纳米羟基磷灰石复合根充糊剂的抑菌性及微渗漏

背景：不同pH值形成纳米羟基磷灰石材料的纳米纯度不同,所形成的根充糊剂是否对抑菌性、根管封闭及根尖组织相容性产生影响尚无报道。 目的：比较不同pH值纳米羟基磷灰石根管充填材料、纳米羟基磷灰石复合材料和传统根管充填材料的抑菌性及与根管的密合性。 方法：采用抑菌环实验,研究pH值为8.0,9.0,10.0的纳米羟基磷灰石复合根充糊剂,Vitapex糊剂和AH-Plus糊剂及对以上各组根充糊剂添加奥硝唑以后的5组实验样本(共10组)对粪肠球菌、白色念球菌、金黄色葡萄球菌的抑菌性能;此外建立微渗漏模型,通过葡萄糖氧化酶比色测定法测量pH值为8.0,9.0的纳米羟基磷灰石复合根充糊剂,pH值为10的纳米羟基磷灰石复合根充糊剂+奥硝唑,氧化锌丁香油,Vitapex糊剂和AH-Plus糊剂与根管的密合性。 结果与结论：不同pH值的纳米羟基磷灰石本身无抑菌性,加入奥硝唑后有抑菌性,对粪肠球菌抑制性最高,其次是金黄色葡萄球菌,最后是白色念珠株菌。Vitapex仅对金黄色葡萄球菌有抑制作用。AH-Plus本身有抑菌性,加入奥硝唑后抑菌性降低。不同pH值纳米羟基磷灰石糊剂的根管封闭性优于氧化锌丁香油糊剂、Vitapex糊剂,但次于AH-Plus糊剂。将奥硝唑加入纳米羟基磷灰石糊剂对根管封闭性短期无影响。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

不同热牙胶旁路充填牙根表面的温度变化

背景：热牙胶充填可以实现完善的三维根管充填效果,但由于扁根管结构的特殊性,特别是在旁路预备过程中,部分牙体组织被过度切削造成局部区域牙体组织薄弱与不规则,同时分离器械为导热良好的金属,那么热牙胶在操作过程中产生的热量是否会烧伤牙周组织？ 目的：利用红外成像仪分析两种热牙胶充填方法在扁根管内器械分离行旁路充填牙根表面的温度变化。 方法：选取40颗扁根管离体人下颌第一前磨牙,将新的15#不锈钢K锉分离在距根尖3 mm处,分离长度      3 mm。在根管手术显微镜下采用TF镍钛锉进行根管旁路预备,随机分为2组,每组20颗,分别运用Thermafil热牙胶充填方法与E&Q plus热牙胶垂直加压充填方法进行根管旁路充填。采用红外成像仪测定根管充填前后离体牙牙根表面的温度变化。 结果与结论：两种热牙胶充填方法在扁根管内器械分离行旁路充填,均引起牙根表面温度升高,但均小于    10 ℃：Thermafil热牙胶充填组温度变化范围为3.2-8.1 ℃,平均4.97 ℃;E&Q plus热牙胶垂直加压充填组变化范围为5.5-9.8 ℃,平均为7.35 ℃,两组温度变化值比较差异有显著性意义(P < 0.05)。表明Thermafil热牙胶充填方法在扁根管内器械分离行旁路充填时会导致牙根表面温度升高,但不会烧伤牙周组织,其充填安全性优于E&Q plus热牙胶垂直加压充填法。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料修复桡骨缺损

