IMMEDIATE AND DELAYED SOLUBILITY OF MINERAL TRIOXIDE AGGREGATE AND PORTLAND CEMENT

This study investigated the solubility of mineral trioxide aggregate (MTA) and Portland cement since its mixture until 672 hours, by means of two complimentary methods. Metal ring molds filled with the cements were covered with distilled water and, at each experimental time (3, 24, 72, 168, 336 and 672 hours), were weighed as soon as the plates in which the samples have been placed. Empty rings served as the control group (n=8). Mean weight gain and loss was determined and analyzed statistically by two-way ANOVA and Tukey''s test for all pairwise comparisons. Only Portland cement showed less than 3% weight loss through 24 hours. Detached MTA residues were heavier than those of Portland cement over the 3 to 168 hours. The weight of MTA rings increased more than that of Portland rings within 672 hours (p=0.05). The findings of the present study indicate that, in an aqueous environment MTA is more soluble than Portland cement and exceeds the maximum weight loss considered acceptable by ISO 6876 standard (2001).     

用罗丹明B染料比较MTA、GIC和银汞合金的根尖封闭性

目的:用罗丹明B染料比较MTA、GC Fuji Ⅱ(GIC)和银汞合金的根尖封闭性.方法:将离体牙分别用以栽上3种材料进行根尖倒充填后,用0.2%罗丹明B溶液染色,再将牙体纵劈,置于解剖显微镜下测量洞壁染料渗透最大深度并拍照.SPSS10.0统计软件进行分析.结果:MTA组的渗漏深度显著小于银汞合金组(P＜0.05),而银汞合金组的渗漏深度显著小于GC Fuji Ⅱ组(P＜0.05).结论:3种材料中,MTA的根尖封闭效果最好,其次为银汞合金,而Fuji Ⅱ的效果最差.     

根尖诱导成形术诱导剂的研究进展

传统的根尖诱导成形术诱导剂是氢氧化钙,其诱导成功率很高,但由于治疗周期长,使得再次感染和根折的风险很高。近年来人们致力于新型诱导剂的研究,该文对其中的无机三氧化合物和生物陶瓷材料的研究进展进行综述。     

应用MTA封闭根尖和修补根管侧穿的临床疗效观察

目的:观察MTA(mineral trioxide aggregate)治疗根尖敞开和根管侧穿患牙的临床疗效.方法:病例选择于解放军第306医院牙体牙髓科门诊患者共计23 例,其中根尖部敞开7 例、根管内吸收、根折造成根管侧穿6 例、医源性根管侧穿10 例.病程0.5～24 个月, X线片显示23 例均有根部或根尖周透射影.常规根管清理消毒、封药,于根管显微镜下采用MTA封闭根尖开放部位,形成屏障后热胶垂直加压法充填根管, 6、 12 个月进行复查.结果:1 例失访, 6 个月复诊根尖周透射影增大1 例,根尖周透射影减小20 例,1 例无明显变化.12 个月复诊根尖区透射影消失9 例,根尖周透射影减小5 例,无明显变化2 例.结论:应用MTA封闭根尖和修补根管侧穿的临床短期疗效良好,在根管显微镜下实施有助于提高MTA充填的准确性和密合性.     

牙髓病治疗新材料MTA的研究进展

MTA是90年代发展的一种用于牙髓病治疗的新材料,研究表明MTA具有良好的组织相容性和封闭性能,应用于穿孔修补、直接盖髓、根尖诱导成形和倒充填等治疗中可以促进组织愈合。本文就其研究状况作一综述。     

MTA用于年轻恒牙活髓切断的临床观察

目的观察MTA在年轻恒牙活髓切断术中的临床疗效。方法随机选择7-13岁患儿79颗牙根未发育完全而露髓的患牙,随机分为2组,分别用MTA和氢氧化钙作为活髓切断后的盖髓药物,随访观察两组疗效的差异,并采用χ2、U检验作统计学分析。结果MTA组成功率96%,氢氧化钙组成功率71%,两组有显著性差异(P<0.05)。结论MTA是良好的活髓保存药物,用于活髓切断时疗效优于氢氧化钙。     

MTA用于根管倒充填临床疗效观察

目的:观察MTA用于根管倒充填的临床疗效.方法:选择需要进行根管外科的病人92例95个患牙,常规牙龈切开,暴露根尖,3例因根裂拔除,其余常规根尖切除,断面处用超声根尖工作头预备与牙体长轴平行的盒型洞,洞深约3 mm,MTA倒充填,术后3、6个月、1年复查.结果:1年复查时,有80例病人82个患牙复诊,74例76个牙成功,2例可疑.4例失败.成功率为92.7%.结论:MTA用于根管倒充填,疗效满意.     

