阅读说明：本技术 一种固化时间稳定的根管充填糊剂及其制备方法 (Root canal filling paste with stable curing time and preparation method thereof ) 是由 何浩 于 2021-07-26 设计创作，主要内容包括：本发明一种固化时间稳定的根管充填糊剂。所述的糊剂所述的糊剂包含无机物粉末体系和有机物混合液体；所述无机物粉末体系在体液环境内能够固化；所述无机物粉末体系含有x射线阻射剂和无机物粉末；所述有机物混合液体含有淀粉接枝丙烯酸钠；所述无机物粉末为钙盐,所述糊剂中水的含量大于等于40％,且水分子被包裹在糊剂有效成分所形成的三维空间网络当中。当此糊剂置于根管内部时,三维网格结构被破坏,其中的水释放出来,促使无机物粉末体系固化。对于不同湿度的根管,糊剂都能迅速发生固化,有效解决了根充糊剂固化时间严重依赖根管水分的问题,使得根管治疗的成功率获得提高。(The invention provides a root canal filling paste with stable curing time. The paste comprises an inorganic powder system and an organic mixed liquid; the inorganic powder system is curable in a liquid environment; the inorganic powder system contains an X-ray radiation-resistant agent and inorganic powder; the organic matter mixed liquid contains starch grafted sodium acrylate; the inorganic powder is calcium salt, the water content in the paste is more than or equal to 40%, and water molecules are wrapped in a three-dimensional space network formed by the active ingredients of the paste. When this paste is placed inside the root canal, the three-dimensional network is destroyed and the water therein is released, causing the inorganic powder system to solidify. For the root canal with different humidity, the paste can be cured rapidly, thereby effectively solving the problem that the curing time of the root filling paste depends on the water content of the root canal, and improving the success rate of the root canal treatment.)

1. A root canal filling paste with stable curing behavior, characterized in that: the paste comprises an inorganic powder system and an organic mixed liquid; the inorganic powder system is curable in a liquid environment; the inorganic powder system contains an X-ray radiation-resistant agent and inorganic powder; the organic matter mixed liquid contains starch grafted sodium acrylate; the inorganic powder is calcium salt, and the water content in the paste is more than or equal to 40%.

2. The root canal filling paste having a stable curing behavior according to claim 1, wherein: inorganic powder including hydroxyapatite, calcium silicate, calcium phosphate, and other additives;

in the inorganic powder, the calcium silicate content is not more than 10 wt%, preferably 3 to 9 wt%;

the content of hydroxyapatite in the inorganic powder is 30 to 40 wt%, preferably 32 to 36 wt%,

the content of other additives in the inorganic powder is not more than 10 wt%; the other additives are selected from at least one of calcium carbonate, calcium hydroxide, calcium pyrophosphate, calcium sulfate and kaolin, and when the other additives contain kaolin, the mass fraction of the kaolin is not more than 5% of the total mass of the inorganic powder;

the balance being calcium phosphate.

3. The root canal filling paste having a stable curing behavior according to claim 2, wherein: the other additives comprise calcium carbonate, calcium hydroxide, calcium pyrophosphate, calcium sulfate and kaolin, and the mass fraction of the kaolin is not more than 5% of the total mass of the inorganic powder.

4. The root canal filling paste having a stable curing behavior according to claim 3, wherein: the other additives are prepared from calcium carbonate, calcium hydroxide, calcium pyrophosphate, calcium sulfate and kaolin according to the mass ratio of calcium carbonate: calcium hydroxide: calcium pyrophosphate: calcium sulfate: kaolin is composed of 1-2:1-3:1-2:1-2: 1-5.

5. The root canal filling paste having a stable curing behavior according to claim 1, wherein: the x-ray blocker mixture is selected from: at least one of iodoform, yttrium carbonate, yttrium sulfate, yttrium oxide, zirconium oxide and barium sulfate, wherein the total mass fraction of the at least one of iodoform, yttrium carbonate, yttrium sulfate, yttrium oxide, zirconium oxide and barium sulfate is not more than 30% of the total mass of the inorganic powder system.

