Effect of mineral trioxide aggregate on cytokine production by peritoneal macrophages

AIM: To test the effect of two commercial brands of grey mineral trioxide aggregate (ProRoot and MTA-Angelus) on cytokine production by M1 and M2 inflammatory macrophages. METHODOLOGY: M1 (from C57BL/6 mice) and M2 peritoneal inflammatory macrophages (from C57BL/6 IL12p40-/- mice) were obtained and cultured in vitro in the presence of MTA. The cellular viability and the production of tumour necrosis factor-alpha, interleukin (IL)-12 and IL-10 in response to stimulation with interferon-gamma and Fusobacterium nucleatum or Peptostreptococcus anaerobius were evaluated. Data were analysed by Mann-Whitney, Kruskal-Wallis and anova tests. RESULTS: The cements did not interfere with cellular viability or with cytokine production by either type of macrophage. However, M2 macrophages produced higher levels of IL-10 when stimulated with F. nucleatum than M1 macrophages (P < 0.05). CONCLUSIONS: The brands of MTA evaluated did not interfere in the cytokine response by M1 or M2 macrophages to the two bacteria tested. However, a difference in cytokine production between the two types of macrophages was found.     

三氧化矿物凝聚体修补根管穿孔的临床疗效观察

目的 观察采用三氧化矿物凝聚体（MTA）修补根管穿孔的短期临床效果。方法对2003年1月至2004年1月于我科进行根管穿孔修补的10例病例，进行定期回访，观察治疗效果。结果 复诊时10例患者均无不适主诉。修补前后X线片对照显示，7例修补前穿孔周围无病变的病例复查时无新发病变。3例术前病变面积较大的病例复查时，其中2例病变完全愈合，1例明显缩小。除1例左上第二磨牙腭根远中侧穿的患牙在远中探及7mm的牙周袋外，其余均无4mm以上的牙周袋。结论 MTA是目前临床上较理想的根管穿孔的修补材料，能够最大限度的保存患牙，短期临床疗效好，长期效果有待于进一步观察。     

Revascularization versus apical barrier technique with mineral trioxide aggregate plug: A systematic review

Aim

To compare the clinical and radiographic outcomes observed in Necrotic Immature Permanent Teeth (NIPT) after revascularization or apexification with MTA-apical plug.

Biocompatibility of two commercial forms of mineral trioxide aggregate

AIM: To examine the biocompatibility of two commercial forms of mineral trioxide aggregate (MTA), by evaluating the morphology of an established cell line. METHODOLOGY: The two cements were cast on glass cover slips and cured for 1 or 28 days. Saos-2 osteosarcoma cells were trypsinized and seeded at a density of 1 x 10(5) cells and were then placed in medium over the material-coated coverslips for 1, 5 and 7 days. After these time intervals the media were discarded and the cells fixed. Cell morphological investigation was performed by scanning electron microscopy at various magnifications ranging from x 250 to x 500. The biocompatibility of cement constituents, alusilicate flux and bismuth oxide was also investigated. RESULTS: All cement samples cured for 1 day showed a confluent cell monolayer after 5 and 7 days. The response to both materials was similar. Materials cured for 28 days showed incomplete cell confluence after 1 and 5 days. Alusilicate flux and bismuth oxide did not demonstrate biocompatibility. CONCLUSIONS: The 1-day cured samples of two commercial forms of MTA showed good biocompatibility. However, the 28-day cured samples were less biocompatible after 1 and 5 days.     

Effect of iRoot SP and mineral trioxide aggregate (MTA) on the viability and polarization of macrophages

ObjectiveThis study was performed to investigate the effect of iRoot SP and mineral trioxide aggregate (MTA) on the viability and polarization of macrophages.MethodsThe effect of iRoot SP and MTA on the viability of RAW 264.7 macrophages was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after 1 and 2 days of culture. The gene expression levels of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), interleukin 10 (IL-10), interleukin 12p40 (IL-12p40) were measured by quantitative real time polymerase chain reaction (qRT-PCR) after stimulation of the RAW 264.7 macrophages with iRoot SP and MTA. The expression levels of CD11c and CD206 in RAW 264.7 macrophages were examined by immunofluorescence and flow cytometry after stimulation with iRoot SP and MTA. The data were analyzed by one-way analysis of variance and the Tukey test.ResultsBoth iRoot SP and MTA were non-toxic to the RAW 264.7 macrophages. The use of iRoot SP and MTA increased the expression of IL-1β, TNF-α, IL-10, IL-12p40 on the first day of culture and could promote macrophage M1 and M2 polarization.ConclusionsMTA and iRoot SP have good biocompatibility with macrophages, and they induced both M1 and M2 polarization of the RAW 264.7 macrophages.     

