canal sealing, and its cytotoxicity is also controversial. It is now used as a control group in new material testing;

[0008] 2. Resin root filling material;

[0009] Resin root filling paste material has the characteristics of good flowability, volume stability and strong adhesion to root canal dentin; the disadvantage is that it contains toxic and harmful ingredients such as formaldehyde and resorcinol;

[0010] 3. Calcium hydroxide-based root canal sealers;

[0011] Calcium hydroxide provides a strong alkaline environment (PH value can be as high as 12.3), which can destroy the bacterial cell membrane and protein structure, thereby inhibiting bacterial growth, and can promote the activation of calcium-mediated adenosine triphosphatase in the process of hard tissue formation, so that the formation of dentin and cementum is active, and the healing of periapical lesions is induced, and the apical sealing is enhanced; but its disadvantage is that the volume of calcium hydroxide paste shrinks after solidification, and has certain solubility and absorption when in contact with tissue fluid, and the absorption of calcium ions from bone tissue reconstruction consumes calcium ions continuously;

[0012] 4. Glass ionomer-based root canal sealers;

[0013] Glass ionomer is mixed from polyacrylic acid aqueous solution and aluminum silicate glass powder, which has very similar physical properties to dentin, can bond with the surface of dentin through the interlocking effect of ultrastructure, and the polyacrylic acid ion in it can undergo irreversible displacement reaction with phosphate in hydroxyapatite, so that it has long-term adhesion with dentin even in humid conditions, and has certain biocompatibility and can release fluoride ions to prevent caries; but the main disadvantage is that the volume shrinkage after solidification is obvious, and studies have shown that the apical sealing performance is significantly worse than the previous three types of root filling agents, and it is not easy to remove after solidification, and if secondary filling is required, it is very difficult;

[0014] 5. Calcium silicate-based bioceramic root canal sealers;

[0015] The new calcium silicate-based bioceramic is mainly represented by MTA and iRootSP products, which are injectable fluid formulations, and their components are: bismuth oxide, tantalum oxide, calcium dihydrogen phosphate, calcium silicate, zirconium oxide, calcium sulfate, calcium hydroxide, thickening agent, etc.; Its advantages are good biocompatibility, small cytotoxicity, good root canal micro-gap sealing, good long-term stability, not easy to dissolve in tissue fluid, and can maintain a high PH value during solidification and a period of time thereafter to inhibit bacterial growth; Its disadvantages are: (1) iRootSP root canal sealant has too high hardness after filling and solidification, and it is very difficult to remove and refill once the filling fails; (2) iRootSP root canal sealant is a pre-mixed injection type fluid, and the injection needle cannot reach the predetermined depth in some small root canals smaller than the diameter of the injection needle, which is easy to produce air bubbles due to air lock effect, thereby affecting the sealing performance; (3) Like other root canal sealers, it still needs to be used in combination with gutta-percha points, which faces the problems of shrinkage and safety hazards of overfilling of gutta-percha points.

[0016] The main component of the gutta-percha point is composed of gutta-percha, zinc oxide, barium sulfate, and various pigments such as titanium dioxide, iron oxide, ultramarine, chromium oxide, dye yellow, etc. Among them, barium sulfate, chromium oxide, dye yellow, etc. have potential toxicity to the human body in theory, and zinc oxide is also reported to have cytotoxicity. If the operation is not careful, the gutta-percha point will exceed the narrow area of the root tip and enter the physiological environment area (it is not uncommon for gutta-percha points to be overfilled in clinical practice), and long-term contact with blood will cause chronic inflammation, bone resorption, necrosis, and other hazards in the root tip area. SUMMARY

[0017] The purpose of the present application is to solve the problems of the existing root canal sealant and gutta-percha point filling, which causes volume shrinkage and leads to root canal filling failure, and the toxic and harmful components contained in the root canal sealant and gutta-percha point may cause potential harm to the patient, and to provide a self-expanding root canal filling instrument combination and its use method.

[0018] In order to solve the above-mentioned problems of the prior art, the present application provides the following technical solutions:

[0019] A self-expanding root canal filling instrument combination, characterized in that it comprises a self-expanding composite bioceramic root canal sealant and a root canal plug tip.

[0020] The self-expanding composite bioceramic root canal sealant is composed of a liquid agent and a powder agent.

[0021] The liquid agent is distilled water or physiological saline, and the powder agent is divided into A component and B component.

[0022] The A component is composed of 55-75vol% of tricalcium silicate and 25-45vol% of beta tricalcium phosphate.

[0023] The B component is composed of 35-40vol% of calcium hydroxide, 21-25vol% of nano-hydroxyapatite, 20-25vol% of nano-zirconium dioxide, 10-15vol% of nano-tantalum oxide, and 3-6vol% of calcium oxide.

[0024] The root canal plug tip is made of medical pure titanium or titanium alloy, and comprises a root canal segment and a handle segment arranged in sequence from bottom to top along the axial direction. The root canal segment is conical, and is provided with a groove structure from the sharpest end to the lower edge of the handle segment. The groove structure is used for storing the self-expanding composite bioceramic root canal sealant. A V-shaped notch is arranged in the middle of the handle segment for cutting off after the root canal plug tip is filled in place.

