KR20120016432A - Root canal retro-filling portland composite - Google Patents

Abstract

PURPOSE: A root canal retro-filling portland cement composition is provided to ensure convenience and radiopacity and to properly control mixing ratio. CONSTITUTION: A root canal retro-filling portland cement composition contains: 30-35 wt% of Portland cement, 12-15 wt% of epoxy resin, 15-25 wt% of epoxy resin hardener, and 30-40 wt% of radiation contrast media. The epoxy resin is bisphenol A epoxy or bisphenol F epoxy. The epoxy resin hardener is polyamide resin. The radiation contrast media contain barium sulfate or bismuth oxide. The composition further contains calcium chloride, calcium nitride/nitrate, or calcium formate.

Description

Root canal reverse filling Portland cement composition {ROOT CANAL RETRO-FILLING PORTLAND COMPOSITE}

The present invention relates to a root canal reverse filling Portland cement composition, and more particularly, to prevent microleakage of the root canal reverse filling and to maintain the biomechanical and biological physical properties of the root canal filling material while improving clinical application efficiency. It relates to a backfilled Portland cement composition.

Endodontics is a specific field of dentistry that involves the treatment of dental pulp and pathoses of the root apical tissue. Teeth are called 'dimensions' of nerves and blood vessels located inside the dentin covering the dimensions, the outermost is composed of hard enamel tissue. Root canal treatment is performed when the pulp tissue, which contains nerves and blood vessels in the teeth, is infected or inflamed.

Root canal treatment of pulp tissue with inflamed or advanced necrosis caused by necrosis usually involves an internal cavity of the tooth called the pulp chamber through an access cavity formed in the crown. This can be done by opening the endodontic instruments and entering the root canal inside the root. Occasionally, in order to maintain a tooth if the general root canal treatment process has not been successful or failed, or if the non-surgical (non-surgical) treatment cannot remove the infected tissue due to the condition or condition of the tooth. Try surgical endodontic surgery. The most common practice is to cut the root end of the tooth (apicoectomy) and attempt to fill it with artificial material by forming a backfill cavity at the end.

This process prevents tissues or bacteria present in the infected root canal from spreading to the tissues around the roots of the teeth (peripheral tissue) to prevent inflammation of the surrounding tissues and to maintain the teeth for a long time. At this time, a variety of materials have been used as the root reversal filling material, and various biological and physical evaluations have been made, and various alternative materials have been developed and used at the same time.

    Gutta-perch, Polycarboxylate cement, Amalgam, super-EBA, Cavit, Zinc-oxide, Yugenol Many materials have been used, including Eugenol, glass-ionomer cement, zinc phosphate cement, and the like. Some of these backfilling materials have been reported to be less physically compatible for use in surgical environments where biocompatibility or blood or other moisture is present.

MTA (Mineral Trioxide Aggregate) cement, which was introduced in 1993 as a root filling material and a closure material for perforations, has been widely applied in various clinical fields as a useful dental material suitable for the purpose of the procedure. The superior sealing effect and biocompatibility of MTA have been demonstrated in various studies, and the advantages of MTA are that MTA can be used for pulp capping, pulpotomy and apexification, as well as for apical reversal and perforation closure. It is a representative dental material used for procedures such as barrier placement, revascularization and apexogenesis procedures.

However, MTA has a problem in that it is not easy to be popularized by clinicians because it is a problem of relatively long curing time and disadvantageous operability in clinical application. Depending on the manufacturer, the curing time for ProRoot MTA (Dentsply Maillefer, USA) is 4-6 hours, but other studies report that it can range from 75 minutes to 4 hours and even 72 hours. This long hardening time requires additional visits of patients in clinical applications for radical occlusion and dimensional demodulation, and especially in the case of root acupoint surgery, which requires exposure to tissue fluid or blood. Alternatively, the phenomenon of flowing down may occur, which may cause failure by micro leakage.

Many clinicians also agree that it is difficult to apply MTA mixed with the manufacturer's recommendation 3: 1 powder: liquid ratio to the near-end backfill vortex. In order to overcome the shortcomings of the MTA, the promotion of curing time by various additives, the development of an application mechanism, the development of new substitutes, etc. are continuously researched and published.

A commonly attempted method is to add a curing accelerator to the MTA. Significant reduction in curing time has been reported when MTA is added to the Portland cement curing accelerators, Calcium chloride, Calcium nitrite and Calcium formate.