背景：课题组前期研制了新型明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料。目的：观察明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料修复兔桡骨缺损的效果。方法：取30只成年健康新西兰大白兔,在一侧桡骨上端制作约15 mm×6 mm的临界性腔隙性骨缺损,随机分为实验组(n=15)、自体骨移植组(n=10)和空白对照组(n=5),实验组将明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料植入骨缺损处,自体骨移植组从对侧桡骨取等长桡骨植入骨缺损处,空白对照组不做任何处理。于术后2,4,8,12周分别行大体观察、组织学观察及X射线平片检查。结果与结论：植入后12周,实验组骨缺损区有明显血管生成,骨性愈合完全,植入复合材料消失,出现板层骨结构,可见小血管,新生骨边缘与原骨边缘连接,表现成骨的连续性,密度较原骨稍降低,骨缺损区不明显;自体骨移植组骨性愈合,骨小梁重建较明显,板层骨较成熟,髓腔再通,骨折线完全消失,骨密度与原骨完全一致;空白对照组髓腔无明显成骨现象,大量纤维组织及炎症细胞浸润,骨折断端未愈合。表明明胶-壳聚糖-羟基磷灰石-米诺环素仿生纳米复合材料可明显促进临界性骨缺损修复,效果与自体骨移植相当。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

次氯酸钠冲洗方式、温度和冲洗时间影响根管玷污层的清除效果

背景：根管预备中,次氯酸钠根管冲洗液清除玷污层的效果与冲洗液接触时间和面积、冲洗液的量、冲洗液温度、冲洗液浓度、冲洗方式等有关。目的：观察在不同冲洗方式、冲洗温度和冲洗时间下,3%次氯酸钠对根管玷污层的清除效果。方法：收集离体人单根前牙180颗,均采用机动ProTaper进行根管预备,以3%次氯酸钠冲洗根管,根据冲洗方式将其随机均分为根管主动清洗组、被动超声荡洗组和侧方开口冲洗针组3大组,再根据冲洗温度和每更换一根锉后的冲洗时间分别将每大组随机均分为6小组,分别为20 ℃ 30 s组、20 ℃ 60 s组、37 ℃    30 s组、37 ℃ 60 s、60 ℃ 30 s组和60 ℃ 60 s组。扫描电镜观察各组根管玷污层清除效果。结果与结论：根管主动清洗组玷污层的总体清除效果优于被动超声荡洗组与侧方开口冲洗针组(P < 0.05)。每组组内,在时间一定的情况下,60 ℃组的玷污层清除效果优于37 ℃组、20 ℃组(P < 0.05);在温度一定的情况下,60 s组的玷污层清除效果优于30 s组(P < 0.05);根冠1/3区的玷污层清除效果优于根中1/3区、根尖1/3区(P < 0.05)。说明以根管主动清洗方式,采用60 ℃的3%次氯酸钠清洗60 s清除玷污层的效果最好。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

骨水泥和纳米骨浆强化椎弓根螺钉植入固定骨质疏松椎体的生物力学特点

背景：纳米骨浆和骨水泥注入是强化椎弓根螺钉固定的两种常用方法,但目前关于两种加强方法的强化效果比较的报道相对较少。 目的：对比骨水泥或纳米骨浆强化椎弓根螺钉植入固定骨质疏松椎体的生物力学特点。 方法：取24个人尸体椎弓根,均符合骨质疏松标准,随机均分为3组,对照组仅植入椎弓根螺钉,骨水泥组在钉道内注入骨水泥后植入椎弓根螺钉,纳米骨浆组在钉道内注入纳米骨浆后植入椎弓根螺钉。植入2 h后,检测各组标本最大轴向拔出力和最大旋出力矩。 结果与结论：骨水泥组、纳米骨浆组的最大轴向拔出力和最大旋出力矩均大于对照组(P < 0.05),并且骨水泥组的最大轴向拔出力和最大旋出力矩大于纳米骨浆组(P < 0.05)。表明骨水泥和纳米骨浆强化可有效提高椎弓根螺钉植入固定骨质疏松椎体的最大轴向拔出力和最大旋出力矩,且骨水泥强化效果更明显。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