6. The root canal filling paste having a stable curing behavior according to claim 1, wherein: the organic matter mixed liquid is composed of starch grafted sodium acrylate, water and at least one of gelatin, guar gum, xanthan gum, glycerol, propylene glycol, sodium dodecyl benzene sulfonate, sodium lauryl ether sulfate and cocamidopropyl betaine; wherein the content of water is 80-90% of the total mass of the organic matter mixed liquid.

7. The root canal filling paste having a stable curing behavior according to claim 1, wherein: the organic matter mixed liquid is prepared by starch grafted sodium acrylate, A, glycerol, propylene glycol, B and water in a mass ratio of: a: glycerol: propylene glycol: b: 2.5-10:2.5-5:3:1.5:0.5: 80-90; the A is selected from at least one of gelatin, guar gum and xanthan gum; and B is selected from at least one of sodium dodecyl benzene sulfonate, sodium lauryl ether sulfate and cocamidopropyl betaine.

8. The root canal filling paste having a stable curing behavior according to claim 1, wherein: the mass ratio of the inorganic powder system to the organic mixed liquid is 1-5:1, preferably 1: 1.

9. A method for preparing the root canal filling paste having stable curing behavior according to any one of claims 1 to 8, characterized in that: distributing and taking each component according to a design group, firstly preparing organic matter mixed liquid according to the designed organic matter mixed liquid component, and then mixing the organic matter mixed liquid with the prepared inorganic matter and X-ray radiation resisting agent powder system; after stirring, a root canal filling paste with stable curing behavior was obtained.

10. The method for preparing a root canal filling paste having a stable curing behavior according to claim 9, wherein: the range of variation in curing time for the same batch of product was less than 3 hours after the composition of the product was determined.

Technical Field

The invention relates to a root canal filling paste with stable curing time and a preparation method thereof; belongs to the technical field of root canal treatment.

Background

Endodontics is an effective method for treating pulpitis, and can remove damaged pulp from a root canal, block infection, and prevent periapical lesions from occurring by preparing, disinfecting, and filling the root canal. Substances used to fill root canals in endodontics are collectively called root canal filling materials. The effectiveness of the endodontic procedure is closely related to the properties of the root canal filling material. Root canal filling materials need to be able to effectively seal the root tip and have good biocompatibility; in addition, the root canal filling material is required to have good X-ray radiation resistance, thereby being beneficial to the operation process and the postoperative observation; other properties include bacteriostasis, ease of removal, lack of staining of the teeth, no irritation, and the like. The currently clinically commonly used root canal sealer mainly comprises silver alloy, zinc oxide, calcium hydroxide, composite resin, glass ions and the like. To date, no root tip filling material has met all of the above requirements.

With the development of oral materials, calcium phosphate and calcium silicate based ceramic filling materials are receiving more and more attention. The main components of the filling material are calcium phosphate and calcium silicate ceramics, the ceramics can generate hydrogel and generate curing reaction when being contacted with the environment of body fluid, and the cured product generates volume expansion, thereby realizing the purpose of sealing the root canal (US Patent 5415547; US Patent 8722100; US Patent 5769638; WO/2011/023199). Patent CN 200880011743.1 discloses a premixed cement paste for medical or dental use. The cement paste is capable of removing calcium hydroxide during hydration and forming a hydroxyapatite/calcium silicate hydrogel composite in situ, thus having high mechanical strength and biocompatibility. Patent CN107080697A discloses that an inorganic dispersant having a suspension stabilizing effect is added to a premix root canal filling material system to prevent the premix system from layering so as to improve its long-term dispersion stability. Patent CN201710205844.3 provides a premixed calcium silicate/magnesium phosphate composite root canal filling material and a preparation method thereof. The composite material combines the advantages of magnesium phosphate and calcium silicate self-curing materials, shortens the curing time and has good biocompatibility. For root canal filling materials, achieving long-term, effective sealing of root canals is a fundamental requirement for root canal filling materials. The sealing property of calcium phosphate and calcium silicate based ceramic filling materials is widely accepted, but the curing time is influenced by many factors.