Another study reported that the 15% Disodium hydrogen orthophosphate (Na ₂ HPO ₄ ) liquid was mixed with MTA, indicating a successful shortening of curing time without any change in physical properties. However, these methods do not provide convenient operability other than curing time or have been clearly developed as a completely substitute material.

The present invention is to solve the above problems, it is an object of the present invention to provide a composite composition using Portland cement and epoxy resin (resin) as a material that can overcome the disadvantages of MTA as a root tooth backfill material. .

It is also an object of the present invention to provide a root canal reverse filling method using the composite composition.

In order to achieve the above object, the present invention

30 to 35 weight percent of Portland Cement;

12 to 15 weight percent epoxy resin;

15 to 25 wt% epoxy resin curing agent; And

It provides a root canal backfill Portland cement composition comprising 30 to 40% by weight of the radiographic contrast agent.

In order to achieve the above another object, the present invention

Mixing the root canal backfill Portland cement composition; And

It provides a root canal backfill method using a root canal backfill Portland cement composition comprising the step of injecting and filling the mixed compound with a dental syringe.

The composite composition of the present invention can be given the convenience that can be applied to the reverse charge vortex by the injection method by using the epoxy resin, and to have an appropriate radiopacity prevention effect by mixing the radio contrast agent, and at the same time excellent micro-leakage prevention effect By appropriately adjusting the mixing ratio, a root canal reverse filling Portland cement composition having excellent properties such as curing time, radiation impermeability, and the like can be obtained.

1A and 1B show experimental specimens and radiopacity, respectively, showing microleakage differences according to Example 1 of the present invention.
2A and 2B show experimental specimens and radiopacity, respectively, showing microleakage differences according to Example 2 of the present invention.
3A and 3B show experimental specimens and radiopacity, respectively, showing microleakage differences according to Example 3 of the present invention.
Figure 4 shows an experimental specimen showing a microleakage difference according to Comparative Example 1 of the present invention.
5 shows an experimental specimen showing a microleakage difference according to Comparative Example 2 of the present invention.
6 shows an experimental specimen showing a microleakage difference according to Comparative Example 3 of the present invention.
7 illustrates an experimental specimen showing a microleakage difference according to Comparative Example 4 of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

30 to 35% by weight of the Portland cement; 12 to 15 weight percent epoxy resin; 15 to 25 wt% epoxy resin curing agent; And it provides a root canal backfill Portland cement composition comprising 30 to 40% by weight of the contrast medium.

Existing MTA has a problem that it is too expensive material. For this reason, many studies have reported that Portland cement, which is similar in chemical composition to MTA, is used as an alternative to MTA, and that Portland cement is similar to Portland cement in terms of biocompatibility. It became.

The alkaline component of Portland cement aids bacteriostatic action and does not interfere with cell regeneration with biotissue compatibility in the surrounding tissues of the application site. Portland cement of the present invention comprises one cement, usually Portland cement, in order to minimize possible cytotoxicity and increase biocompatibility.

Epoxy resins are used as substrates to filler Portland cement powders, and the mixtures will have adequate consistency and flowability that can be applied by injection methods. Specifically, the epoxy resin is preferably bisphenol A epoxy or bisphenol F epoxy.

An epoxy resin curing agent is used to cure an epoxy resin as a main material, and the epoxy resin curing agent may be a polyamide resin, a modified polyamide resin, a modified epoxy, or the like, and preferably a polyamide resin may be used.

Radiographic agents impart radiopacity to allow observation of material in radiographs and provide sufficient opacity to distinguish the dentin. In addition, by controlling the consistency, it is possible to minimize the backfill material from being washed into the tissue during the initial curing reaction after application to the clinical procedure. The radiocontrast agent preferably contains at least one selected from barium sulfate and bismuth oxide.

The composite composition of the present invention may optionally further include an accelerator, and may further include one or more selected from the group consisting of calcium chloride, calcium nitride / nitrate, and calcium formate as accelerators.

The proportion of each component of the composition in the present invention can be adjusted and applied according to the physical properties required. The content of portland cement is preferably 30 to 35% by weight. If the content of the Portland cement exceeds 35% by weight, improper mixing process is performed due to excessive increase in consistency, and it is not preferable because defects such as bubble mixing may occur and micro leakage may occur, and the content of Portland Cement is 30 If it is less than the weight%, it is not preferable because the biocompatibility obtained from the first Portland cement may not be sufficient, and the toxic effect by the organic component of the epoxy resin may be exhibited.