三氧化矿物凝聚体修补医源性根管穿孔的疗效分析

目的 评价三氧化矿物凝聚体(mineral trioxide aggregate,MTA)修补根管医源性穿孔的临床效果.方法 选取根管医源性穿孔病例21例,预备根管、彻底清理穿孔区,根管显微镜下以MTA修补根管穿孔,完成充填.定期回访,收集患者术前、修补后即刻和术后复查的X线片,根据临床检查和X线片检查评价结果.结果 复诊时21例中除2例为有效(存在密度减低影但较术前明显缩小)外,其余19例均为愈合(无密度减低影),无失败病例.结论 MTA治疗医源性穿孔的临床疗效较好.

Abstract：

Objective To observe the clinical effect of iatrogenic perforation repaired by mineral trioxide aggregate(MTA). Methods Twenty-one iatrogenic perforation cases were included. The root canals were shaped and cleaned and then obturated after MTA was used to repair the perforation with microscopes.Preoperative, immediate postoperative, and follow-up radiographs were evaluated to determine the pathologic changes adjacent to the perforation site. Results Nineteen cases healed and two cases were healing. No cases failed. Conclusions MTA is effective in the treatment of iatrogenic perforation.     

MTA形成根尖屏障的疗效观察

目的:评价在手术显微镜下采用无机三氧化聚合物(mineraltrioxideaggregate,MTA)形成根尖屏障、治疗根尖孔未闭合患牙的临床疗效。方法:选取根尖孔未闭合的患牙23颗,完成根管预备后,在手术显微镜下将MTA充填于根尖1/3段,形成3～5㎜的根尖屏障,硬固后完成根管中、上段的充填及冠部修复,观察疗效。结果:所有病例在2～3周内完成根管充填,术后X线片显示16颗患牙适充,7颗超充约1～2㎜,根充致密;除失访及不能亲自前来复诊检查的患者外,其余19颗均达到成功要求,患牙无不适,瘘管闭合,无叩痛;复查X线片示根尖周病变明显缩小或消失,无新的暗影出现。结论:MTA治疗根尖孔未闭合的患牙治疗周期短,临床疗效好,少量超充不影响疗效。     

三氧化矿物凝聚体对牙乳头细胞增殖和分化影响的实验研究

目的 研究不同质量浓度的三氧化矿物凝聚体(mineral trioxide aggregate,MTA)对大鼠牙乳头细胞(rat dental papilla cells,RDPC)增殖和分化能力的影响,探讨MTA在根尖诱导方面的作用.方法 组织块法原代培养RDPC并鉴定.制备不同质量浓度的MTA浸提液(0.002、0.02、0.2、2及20 g/L)并处理第3代RDPC 3 d,以普通培养液的RDPC作为空白对照组(每组6孔),用甲基噻唑基四唑(methyl thiazolyl tetrazolium,MTT)比色法检测细胞增殖能力,筛选最适合细胞生长的质量浓度.用0.002 g/L MTA培养RDPC,以普通培养液的RDPC作为空白对照组,检测1、3、5、7 d RDPC的碱性磷酸酶(alkaline phosphatase,ALP)活性和1、3、5 d RDPC的Ⅰ型胶原含量.用方差分析对不同浓度MTA干预后RDPC的增殖能力进行统计学分析,用t检验对0.002 g/L MTA干预后RDPC分泌的ALP活性和Ⅰ型胶原含量进行统计学分析.结果 MTT法检测不同质量浓度MTA对RDPC增殖能力影响中,培养3d后的A值20 g/L组(0.092±0.011)显著低于空白对照组(0.249±0.006),差异有统计学意义(P＜0.01)；0.02和0.002 g/L组的A值(分别为0.267±0.005、0.276±0.006)均显著高于空白对照组(0.249±0.006),差异均有统计学意义(P＜0.01).ALP活性检测结果显示,MTA组3、5、7d的A值[分别为(0.217 ±0.008)、(0.253±0.005)和(0.279±0.004)]均显著高于空白对照组相应时间点的A值[分别为(0.166±0.006)、(0.221±0.006)、(0.242±0.004)],差异均有统计学意义(P＜0.01).3、5d的Ⅰ型胶原含量MTA组[分别为(78.46±2.72)、(90.73±3.08) μg/L]均显著高于相应时间点的空白对照组[分别为(66.75±3.08)、(74.27±3.50) μg/L],差异均有统计学意义(P＜0.01).结论 高浓度的MTA抑制RDPC的生长,低浓度的MTA可以促进RDPC的增殖和分化.     