It is reported that the curing time of the conventional bioceramic root canal filling paste greatly varies in different environments. For the same Bioceramic filling paste, it was found that the setting time was 52 hours (Zamprinti F, Siboni F, Prati C, et al.Properties of calcium-monobasic calcium phosphate materials for the incorporation of additives and additives [ J ]. Clinical organic investments, 2018.), and that the setting time was 168 hours (Bethany A.Loushi and Thomas E.Bryan and Stephen W.Looney and Brim.Gillen and Robert J.Loushi and R.Norman well and David H.Pashil and Franklin R.Tatariy.SettedCytozoa et al.J.Biochemical of company J.2011.J. [ J. [ J.Biochemical of biological J. ]). More studies found that this paste did not set completely within 4 weeks in a humid incubator (Kyung L J, Won K S, Jung-Hong H, et al. physiochemical Properties of Epoxy Resin-Based and Bioceramic-Based Root computers [ J ]. Bioorganic Chemistry and Applications,2017, (2017-01-22),2017,2017: 2582849.). In addition, the paste was reported to set under the same conditions in 2.7H (Zhou H M, Dds Y S, Zhong W, et al. physical Properties of 5Root Canal Sealers [ J ]. Journal of endometrics, 2013,39(10):1281-1286.) and 4.7H (Tanomau-Filho M, Torres F, GM Ch. vez-Andreade, et al. physical Properties and Volumetric Change of Silicone/biological Glass and calcium silicate-based endometrics Seaters [ J ]. J209Endod, 2017: 7-2101.), respectively. Unstable curing time may adversely affect the root canal treatment.

The degree of wetting (water content) of the root canal has a major effect on the curing behavior of the bioceramic root-filling paste. The bioceramic root paste needs to be in a water environment for curing to occur. The hydrogel particles produced during curing are small, typically on the order of nanometers. These nanoparticles have a large specific surface area and adsorb water molecules on the surface. These surface adsorbed water cannot continue to participate in the hydration reaction, resulting in a reduction in the amount of water that can undergo hydration reaction. When the water content is reduced to a certain degree, the paste can generate self-drying phenomenon, so that the curing can not be continued. Thus, the root canal is too dry resulting in slow and long curing times. Patent CN 200880011743.1 added water in an amount not exceeding 20% by weight of the paste. However, the curing time was reported to still be from 2.7 hours to 4 weeks without complete curing, indicating that the paste composition was mainly dependent on the degree of moisture of the external environment (e.g., root canal). Increasing the water content of the paste facilitates curing of the paste. However, the addition of too much water to the paste causes the paste to solidify immediately during storage, and thus cannot be put to practical use. In view of the above, achieving a stable cure time from the design aspect of the paste itself remains an unsolved problem with existing root-filling pastes.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a root canal filling paste with stable curing behavior and a preparation method thereof.

The invention relates to a root canal filling paste with stable curing behavior, which comprises an inorganic substance powder system and an organic substance mixed liquid; the inorganic powder system is curable in a liquid environment; the inorganic powder system contains an X-ray radiation-resistant agent and inorganic powder; the organic matter mixed liquid contains starch grafted sodium acrylate; the inorganic powder is calcium salt, and the water content in the paste is more than or equal to 40%.

Preferably, the root canal filling paste with stable solidification behavior of the present invention, the inorganic powder comprises hydroxyapatite, calcium silicate, calcium phosphate, other additives;

in the inorganic powder, the calcium silicate content is not more than 10 wt%, preferably 3 to 9 wt%;

the content of hydroxyapatite in the inorganic powder is 30 to 40 wt%, preferably 32 to 36 wt%,

the content of other additives in the inorganic powder is not more than 10 wt%; the other additives are selected from at least one of calcium carbonate, calcium hydroxide, calcium pyrophosphate, calcium sulfate and kaolin, and when the other additives contain kaolin, the mass fraction of the kaolin is not more than 5% of the total mass of the inorganic powder;

the balance being calcium phosphate. Preferably, the root canal filling paste with stable curing behavior comprises calcium carbonate, calcium hydroxide, calcium pyrophosphate, calcium sulfate and kaolin, and the mass fraction of the kaolin is not more than 5% of the total mass of the inorganic powder.