银汞材料与MTA材料作为根尖倒充填材料的临床效果评价

目的比较银汞材料与MTA材料作为根尖倒充填材料的不同临床疗效。方法采集既往实施根尖外科手术病例86例,按倒充填材料不同分为2组,A组47例,用MTA材料;B组39例,用银汞合金胶囊。2组均在根管显微镜下使用超声器械进行根尖倒预备。根据临床及X线片判定标准判定术后疗效,分为完全愈合、不完全愈合、不确定愈合、失败4组,统计术后1年手术成功率。结果不同的倒充填材料间成功率比较无统计学差异。结论银汞合金与MTA材料在显微超声根尖倒预备中,作为倒充填材料的临床效果无显著性差异。     

三氧化矿物凝聚体修补髓室底穿孔的疗效观察

髓室底穿孔在牙髓病治疗中常见,但预后较差.临床上常用光固化氢氧化钙进行修补,但由于充填物边缘微渗漏易导致穿孔区炎症复发使疗效不理想.我院采用三氧化矿物凝聚体(MTA)修补髓室底穿孔42 例,观察1 年以上,成功率明显优于常规修补材料.MTA具有较好的封闭性、生物相容性,是一种良好的髓室底穿孔修复材料,值得临床推广应用.     

4种材料诱导犬年轻恒牙根尖形成的比较研究

目的:比较碘仿糊剂、Vitapex、mineral trioxide aggregate(MTA)和氢氧化钙(calcium hydrox-ide,CH)诱导犬年轻恒牙根尖形成的效果.方法:选用3只3～4个月犬的36个恒切牙,随机分为4组.建立慢性牙髓炎模型后,清理并消毒根管,根管内分别充填碘仿糊剂、Vitapex、MTA和CH,根充术后12周处死动物.制作组织学切片,用组织形态学表现并辅助计算机图文分析系统评价硬组织形成情况.结果:在诱导根尖闭合的程度上,MTA组优于碘仿组(P<0.05);4种材料在诱导根尖硬组织形成的量上无显著性差异(P>0.05);组织形态学观察:MTA组为成熟的牙骨质;Vitapex和CH组为类牙骨质和大量的成牙骨质细胞;碘仿组为少量的类牙骨质、胶原纤维和毛细血管.结论:MTA诱导根尖硬组织形成的速度快于其它3种材料,是较理想的诱导剂.     

MTA 应用于切髓术、根尖诱导成形术疗效观察

目的：探讨牙根未发育完全的根尖周炎应用MTA行根尖诱导成形术的临床疗效。方法：将9～16岁病人的98个牙根未发育完全的牙髓炎或尖周炎患牙纳入研究，随机分为2组，分别应用MTA和氢氧化钙行根尖诱导成形术，观察两组根尖孔关闭和根尖硬组织形成的量。结果：MTA组中92％根尖孔关闭，有钙化屏障形成，对照组中52％根尖孔关闭，两组差异显著，有统计学意义（P〈0．05）。结论：MTA应用于根尖诱导成形术是一种有前途的治疗方法，但应掌握好适应证。     

根尖诱导成形术中应用MTA的疗效观察

年轻恒牙由于根尖未形成完全,根管治疗去除牙髓后影响根尖孔形成,易造成术后逆行感染,最终导致治疗失败。以前常用Ca(OH)2糊剂对其根尖部诱导成     

不同根尖倒充填材料的微渗漏研究

目的 评价MTA、玻璃离子水门汀、复合树脂3种根尖倒充填材料根尖封闭性能.方法 60颗实验牙沿釉牙骨质界截冠,冷侧压法充填根管后,切除根尖3 mm.实验组超声倒预备3 mm,分别以MTA、玻璃离子水门汀、复合树脂做倒充填,固化后上段取出牙胶.对照组保留根尖3 mm牙胶.连接于改良葡萄糖定量检测微渗漏模型,分别在1、2、4、7、10、15、20、30 d测定从冠方向根方渗漏的葡萄糖的量.结果 MTA、玻璃离子水门汀、复合树脂3种材料葡萄糖渗漏量均小于0.60 μl/24 h,从第4 d起,MTA的渗漏量显著低于玻璃离子水门汀和复合树脂(P＜0.05).结论 MTA、玻璃离子水门汀、复合树脂3种材料短期内的根尖封闭性均较好,MTA优于其它两种材料.     

