• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.149-151
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• 2010

Since its introduction in 1993, Mineral Trioxide Aggregate (MTA) has been shown to be superior to others in sealing, biocompatibility, and many other aspects of clinical endodontics. MTA is primarily Portland cement with bismuth oxide as a radiopacitifier. Although some studies suggested that the reasonable-priced Portland cement could be used instead of MTA, but MTAs are different from Portland cement in its composition, especially in heavy metal contents. Therefore, clinicians should be meticulous adapting the Portland cement as a MTA substitute.

• Restorative Dentistry and Endodontics
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• v.37 no.4
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• pp.188-193
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• 2012

Mineral trioxide aggregate (MTA) was developed in early 1990s and has been successfully used for root perforation repair, root end filling, and one-visit apexification. MTA is composed mainly of tricalcium silicate and dicalcium silicate. When MTA is hydrated, calcium silicate hydrate (CSH) and calcium hydroxide is formed. Formed calcium hydroxide interacts with the phosphate ion in body fluid and form amorphous calcium phosphate (ACP) which finally transforms into calcium deficient hydroxyapatite (CDHA). These mineral precipitate were reported to form the MTA-dentin interfacial layer which enhances the sealing ability of MTA. Clinically, the use of zinc oxide euginol (ZOE) based materials may retard the setting of MTA. Also, the use of acids or contact with excessive blood should be avoided before complete set of MTA, because these conditions could adversely affect the hydration reaction of MTA. Further studies on the chemical nature of MTA hydration reaction are needed.

• Journal of Periodontal and Implant Science
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• v.39 no.3
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• pp.359-365
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• 2009

Purpose: The purpose of this study was to investigate the ability of Mineral trioxide aggregate(MTA) to support osteoclastic differentiation from fetal rat calvarial cell. Methods: In this study, response of IL-6, RANKL, and OPG in fetal rat calvarial cells stimulated with IL-$1{\beta}$ on MTA was evaluated by ELISA and RT-PCR. Results: The results were as follows; there was no significant difference between glass and MTA at 5days. In ELISA analysis, Glass group and MTA group showed similar IL-6 expression, Glass+IL-$1{\beta}$ group and MTA+IL-$1{\beta}$ group showed similar IL-6 expression. In RT-PCR analysis, Glass group and MTA group showed similar IL-6, RANKL, OPG mRNA expression, MTA+IL-$1{\beta}$ group and Glass+IL-$1{\beta}$ group showed 3 fold increase of IL-6 and RNAKL mRNA expression when compared with MTA group. All groups showed similar OPG mRNA expression. Conclusions: MTA does not suppress cell proliferation and increase the proinflammatory cytokine that induce osteoclastogenesis. Thus, MTA is biocompatible material that could be used in various clinical conditions.

• Restorative Dentistry and Endodontics
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• v.35 no.5
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• pp.344-352
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• 2010

Objectives: The purpose of this study was to determine the setting time, compressive strength, solubility, and pH of mineral trioxide aggregate (MTA) mixed with glass ionomer cement (GIC) and to compare these properties with those of MTA, GIC, IRM, and SuperEBA. Materials and Methods: Setting time, compressive strength, and solubility were determined according to the ISO 9917 or 6876 method. The pH of the test materials was determined using a pH meter with specified electrode for solid specimen. Results: The setting time of MTA mixed with GIC was significantly shorter than that of MTA. Compressive strength of MTA mixed with GIC was significantly lower than that of other materials at all time points for 7 days. Solubility of 1 : 1 and 2 : 1 specimen from MTA mixed with GIC was significantly higher than that of other materials. Solubility of 1 : 2 specimen was similar to that of MTA. The pH of MTA mixed with GIC was 2-4 immediately after mixing and increased to 5-7 after 1 day. Conclusions: The setting time of MTA mixed with GIC was improved compared with MTA. However, other properties such as compressive strength and pH proved to be inferior to those of MTA. To be clinically feasible, further investigation is necessary to find the proper mixing ratio in order to improve the drawbacks of MTA without impairing the pre-existing advantages and to assess the biocompatibility.

