KR101005554B1 - Root Canal Filler Composed of Mineral Tri-Aggregate And Fabrication Method Thereof - Google Patents

Abstract

The present invention relates to a powdery root canal filler capable of orthograde filling and a method of manufacturing the same. The present invention provides a CaO-SiO ₂ -Al ₂ O ₃ -based powder root canal filler, characterized in that it comprises less than 1.5% by weight of residual CaO. According to the present invention, it is possible to provide a dental root canal filling material which is suitable for being applied to a conservative root canal filling method, suppresses the occurrence of root fractures, has a very low impurity content, excludes harmful components to the human body, and improves injection property. Will be.

MTA, root canal, filling, conservative root canal filling, root canal backfill

Description

MTA system root canal filler and manufacturing method thereof {Root Canal Filler Composed of Mineral Tri-Aggregate And Fabrication Method Thereof}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to dental root canal fillers, and more particularly, to a powdered dental root canal filler capable of orthograde filling and a method of manufacturing the same.

Ideal root canal fillers include biocompatibilty, bacterididal properties, sealing properties, stability, workability, easely placed and distributed properties, and hardening time. Time, Enhance tooth structure, Homogeneity, Radio opacity should be excellent.

Conventional materials used as root canal filling materials include gutta percha and sealer. Root canal treatment using Kata Percha and sealer is called orthograde filling. There are two general methods.

First, Figure 1 is a photograph illustrating the lateral compression method, one of the conservative root canal treatment. Referring to FIG. 1, a Gator perchacon (cone; B, C, D) is placed inside the root canal and presses the cone to the side using a spreader to fill the root canal. The empty space between the filled Kata Percha and the root canal is filled with a sealer.

FIG. 2 is a diagram for explaining a vertical compression method which is another method of conservative root canal treatment. Referring to FIG. 2, a gutta percussion is inserted into the root canal and the root canal is filled by pressing the gutta percussion in a vertical direction using a tool called a plugger.

However, in the case of a procedure using a gatta percussion, there is almost no initial sealability of the root portion, and there is a fundamental drawback that the gata percussion is absorbed in a living body and thus cannot be maintained in the long term. In addition, most sealers have poor initial sealability, such as cytotoxicity at the initial curing stage and bubbles within the root canal space.

Orthograde filling material for conservative root canal treatment should be able to completely close the space around the neural tube, 3 mm area of the root canal, especially in the 3 mm area of the root end. However, the conventional root canal filling method using gataperture is insufficient to obtain the root canal sealing effect that clinically determines the success of the root canal treatment.

After treatment with conventional root canal filling, if the lesion is recurred in the root region, the following surgical treatment is performed. 3 is a series of diagrams for explaining surgical root canal treatment, and consists of the following procedure.

(i) Gum incision after anesthesia (A)

(ii) exposing the gum bone (C)

(iii) exposing the root tip of the lesioned area with a surgical drill (D)

(iv) Tooth anesthesia (E)

(v) Root-end sofa of teeth (F)

(vi) forming a hole at the root end (G)

(v) Filling the root end with filler material (H)

 Unlike the conservative root canal treatment that fills the root canal at the top of the root canal, this method is also called reverse root canal filling, or retrograde filling, in that the root canal is filled at the root end. At this time, as a filling material, a material called ProRoot of DENTSPLY in the United States is mainly used. This material is a powdery filler and exhibits a good sealing effect as compared to gataperture, and its composition is MTA (Mineral Tri Aggregate), which is estimated to be described in US Patent Publication No. 2004-226478.

The present inventors have found that a commercial proroute was used for the orthograde filling and found that the proroute did not show a satisfactory sealing effect at the 3 mm root portion of the root. In addition, this filling material may cause root fractures after root canal closure due to swelling upon curing and is not biocompatible because it contains a heavy metal called bismuth.

In order to achieve the above technical problem, an object of the present invention is to provide a filling material for the treatment of the root canal suitable for use in conservative root canal filling method, that is, forward oral filling.

Moreover, an object of this invention is to provide the filling material for root canal treatment which can fully seal a root part 3mm in a root canal filling method.

In addition, an object of the present invention is to provide a filler for root canal treatment that can suppress the occurrence of root fracture due to swelling after the procedure.

It is another object of the present invention to provide a biocompatible filler for root canal treatment.