纳米羟基磷灰石/聚羟基丁酸酯骨组织工程支架的制备及性能表征

背景：高分子聚合物聚羟基丁酸酯具有优良的生物相容性、生物降解性及压电性,但也存在脆性大、亲水性较差等不足。 目的：制备不同组成比例的电纺纳米羟基磷灰石/聚羟基丁酸酯纤维支架材料,分析其结构及性能。 方法：通过气流-高压静电纺丝技术制备纳米羟基磷灰石质量百分比分别为0、10%、20%、30%的电纺纳米羟基磷灰石/聚羟基丁酸酯纤维支架,检测支架材料的微观结构、基团组成、晶相分布、热学性能及表面润湿性。 结果与结论：扫描电镜观察显示,随着纳米羟基磷灰石含量的增大,越来越多的纳米羟基磷灰石颗粒分布于复合纤维表面且分布趋于均匀,到含量达到30%时,纳米羟基磷灰石已基本布满纤维表面,纤维表面的粗糙度也随之增加;差示扫描量热法及X射线衍射结果表明,纳米羟基磷灰石的加入可以降低复合纤维中聚羟基丁酸酯的结晶度及结晶规整程度,且纳米羟基磷灰石含量越大效果越明显;随着纳米羟基磷灰石含量的增大,复合支架表面的接触角逐渐降低,亲水性有所提高。表明将纳米羟基磷灰石与聚羟基丁酸酯复合进行电纺可以有效提高材料的表面润湿性及结晶度,改善材料的亲水性及脆性,且纳米羟基磷灰石含量越高作用越明显。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

纳米羟基磷灰石/聚己内酯电纺支架修复种植体周围骨缺损

背景：牙齿缺失导致牙槽嵴骨质的改建和持续吸收,严重影响种植体植入的条件和种植区软硬组织的美观。目的：评价纳米羟基磷灰石/聚己内酯电纺支架促进即刻种植体周围骨缺损的成骨效果。方法：制作犬骨髓间充质干细胞复合纳米羟基磷灰石/聚己内酯电纺支架的组织工程化骨。拔除6只实验犬双侧下颌第二前磨牙,在其近中根牙槽窝处制备种植床,即刻植入种植体,在钛钉颊侧制作三壁骨缺损,两侧骨缺损处分别植入组织工程化骨与Bio-Oss小牛无机骨粉,并在材料表面覆盖Bio-Gide胶原膜。术后即刻、4周、8周、12周X射线测量种植体周围骨灰度值;12周后完整取出下颌骨,甲苯胺蓝染色观察骨缺损区的微观结构,新生骨量、形态结构及种植体-骨结合情况。结果与结论：两组间术后各时间点骨密度变化无明显差异,表明两组材料在促进骨再生过程中的成骨效果基本一致。组织工程化骨组骨缺损区内形成致密板状骨,可见成熟骨细胞,哈弗氏管,新生骨-种植体结合较紧密;Bio-Oss小牛无机骨粉组板层骨致密,新骨中有少量Bio-Oss颗粒分布,成骨细胞较组织工程化骨组少,部分哈弗管结构内可见到毛细血管,新骨与植入材料之间形成桥形连接,与种植体结合紧密。表明纳米羟基磷灰石/聚己内酯支架复合骨髓间充质干细胞、Bio-Gide胶原膜可促进种植体周围牙槽骨再生。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

热牙胶充填行不同桩核系统修复后牙根的抗折性

背景：由于旁路充填后扁根管形态的复杂性与不规则性,以及桩核对牙体应力变化的特殊性,至今尚未找到一种合理的桩核修复系统适用于扁根管旁路充填后牙体的修复。目的：比较扁根管旁路热牙胶充填后分别行钴铬合金铸造桩核、二氧化锆桩核及CAD/CAM一体化玻璃纤维桩核修复后牙体的抗折能力。方法：获取离体人下颌第一前磨牙(单根)90颗,采用ObturaⅡ&System B热牙胶系统进行根管旁路充填后,随机均分为3组,分别采用钴铬合金铸造桩核、二氧化锆桩核及CAD/CAM一体化玻璃纤维桩核进行牙体修复,再均以钴铬金属全冠修复。测试并记录各组样本折裂强度及折裂类型。结果与结论：钴铬合金铸造桩核组、二氧化锆桩核组抗折能力强于玻璃纤维桩核组(P < 0.05),前2组抗折能力比较差异无显著性意义。钴铬合金铸造桩核组折裂部位为牙根部,为不可修复性折裂;二氧化锆桩核组折裂部位为牙根颈部与牙根部,为可修复性折裂;玻璃纤维桩核组折裂部位为牙颈部,为可修复性折裂。表明采用钴铬合金铸造桩核进行牙体修复能承受较大的咬合力,但牙根折裂的概率较大;CAD/CAM一体化玻璃纤维桩核修复后牙根折裂的概率较低。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

