• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.2
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• pp.174-179
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• 2014

Dens invaginatus is a developmental anomaly resulting from an infolding of the enamel organ into the dental papilla prior to calcification of the dental tissue. Clinical and radiographic presentation of dens invaginatus shows a lot of variation. The classification proposed by Oehlers(1957) is most commonly used among classifications of dens invaginatus. Several treatments have been suggested to treat Type III dens invaginatus where the pulp remains healthy but the invagination is associated with a periodontitis. The top priority objective is to preserve pulp as sound as possible. Thus, if there is no definite evidence of pulpal disease, the conservative access which treat invagination as distinct from the pulp is necessary. But, Endodontic treatment of Type III dens invaginatus has the particular problems associated with achieving adequate chemomechanical debridement of the root canal system and invagination, predictable length control and consistent filling. In this case report, the endodontic treatment limited within invagination was performed for treatment of Type III dens invaginatus, and filling with Mineral Trioxide Aggregate(MTA) resulted in good prognosis.

• 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.

• Restorative Dentistry and Endodontics
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• v.45 no.2
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• pp.4.1-4.6
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• 2020

Although numerous studies have been conducted on apexification using mineral trioxide aggregate (MTA), direct observation of extracted human teeth after the procedure has been rarely reported. This case report describes a mandibular premolar treated 2.5 years ago and extracted recently for orthodontic treatment. The tubercle of the right mandibular premolar of a 12-year-old boy with dens evaginatus was fractured and the pulp was exposed. The tooth was diagnosed with pulp necrosis and asymptomatic periapical abscess. During the first visit, copious irrigation was performed with 2.5% sodium hypochlorite. Calcium hydroxide paste was placed as an intracanal medicament. The sinus tract had disappeared at the second visit after 3 weeks. MTA was applied on to the bleeding point as a 4-mm-thick layer, followed by a 3-mm-thick gutta-percha filling and resin core build-up. After 2.5 years, the tooth and three other premolars were extracted for orthodontic treatment. The right and left mandibular premolars were scanned with micro-computed tomography to determine the root shape and canal anatomy. Irregular root growth was observed and the root outline of the right mandibular premolar differed from that of the contralateral tooth. Apexification with MTA leads to the formation of roots with irregular morphology, without any pulpal space.

• Restorative Dentistry and Endodontics
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• v.42 no.3
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• pp.176-187
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• 2017

Objectives: This study aimed to evaluate the chemical and biological properties of fast-set white mineral trioxide aggregate (FS WMTA), which was WMTA combined with calcium chloride dihydrate ($CaCl_2{\cdot}2H_2O$), compared to that of WMTA. Materials and Methods: Surface morphology, elemental, and phase analysis were examined using scanning electron microscope (SEM), energy dispersive X-ray microanalysis (EDX), and X-ray diffraction (XRD), respectively. The cytotoxicity and cell attachment properties were evaluated on human periodontal ligament fibroblasts (HPLFs) using methyl-thiazoldiphenyltetrazolium (MTT) assay and under SEM after 24 and 72 hours, respectively. Results: Results showed that the addition of $CaCl_2{\cdot}2H_2O$ to WMTA affected the surface morphology and chemical composition. Although FS WMTA exhibited a non-cytotoxic profile, the cell viability values of this combination were lesser than WMTA, and the difference was significant in 7 out of 10 concentrations at the 2 time intervals (p < 0.05). HPLFs adhered over the surface of WMTA and at the interface, after 24 hours of incubation. After 72 hours, there were increased numbers of HPLFs with prominent cytoplasmic processes. Similar findings were observed with FS WMTA, but the cells were not as confluent as with WMTA. Conclusions: The addition of $CaCl_2{\cdot}2H_2O$ to WMTA affected its chemical properties. The favorable biological profile of FS WMTA towards HPLFs may have a potential impact on its clinical application for repair of perforation defects.