As described above, the conventional Root canal filling material, that is, ProRoot of DENTSPLY, has a relatively high content of residual CaO in the raw material of 1.7 wt% or more, so that the root canal after a certain period of time after filling the root canal There is a possibility of cracking due to expansion pressure at the site. In addition, the conventional filler called gataperture has a defect that can not be completely closed in the root canal by contraction. Thus, the filler should have as low shrinkage and expansion properties as possible.

The present invention is characterized by controlling the residual CaO content to suppress the expansion properties of the filler. More specifically, the residual CaO content in the present invention is preferably maintained at 1.5 wt% or less, more preferably 1.0 wt% or less, most preferably 0.8 wt% or less of the composition.

On the other hand, it is necessary to improve the whiteness of the filler because the filler does not look aesthetically good when it shows coloration. In order to improve the whiteness of the MTA-based filler, it is necessary to lower the content of impurities such as Fe 2 O 3 in the starting materials. However, if the content of Fe2O3 is reduced, it is difficult to synthesize 3CaO® SiO2. The present invention provides a filler having a sufficient content of 3CaO SiO2 while suppressing impurities such as Fe2O3.

In addition, the present invention is characterized in that the filler composition is 3CaO SiO2, 2CaO SiO2 and 3CaOAl2O3 as the main component, the content of the component is 95% by weight or more based on the total weight of the CaO-SiO2-Al2O3 compound.

In addition, the filling material for the root canal treatment generally contains a heavy metal component for X-ray imaging after filling. However, heavy metal components such as bismuth are harmful to the human body. Therefore, the present invention uses a glass material such as strontium glass, barium glass, barium sulfate (BaSO4), ytterbium fluoride (YbF3) as a radiopaque material. . It is preferable to use strontium glass, barium glass and barium sulfate having an average particle diameter of 2 µm or less, and ytterbium fluoride having a raw material having a size of 200 nm or less, preferably 100 nm, more preferably 40 nm. It is effective. The compound is preferably 30 parts by weight or less based on 100 parts by weight of the CaO-SiO 2 -Al 2 O 3 -based total compound.

In addition, one of the most important characteristics of the root canal filling material is the preparation of filling in the root canal. The operability means that the filler has a good injection property into the root canal and ensures the sealing property after the injection. For this purpose, there are no coarse particles in the raw material, the particle size should be uniform and the particle size should be small. Have The present invention is characterized in that the root canal filler has an average particle of 0.1 to 2 mu m, and coarse particles of 5 mu m or more are removed. In addition, such small particles also play an important role in showing complete sealability near the root canal 3 mm after filling.

In addition, the root canal filling material is biocompatible and needs to be maintained for a long time. In addition, the filler can be said to be the ideal root canal filling material if it can greatly help the healing of root roots by promoting differentiation of various blasts.

Therefore, this invention provides the filler which has the following structures, and its manufacturing method.

First, the present invention provides a CaO-SiO ₂ -Al ₂ O ₃ -based powder root canal filler, characterized in that it comprises less than 1.5% by weight of residual CaO. The root canal filler of the present invention contains 3CaOSiO2, 2CaOSiO2 and 3CaOAl2O3 as main components, and the content of this component is preferably 95% by weight or more based on the total weight of the CaO-Al2O3-Al2O3 compound. The present invention may also further comprise a barium-based X-ray impermeable material. In the present invention, the residual CaO content is more preferably 1.0% by weight or less. In the present invention, the filler preferably has an average particle of 0.1 ~ 2㎛, the maximum particle size is preferably 5㎛ or less.

The present invention also provides a method for preparing a root canal filling reagent, which comprises mixing the powdered root canal filler with an appropriate amount of water so as to be suitable for hydration to prepare a mixed solution and centrifuging the mixture. . For example, the content of the water and the filler may be in the range of 1: 0.1 to 1: 3 by weight.

In another aspect, the present invention provides a step of providing CaO, SiO 2 and Al 2 O 3 as a raw material, mixing and firing the raw material, pulverizing the fired body and sieving the pulverized fired body has a maximum particle diameter of 5 ㎛ or less It provides a CaO-SiO2-Al2O3-based powder type root canal filler manufacturing method comprising the step of preparing a filler.

The manufacturing method of the present invention may include mixing the pulverized root canal filler with a barium-based X-ray impermeable material.