In a further preferred embodiment, the present invention provides a root canal filling paste with stable setting behavior, wherein the other additives are calcium carbonate, calcium hydroxide, calcium pyrophosphate, calcium sulfate, and kaolin, and the mass ratio of calcium carbonate: calcium hydroxide: calcium pyrophosphate: calcium sulfate: kaolin is composed of 1-2:1-3:1-2:1-2: 1-5. The inorganic substance has a powder particle size of 10-100nm, preferably 60-90 nm.

Preferably, the present invention provides a root canal filling paste with stable curing behavior, wherein the x-ray radiation-blocking agent mixture is selected from the group consisting of: at least one of iodoform, yttrium carbonate, yttrium sulfate, yttrium oxide, zirconium oxide and barium sulfate, wherein the total mass fraction of the at least one of iodoform, yttrium carbonate, yttrium sulfate, yttrium oxide, zirconium oxide and barium sulfate is not more than 30% of the total mass of the inorganic powder system. The particle size of the x-ray radiation-blocking agent is 0.01-5 microns.

Preferably, the root canal filling paste with stable curing behavior comprises an organic mixed liquid, wherein the organic mixed liquid is composed of starch grafted sodium acrylate, water and at least one of gelatin, guar gum, xanthan gum, glycerol, propylene glycol, sodium dodecyl benzene sulfonate, sodium lauryl ether sulfate and cocamidopropyl betaine; wherein the content of water is 80-90% of the total mass of the organic matter mixed liquid.

Preferably, the root canal filling paste with stable curing behavior is prepared by mixing starch grafted sodium acrylate, A, glycerol, propylene glycol, B and water in a mass ratio of starch grafted sodium acrylate: a: glycerol: propylene glycol: b: 2.5-10% of water: 2.5-5:3:1.5:0.5: 80-90; the A is selected from at least one of gelatin, guar gum and xanthan gum; and B is selected from at least one of sodium dodecyl benzene sulfonate, sodium lauryl ether sulfate and cocamidopropyl betaine.

In a preferred embodiment, the root canal filling paste with stable curing behavior of the present invention has a mass ratio of the inorganic powder system to the organic mixed liquid of 1 to 5:1, preferably 1: 1.

The invention relates to a preparation method of root canal filling paste with stable curing behavior, which comprises the following steps of distributing and taking all components according to a design group, preparing organic matter mixed liquid according to the designed organic matter mixed liquid component, and then mixing the organic matter mixed liquid with an inorganic matter and X-ray radiation inhibitor powder system; after stirring, a root canal filling paste with stable curing behavior was obtained.

According to the product designed and prepared by the invention, after the components of the product are determined, the fluctuation range of the curing time of the product in the same batch is less than 3 hours, after optimization, the fluctuation range of the curing time is less than or equal to 120min, and after further optimization, the fluctuation range of the curing time is less than 90 min.

Principles and advantages

The curing time of the existing bioceramic root filling paste is greatly influenced by the moisture degree (water content) of the root canal, and the curing time is different from 2.7 hours to 672 hours, so that the effect of root canal treatment is influenced. The invention provides a root canal filling paste with stable curing time and a preparation method thereof. The core of the paste is that the paste contains more than 40-45% of water. Typically, such high levels of water in the paste result in the paste curing during storage. The invention is optimized and then adds proper amount of starch graft sodium acrylate and kaolin into the paste, and the proper amount of substances can form a large-volume three-dimensional space network structure when meeting water. And the surface of the powder is kept out of the three-dimensional network space due to the charge repulsion action generated on the surface of the particles by adding a proper amount of sodium dodecyl benzene sulfonate and/or sodium lauryl alcohol ether sulfate and/or cocamidopropyl betaine. The water molecules encapsulated in the three-dimensional space network do not contact with the powder and can be kept stable in storage (the fluidity of the paste is kept good when measured according to the method of 7.2 in YY0717-2009 standard). When the root canal is filled, the paste breaks the three-dimensional space network through the exchange action with the liquid in the root canal, releases water in the three-dimensional space network, and enables the root canal to have enough water to enable the paste to be stably solidified (the water content of the paste and the solidification time have good corresponding relation, and the error is not more than 3 hours).

Drawings

FIG. 1 is a schematic diagram showing the results of a fluidity test conducted according to the method of 7.2 in YY0717-2009 after 9 months of storage of the paste obtained in example 1.