• Restorative Dentistry and Endodontics
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• v.35 no.5
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• pp.359-367
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• 2010

Objectives: The purpose of the present in vitro study was to evaluate the biocompatibility of mineral trioxide aggregate (MTA) mixed with glass ionomer cement (GIC), and to compare it with that of MTA, GIC, IRM and SuperEBA. Materials and Methods: Experimental groups were divided into 3 groups such as 1 : 1, 2 : 1, and 1 : 2 groups depending on the mixing ratios of MTA powder and GIC powder. Instead of distilled water, GIC liquid was mixed with the powder. This study was carried out using MG-63 cells derived from human osteosarcoma. They were incubated for 1 day on the surfaces of disc samples and examined by scanning electron microscopy. To evaluate the cytotoxicity of test materials quantitatively, XTT assay was used. The cells were exposed to the extracts and incubated. Cell viability was recorded by measuring the optical density of each test well in reference to controls. Results: The SEM revealed that elongated, dense, and almost confluent cells were observed in the cultures of MTA mixed with GIC, MTA and GIC. On the contrary, cells on the surface of IRM or SuperEBA were round in shape. In XTT assay, cell viability of MTA mixed with GIC group was similar to that of MTA or GIC at all time points. IRM and SuperEBA showed significantly lower cell viability than other groups at all time points (p < 0.05). Conclusions: In this research MTA mixed with GIC showed similar cellular responses as MTA and GIC. It suggests that MTA mixed with GIC has good biocompatibility like MTA and GIC.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.700-708
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• 2001

Traumatic injuries in young patients can result in the interruption of the development of the incompletely formed roots. In teeth with incomplete root-end formation and necrotic pulps, the root canals must be completely debrided. Because of a lack of an apical stop and the presence of thin and fragile walls in these teeth, it is imperative to perform apexification to obtain an adequate apical seal. Calcium hydroxide has become the material of choice for apexification. Despite its popularity for the apexification procedure, calcium hydroxide therapy has some inherent disadvantages that include variablility of treatment time, unpredictability of apical closure, difficulty in patient follow-up, and delayed treatment. An alternative treatment to long-term apexification procedure is the use of an artificial apical barrier that allows immediate obturation of the canal. MTA(Mineral Trioxide Aggregate) is a powder consisting of fine hydrophilic particles of tricalcium silicate, tricalcium aluminate, tricalcium oxide and silicate oxide. MTA has a pH of 12.5 after setting, similar to calcium hydroxide. This may impart some antimicrobial properties. MTA has low solubility and a radiopacity slightly eater than that of dentin. Also, MTA leaked significantly less than other materials and induced hard-tissue formation more than other materials.

• Restorative Dentistry and Endodontics
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• v.37 no.4
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• pp.194-200
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• 2012

Objectives: New resin cement (NRC) has been developed as a root repairing material and the material is composed of organic resin matrix and inorganic powders. The aim of this study was to compare the rat subcutaneous tissue response to NRC and mineral trioxide aggregate (MTA) cement and to investigate the tissue toxicity of both materials. Materials and Methods: Sixty rats received two polyethylene tube-implants in dorsal subcutaneous regions, MTA and NRC specimens. Twenty rats were sacrificed respectively at 1, 4 and 8 wk after implantation and sectioned to 5 ${\mu}m$ thickness and stained with Hematoxylin-Eosin (H-E) or von-Kossa staining. The condition of tissue adjacent to the implanted materials and the extent of inflammation to each implant were evaluated by two examiners who were unaware of the type of implanted materials in the tissues. Data were statistically analyzed with paired t-test (p < 0.05). Results: In specimens implanted with both NRC and MTA, severe inflammatory reactions were present at one wk, which decreased with time. At eighth wk, MTA implanted tissue showed mild inflammatory reaction, while there were moderate inflammatory reactions in NRC implanted tissue, respectively. In NRC group, von-Kossa staining showed more calcification materials than MTA group at eighth wk. Conclusions: It was concluded that the calcium reservoir capability of NRC may contribute to mineralization of the tissues.