[0025] Further, the A component is composed of 65 vol% of tricalcium silicate, 35 vol% of β tricalcium phosphate; the B component is composed of 37.5 vol% of calcium hydroxide, 23.5 vol% of nano-hydroxyapatite, 22.5 vol% of nano-zirconium dioxide, 12.5 vol% of nano-tantalum oxide, and 4 vol% of calcium oxide.

[0026] Further, the root canal section is sequentially divided into a blade part and a threaded part from top to bottom along the axial direction; the groove structure located in the blade part is composed of multiple rings of equidistantly arranged horizontal annular blades; the groove structure located in the threaded part is composed of external threads with an overall thread slope that tends to be horizontal from top to bottom; the external threads of the threaded part and the lower half of the horizontal annular blades of the blade part store the self-expanding composite bioceramic root canal sealant, which is used for apical sealing and root canal filling; the upper half of the horizontal annular blades of the blade part fills adhesive, which is used for fixing the root plug tip in the root canal.

[0027] Further, the groove structure is composed of multiple rings of equidistantly arranged horizontal annular blades arranged from the sharpest end to the lower edge of the handle section; the horizontal annular blades of the lower half of the root canal section store the self-expanding composite bioceramic root canal sealant, which is used for apical sealing and root canal filling; the horizontal annular blades of the upper half of the root canal section fill adhesive, which is used for fixing the root plug tip in the root canal.

[0028] Further, the taper of the root canal plug tip root canal section is 04, 06, or 08 taper, respectively, and the tip diameter is consistent with the 025, 030, 035, or 040 nickel-titanium mechanical expansion needle; the handle section is provided with a scale structure.

[0029] Further, the A component is composed of 65 vol% of tricalcium silicate, 35 vol% of β tricalcium phosphate; the B component is composed of 37.5 vol% of calcium hydroxide, 23.5 vol% of nano-hydroxyapatite, 22.5 vol% of nano-zirconium dioxide, 12.5 vol% of nano-tantalum oxide, and 4 vol% of calcium oxide.

[0030] A use method of the above-mentioned self-expanding root canal filling instrument combination, which is special in that the calcium oxide contained in the B component composite bioceramic endows the root canal sealant with self-expanding characteristics, and the combination of the sealant and the titanium material root plug tip automatically expands in the root canal.

[0031] Meanwhile, the application provides a use method of the above-mentioned self-expanding root canal filling instrument combination, which is special in that the bioceramic two-layer root canal filling method and the combination of the titanium material root plug tip automatically expand to seal the root tip hole in the root canal, and comprises the following steps:

[0032] Step 1, filling the first layer of high-purity biologically active ceramic;

[0033] Step 1.1, select a root canal plug tip matching the root canal taper and length to be filled; mix the liquid with the A component to form a paste with better flowability;

[0034] Step 1.2, dip the root canal section of the root canal plug tip into the paste and introduce it into the root canal, and continuously press several times quickly, so that the paste fills the root canal and the physiological environment zone of the root tip, and the first layer of high-purity bioactive ceramic in the root canal is filled;

[0035] Step 2, fill the second layer of bio-ceramic;

[0036] Take an appropriate amount of B component powder on the mixing plate, and after the root canal plug tip is taken out, place it in the B component dry powder and rotate and roll, so that the B component powder sticks to the surface of the paste remaining in the root canal section groove structure; the root canal plug tip coated with B component powder is quickly rotated and inserted into the preset position of the root canal to be filled and compacted, which completes the filling of the second layer of composite bio-ceramic;

[0037] Step 3, the calcium oxide in the B component powder in the root canal section groove structure of the root canal plug tip reacts with the moisture in the A component paste in the root canal to expand, and the handle part is radially broken from the V-shaped notch of the root canal plug tip. Use a dental three-way gun to rinse and dry the excess self-expanding composite bio-ceramic root canal sealant in the root canal and the crown cavity, and then inject fluid light-cured resin and light-cure, or glass ionomer cement at room temperature. Natural curing, realize the two-time separate filling of tooth partition and material group.

[0038] Further, the B component composite bio-ceramic contains calcium oxide, which gives the root canal sealant self-expanding properties and the combination of the sealant and the titanium material root canal plug tip in the root canal in the automatic expansion mode.

[0039] Further, the step 1.1 further comprises that the root canal plug tip is electrically connected with an electronic root length measuring instrument, and the filling is performed after measurement, or the accurate measurement is performed while filling, or the measurement is performed after filling.

[0040] Compared with the prior art, the beneficial effects of the present application are:

[0041] (1) The present application changes the existing root canal filling mode. The existing gutta-percha point + sealant root canal filling mode is mainly based on gutta-percha point, and sealant is auxiliary. After root filling, the gutta-percha point is compressed and deformed by external force (cold gutta-percha lateral pressure or hot gutta-percha vertical pressure method) to fill the root canal and close the root tip hole. The mode of the present application is to let the sealant expand in the root canal (the calcium oxide in the B component will react with the moisture in the A component paste to produce a chemical expansion reaction after mixing in the root canal) to fill the root canal and close the root tip hole, and the titanium material root canal plug tip only plays a role of a drug stent. Compared with the existing gutta-percha point + sealant filling mode, the root canal filling mode of the present application is simpler, more efficient, safer, and beneficial.