牙本质黏结剂增强根管倒充填材料密闭性能的实验研究

目的观察在使用MTA进行根尖倒封闭术时,牙本质粘结剂对其密闭抗微渗漏的影响.方法取40颗离体单根恒牙,分别用MTA、MTA 牙本质粘结剂进行根尖倒封闭术,用染料渗透法检测根尖微渗漏的情况.结果MTA 牙本质粘结剂组的根尖密闭效果明显优于单纯使用MTA组,其差别具有统计意义(P<0.05).结论在使用MTA进行根尖倒封闭术时,使用牙本质粘结剂可提高充填体的密闭效果.     

无机三氧化复合物性能的研究现状

许多体内外实验研究表明，无机三氧化复合物(Mineral Trioxide Aggregate，MTA)作为牙髓病的修复性材料，它具有防止微漏、生物相容性好、促进组织再生等诸多优点。本文对MTA的性能和临床应用现状作一综述。     

MTA直接盖髓的动物实验研究

目的 比较MTA（mineraltrioxideaggregate）及氢氧化钙犬牙直接盖髓后牙髓的反应。方法 将三只健康雄性杂种犬共72颗牙齿机械开髓，然后用MTA和氩氧化钙分别盖髓。窝洞用玻璃离子水门汀充填。在5，7，9个月后。对实验牙齿进行组织切片制备，借助计算机图文处理系统对所形成的修复性牙本质宽度进行测量，对成牙本质细胞、牙髓细胞及毛细血管进行计数、分析。结果 5个月后，MTA及氢氧化钙盖髓效果相似。在7，9个月后。MTA组牙髓较氢氧化钙组可见更明显的修复性牙本质形成，更多的成牙本质细胞和牙髓细胞。结论 MTA具有临床活髓保存治疗应用价值。     

A comparative study of white and grey mineral trioxide aggregate as pulp capping agents in dog's teeth

Abstract –  Mineral trioxide aggregate (MTA) is widely used for different perforation repairs, root-end filling, pulp capping and many other endodontic procedures. Because of potential discoloration effect of gray MTA, white MTA has been introduced into endodontic treatment for the same purposes. This study examined the dental pulp responses in dogs to both types of MTA used as a pulp-capping agent. The pulps of 24 teeth of four male dogs were exposed with a No.1 round bur and capped with either gray or white MTA. Histologic analysis was performed one and 2 weeks after treatment. Calcified bridge could be seen 1 week after treatment with both types of MTA, with no significant differences between the two treatments.     

Cytotoxicity of Newly Developed Ortho MTA Root-end Filling Materials

Introduction

Various materials have been advocated for use as root-end filling materials. The purpose of the present in vitro study was to compare the cytotoxicity of 4 root-end filling materials: glass ionomer cement (GIC; Fuji II, GC Corp, Tokyo, Japan), reinforced zinc oxide–eugenol cement (IRM; Dentsply Tulsa Dental, Tulsa, OK), and 2 types of mineral trioxide aggregate.

Methods

This study used MG-63 cells derived from a human osteosarcoma. To quantitatively evaluate the cytotoxicity of test materials, the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (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. Each specimen was examined by scanning electron microscopy for the observation of cell morphology.

Results

The XTT assay showed that the cell viability of ProRoot MTA (Dentsply Tulsa Dental) was higher than that of GIC and Ortho MTA (BioMTA, Seoul, Republic of Korea) at all time points. IRM showed significantly lower cell viability than the other groups. The scanning electron microscopic analysis revealed that elongated, dense, and almost confluent cells were observed in the cultures of GIC, Ortho MTA, and ProRoot MTA specimens. In contrast, cells on the surface of IRM were rounded in shape, and the numbers and the density of the cells were smaller than that in the other groups.

Conclusions

ProRoot MTA and GIC showed good biocompatibility in this study. However, Ortho MTA showed lower biocompatibility compared with ProRoot MTA and GIC.