According to the present invention, when applied to the conservative root canal filling method, it is possible to completely seal the root portion 3mm. In addition, the present invention has a low CaO content can suppress the occurrence of root fracture due to expansion after the procedure. In addition, the filler of the present invention has a high content of crystalline components, and thus the impurities content is very low, it is possible to completely exclude components harmful to the human body.

In addition, the present invention can improve the operability by improving the implantability, using a radiopaque material harmless to the human body instead of heavy metals. The new MTA root canal filler thus prepared is very effective as a material that not only improves mechanical and physical properties, but also promotes differentiation of blast cells and greatly helps root healing.

The present invention provides a powdery root canal filler based on CaO-Si02-Al2O3 based on 3CaOSiO2, 2CaOSiO2 and 3CaOAl2O3, which is designed to be suitable for conservative root canal filling. To this end, the conditions for maintaining the shrinkage and expansion rate of the filler to a very low level, improving the whiteness, easy to operate and operate, and exhibit sterilization and biocompatibility, to suppress the amount of residual CaO from the starting material as much as possible It mixes and bakes.

Existing fillers have a relatively high amount of residual CaO in the raw material, such as 1.7 wt% or more. Therefore, after a certain period of time after filling the root canal, there is a possibility of cracking due to expansion pressure in the root canal area. very important. In addition, shrinkage and expansion should be as low as possible, and in particular, when contraction, the sealing property in the root canal is worsened, and when there is expansion, there is a cracking problem due to expansion. As a method for reducing the length change rate due to drying shrinkage, it is necessary to suppress the amount of residual CaO in the raw material. The amount of residual CaO is influenced by the mixing conditions of the starting materials and the firing temperature and time. In addition, it is necessary to raise the whiteness of the raw material as much as possible if the filler shows coloration because it is not aesthetically good. As a method of improving the whiteness, Fe2O3 should not be used as a starting material, and it is a radioactive impermeable raw material without using bismuth (yellow powdery raw material), ytterbium fluoride, strontium glass, barium glass, barium sulfate, etc. Is more effective to use. The radiopaque material is preferably used in an appropriate content, such as about 30 parts by weight or less based on 100 parts by weight of the filler.

   In addition, operability is very important for root canal filling. In order to improve the operability, the filler should be smoothly dispersed and injectable. The filler should have a relatively uniform particle size distribution, no coarse particles, and a lower average particle diameter. In order to satisfy these characteristics, the grinding condition of the filler after firing is very important. Root canal fillers must also be biocompatible and have good bactericidal properties. Therefore, it is very important to show strong alkalinity and to promote the differentiation of various blast cells to help the healing of root roots.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention.

Characteristics of Root Canal Fillers

≪ Example 1 >

After weighing and mixing CaCO3 raw material in 71 parts by weight of CaO made by decarbonization at 1000 ° C, 25 parts by weight of SiO2 and 4 parts by weight of Al2O3 were mixed, the mixed raw materials were placed in a platinum crucible and fired at 1450 ° C for 8 hours, and then in the air. Quench. When the quenched raw materials reach room temperature, they are placed in a ball mill and ball milled under wet conditions for 72 hours. At this time, the solvent used was ethanol because water can not be used. After drying the pulverized raw material, the sieve was filtered to remove particles having a particle diameter of 5 μm or more, and a predetermined amount of barium sulfate was added thereto, followed by sufficient stirring to form a homogeneous mixture, thereby preparing a root canal filler powder. Thus prepared powder was quantitatively analyzed using PW 1710 of Philips, The Netherlands. At this time, the measurement conditions were 2θ = 5 to 60 °, scan speed = 4 ° / min, Target = Cukα1, acceleration voltage 40kV, and 30mA. In addition, the particle size of the root canal filler was analyzed by Malvern's Mastersizer S, Ver. 2.15. In addition, the size of the particles was analyzed by scanning electron microscopy of the root canal filler powder, and curing of the root canal filler particles was performed using a laser displacement sensor MICRO TRACK 7000 manufactured by Mechanical Technology Inc. of the United States. The rate of change in length over time was measured. In addition, the content of residual CaO contained in the prepared powder was measured according to KSL 5120.