• Restorative Dentistry and Endodontics
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• v.39 no.4
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• pp.253-257
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• 2014

Objectives: This study aimed to compare the surface microhardness of mineral trioxide aggregate (MTA) samples having different thicknesses and exposed to human blood from one side and with or without a moist cotton pellet on the other side. Materials and Methods: Ninety cylindrical molds with three heights of 2, 4, and 6 mm were fabricated. In group 1 (dry condition), molds with heights of 2, 4, and 6 mm (10 molds of each) were filled with ProRoot MTA (Dentsply Tulsa Dental), and the upper surface of the material was not exposed to any additional moisture. In groups 2 and 3, a distilled water- or phosphate-buffered saline (PBS)-moistened cotton pellet was placed on the upper side of MTA, respectively. The lower side of the molds in all the groups was in contact with human blood-wetted foams. After 4 day, the Vickers microhardness of the upper surface of MTA was measured. Results: In the dry condition, the 4 and 6 mm-thick MTA samples showed significantly lower microhardness than the 2 mm-thick samples (p = 0.003 and p = 0.001, respectively). However, when a distilled water- or PBS-moistened cotton pellet was placed over the MTA, no significant difference was found between the surface microhardness of samples having the abovementioned three thicknesses of the material (p = 0.210 and p = 0.112, respectively). Conclusions: It could be concluded that a moist cotton pellet must be placed over the 4 to 6 mm-thick MTA for better hydration of the material. However, this might not be necessary when 2 mm-thick MTA is used.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.50.1-50.11
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• 2020

Objectives: In this study, we investigated the potential of amoxicillin-loaded polymeric microspheres to be delivered to tooth root infection sites via a bioactive reparative cement. Materials and Methods: Amoxicillin-loaded microspheres were synthesized by a spray-dray method and incorporated at 2.5% and 5% into a mineral trioxide aggregate cement clinically used to induce a mineralized barrier at the root tip of young permanent teeth with incomplete root development and necrotic pulp. The formulations were modified in liquid:powder ratios and in composition by the microspheres. The optimized formulations were evaluated in vitro for physical and mechanical eligibility. The morphology of microspheres was observed under scanning electron microscopy. Results: The optimized cement formulation containing microspheres at 5% exhibited a delayed-release response and maintained its fundamental functional properties. When mixed with amoxicillin-loaded microspheres, the setting times of both test materials significantly increased. The diametral tensile strength of cement containing microspheres at 5% was similar to control. However, phytic acid had no effect on this outcome (p > 0.05). When mixed with modified liquid:powder ratio, the setting time was significantly longer than that original liquid:powder ratio (p < 0.05). Conclusions: Lack of optimal concentrations of antibiotics at anatomical sites of the dental tissues is a hallmark of recurrent endodontic infections. Therefore, targeting the controlled release of broad-spectrum antibiotics may improve the therapeutic outcomes of current treatments. Overall, these results indicate that the carry of amoxicillin by microspheres could provide an alternative strategy for the local delivery of antibiotics for the management of tooth infections.

• 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.3
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• pp.185-193
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• 2013

Mineral trioxide aggregate (MTA) has recently been used as a pulpotomy medicament for primary molars. The aim of this study was to evaluate and compare the proliferation and differentiation potential of dental pulp stromal cells of permanent teeth and deciduous teeth cultured on MTA-coated surface. Human dental pulp stromal cells were obtained from human permanent premolars and deciduous teeth and cultured on MTA-coated culture plates. The cells were subjected to proliferation assay and cell cycle analysis. Their differentiation potential was evaluated by analysing changes in the mRNA expressions of runt-related transcriptional factor 2 (Runx2) and alkaline phosphatase (ALP). Morphological changes of cells in direct contact with MTA were observed using scanning electron microscopy (SEM). The proliferation rates, distribution of cell cycles and mRNA expression patterns of Runx2 and ALP were similar in both types of pulpal cells. SEM observations revealed that both types changed into more dendrite-like cells. On the surface of MTA, human dental pulp stromal cells from deciduous and permanent teeth were able to both proliferate and differentiate into cells that induce mineralization. MTA is suitable as a biocompatible pulpotomy medicament for primary teeth.