[0042] (2) The self-expanding composite bioceramic root canal sealant and root canal plug tip of the present application are used in combination, which can control the chemical expansion reaction of the composite bioceramic root canal sealant in the root canal precisely and quickly, and the sealant expands immediately after filling, and automatically performs secondary extrusion filling on the fine gap of the root canal.

[0043] (3) The composite bioceramic root canal sealant provided by the present application has the advantages of high safety and stable long-term efficacy compared with existing sealants. The A component and the B component do not contain any harmful components to the human body, and the way of filling the A component and the B component in different zones, layers and groups ensures the high purity of the A component bioceramic in the physiological environment zone of the tooth, avoiding the harm caused by the harmful components in the traditional sealant entering the physiological environment zone of the tooth. The high-purity bioceramic in the A component degrades after a period of time in the physiological environment zone of the tooth, which can promote the proliferation of bone cells and mineralization in the apical zone, forming an ideal apical biological seal. In the root canal cavity in the non-physiological environment zone, the mixture of the A component paste and the B component powder completes the self-expanding filling of the second layer of bioceramic. The calcium oxide hydration expansion reaction generates twice the volume of calcium hydroxide and consumes excess water, maintaining the strong alkalinity and dryness of the root canal, and the AB component mixed bioceramic does not degrade in the dry alkaline non-physiological environment zone, ensuring the stability of the long-term efficacy of root canal filling.

[0044] (4) The root canal plug tip provided by the present application is made of medical pure titanium or titanium alloy, which has excellent biocompatibility and safety. The root canal plug tip made of pure titanium material allows the titanium tip to exceed the tooth root hole and enter the apical physiological environment zone, and the surface of the titanium tip will form bone cell adhesion and deposition, forming a dense bone plate in the apical zone. The root canal plug tip avoids the damage caused by toxic components in traditional gutta-percha to the human body. The root canal plug tip can realize layered, zoned and grouped filling of high-purity bioceramic, induce new bone cell growth into the root hole to form a biological seal, and has potential value.

[0045] (5) In the self-expanding root canal filling instrument combination of the present application, the root canal plug tip serves as a storage support for root filling drugs and dental filling materials with plasticity and elasticity. After the threaded interior is filled with the composite bioceramic root canal sealant, a drug shape with the shape of the root canal cavity is formed, which can be directly rotated and inserted into the prepared tooth root canal cavity. The composite bioceramic root canal sealant is uniformly compressed and filled by each thread of the root canal plug tip in the root canal cavity, and the filling density is much higher than that of the existing sealant plus gutta-percha. In addition to the expansion of the composite bioceramic root canal sealant itself, the design structure of the conical thread of the root canal plug tip also has the effect of compressing the sealant when rotating and advancing in the conical root canal cavity.

[0046] (6)In the self-expanding root canal filling instrument combination of the present application, the root canal plug tip made of medical pure titanium or titanium alloy has electrical conductivity and can be directly electrically connected with the electronic root length measuring instrument, so that the root canal length can be directly measured during filling, the accuracy required for inserting the root canal can be controlled to 0.1 mm, and digital precise root canal filling can be realized. However, the existing gutta-percha point + sealant root filling needs to measure the root length, try the point, take a picture, try the point again, take a picture again, and confirm the working length of the gutta-percha point several times, and even so, the overfilling or underfilling of the gutta-percha point in the root canal still occurs in the clinic.

[0047] (7)The self-expanding root canal filling instrument combination of the present application greatly reduces the operation difficulty of the doctor and shortens the operation time. Compared with the soft texture, poor size accuracy, and easy bending deformation of the gutta-percha point when encountering moisture and resistance, the root canal filling is difficult and time-consuming and laborious, the root canal plug tip has good flexibility, can ignore the influence of the narrowness of the tooth root canal, resistance, and the viscosity of the sealing agent in the root canal, and can complete the root canal filling by inserting to the bottom, and can be cut off by slightly applying a radial force after filling in place, which is simple and efficient, greatly reduces the operation difficulty of the doctor, and shortens the clinical operation time.

[0048] (8)The self-expanding root canal filling instrument combination of the present application greatly improves the breakage resistance of the affected tooth and prolongs the service life of the affected tooth. The existing technology has the problems of soft texture, poor size accuracy, and difficulty in filling due to resistance in the root canal, so the root canal preparation amount is relatively large. The root canal plug tip has a certain flexibility and can be forcibly inserted with moderate force. Compared with the tooth preparation amount when using the gutta-percha point, the use of the root canal plug tip of the present application can effectively reduce the unnecessary preparation and cutting damage to the healthy tooth body during the preparation of the root canal, improve the breakage resistance of the affected tooth, and the root canal plug tip is designed in an integrated manner with a threaded root tip section and a handle section with a scale. After root filling, the handle part is retained in the crown cavity to replace the root canal pin or fiber post, without the need for a second root canal pin or fiber post, reducing the unnecessary damage of the healthy root canal tissue during the second cutting preparation after the root canal filling, retaining more healthy tooth tissue, and improving the breakage resistance of the affected tooth. The design of the conical body with threads in the root canal section of the root canal plug tip can disperse the stress generated after the tooth is stressed, avoid the stress concentration of the traditional root canal post in the middle section of the root canal, and reduce the risk of root breakage of the affected tooth. After the root canal filling is completed using the present application, there is one to several titanium metal bodies in the tooth body from the root tip to the crown, which greatly improves the overall breakage resistance. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 FIG. 1 is a structural schematic view of the root canal plug tip in the self-expanding root canal filling instrument combination of the present application;

[0050] Figure 2Figure 2 is a schematic view of the structure of the root canal plug tip in the second embodiment of the self-expanding root canal filling instrument combination of the present application.