<Example 2>

Example 2 uses the same raw materials as in Example 1, but changed the mixing ratio of the raw materials. CaO was weighed and mixed with 68 parts by weight, 26 parts by weight of SiO2, and 6 parts by weight of Al2O3, and the obtained raw material was placed in a platinum crucible and calcined at 1450 ° C for 8 hours, followed by quenching in air. When the quenched raw materials reach room temperature, they are placed in a ball mill and ball milled under wet conditions for 72 hours. In this case, ethanol was used in the same manner as in Example 1. As in Example 1, the pulverized raw material was dried, sieved, and a predetermined amount of barium sulfate was added thereto, followed by sufficiently stirring to uniformly mix, thereby preparing a root canal filler powder. The physical properties and properties of the prepared filler were evaluated in the same manner as in Example 1.

<Example 3>

The root canal filler material composition used in Example 1 was prepared with a ball milling time of 24 hours after firing. Except for the ball milling time, the manufacturing method was the same as in Example 1, and the characteristics of the fillers prepared in the same manner were evaluated.

Comparative Example

For comparison with the examples, commercial ProRoot MTA (DENTSPLY, USA) was subjected to QXRD analysis, particle size measurement, and scanning electron microscopy. Similarly, the length change rate with curing time was measured, and the amount of residual CaO was analyzed. .

4 to 7 are photographs taken by electron microscope of filler powders of Examples 1, 2, 3 and Comparative Example 1, respectively. As can be seen from the photograph, it can be seen that the filler powder of the example is smaller in particle size and uniform in size than the comparative example. In addition, the filler powder of the Example it can be seen that the sphericity of the powder is relatively higher than the comparative example.

Table 1 below is a table showing the results of quantitative analysis of the residual CaO content of Examples 1 to 3 and Comparative Examples.

Example 1 Example 2 Example 3 Comparative example Residual CaO (wt%) 0.66 0.84 0.89 1.74

From the above table it can be seen that the residual CaO content of the embodiments of the present invention is 1% by weight or less by weight of the composition. This shows a residual CaO content of about 1/2 or less as compared to 1.74 wt% for the comparative example.

On the other hand, the present invention is characterized in that the content of crystalline components in the filler composition is very high because the residual CaO content is low and the impurities of the starting raw material are low.

8 and 9 are QXRD analysis graphs of Example 1 and Comparative Example 1, respectively. The content of the components of 3CaO · SiO 2, 2CaO · SiO 2, and 3CaO · Al 2 O 3 obtained from this graph is shown in the following table.

division Example 1 Comparative Example 1 3CaOSiO2 76 66  2CaOSiO2 12 7 3CaOAl2O3 8 20 Sum 96 93

From the above table it can be seen that the content of more crystalline components produced in the embodiment of the present invention.

Table 3 below shows the average particle size obtained by particle size analysis of the root canal filler in Examples and Comparative Examples.

division Example 1 Example 2 Example 3 Comparative example Average particle size (㎛) 1.1 1.6 2.0 6.9

As can be seen in the above table, the root canal fillers of the examples all show a lower particle diameter than the comparative example.

Table 4 below is a table showing the results of measuring the change in length according to the curing time of Examples and Comparative Examples.

As can be seen in the above table, the root canal fillers of the Example was found to have a very low rate of change in length over 28 days compared to the comparative example. This is presumed to be due to the embodiments of the present invention having a low CaO content.

Root canal seal test (Sealing Effectiveness Test)

Experimental Example 1 (in the case of using a ttaperture and a sealer)

Root canal filling experiments were performed using a conventional Gutta percha (trade name: Gutta percha point manufacturer: Metabiomed) ZOE sealer (trade name: ZOBSEAL manufacturer: Metabiomed). First, the root canal was enlarged according to the method of the test subject, and the root canal filling was performed with a gataperture and a sealer. After filling the root canal, the root end 2mm was immersed in the dye and immersed for 6 hours and dried. The dried teeth were sliced at the root portion of 1mm / 2mm /..../ 10mm, and the cross sections of each slice were observed with a digital light microscope. Observation was carried out at a magnification of 200 times.

10 to 17 are optical micrographs taken in the cross section of each section from the root end 1 mm to 8 mm. Penetration and diffusion of the dye were confirmed from the photograph to the root region of 8 mm. As such, it can be seen that the conventional root filling material composed of the gataperture and the sealer has a colorant permeation occurring 6 hours after the root canal filling, and it shows that there is no root seal up to the root length of 8 mm.