• Restorative Dentistry and Endodontics
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• v.25 no.4
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• pp.536-542
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• 2000

임상에서 점차 Mineral Trioxide Aggregate (MTA)에 대한 우수성이 소개되면서, apical matrix로의 사용은 주목할 만하다 할 수 있다. 본 연구의 목적은 개방형근관에서 MTA가 apical matrix로 사용될 때의 치근단 밀폐효과를 알아 보고, 근관충전의 시기와 matrix의 두께가 치근단 밀폐에 미치는 영향을 치근단 미세누출의 측면과 matrix탈락빈도의 측면에서 관찰하고자 하는 것이다. 개방형 근관을 재현하고자 45개의 발거된 단근치에 #90크기로 근단공을 형성하였고, 투명레진등을 이용하여 치근단 병소를 갖는 치조골을 재현한 후, 4개의 실험 군과 1개의 대조 군으로 분류하였다. A군: 2mm두께의 MTA matrix 형성후, 열연화된 Gutta-percha와 AH26 sealer를 이용하여 즉시 근관충전. B군: 2mm 두께의 MTA matrix 형성후, A군과 같은 방법으로 24시간 후 근관충전. C군: 4mm 두께의 MTA matrix 형성후, A군과 같은 방법으로 즉시 근관충전. D군: 4mm 두께의 MTA matrix 형성후, A군과 같은 방법으로 24시간 후 근관충전. 대조군: matrix를 사용하지 않고 열연화된 Gutta-percha와 AH26 sealer를 이용하여 근관충전하였다. Matrix의 탈락이 있는 경우 기록하고 완전 수세 후 다시 시행하였다. 색소침투정도의 평가를 위해 methylene blue에 치아를 48시간 침수시킨 후 협설로 양분하였다. 각 시편들을 고배율 현미경 관찰 후 비디오촬영 하였고, digitalized image analysing program을 이용하여 두명의 관찰자가 누출의 정도를 평가한 후, One-way ANOVA로 통계적 유의성을 검증하여 다음과 같은 결과를 얻었다. 1. Matrix를 사용한 실험 군이 matrix를 사용하지 않은 대조 군에 비해 유의성 있게 낮은 누출을 보였다(p<0.05). 그러나 근관충전시기와 matrix의 두께를 달리한 실험군 내에서는 누출에 유의성 있는 차이가 나타나지 않았다. 2. 모든 실험군에서 gutta-percha를 이용한 근관충전의 시기에 matrix탈락 및 gutta-percha의 압출은 발생하지 않았다.

• Restorative Dentistry and Endodontics
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• v.32 no.3
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• pp.191-197
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• 2007

Mineral trioxide aggregate (MTA) would influence healing of periapical tissues by modulating the production of growth factors and cytokines from PDL fibroblasts, however, the studies are insufficient. Therefore, the purpose of this study was to monitor the expression of transforming growth factor-beta1 $(TGF-\beta1)$, fibroblast growth factor-2 (FGF-2), and interleukin-6 (IL-6) from PDL fibroblasts in the presence of MTA. The human PDL fibroblasts were seeded onto the set MTA or IRM at a level of $1\times10^5$ cells per unit well, and further incubated for 6, 12, 24, and 48 hours. The levels of $TGF-\beta1$, FGF-2 and IL-6 from the supernatant were measured by enzyme-linked immunosorbent assay (ELISA) The data were analyzed using one-way ANOVA. The level of $TGF-\beta1$ was down-reg ulated when the cells were grown in the presence of MTA except at 6 hours. The levels of FGF-2 release were significantly suppressed when PDL fibroblasts were grown in the presence of MTA or IRM at all time intervals (p < 0.05). The expressions of IL-6 from MTA treated co)Is were comparable to those of untreated control cells throughout the observation periods. We presume that this material inhibits the stimulatory function of growth factors on granulation tissue formation and in turn, it promotes the healing process modulated by other bone-remodeling cells.