[0051] The reference numerals are explained as follows: 1-root canal segment; 2-handle segment; 3-threaded portion; 4-blade portion; 5-horizontal annular blade; 6-V-shaped notch. DETAILED DESCRIPTION

[0052] The present application is further described below in conjunction with the accompanying drawings and exemplary embodiments.

[0053] Embodiment 1

[0054] A self-expanding root canal filling instrument combination, comprising a composite bioceramic root canal sealant and a root canal plug tip; the composite bioceramic root canal sealant is composed of a liquid agent and a powder agent.

[0055] The liquid agent is distilled water; the powder agent is divided into A component and B component; the A component is composed of 65vol% tricalcium silicate and 35vol% beta tricalcium phosphate; the B component is composed of 37.5vol% calcium hydroxide, 23vol% nano-hydroxyapatite, 22.5vol% nano-zirconium dioxide, 12.5vol% nano-tantalum oxide and 4.5vol% calcium oxide.

[0056] Analysis of the effect of the composite bioceramic root canal sealant:

[0057] The A component is a degradable bioactive ceramic material, and after being mixed with the liquid agent, it reacts to generate a calcium silicate hydrate (CSH)-based silicon / calcium phosphate paste, a small part of which will inevitably be squeezed out of the root canal apical narrow area into the physiological environment area of the root tip, which can induce the mineralization of the dentin and cementum in the root tip area, induce the proliferation of cementoblasts and osteoblasts, form bone-cement-dentin bone combination, and achieve the most ideal root canal filling effect brought by the biological sealing and filling concept of the root tip.

[0058] The B component is mainly a non-degradable bioceramic material, and 4% of superfine powder calcium oxide is added, which can quickly expand due to the chemical reaction of calcium oxide with water and humidity, so that the composite bioceramic root canal sealant of the present application has the self-expanding property, and when used in combination with the root canal plug tip, it can solve the industry problem of volume shrinkage after root canal filling.

[0059] When the A component and the B component are mixed in the root canal, calcium oxide reacts with water in the paste to generate calcium hydroxide, and the volume expansion rate after the hydration reaction is about 200%; although calcium oxide only accounts for 4% in the B component, it is an important component that cannot be replaced and determines whether the composite bioceramic root canal sealant has the self-expanding property.

[0060] The A component and the B component mixed ingredients are not degraded in the root canal in a non-physiological environment zone, wherein the nano-hydroxyapatite and the nano-zirconium dioxide can directly enter the dentin tubules (the diameter of the dentin tubules is about 2-4 microns), thereby blocking the dentin tubules. The nano-zirconium dioxide can increase the flexibility and operability of the B component, and has certain X-ray imaging effect due to its large density; the calcium hydroxide has a pH value as high as 12.5, can maintain a strong alkaline environment of the root canal, and has a sterilization and disinfection effect; the calcium oxide generates calcium hydroxide after reacting with the liquid agent and has a 200% volume expansion, so that it has a self-expanding property and is filled and expanded. The calcium oxide also has a drying effect, and can maintain the root canal in a dry and sterile state.

[0061] Analysis of the effects of the components in the composite bioceramic root canal sealant:

[0062] The tricalcium silicate has good biological activity and the ability to induce deposition of bone-like hydroxyapatite, and promotes the formation of chemical bonding with soft / hard tissues, and reacts with the liquid agent to generate calcium silicate hydrate gel (CSH) and calcium hydroxide; the amorphous calcium phosphate nanoparticles generated by the calcium silicate hydrate gel after being introduced into the root canal will block the dentin pores, lateral root canals and main root apertures, and the generated calcium hydroxide and beta tricalcium phosphate will react to generate hydroxyapatite (Wang Xiaohong, Chang Jiang, Sun Hongchen. Experimental study on tricalcium silicate blocking dentin tubules [J]. Oral Medicine Research, 2007, 23(2): 176-178. DOI: 10.3969 / j.issn.1671-7651.2007.02.017.; Fei Li, Sun Jiao. Preliminary study on the in vitro osteogenic effect of different content of calcium silicate bioceramics [J]. Shanghai Stomatology, 2011, 20(3): 241-245.; Liu Yong, Wang Zhen, Lin Kaili, et al. In vitro and in vivo degradation of alpha-calcium silicate and beta-calcium silicate [J]. Science, Technology and Engineering, 2009, 9(10): 2569-2573, 2582. DOI: 10.3969 / j.issn.1671-1815.2009.10.007.).

