MTA充填对牙根抗折强度的影响

目的：研究MTA充填后对牙根抗折强度的影响。方法：选取32颗猪尖牙,在釉牙骨质界处截去牙冠、在距釉牙骨质界30 mm处截去根尖,制备成统一长度标本并随机等分为4组,分别在根管内充填不同药物后,在不同时间检测导致牙根折裂时所需的最小压力,得到牙本质的三点弯曲强度。结果：各组牙根折裂时的三点弯曲强度分别为：167.86-i-9.83MPa、154.99-i-11.30MPa、173.87-i-13.85MPa、150.45-i-9.40MPa。单因素方差分析,F=8.66（P〈0.05）。结论：无髓牙随着时间增加,牙根抗折性降低;MTA充填后牙根的三点弯曲强度增强,MTA增强了牙根的抗折性;Viatapex糊剂长时间对牙根的三点弯曲强度的改变不明显。     

Effect of dental materials calcium hydroxide-containing cement, mineral trioxide aggregate, and enamel matrix derivative on proliferation and differentiation of human tooth germ stem cells

Introduction

Biocompatibility of pulp capping materials is important for successful use in dentistry. These materials should be nontoxic and permissive for proliferation and induction of odontogenic differentiation of pulp cells. The aim of our study was to evaluate the effects of enamel matrix derivative (EMD), mineral trioxide aggregate (MTA), and calcium hydroxide-containing cement (DYCAL) on proliferation and odontogenic differentiation of human tooth germ stem cells (hTGSCs) in which cells belonging to both pulp tissue and dental follicle exist.

Methods

The 96-well plates, 24-well plates, and special chamber slides were coated with biomaterials for cell proliferation, differentiation, and scanning electron microscopy analysis. Odontogenic differentiation of hTGSCs was evaluated by analyzing mRNA expression of dentin sialophosphoprotein (DSPP) by real-time polymerase chain reaction expression analysis, measurement of alkaline phosphatase activity, and visualization of calcium depositions by von Kossa staining.

Results

Our results demonstrate that EMD is the best material in terms of inducing differentiation and proliferation of hTGSCs. DYCAL was found to be toxic to hTGSCs; however, EMD-coated DYCAL showed less toxicity. EMD-coated MTA was not efficient at inducing proliferation and differentiation.

Conclusions

Pulp capping materials come in direct contact with dental pulp cells; thus, they require comprehensive evaluation of interactions between cells and biomaterials. Therefore, we cultured hTGSCs, capable of odontogenic differentiation, on pulp capping materials directly. Our results suggest that combination of capping materials with EMD would increase the quality of capping by increasing biocompatibility of capping materials.     

Similar expression of through-and-through fluid movement along orthograde apical plugs of MTA Bio and white Portland cement

Aim To compare the sealing ability of four hydraulic cements when used as an apical plug in teeth with wide‐open apices. Methodology A sample of 70 maxillary central incisors were divided into four groups (n = 15) and a further 10 teeth served as controls. An artificial open apex was created in the teeth using Gates Glidden drills numbers 6‐1 in a crown‐down manner until the size 1 bur passed through the foramen. A divergent open apex was prepared to a size of 1.24 mm at the foramen by retrograde apical transportation using a number 8 (0.60) Profile Series 29 0.4 taper instrument inserted to the length of the cutting blade. In G1, the open apices were repaired with WMTA Angelus whilst in G2, G3 and G4 MTA Bio?, Pro‐Root MTA and Portland cement was employed respectively. Each root was assembled in a hermetic cell to allow the evaluation of fluid filtration. Leakage was measured by the movement of an air bubble travelling within a pipette connected to the teeth. Measurements of the air bubble movement were made after 10 min at a constant pressure of 50 cm H₂O. The Kruskal–Wallis H‐test was applied to the fluid flow data to detect differences between the experimental groups (P < 0.05). Results Fluid movement occurred in every sample but was variable in all the experimental groups, ranging from 0.61 to 2.45 μL min^?1. There was no significant difference in mean fluid flow between the experimental groups (P > 0.05). Conclusions Fluid movement through teeth with open apices and filled with four hydraulic cements was similar. All cements allowed fluid movement.     

MTA1、VEGF在化疗后骨肉瘤组织中的表达及其相关性

目的探讨转移相关蛋白（Mta-1）和血管内皮生长因子（VEGF）在化疗后骨肉瘤组织中表达与化疗后骨肉瘤患者预后之间的关系。方法采用免疫组织化学 SP法,检测 31例化疗后骨肉瘤组织中 MTA1与VEGF的表达。并应用统计学方法分析其与预后的相关性。结果统计学分析显示化疗后骨肉瘤组织中 MTA1与VEGF表达与骨肉瘤患者预后显著相关（P<0.05）,MTA1与VEGF联合检测对化疗后骨肉瘤患者预后更有指导意义。 结论VEGF与MTA1均为阴性预后较好;VEGF、MAT1均为阳性预后较差。联合检测MTA1与VEGF可以用于评估化疗后骨肉瘤患者的预后。     

Short-Hairpin RNA-Mediated MTA2 Silencing Inhibits Human Breast Cancer Cell Line MDA-MB231 Proliferation and Metastasis