FIG. 2 is a schematic diagram showing the results of a fluidity test conducted according to the method of 7.2 in YY0717-2009 after the paste obtained in example 1 was stored for 15 months.

FIG. 3 is a schematic diagram showing the results of a fluidity test conducted by the method of 7.2 in YY0717-2009 after the paste obtained in example 1 was stored for 24 months.

Detailed Description

Example 1

The calcium silicate content was 3% (average particle size 60nm) calculated on the total mass of the powder as 100. 32% of hydroxyapatite (average particle size of 20nm), 1% of calcium carbonate (average particle size of 50nm), 1% of calcium hydroxide (average particle size of 100nm), 2% of calcium pyrophosphate (average particle size of 100nm), 2% of calcium sulfate (average particle size of 100nm), 1% of kaolin (average particle size of 50nm), and 28% of calcium phosphate (average particle size of 20 nm). 10 wt% of iodoform, 10 wt% of yttrium carbonate (average particle size of 1 micron), 10 wt% of zirconium oxide (average particle size of 20 nm). Based on the total mass of the organic matter mixed solution as 100, 10 wt% of starch grafted sodium acrylate, 5 wt% of gelatin, 3 wt% of glycerol, 1.5 wt% of propylene glycol, 0.5 wt% of sodium dodecyl benzene sulfonate and 80 wt% of water are selected. Preparing organic mixed liquor according to the designed components; then, mixing the powder and the organic matter mixed solution according to the mass ratio of 1:1, adding the prepared powder into the organic mixed solution, and uniformly mixing the powder by a mixing roll in a mechanical stirring mode. The curing time is 48 +/-0.5 h.

After the paste is stored for 9 months, the detection of the fluidity test is carried out according to the method of 7.2 in the YY0717-2009 standard, and the diameter of a test piece is 25 mm; the detection result is qualified. The picture of the detected object is shown in figure 1.

After the paste is stored for 15 months, the detection of the fluidity test is carried out according to the method of 7.2 in the YY0717-2009 standard, and the diameter of a test piece is 25 mm; the detection result is qualified. The picture of the detected object is shown in figure 2.

After the paste is stored for 24 months, the detection of the fluidity test is carried out according to the method of 7.2 in the YY0717-2009 standard, and the diameter of a test piece is 25 mm; the detection result is qualified. The picture of the detected object is shown in figure 3.

Examples 1 to 1

The other conditions were the same as in example 1 except that: the water content in the organic matter is increased to 82.5 percent; namely, based on the total mass of the organic matter mixed solution as 100, 7.5 wt% of starch grafted sodium acrylate, 5 wt% of gelatin, 3 wt% of glycerol, 1.5 wt% of propylene glycol, 0.5 wt% of sodium dodecyl benzene sulfonate and 82.5 wt% of water are selected.

The detection is carried out according to the method of 7.4 in the YY0717-2009 standard, and the detection results are shown in Table 1.

Examples 1 to 2

The other conditions were the same as in example 1 except that: the water content in the organic matter is increased to 85 percent; namely, based on the total mass of the organic matter mixed solution as 100, 5 wt% of starch grafted sodium acrylate, 5 wt% of gelatin, 3 wt% of glycerol, 1.5 wt% of propylene glycol, 0.5 wt% of sodium dodecyl benzene sulfonate and 85 wt% of water are selected.

The detection is carried out according to the method of 7.4 in the YY0717-2009 standard, and the detection results are shown in Table 1.

Examples 1 to 3

The other conditions were the same as in example 1 except that: the water content in the organic matter is increased to 87.5 percent; namely, based on the total mass of the organic matter mixed solution as 100, 2.5 wt% of starch grafted sodium acrylate, 5 wt% of gelatin, 3 wt% of glycerol, 1.5 wt% of propylene glycol, 0.5 wt% of sodium dodecyl benzene sulfonate and 87.5 wt% of water are selected.

The detection is carried out according to the method of 7.4 in the YY0717-2009 standard, and the detection results are shown in Table 1.