[0063] β-tricalcium phosphate has good biodegradability, bone induction and conduction, biocompatibility and biosafety. When it is implanted into the human body, the degraded Ca ions and P ions can enter the circulating system of the living body to form new bone. β-tricalcium phosphate alone can also achieve bone-dentin-bone combination and biological closure of the root tip. The β-tricalcium phosphate solidification process does not produce heat, and the combination with calcium silicate has a positive effect on maintaining the normal physiological environment balance of the root tip. The solidification strength of β-tricalcium phosphate is lower than that of calcium silicate after solidification, and the combination with calcium silicate can reduce the strength of the root canal filling, which is beneficial to the subsequent removal of the root canal filling for root canal refilling. The degradation rate of β-tricalcium phosphate in the physiological environment is less than that of calcium silicate and greater than that of hydroxyapatite. For the root tip bone absorption or larger bone defect area, the proliferation rate of bone cells often cannot keep up with the degradation rate of single calcium silicate or calcium phosphate material, and the combination of β-tricalcium phosphate, β-tricalcium phosphate and hydroxyapatite can make the degradation rate of the material closer to the proliferation rate of bone cells. β-tricalcium phosphate can react with calcium hydroxide generated by the hydration reaction of calcium silicate to generate hydroxyapatite.

[0064] Hydroxyapatite is the main inorganic component of human and animal bones and teeth, is a typical biomaterial, has excellent biological activity and biocompatibility, is not easy to degrade in a physiological environment, can be used as a bone repair matrix material to provide a scaffold for bone repair, has bone conduction, and new bone cells can crawl along its surface until fusion to achieve the purpose of biological closure of the root tip hole.

[0065] Calcium hydroxide has a pH value as high as 12.5, can damage bacterial cell membranes, denature bacterial proteins, release hydrogen ions to break DNA chains, and kill bacteria. Calcium hydroxide can penetrate dentin tubules to kill bacteria; calcium hydroxide can neutralize acidic substances produced during the inflammatory process to 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 to promote the formation of hard tissue; in addition, calcium hydroxide has good biocompatibility, no irritation to the body and dental pulp tissue, no toxicity, can promote and induce the formation of dentin bridges, promote the closure of the root tip hole, and promote the repair of periradicular bone tissue.

[0066] Nano zirconium dioxide is an excellent bio-inert material, with high strength, good chemical stability, no reaction with other chemical components, no hemolytic reaction, no degradation, no cytotoxicity, no rejection reaction with bone cells, large specific surface area, strong oxygen storage capacity, and can increase the flexibility of the material when used with nano hydroxyapatite, reduce the looseness and brittleness of hydroxyapatite, increase the operability and strength of the material, and has relatively large density. When used with tantalum oxide, it can block X-rays and be used as a developer (Tang Y J, Wang X L, Zhou Z H, et al. Effect of nano zirconium dioxide toughened hydroxyapatite biocomposite ceramic on proliferation and differentiation of rabbit bone marrow stromal cells [J]. Chinese Journal of Research and Clinical Rehabilitation, 2011, 15(3): 450-452. DOI:10.3969 / j.issn.1673-8225.2011.03.017.).

[0067] The combination of nano tantalum oxide and nano zirconium oxide can enhance the X-ray blocking effect and be used as a developer for convenient post-filling radiographic examination. Tantalum has good biocompatibility, no irritation to body tissues, good stability, no degradation, no cytotoxicity, can promote mesenchymal stem cell differentiation, and is beneficial to the aggregation, proliferation and differentiation of osteoblast precursors and the secretion of matrix, and can promote new bone formation (Cai H Z, He H X. Research progress of tantalum metal in clinical application [J]. Journal of Oral and Maxillofacial Prosthodontics, 2017, 18(1): 46-50. DOI:10.3969 / j.issn.1009-3761.2017.01.012.). Nano tantalum has a good proliferation induction effect when in contact with osteoblasts, which is related to the particle concentration and size (Lu B, Liu B H. Effect of nano-tantalum on proliferation of osteoblasts and expression of related genes [J]. Journal of Oral and Maxillofacial Surgery, 2020, 30(5): 295-299. DOI:10.3969 / j.issn.1005-4979.2020.05.006.).

[0068] As shown in Figure 1 The root canal plug tip provided by the embodiment is made of medical pure titanium or titanium alloy, and comprises a root canal section 1 and a handle section 2 in sequence from top to bottom along the axial direction. The root canal section 1 is conical, and the root canal section 1 is sequentially provided with a threaded portion 3 and a blade portion 4 from the most pointed end of the root canal plug tip to the handle section 2. The groove structure of the threaded portion 3 is composed of external threads with a whole thread slope that tends to be horizontal from top to bottom, and the external threads are thin teeth. The groove structure of the blade portion 4 is composed of a plurality of horizontally arranged annular blades 5 at equal intervals. The handle section 2 is provided with a scale structure, which is a digital annular scale line. A V-shaped notch 6 is arranged in the middle of the handle section 2, which is used to cut off after the root canal plug tip is filled in place.

[0069] The outer thread of the threaded portion 3 and the lower half of the horizontal annular blade 5 of the blade portion 4 store the composite bioceramic root canal sealant for apical sealing and root canal filling; the upper half of the horizontal annular blade 5 of the blade portion 4 fills the adhesive for fixing the root canal plug tip in the root canal.