Hydration mechanisms of mineral trioxide aggregate

AIM: To report the hydration mechanism of white mineral trioxide aggregate (White MTA, Dentsply, Tulsa Dental Products, Tulsa, OK, USA). METHODOLOGY: The chemical constitution of white MTA was studied by viewing the powder in polished sections under the scanning electron microscope (SEM). The hydration of both white MTA and white Portland cement (PC) was studied by characterizing cement hydrates viewed under the SEM, plotting atomic ratios, performing quantitative energy dispersive analyses with X-ray (EDAX) and by calculation of the amount of anhydrous clinker minerals using the Bogue calculation. RESULTS: Un-hydrated MTA was composed of impure tri-calcium and di-calcium silicate and bismuth oxide. The aluminate phase was scarce. On hydration the white PC produced a dense structure made up of calcium silicate hydrate, calcium hydroxide, monosulphate and ettringite as the main hydration products. The un-reacted cement grain was coated with a layer of hydrated cement. In contrast MTA produced a porous structure on hydration. Levels of ettringite and monosulphate were low. Bismuth oxide was present as un-reacted powder but also incorporated with the calcium silicate hydrate. CONCLUSIONS: White MTA was deficient in alumina suggesting that the material was not prepared in a rotary kiln. On hydration this affected the production of ettringite and monosulphate usually formed on hydration of PC. The bismuth affected the hydration mechanism of MTA; it formed part of the structure of C-S-H and also affected the precipitation of calcium hydroxide in the hydrated paste. The microstructure of hydrated MTA would likely be weaker when compared with that of PC.     

无机三氧化复合物修补髓室底和根管穿孔的临床效果

目的：评价MTA用于髓室底和根管穿孔修补的临床价值。方法：髓室底穿孔12例，随机分为2组，分别用MTA和IRM（对照组）修补，进行根管治疗，术后3、6、12个月复查，拍平行投照x线片，双盲法评价穿孔处根周组织的变化。用，检验比较2组治疗效果。根管穿孔9例：用MTA修补并完成根管治疗。复查时间和方法同前。纵向观察MTA修补根管穿孔的效果。结果：MTA组和IRM组治疗髓室底穿孔的有效率12个月时分别为80％和75％，两者间无明显差异（P=0．722）。MTA修补根管穿孔的病例治疗均有效。结论：MTA治疗髓室底和根管穿孔时能取得很好的治疗效果，可提高穿孔牙齿预后。     

Direct pulp capping with mineral trioxide aggregate: an observational study

BACKGROUND: Pulp capping in carious teeth has been considered unpredictable and therefore contraindicated. A recently developed material, mineral trioxide aggregate (MTA), resists bacterial leakage and may provide protection for the pulp, allowing repair and continued pulp vitality in teeth when used in combination with a sealed restoration. METHODS: Forty patients aged 7 to 45 years accepted pulp-capping treatment when they received a diagnosis no more severe than reversible pulpitis after undergoing cold testing and radiographic examination. The primary author removed caries using a caries detector dye and sodium hypochlorite solution for hemostasis and placed MTA over the exposures and all surrounding dentin. The operator then restored the teeth provisionally with unbonded Clearfil Photocore (Kuraray Medical, Okayama, Japan). During a second visit, the operator restored the teeth with bonded composite after sensibility testing and confirmed MTA curing. At recall appointments, patients were evaluated for reparative dentin formation, pulpal calcification, continued normal root development and evidence of pathosis. RESULTS: Over an observation period of nine years, the authors followed 49 of 53 teeth and found that 97.96 percent had favorable outcomes on the basis of radiographic appearance, subjective symptoms and cold testing. All teeth in younger patients (15/15) that initially had open apexes showed completed root formation (apexogenesis). CONCLUSIONS: MTA can be a reliable pulp-capping material on direct carious exposures in permanent teeth when a two-visit treatment protocol is observed. PRACTICE IMPLICATIONS: Vital pulp therapy using MTA is a treatment option for teeth diagnosed with a condition no more severe than reversible pulpitis.     