Objective: To observe the effects of metastasis-associated tumor gene family 2 (MTA2) depletion on humanbreast cancer cell proliferation and metastasis. Methods: A short-hairpin RNA targeting MTA2 was chemicallysynthesized and transfected into a lentivirus to construct Lv-shMTA2 for infection into the MDA-MB231human breast cancer cell line. At 48 hours after infection cells were harvested and mRNA and protein levels ofMTA2 were determined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting,respectively. Cell viability and metastasis were assessed by CCK-8, wound-healing assay and Transwell assay,respectively. In addition, a xenograft model of human breast cancer was constructed to investigate cancerouscell growth and capacity for metastasis. Results: After infection with Lv-shMTA2, mRNA and protein levelsof MTA2 was significantly reduced (p<0.05) and MDA-MB231 cell proliferation and metastasis were inhibited(p<0.05). In addition, mean tumor size was smaller than that in control group nude mice (p<0.05) and numbersof metastatic deposits in lung were lower than in control group mice (p<0.05). Depletion of MTA2 affectedMMP-2 and apoptosis-related protein expression. Conclusions: For the first time to our knowledge we showedthat MTA2 depletion could significantly inhibit human breast cancer cell growth and metastasis, implying thatMTA2 might be involved in the progression of breast cancer. The role of MTA2 in breast cancer growth andmetastasis might be linked with regulation of matrix metalloproteinase and apoptosis.     

MTA、GIC、银汞合金修复髓腔穿孔的临床效果比较研究

[摘要] 目的 比较无机三氧化聚合物(MTA)、玻璃离子水门汀(GIC)和银汞合金3种修复材料治疗医源性髓腔穿孔的临床效果。方法 所有临床病例随机分组,共有62例髓腔穿孔病例纳入分析,其中MTA组21例,GIC组22例,银汞合金组19例。分别进行穿孔修补并进行彻底的根管治疗和充填,术后3个月,根据临床症状评价短期疗效。结果 MTA组有效率为90.48%(19/21),GIC组有效率为59.09%(13/22),银汞合金组有效率为52.63%(10/19)。MTA组与其他2组存在统计学差异,MTA组有效率高于GIC组和银汞合金组(P<0.05)。结论 MTA具有良好生物相容性,能够促进硬组织的形成,封闭性能好,在髓腔穿孔修补中的临床效果优于GIC和银汞合金。     

沉默MTA1表达对胃癌SGC7901细胞增殖和侵袭能力的影响

目的:观察转移相关基因1（MTA1）基因沉默对人胃癌细胞SGC7901增殖和迁移侵袭能力的影响,探讨 MTA1基因在胃癌发生发展中的作用。方法:利用脂质体法将靶向MTA1的小分子干扰 RNA（siRNA） 转染到胃癌细胞株 SGC7901中。运用Real time PCR 和Western blot 技术检测SGC7901细胞内MTA1的 mRNA和蛋白表达水平。CCK-8法检测细胞增殖能力,Transwell小室实验观察细胞迁移和侵袭能力。结果:MTA1 siRNA 可有效抑制SGC7901细胞MTA1基因在 mRNA 和蛋白水平上的表达（P﹤0.01）。CCK-8实验表明MTA1 siRNA 转染后细胞增殖不受影响;Transwell小室实验表明细胞迁移和侵袭能力明显下降。结论:沉默MTA1表达可抑制胃癌细胞株 SGC7901迁移和侵袭,而不影响细胞增殖。MTA1在胃癌侵袭转移过程中可能发挥重要作用。     

Alveolar mucosa necrosis induced by utilisation of calcium hydroxide as root canal dressing

This case demonstrates the ability of calcium hydroxide to cause connective tissue necrosis. A patient with a history of trauma exhibited a large area of external inflammatory root resorption affecting the cervical and middle thirds of tooth 12. After root canal cleaning, a calcium hydroxide root canal dressing was applied to control the resorption process. After three days when the patient attended for replacement of the dressing an irregular zone of necrosis was observed on the buccal aspect of the alveolar mucosa. Careful curettage and irrigation was then performed to remove the extruded calcium hydroxide and necrotic tissue. After curettage, the root canal was accessed and irrigated with saline solution for removal of remnants of the dressing. The dressing was than replaced taking care to avoid contact with soft tissue, which might induce further damage, minimising the overflow of material. Improvement in healing was observed at 15-day follow-up, with complete closure of the lesion by soft tissue. At the 120-day follow-up, no scar was detected. At 180-day follow-up, the root canal was filled only with mineral trioxide aggregate (MTA) with aid of K files #20 and #50. At two-year follow-up, there were no symptoms and the resorption process seemed to have ceased. It is important to emphasise the damage that may occur when calcium hydroxide is in close and extended contact with the soft tissues, which could happen when dressing material is extruded through a root resorption.     

显微根尖手术联合MTA治疗难治性慢性根尖周炎的研究

目的:研究在显微根尖手术治疗难治性慢性根尖周炎时应用MTA的可行性、特点、成功率及相关影响因素。方法:分析2013年1月~2015年12月间本院牙体牙髓科完成的显微根尖外科手术106例计146颗难治性慢性根尖周炎患牙的临床资料,其中上颌前牙75例、下颌前牙13例、上颌前磨牙6例、下颌前磨牙4例、上颌磨牙4例、下颌磨牙4例。手术包括根尖切除、根尖倒预备、根尖倒充填主要步骤,术后1年回访,通过临床症状和放射学检查评估疗效,并对预后影响因素进行卡方检验分析。结果:显微根尖外科手术联合MTA应用的1年成功率达95.9％(140/146),根据患者性别、年龄、牙位、根尖病灶范围分别统计手术疗效,组间差异均无统计学意义。失败5例6颗患牙,主要原因为根折及合并重度牙周炎。结论:在治疗难治性慢性根尖周炎时采用显微根尖手术联合MTA应用可取得满意效果;显微根尖手术是治疗慢性根尖周炎的有效手段。