[0070] In this embodiment, the thread of the threaded portion 3 starts at a position 0.5-1 mm away from the tip (the position 0.5-1 mm is a smooth surface) and ends at the lower edge of the lowermost horizontal annular blade 5 of the blade portion 4, or the thread of the threaded portion 4 starts at the tip of the root canal plug tip and ends at the lower edge of the lowermost horizontal annular blade 5 of the blade portion 4. The overall thread slope of the threaded portion 3 tends to be horizontal from top to bottom, and when filling the root canal, it rotates and advances in the root canal cavity that matches the taper of the root canal plug tip. Because the groove structure of the threaded portion 3 is interrupted by the blade portion 4, the paste formed by the liquid agent and the A group cannot rotate and overflow from the groove structure, and a certain pressure will cause more paste to be uniformly pressed into the root canal to be filled.

[0071] The root canal plug tip can be electrically connected with an electronic root length measuring instrument for directly measuring the tooth length.

[0072] The application discloses a use method of the self-expanding root canal filling instrument combination, which comprises the following steps:

[0073] Step 1, filling the first layer of high-purity bioactive ceramic;

[0074] Step 1.1, selecting a root canal plug tip matched with the taper and length of the root canal to be filled, electrically connecting the handle section 2 of the root canal plug tip with an electronic root length measuring instrument, measuring the length of the root canal to be filled, and mixing the liquid agent with the A group to form a paste;

[0075] Step 1.2, filling the paste in the threaded portion 3 and the lower half of the blade portion 4; referring to the scale structure on the handle section 2, guiding the paste into the apical physiological environment zone and the inner wall of the root canal through the root canal plug tip, and continuously and quickly increasing the pressure for several times;

[0076] Step 1.3, repeating step 1.2 once to complete the filling of the first layer of high-purity bioactive ceramic;

[0077] This step makes the beta-tricalcium phosphate and calcium silicate hydrogel fill the entire root canal. Under the repeated extrusion of the vertical and horizontal components of the conical shape of the root canal section 1, the calcium phosphate and calcium silicate hydrogel will seep into the dentin tubules and other microspaces, and a small part of the calcium phosphate hydrogel will inevitably be squeezed out of the apical narrow zone into the apical physiological environment zone, and the filling, coating and sealing of the first layer of high-purity bioactive ceramic are completed in the apical physiological environment zone and the inner wall of the root canal;

[0078] The apical physiological environment zone is the micro-trumpet-shaped apical foramen zone, the apical periodontal zone, and the physiological environment zone of the fine channels on the surface of the root canal and the side branch root canal, which has blood circulation and participates in metabolism, except for the narrowest part of the root tip (the root tip base point);

[0079] Step 2, filling the second layer of bioceramics;

[0080] An appropriate amount of the B component is taken on a mixing plate, the root canal plug tip is taken out from the root canal in the reverse screw thread direction, and then is placed in the B component dry powder to rotate and roll, so that the B component is adhered to the residual paste on the lower half of the thread part 3 and the blade part 4. The root canal plug tip is quickly inserted into the root canal in the screw thread direction according to the scale structure on the handle section 2 to pre-set the position and to compact, so that the mixture of the A component paste and the B component enters the root canal at the predetermined position in the non-physiological environment zone, that is, the filling of the second layer of bioceramics is completed. The thread part 3 of the root canal section 1 has fine thread teeth, and the overall thread inclination tends to be horizontal. When the root canal is filled, the A component and the B component are rotated and pushed into the root canal to be filled. Because the groove structure of the thread part 3 is interrupted by the blade part 4, the medicament cannot rotate and overflow from the groove structure, and a certain pressure is generated to press more medicament into the root canal to be filled in layers.

[0081] In this step, the principle that calcium oxide will quickly expand when it meets water or moisture is used to make the B component in the thread of the root canal plug tip and the water in the paste have a chemical expansion reaction. At this time, a small part of the nano-hydroxyapatite and nano-zirconium dioxide in the B component will also enter the root canal cavity micro-gap, the side branch root canal, and the dentin tubule under the extrusion of the expansion force, to complete the root canal filling of the second layer of bioceramics in the non-physiological environment zone of the root canal. The second layer of bioceramics will further extrude the first layer of bioceramics into more microscopic gaps to achieve a more ideal root canal filling effect.

[0082] The root canal non-physiological environment zone is the root canal cavity zone inside the narrow part of the root tip without vital pulp and metabolism;

[0083] Step 3, the handle part is radially broken off from the V-shaped notch 6 of the root canal plug tip, the excess composite bioceramic root canal sealant in the root canal opening and the dental crown cavity is washed and dried by a dental three-purpose gun, and then the upper half of the blade part 4 is injected with a fluid light-curing resin for light curing, to realize two-time filling of the tooth in sections and the material in groups.

[0084] The root canal plug tip can accurately transport and control the chemical reaction process of the expansion of the composite bioceramics in the root canal. When the composite bioceramics is away from the root canal plug tip, the expansion of the composite bioceramics will become uncontrollable. Other tools such as a root canal reamer, a smooth probe, and a gutta-percha tip cannot fill and compact the A component and the B component in proportion, uniformly, and quickly before the chemical expansion reaction in the root tip area.