Dissolution of bio-active dentine matrix components by mineral trioxide aggregate

OBJECTIVES: To analyze the soluble components of setting and set mineral trioxide aggregate (MTA), assess the abilities of two varieties of MTA and Ca(OH)(2) solutions to solubilise dentine matrix proteins (DMPs) and determine if these extracts contain signalling molecules important to pulpal repair and regeneration. METHODS: The metallic ion composition of solutions of white and grey MTA (pH 11.7), 0.02M Ca(OH)(2) (pH 11.9) and 10% EDTA (pH 7.2) was determined using atomic absorption spectroscopy. Extracellular dentine matrix components from powdered human dentine were extracted using all solutions over 14 days. Extracts were analysed for concentrations of non-collagenous proteins (NCPs) and glycosaminoglycans (GAGs), and protein profiles were examined using 1D-polyacrylamide gel electrophoresis (1D-PAGE). ELISAs for TGF-beta1 and adrenomedullin (ADM) were also performed. RESULTS: Aluminium, calcium, potassium, and sodium ions were detected in both white and grey MTA solutions. MTA and Ca(OH)(2) solutions liberated similar amounts of GAGs and NCPs although yields were considerably lower than those obtained using the EDTA solution. 1D-PAGE analysis demonstrated differences in protein profiles solubilised from dentine for all solutions. All extracts contained TGF-beta1 and ADM, EDTA solution liberated significantly greater amounts of TGF-beta1, and Ca(OH)(2) and grey MTA solutions released more ADM. CONCLUSIONS: These data imply that when placed clinically soluble components of set and setting MTA may release dentine matrix components that potentially influence cellular events for dentine repair and regeneration.     

三氧化矿物凝聚体(MTA)的研究进展

一种新型生物材料，三氰化矿物凝聚体(Mineral trioxide aggregate MTA)，广泛应用于牙科治疗中的直接盖髓、活髓切断、根尖成形、髓室底穿孔及根管侧穿修补、根管倒充填等多个领域。体外和体内试验证实，MTA具有良好的生物相容性，可有效促进硬组织的再生，并且具有一定的抗菌和抑菌性,对组织无毒其持久的封闭性大大提高了侧穿修补和根尖倒充填的成功功率、MTA可通过调节细胞因子的分泌，激活细胞外信号调节性激酶活性和促进骨钙素的表达等途径，影响骨的吸收和改建，进而促促进病变的愈合.虽然MTA也有其局限性，但仍是一种极具潜力的牙科新型材料。     

MTA表面晶体形成的体外研究

目的:观察和检测MTA在体外不同条件下材料表面形态和组成成分的变化。方法:将银汞合金,Dycal,Dyract和MTA分别充填入预备过的不同根块中,含材料的根块分别浸泡于蒸馏水或SBF溶液中5d,扫描电镜和X射线能谱(EDS)对材料的表面形貌和化学成分进行观察检测。结果:MTA的表面形貌和成分都发生了改变,在SBF溶液中材料表面形成大小均匀的球形有序晶体,EDS分析结果显示晶体的化学组成与磷酸三钙钙磷摩尔比相近。结论:在适宜的条件下MTA具有形成磷灰石晶体的生物学潜力和活性。     

Evaluation of rat alveolar bone response to Angelus MTA or experimental light-cured mineral trioxide aggregate using fluorochromes

Introduction

The aim of this study was to evaluate the rat alveolar bone response after the implantation of experimental light-cured mineral trioxide aggregate (MTA) or Angelus MTA (Angelus, Londrina, Paraná, Brazil) by histological and fluorescence analysis.

Methods

Thirty Wistar Albino rats were divided into three groups. In the control group, empty polyethylene tubes were inserted into the rat alveolar sockets immediately after extraction. In the other groups, the tubes were filled with light-cured MTA or Angelus MTA. Five animals from each group were injected with calcein on day 7, alizarin on day 14, and oxytetracycline on day 21. On day 30, these animals were killed, and the right hemimaxillas were removed and histologically processed. Half of the maxillas were processed and stained with hematoxylin and eosin. The remaining maxillas were processed for fluorescence analysis and stained with Stevenel blue and alizarin red. New bone was histomorphometrically evaluated using a Merz grid.