The content of the epoxy resin is 12 to 15% by weight, the content of the epoxy resin curing agent is preferably 15 to 25% by weight. In this case, when the content of the epoxy resin exceeds 15% by weight, the viscosity is lowered and flowability is improved, but initial curing is delayed. The delay of the curing time can be controlled by increasing the content of the curing agent of the epoxy resin, but can be relatively low biocompatibility. On the contrary, when the content of the epoxy resin is less than 12% by weight, the initial curing becomes faster due to the increase of the relative curing agent ratio, but it is not preferable because the flow rate deteriorates as the cement powder ratio increases and the viscosity increases in the total content.

The content of the radiocontrast is preferably 30 to 40% by weight. If the content of the radiographic contrast agent is less than 30% by weight, there is a problem in the radiopacity problem, and if it exceeds 40% by weight it is not preferable because the fine leakage occurs by reducing the content of portland cement and the like.

In addition, in the present invention, the content of Portland cement and radiographic contrast agent is correlated with each other. If the content of Portland cement is high, the amount of radiocontrast not too high will maintain adequate clinical efficiency. In other words, if the content of both the portland cement and the radiocontrast is high, the powder content is excessive, and thus it is not preferable because the complete curing may be delayed or the long density with the root end reverse filling cavity wall may be reduced (increase in fine leakage). In view of this, it is desirable to adjust the total weight of Portland cement and radiographic contrast agent to no more than 70%.

Portland epoxy composites according to the present invention showed significantly less microleakage than when using MTA alone. This is due to the fact that sufficient pressurization was possible after injection filling by improved operability and its own closing effect.

The long curing time is a problem of wash-out of the filled material due to the nature of the root filling material which needs to be exposed to tissue fluid and blood for a long time, and many studies and attempts have been made to overcome it.

The material of the present invention showed a relatively very short curing time in comparison with the conventional backfill material MTA in both initial curing time and final curing time, which can be a great advantage in clinical applications.

Most dental materials are recommended to have radiopacity higher than that of dentin and are generally required to be at least 2mmAl. The composite according to the present invention satisfies the conditions imparted to conventional dental materials and has a degree of opacity similar to that of MTA, which is sufficient to distinguish the radiograph from clinical practice.

With the main formulation of the cement of the present invention, the radiocontrast at the total weight of the Portland cement and the epoxy component may be further added as needed and at the same time may be a means of controlling some consistency.

Due to the nature of the apical surgical procedure, the field of view is narrow and the accessibility of the instrument is limited, and the operability of materials used in these areas is a very important factor in clinical use.

According to another aspect of the invention, Portland cement 30 to 35% by weight; 12 to 15 weight percent epoxy resin; 15 to 25 wt% epoxy resin curing agent; And mixing the root canal backfill Portland cement composition comprising 30 to 40% by weight of a radiographic agent; And injecting and filling the mixture into a dental syringe.

MTA, which is a conventional material, is difficult to control viscosity by using cement powder or moisture, and is poor in operability. Various apparatuses are used to fill the backfill vortex, and the composition according to the present invention can be filled with the backfill vortex using a simple injection device (used to use a dedicated or existing dental syringe), and then injected using the backfill vortex. Pressurization finishing using alcohol noodles or the like has easy operability. This process results in an increase in closing force.

Injection syringes may be used for filling the composite material of the present invention, and the syringes may have a conventional paste injection syringe form, and may be applied to various types of dental syringes (eg, Centrix syringes).

Hereinafter, the present invention will be described with reference to Examples, which are merely exemplary and the present invention is not limited or limited to the following Examples.

Example

Example 1

33% by weight of Portland cement, 13% by weight of epoxy resin (Dongyang Epoxy Co., Ltd., product name: DY-123), 19% by weight of polyamide curing agent (product name: DY-123); And a root canal backfill Portland cement composite comprising 35% by weight of barium sulphate.

The Portland cement composites were applied using toothed teeth with tooth root formation complete. In order to reproduce the clinical situation, the root canal was measured, and the root canal molding was performed, followed by filling the root canal by the continuous wave of condensation technique using a thermoplastic gatapercha. Root canal cavities were filled with autopolymerized glass ionomer cement. The proximal end was cut by 3 mm, and a back filling cavity having a depth of 3 mm was formed, and then the composite material, which was mixed according to the embodiment, was back charged by the injection method.