[0085] Further, the side effect of calcium oxide is heat production during hydration, but since the content of calcium oxide in the composite bioceramic root canal sealant is very small, and the handle section 2 of the root plug tip is outside the tooth, the metal body can also absorb, cool and export part of the heat, so the actual heat produced is lower than that caused by the traditional hot gutta-percha filling method, which can be ignored.

[0086] Embodiment two

[0087] A self-expanding root canal filling instrument combination comprises a composite bioceramic root canal sealant and a root plug tip; the composite bioceramic root canal sealant is composed of a liquid agent and a powder agent.

[0088] The liquid agent is physiological saline; the powder agent is divided into A component and B component; the composition of the A component is 55vol% tricalcium silicate and 45vol% beta tricalcium phosphate; the composition of the B component is 36vol% calcium hydroxide, 21vol% nano-hydroxyapatite, 25vol% nano-zirconium dioxide, 15vol% nano-tantalum oxide and 3vol% calcium oxide.

[0089] As shown in Figure 2 The groove structure in the embodiment is composed of multiple equally spaced horizontal annular blades 5 arranged from the tip to the lower edge of the handle section 2; the composite bioceramic root canal sealant is stored in the horizontal annular blades 5 of the lower half of the root canal section 1 for root tip area sealing and root canal filling; the horizontal annular blades 5 of the upper half of the root canal section 1 are filled with adhesive for fixing the root plug tip in the root canal. The rest of the root plug tip in the embodiment is the same as that in embodiment one, and the processing and manufacturing are simpler, and the overall flexibility is better.

[0090] The application discloses a use method of the self-expanding root canal filling instrument combination, which comprises the following steps:

[0091] Step 1, filling a first layer of high-purity bioactive ceramic;

[0092] Step 1.1, selecting a root plug tip matched with the taper and length of the root canal to be filled; mixing the liquid agent with the A component to form a paste;

[0093] Step 1.2, filling the paste into the external thread of the root canal section 1; referring to the scale structure on the handle section 2, guiding the paste into the root tip physiological environment area and the root canal inner wall through the root plug tip, and continuously and quickly increasing the pressure for several times; the handle section 2 can also be electrically connected with an electronic root length measuring instrument to accurately detect the depth of the root plug tip entering the root canal;

[0094] Step 1.3, repeating step 1.2 twice, that is, completing the filling of the first layer of high-purity bioactive ceramic;

[0095] Step 2, filling a second layer of bioactive ceramic;

[0096] After the root canal plug tip is taken out, it is placed in the B component and rotated to roll, so that the outer thread of the root canal segment 1 is covered with the B component; the root canal plug tip is quickly inserted into the pre-set position of the root canal to be filled and compacted by referring to the scale structure on the handle segment 2, or the depth of the root canal plug tip into the root canal is measured while filling, so as to accurately seal the root tip hole; the mixture of the paste and the B component enters the non-physiological environment area, that is, the filling of the second layer of bioceramics is completed.

[0097] Step 3, the excess handle part 2 is radially broken off from the V-shaped notch 6 of the root canal plug tip, the excess composite bioceramic root canal sealant in the root canal opening and the crown cavity is washed and dried by the dental three-purpose gun, and then the glass ionomer cement is injected into the multiple grooves formed by the horizontal annular blades 5 on the upper half of the root canal segment 1 and naturally solidified at room temperature, that is, the tooth is partitioned and the materials are grouped, and the filling is completed in two times.

[0098] Example Three

[0099] A self-expanding root canal filling instrument combination comprises a composite bioceramic root canal sealant and a root canal plug tip; the composite bioceramic root canal sealant is composed of a liquid agent and a powder agent.

[0100] The liquid agent is raw distilled water; the powder agent is divided into an A component and a B component; the A component is composed of 75 vol% of tricalcium silicate and 25 vol% of beta tricalcium phosphate; the B component is composed of 39 vol% of calcium hydroxide, 25 vol% of nano-hydroxyapatite, 20 vol% of nano-zirconium dioxide, 10 vol% of nano-tantalum oxide and 6 vol% of calcium oxide.

[0101] In this embodiment, the root canal plug tip is the same as that in Example One.

[0102] Example Four

[0103] A self-expanding root canal filling instrument combination comprises a composite bioceramic root canal sealant and a root canal plug tip; the composite bioceramic root canal sealant is composed of a liquid agent and a powder agent.

[0104] The liquid agent is raw distilled water; the powder agent is divided into an A component and a B component; the A component is composed of 75 vol% of tricalcium silicate and 25 vol% of beta tricalcium phosphate; the B component is composed of 39 vol% of calcium hydroxide, 25 vol% of nano-hydroxyapatite, 20 vol% of nano-zirconium dioxide, 10 vol% of nano-tantalum oxide and 6 vol% of calcium oxide.

[0105] In this embodiment, the root canal plug tip is the same as that in Example One.

[0106] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application. For those skilled in the art, the specific technical solutions described in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent features, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions protected by the present application.