Results

The light-cured MTA presented a similar response when compared with Angelus MTA; it was characterized by a mild inflammatory response and complete bone healing. In the light-cured MTA group, the fluorescence areas were more evident at 21 days, showing an increase in bone formation. However, dystrophic mineralization was observed only with Angelus MTA.

Conclusions

It was concluded that both materials present a similar inflammatory response and bone healing, but dystrophic mineralization was observed only with Angelus MTA.     

Management of open apices in thirteen traumatized permanent incisors using mineral trioxide aggregate: Case series

AimThe partial pulpotomy can offer a successful outcome for the treatment of traumatic complicated crown fractures. The aim of this clinical report was to evaluate the effect of mineral trioxide aggregate (MTA) in apexogenesis of traumatized immature permanent incisors with pulp exposure.Case reportAccording to clinical and radiological examinations complicated crown fractures and open apices were identified in 13 permanent upper incisors in ten patients (age range 7–10 years). Partial pulpotomy procedures were performed and the teeth were treated with MTA. In this report, periodic clinical and radiological follow-ups were performed. At recall examinations, all teeth were asymptomatic, and clinical and radiological investigations revealed excellent healing patterns with continued apexogenesis.ConclusionRegular examination of immature traumatized permanent teeth is critical for vitality and apexification. In this report, clinical and radiological findings confirm that partial pulpotomy with MTA is a reliable and effective treatment approach in apexogenesis of traumatized immature permanent incisors with pulp exposure.     

Replacement of radiopacifier in mineral trioxide aggregate; characterization and determination of physical properties

Objective

Investigation of the replacement of bismuth oxide by zirconium oxide in mineral trioxide aggregate (MTA) and characterization and evaluation of the radiopacity and physical properties of varying replacements of zirconium oxide mixed at either water-powder or water-cement proportions of 0.3. The suitable filler loading of zirconium oxide for Portland cement in a MTA system for use as a root-end filling material was thus determined.

Methods

Portland cement replaced by zirconium oxide in varying amounts ranging from 0% to 50% in increments of 10 was mixed with water either at a water/powder (WP) proportion or at a water/cement (WC) proportion of 0.3. Portland cement and ProRoot MTA were used as controls. The materials’ microstructures were investigated using optical light microscopy. The radiopacity, strength, setting time, water uptake, solubility, sorption and porosity of the specimens were also evaluated. The optimum formulation was selected using the digital logic method.

Results

Portland cement replaced with 30% zirconium oxide mixed at a water/cement proportion of 0.3 resulted to have the optimum combination of properties. This material exhibited radiopacity, compressive strength, setting time, water uptake, solubility and sorption comparable to ProRoot MTA. Both microscopy and the evaluation of porosity from the solubility and sorption experiments indicated a degree of porosity consisting mainly of capillary pores and entrapped air voids.

Significance

A filler loading of 30% zirconium oxide to Portland cement mixed at a water to cement proportion of 0.3 resulted in a material with comparable properties to mineral trioxide aggregate.     

Characterization of hydration products of mineral trioxide aggregate

Objective To characterize the hydration products of white mineral trioxide aggregate (MTA). Methodology Mineral trioxide aggregate, white Portland cement and bismuth oxide were evaluated using X‐ray diffraction (XRD) analysis and Rietveld XRD. The cements were tested un‐hydrated and after hydration and curing for 30 days at 37 °C. Analysis of hydrated cement leachate was performed weekly for five consecutive weeks from mixing using inductively coupled plasma atomic emission spectroscopy after which the cements were viewed under the scanning electron microscope to evaluate the cement microstructure. Quantitative energy dispersive analysis with X‐ray was performed and atomic ratios were plotted. Results Both Portland cement and MTA produced calcium silicate hydrate (C‐S‐H) and calcium hydroxide (CH) on hydration. The tricalcium aluminate levels were low for MTA which resulted in reduced production of ettringite and monosulphate. On hydration the bismuth level in the hydrated MTA decreased; bismuth oxide replaced the silica in the C‐S‐H and was leached out once the C‐S‐H decomposed with time. Both MTA and Portland cement released a high amount of calcium ions which decreased in amount over the 5‐week period. Conclusions The hydration mechanism of MTA is different to that of Portland cement. In MTA the bismuth oxide is bound to the C‐S‐H and is leached out from the cement with time as the C‐S‐H decomposes. MTA produces a high proportion of calcium ions from CH a by‐product of hydration and also by decomposition of C‐S‐H. The release of calcium ions reduces with time.