Example 2

Root canal backfill Portland cement composites containing 35 wt% Portland cement; 12 weight% of epoxy resin (Purchase: Dongyang Epoxy Co., Ltd., product name: DY-123); 18 wt% of an epoxy resin curing agent (trade name: DY-123); And it was carried out in the same manner as in Example 1 except that it consists of 35% by weight of barium sulfate.

Example 3

Root canal backfill Portland cement composites comprising 30% by weight of Portland cement; 15 weight% of epoxy resin (Purchase: Dongyang Epoxy Co., Ltd., product name: DY-123); 25% by weight of an epoxy resin curing agent (product name: DY-123); And it was carried out in the same manner as in Example 1 except that it consists of 30% by weight of barium sulfate.

Comparative Example 1

MTA (Mineral Trioxide Aggregate) was mixed with powder: liquid = 3: 1 and the root canal plugger was used to fill the root cavities. All root root vortices were finished using cotton balls soaked in sterile distilled water.

Comparative Example 2

A mixture of MTA (Mineral Trioxide Aggregate) and AH-plus root canal sealer (1: 1 wt. Ratio), an epoxy resin root canal filling sealer, was injected and filled using a dental syringe for filling and vertically pressurized using a hand plugger. The excess filling was then removed using alcohol cotton.

Comparative Example 3

Portland cement 38% by weight; 13 weight% of epoxy resin (Purchase: Dongyang Epoxy Co., Ltd., product name: DY-123); 15 wt% of an epoxy resin curing agent (trade name: DY-123); And a root canal backfilled Portland cement composite comprising 34% by weight of barium sulphate.

Comparative Example 4

Portland cement 37% by weight; 11 weight% of epoxy resin (Purchase: Dongyang Epoxy Co., Ltd., product name: DY-123); 10 wt% of an epoxy resin curing agent (trade name: DY-123); And a canal backfill Portland cement composite comprising 42% by weight of barium sulphate.

Assessment Methods

Microleakage evaluation

All of the experimental groups in which the reverse charging was completed were covered with wet gauze at room temperature and cured in an airtight container for curing of the reverse charging material. After storage for 24 hours, it was immersed in 1% Methylene blue solution for 72 hours. After the roots have been cleaned and dried, use a low-speed diamond disk to separate the root end at least 5 mm in the longitudinal direction of the tooth to terminate the near-end refilling material, and then cut the coronal section of the cut area perpendicular to the long axis of the tooth and fracture. Produced. In order to evaluate the near-term microleakage, the cutting surface of each specimen was photographed using a digital camera.

The microleakage was evaluated for leakage along the vertical wall of the backfill vortex, where there was no vertical leakage, 0 points, 1 point within 1mm, 2 points for 1-2mm, 3 points for 2-3mm, vortex shaft wall In the case of pigmentation over the proximal end of the distal filling of the proximal end, the score was assigned to 4 points and evaluated.

Curing time evaluation

The curing time of each material was measured using a custom-made Vicat apparatus. A Vicat needle with a diameter of 1 mm was used, and a press load was applied to the specimen with a weight of 300 g. The experimental group was prepared by the same method applied to the reverse charging, and the degree of curing was evaluated at intervals of 5 minutes from the completion of the mixing.

The initial setting time was determined as the time for the vicat needle to start sinking to a depth within 5 mm. The final curing time was the time when no indentation was caused by the vicat needle on the surface of the blend. (final setting time) was recorded. Specimens were kept in a confined space except for measurement time so that curing time difference due to atmospheric humidity (dryness) did not appear.

radiation Opacity  evaluation

Each material was mixed according to the experimental ratio and filled into a custom-made metal washer with a thickness of 1 mm and an inner diameter of 8 mm to prepare a radiopacity test specimen. Three fully cured specimens were made, and radiographs were taken with aluminum step wedges (1 mm to 10 mm thick) made from pure aluminum. A digital X-ray sensor (Schick technology Inc., Long Island City, NY, USA) was used to shoot at 10 cm from the specimen under 60 Kv, 2 mA, 0.08 second exposure time. Digital X-ray images were evaluated with aluminum wedge equivalent thickness (mmAl) using a Photoshop program (Adobe photoshop 7.0; Adobe systems Incorporated, San Jose, Calif., USA).