Experimental Example 2

Root canal filling was performed using Pro Root MTA (manufacturer). In the root canal filling method, the mixture was mixed at a ratio of 1: 1 by weight with distilled water, and then centrifuged in a centrifuge. However, the root was immersed in the dye for 48 hours and the cross section was observed.

18 to 26 are optical micrographs observing the cross section of each section at intervals of 1 mm from the root end.

First, in FIG. 18, it can be seen that a space that is not sealed at the root portion 1 mm is observed, and the penetration of the space and the dye that is not sealed at the root end 2 mm to 3 mm is shown (FIGS. 19 and 20), and the root length 4 mm to 9 mm. It can be seen that the space which is not sealed is observed in FIGS. 21 to 26.

Experimental Example 3

Root canal filling was performed with the filler prepared according to Example 3 of the present invention in the same manner as in Experiment 2. At this time, no contrast agent was used. 27 to 34 are optical micrographs observing the cross section of each section at 1 mm intervals from the root end. A small amount of dye penetration was observed near the root end of 1 mm (Fig. 27), but no dye penetration was observed from the root end of 2 mm (Figs. 28 to 34), indicating excellent sealing properties.

Experimental Example 4

Root canal filling was performed in the same manner as Experimental Example 3 with the filler prepared in Example 1. 35 to 43 are optical micrographs observing the cross section of each section from the root end 1mm to the root end 9mm. A slight staining of the dye was observed around 1 mm of the apical root (FIG. 35), but it was not observed from 2 mm of the apical root, indicating a very good sealing property.

In order to use it as a root canal filler, it is desirable to exhibit complete sealing at the root portion of 3 mm. However, it has been found that conventional fillers such as GATAPERPER + SEALER and PRORUUT are not suitable for root canal filling due to insufficient sealing. This is thought to be due to the fact that the proroot has an average particle size of about 5 μm and does not have a uniform particle size. In particular, it has the disadvantage of creating a space where bacteria can inhabit the root portion of the root of the tooth 3mm, the root end of the tooth, as a result can not improve the success rate of root canal treatment. However, the filler according to the present invention maintains an average particle size of 2 μm or less, and has a uniform particle size, so the sealing effect is excellent for the root end 3 mm and there is no space in the root canal after the root canal filling. As a result, clinical success can improve the success rate of neurotherapy. This is because the space created in the root canal is a place for the growth of anaerobic bacteria and an area where antibiotics cannot be reached.

In the case of the proroot, when the root canal recharge was accompanied with a surgical procedure called root apectomy, a large sized vortex of 1 mm in depth and 3 mm in diameter was sufficient to fill and fill the cavity, but during orthograde filling during conservative treatment It is speculated that the particle size is too large to fill and seal the fine root canal with a diameter of 0.25 mm to 0.35 mm. In other words, the Pro Root product has an average particle size of more than 5 ㎛ and the standard deviation of the average particle size is so large that coarse particles are difficult to handle during the root canal sealing process. It is understood that satisfactory root canal sealing effect cannot be obtained.

1 is a photograph illustrating a lateral compression method, which is one of conservative root canal treatments.

FIG. 2 is a diagram for explaining a vertical compression method which is another method of conservative root canal treatment.

3 is a series of diagrams for explaining surgical root canal treatment.

4 to 7 are photographs taken by electron microscope of filler powders of Examples 1, 2, 3 and Comparative Example 1, respectively.

8 and 9 are QXRD analysis graphs of Example 1 and Comparative Example 1.

10 to 17 are optical micrographs taken in the cross section of each section from the root end 1 mm to 8 mm area according to Experimental Example 1.

18 to 26 are optical micrographs observing the cross section of each section from the root root 1mm to the root root 10mm in accordance with Experimental Example 2.

27 to 34 are optical micrographs observing the cross section of each section from the root root 1mm to the root root 8mm in accordance with Experimental Example 3.

35 to 43 are optical micrographs observing the cross section of each section from the root end 1mm to the root end 9mm in accordance with Experimental Example 4.

Claims (7)

A CaO-SiO2-Al2O3 compound, the particle size of which is less than 5 microns, including 3CaOSiO2, 2CaOSiO2, 3CaOAl2O3, and the content of the three compositions is 95% by weight based on the total weight of the CaO-SiO2-Al2O3 compound CaO-SiO ₂ -Al ₂ O ₃ -based powder type MTA root canal filling material characterized in that the above. delete delete delete delete delete delete

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