• Restorative Dentistry and Endodontics
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• v.39 no.3
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• pp.187-194
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• 2014

Objectives: The effects of bone morphogenetic protein-2 (BMP-2) and enamel matrix derivative (EMD) respectively with mineral trioxide aggregate (MTA) on hard tissue regeneration have been investigated in previous studies. This study aimed to compare the osteogenic effects of MTA/BMP-2 and MTA/EMD treatment in MC3T3-E1 cells. Materials and Methods: MC3T3-E1 cells were treated with MTA (ProRoot, Dentsply), BMP-2 (R&D Systems), EMD (Emdogain, Straumann) separately and MTA/BMP-2 or MTA/EMD combination. Mineralization was evaluated by staining the calcium deposits with alkaline phosphatase (ALP, Sigma-Aldrich) and Alizarin red (Sigma-Aldrich). The effects on the osteoblast differentiation were evaluated by the expressions of osteogenic markers, including ALP, bone sialoprotein (BSP), osteocalcin (OCN), osteopontin (OPN) and osteonectin (OSN), as determined by reverse-transcription polymerase chain reaction analysis (RT-PCR, AccuPower PCR, Bioneer). Results: Mineralization increased in the BMP-2 and MTA/BMP-2 groups and increased to a lesser extent in the MTA/EMD group but appeared to decrease in the MTA-only group based on Alizarin red staining. ALP expression largely decreased in the EMD and MTA/EMD groups based on ALP staining. In the MTA/BMP-2 group, mRNA expression of OPN on day 3 and BSP and OCN on day 7 significantly increased. In the MTA/EMD group, OSN and OCN gene expression significantly increased on day 7, whereas ALP expression decreased on days 3 and 7 (p < 0.05). Conclusions: These results suggest the MTA/BMP-2 combination promoted more rapid differentiation in MC3T3-E1 cells than did MTA/EMD during the early mineralization period.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.310-317
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• 2009

Dens evaginatus is a dental anomaly involving an extra cusp or tubercle that protrudes from the occlusal surface of the affected tooth. The prevalence of dens evaginatus is 1 to 4 percent, and dens evaginatus is observed most commonly in premolars. It can be worn or fractured easily, resulting in pulpal exposure, pulpal infection, loss of vitality, facial infection and osteomyelitis. Since the tooth frequently has the immature apex when the tubercle is fractured, there is difficulty in treatment. Although calcium hydroxide is widely used for pulp treatment of an immature permanent tooth, several alternatives have been suggested to reduce patient's appointments. Mineral trioxide aggregate is considered biocom-patible and has excellent marginal sealing ability. In addition, it can minimize patient's visits. In this case report, apexification with MTA was attempted on the immature premolars in patients with cellulitis patient, caused by pulp necrosis due to dens evaginatus. Favorable clinical and radiologic results were achieved. In one case, continued root formation was observed.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.30-38
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• 2008

Dental pulp cells are assumed to possess the capacity to elaborate both bone and dentin matrix under the pathological conditions following tooth injury. The purpose of this study is to examine the effects of mineral trioxide aggregate (MTA) on various gene expression regarding dentinogenesis and cell viability assay in cultured primary human dental pulp cells. The author also examined the effects of this material on cellular alkaline phosphatase activity as a potential indicator of dentinogenesis. For gene expression on MTA, reverse transcriptase polymerase chain reaction was performed using primer sets of glyceraldehyde-3-phosphate dehydrogenase, type I collagen, alkaline phosphatase(ALP), osteonectin, and dentin sialoprotein after 2 and 4 days. Cell viability assay showed that the proportion of MTA-treated pulp cells which had been exposed for 5 days to MTA was higher than that of the control cells. Among the genes investigated in this study, ALP and osteonectin(SPARC) were increased in MTA treated group than in control. These findings suggest that this dental pulp culture system may be useful in the future as a model for studying the mechanisms underlying dentin regeneration after the treatment with MTA. Exposure to MTA material would not induce cytotoxic response in the dental pulp cells. In addition, MTA could influence the behavior of human pulp cells by increasing the ALP activity and SPARC synthesis.