Evaluation results

Microleakage

Example 1 showed very low microleakage, which is shown in FIG. 1A and can be confirmed with reference to FIG. 1A. Example 2 showed a considerably high consistency at the time of mixing, and the results of microleakage are shown in FIG. 2A and the results of impermeability in FIG. 2B, respectively. 2A and 2B, no microleakage occurred, and the radiopacity was found to be appropriate. In Example 3, the mixing process was relatively easy, and the results of microleakage are shown in FIG. 3A and the results of impermeability in FIG. 3B, respectively. 3A and 3B, no microleakage occurred and the radiopacity was found to be appropriate.

In Comparative Example 1, a microleak was generated to some extent, which is illustrated in FIG. 4A, which can be confirmed by referring to FIG. 4A. In Comparative Example 2, microleakage did not occur, which is illustrated in FIG. 5, which can be confirmed with reference to FIG. 5. Comparative Example 3 shows that defects such as bubble mixing may occur due to excessive increase in consistency. The microleakage test results are shown in FIG. 6, and microleakage did not occur in the photograph, but may cause a lot of leakage depending on the location of the bubble defect. In Comparative Example 4, the operability was reduced due to excessive consistency, and the injection was not smooth. Referring to FIG. 7, it can be seen that microleakage occurs between the backfill vortex wall.

The experimental results (average) of the microleakage according to Example 1-3 and Comparative Example 1-4 are shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Microleakage
Result (point) 1.0 1.0 0.8 2.8 0.8 1.8 2.3

Referring to Table 1, the microleakage test results showed that the composite material of the Example showed significantly less microleakage. This result seems to be due to the fact that sufficient pressurization was possible after injection filling due to the improved operability and the self-closing effect of the epoxy resin, and is suitable for clinical use of the material of the present invention.

Curing time

Example 1 showed a final curing time of 83 minutes. The final curing time took about 10 hours for Comparative Example 1 and about 7 hours for Comparative Example 2. Portland epoxy composite cement, a material of the present invention, exhibited a relatively very short curing time of less than 100 minutes in Examples 1-3, which can be a great advantage in clinical applications.

radiation Opacity

Examples of radiographs measuring aluminum equivalent radiopacity of Examples and Comparative Examples are shown in FIGS. 1B, 2B, 3B, and 4B.

Example 1 showed an impermeability of 5.2 mmAl, Example 2 6 mmAl, and Example 3 showed 5.0 mmAl impermeability. On the other hand, Comparative Example 1 exhibited an impermeability of 5.7 mmAl, Comparative Example 2 of 9.7 mmAl, Comparative Example 3 of 5 mmAl, and Comparative Example 4 of 6.2 mmAl.

The radiopacity of this example was similar to that of MTA (5-6mm Aluminum thickness), and it can be confirmed that it is sufficient to distinguish it on a radiograph in clinical practice.

From the above results, the root canal reverse filling Portland cement composition used in the present invention exhibits suitable results in both microleak blocking, curing time, and radiation impermeability, and functionally ensures operability for reverse filling and at the same time improves microleak containment. You can see that it can be obtained.

Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (7)

30 to 35 weight percent of Portland Cement;
12 to 15 weight percent epoxy resin;
15 to 25 wt% epoxy resin curing agent; And
Root canal backfill Portland cement composition comprising 30 to 40% by weight of a radiographic agent.
The method of claim 1,
The epoxy resin is a root canal backfill Portland cement composition, characterized in that the bisphenol A epoxy or bisphenol F epoxy.
The method of claim 1,
The root canal backfill Portland cement composition, wherein the epoxy resin curing agent is a polyamide resin.
The method of claim 1,
And the radiographic agent comprises at least one selected from barium sulphate and bismuth oxide.
The method of claim 1,
Root canal backfill Portland cement composition, characterized in that the composition further comprises one or more selected from the group consisting of calcium chloride, calcium nitride / nitrate, and calcium formate as an accelerator.
The method of claim 1,
Root canal backfill Portland cement composition, characterized in that the content of the Portland cement and radiographic contrast agent is 70% by weight or less.
Mixing the root canal backfill Portland cement composition according to any one of claims 1 to 6; And
Root canal backfill method using the root canal backfill Portland cement composition comprising the step of filling the mixture into a dental syringe.

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