Examples 1 to 4

The other conditions were the same as in example 1 except that: the water content in the organic matter is increased to 90 percent; namely, based on the total mass of the organic matter mixed solution as 100, 2.5 wt% of starch grafted sodium acrylate, 2.5 wt% of gelatin, 3 wt% of glycerin, 1.5 wt% of propylene glycol, 0.5 wt% of sodium dodecyl benzene sulfonate and 90 wt% of water are selected.

The detection is carried out according to the method of 7.4 in the YY0717-2009 standard, and the detection results are shown in Table 1.

TABLE 1 paste curing time Table

TABLE 1

Example 2

The calcium silicate content was 6% (average particle size 75nm) calculated on the total mass of the powder as 100. 34% of hydroxyapatite (average particle size of 40nm), 2% of calcium carbonate (average particle size of 20nm), 2% of calcium hydroxide (average particle size of 100nm), 1% of calcium pyrophosphate (average particle size of 100nm), 1% of calcium sulfate (average particle size of 70nm), 2.5% of kaolin (average particle size of 80nm), and 31.5% of calcium phosphate (average particle size of 85 nm). 5 wt% of iodoform, 5 wt% of yttrium carbonate (average particle size of 2 microns), 5 wt% of zirconium oxide (average particle size of 500nm), and 5 wt% of barium sulfate (average particle size of 5 microns). Based on the total mass of the organic matter mixed solution as 100, 5 wt% of starch grafted sodium acrylate, 5 wt% of guar gum, 3 wt% of glycerol, 1.5 wt% of propylene glycol, 0.5 wt% of sodium laureth sulfate and 85 wt% of water are selected. The mass ratio of the powder to the organic matter mixed liquid is 1:1, and uniformly mixing the components by a mixer in a mechanical stirring mode. The average curing time is 38.2h, and the fluctuation range of the curing time is 120 min.

Example 3

The calcium silicate content was 9% (average particle size 90nm) calculated on the total mass of the powder as 100. 36% by weight of hydroxyapatite (average particle size of 15nm), 1% by weight of calcium carbonate (average particle size of 120nm), 3% by weight of calcium hydroxide (average particle size of 100nm), 2% by weight of calcium pyrophosphate (average particle size of 30nm), 2% by weight of calcium sulfate (average particle size of 60nm), 5% by weight of kaolin (average particle size of 90nm), and 17% by weight of calcium phosphate (average particle size of 40 nm). 5 wt% of yttrium oxide (average particle size of 1 μm), 5 wt% of yttrium sulfate (average particle size of 3 μm), 5 wt% of yttrium carbonate (average particle size of 3 μm), 5 wt% of zirconium oxide (average particle size of 5 μm), and 5 wt% of barium sulfate (average particle size of 2 μm). Calculated by taking the total mass of the organic matter mixed solution as 100, 2.5 wt% of starch grafted sodium acrylate, 2.5 wt% of xanthan gum, 3 wt% of glycerol, 1.5 wt% of propylene glycol, 0.5 wt% of cocamidopropyl betaine and 90 wt% of water are selected. The mass ratio of the powder to the organic matter mixed liquid is 1:1, and uniformly mixing the components by a mixer in a mechanical stirring mode. The average curing time was 28.9h, and the fluctuation range of the curing time was 100 min.

Comparative example 1;

the other conditions were the same as in example 1 except that: starch grafted sodium acrylate was not added, and the results were: the storage period is not more than 3 months, the long-term stable storage can not be realized, and the fluctuation range of the curing time is 600 min.

Comparative example 2

The other conditions were the same as in example 1 except that: no starch grafted sodium acrylate and kaolin were added; the result is: the storage period is no longer than 15 days, the product can not be stably stored for a long time, and the fluctuation range of the curing time is 720 min.

Comparative example 3

The other conditions were the same as in example 1 except that: the starch grafted sodium acrylate added into the organic matter mixed liquid is 15 percent, and the result is that: the powder-grafted sodium acrylate added into the liquid is too much, the liquid viscosity is too high, the ratio of the prepared paste powder system to the organic matter mixed liquid is not 1:1, and meanwhile, the system cannot be stored for a long time.

The above design parameters are only some examples of the present invention, and therefore, the scope of the present invention should not be limited by these examples, and all equivalent changes and modifications made within the scope of the present invention and the specification should be included within the scope of the present invention.