Claims

1. A method of using a self-expanding root canal filling instrument assembly, characterized in that: The self-expanding root canal filling instrument assembly includes a self-expanding composite bioceramic root canal sealant and a root canal plug tip; The self-expanding composite bioceramic root canal sealant is composed of liquid and powder. The liquid is distilled water or physiological saline; the powder is divided into component A and component B. The composition of component A is 55-75 vol% tricalcium silicate and 25-45 vol% tricalcium β-phosphate; The composition of component B is 35-40 vol% calcium hydroxide, 21-25 vol% nano hydroxyapatite, 20-25 vol% nano zirconium dioxide, 10-15 vol% nano tantalum oxide, and 3-6 vol% calcium oxide; The root canal plug tip is made of medical-grade pure titanium or titanium alloy. The root canal plug tip includes a root canal segment (1) and a handle segment (2) arranged sequentially from bottom to top along the axial direction. The root canal segment (1) is conical. The root canal segment (1) is provided with a groove structure from the tip to the lower edge of the handle segment (2). The groove structure is used to store the self-expanding composite bioceramic root canal sealant. The handle segment (2) is provided with a V-shaped groove (6) in the middle, which is used to cut off after the root canal plug tip is filled in place. Includes the following steps: Step 1: Fill the first layer with high-purity bioactive ceramic; Step 1.1: Select a root canal tip that matches the taper and length of the root canal to be filled and prepare it for use. Mix the liquid with component A to form a free-flowing paste. Step 1.2: Dip the root canal segment (1) of the root canal plug tip into the paste and introduce it into the root canal. Then, continuously and quickly apply pressure several times to fill the root canal and the physiological environment area of ​​the root apex with the paste, thus completing the filling of the first layer of high-purity bioactive ceramic in the root canal. Step 2: Fill with the second layer of bioceramic; Take an appropriate amount of component B powder on the mixing board for later use. After taking out the root canal plug tip, place it in the component B dry powder and rotate it so that the surface of the residual paste in the groove structure of the root canal segment (1) is covered with component B powder. Quickly rotate the root canal plug tip covered with component B powder and insert it into the preset position of the root canal to be filled and compact it to complete the filling of the second layer of composite bioceramic. Step 3: The calcium oxide in the B component powder of the root canal segment (1) reacts with the water in the A component paste in the root canal and expands. The handle is radially broken off from the V-shaped groove (6) of the root canal tip. The root canal orifice and crown cavity are rinsed and dried with a dental three-way gun. Excess self-expanding composite bioceramic root canal sealant is then injected and cured by light curing, or glass ionomer cement is cured naturally at room temperature. This achieves tooth partitioning and material grouping for two separate fillings.

2. The method of using the self-expanding root canal filling instrument assembly according to claim 1, characterized in that: The composition of component A is 65 vol% tricalcium silicate and 35 vol% tricalcium β-phosphate; the composition of component B is 37.5 vol% calcium hydroxide, 23.5 vol% nano-hydroxyapatite, 22.5 vol% nano-zirconium dioxide, 12.5 vol% nano-tantalum oxide, and 4 vol% calcium oxide.

3. The method of using the self-expanding root canal filling instrument assembly according to claim 1 or 2, characterized in that: The root canal segment (1) is divided into a blade section (4) and a threaded section (3) from top to bottom along the axial direction. The groove structure located on the outer periphery of the blade section (4) is composed of multiple horizontally spaced annular blades (5). The groove structure located on the threaded section (3) is composed of an external thread with an overall thread slope that tends to be horizontal from top to bottom. The external thread of the threaded section (3) and the lower half of the horizontal annular blades (5) of the blade section (4) store the self-expanding composite bioceramic root canal sealant for apical sealing and root canal filling. The upper half of the horizontal annular blades (5) of the blade section (4) is filled with adhesive for fixing the root canal plug tip in the root canal.

4. The method of using the self-expanding root canal filling instrument assembly according to claim 1 or 2, characterized in that: The groove structure consists of multiple equally spaced horizontal annular blades (5) arranged from the tip to the lower edge of the handle section (2); the horizontal annular blades (5) of the lower half of the root canal section (1) store self-expanding composite bioceramic root canal sealant for apical sealing and root canal filling; the horizontal annular blades (5) of the upper half of the root canal section (1) are filled with adhesive for fixing the root canal plug tip in the root canal.

5. The method of using the self-expanding root canal filling instrument assembly according to claim 4, characterized in that: The root canal plug tip root canal section (1) has tapers of 04, 06, and 08 respectively, and the tip diameter is consistent with that of nickel-titanium machine reamers of No. 025, 030, 035, and 040; the handle section (2) is provided with a scale structure.

6. The method of using the self-expanding root canal filling instrument assembly according to claim 1 or 2, characterized in that: The calcium oxide contained in the B-component composite bioceramic imparts self-expanding properties to the root canal sealant and enables the sealant to be used in combination with titanium root canal plugs in an automatic expansion mode within the root canal.

7. The method of using the self-expanding root canal filling instrument assembly according to claim 6, characterized in that, Step 1.1 further includes: selecting a suitable root canal plug tip and electrically connecting it to an electronic root length measuring instrument, performing measurement before filling, or precise measurement while filling, or measurement after filling.

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