铸造桩核烤瓷联冠修复已分离下颌磨牙残根42例

背景：大量研究表明,铸造金属桩核具有根管壁密合、强度高、根外段核形状可根据需要塑型等优点,具有较好的固位性、抗力性,临床修复缺损牙齿效果良好。目的：观察钴铬合金铸造桩核烤瓷联冠修复已分离下颌磨牙残根残冠的临床效果。方法：纳入已分离下颌磨牙残根残冠患者28例,共42颗患牙,其中男10例,女18例,年龄18-32岁,经完善的根管治疗、部分行牙冠延长后,行钴铬合金铸造桩核烤瓷联冠修复,随访2年,结合临床表现及X射线片检查评价修复效果。结果与结论：随访2年,修复成功26例,失败2例,其中1例为根尖有炎症,另外1例为牙周炎症,表明铸造桩核烤瓷联冠修复已分离下颌磨牙残根残冠具有良好的临床效果。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

墨鱼骨转化羟基磷灰石制备及细胞相容性

背景：从自然界中寻找骨移植替代材料来充填骨缺损是目前骨组织工程支架是研究的热点。目的：探索墨鱼骨转化羟基磷灰石三维支架及其作为骨组织工程支架材料的可行性。方法：以墨鱼骨为原料,与磷酸氢二铵在特定条件下发生水热反应,利用X射线衍射、傅里叶变换红外光谱、X射线光电子能谱法和扫描电镜分别对水热反应产物进行表征。结果与结论：墨鱼骨水热反应产物为羟基磷灰石。墨鱼骨转化羟基磷灰石保持了良好的文石相结构,将其与MG63细胞体外培养并考察其细胞相容性,证实墨鱼骨转化羟基磷灰石材料对细胞的生长无明显影响且无明显毒性,不影响细胞的正常增殖,可作为新型骨组织工程细胞支架材料。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

矿物三氧化物凝聚体根尖屏障后的根尖微渗漏

BACKGROUND: Because of its good sealing property and biocompatibility, mineral trioxide aggregate can promote the regeneration of bone tissue, induce the differentiation of periodontal cells. and reduce the apical micro-leakage. OBJECTIVE: To compare the micro-leakage of hot gutta-percha filling after mineral trioxide aggregate apical barrier and continuous hot gutta-percha filling techniques. METHODS: Totally 36 in vitro single root canal molars were selected and randomly divided into experimental and control groups. In the experimental group, mineral trioxide aggregate apical barrier was conducted, and then hot gutta-percha root canal filling was conducted after operation. Continuous wave of hot gutta-percha root canal filling was conducted in the control group. The apical micro-leakage was detected by glucose oxidase method. RESULTS AND CONCLUSION: The root canals were successfully and tightly sealed in these two groups. The apical micro-leakage gradually increased with the time. In the experimental group, the apical micro-leakage values at 1, 7, 14, 21 and 28 days of filling were all significantly lower than those in the control group (P < 0.05). These results demonstrate that hot gutta-percha root canal filling has a relatively good apical sealing effect after the mineral trioxide aggregate apical barrier, and can significantly reduce micro-leakage.       

The response of subcutaneous connective tissue to a new endodontic filling material

The purpose of this histopathologic study was to assess and compare the subcutaneous connective tissue reaction to a new root canal filling material, Resilon and gutta-percha. The test materials were directly inserted subcutaneously into the dorsal connective tissue of Wistar albino rats. Histopathological examinations were done at 7, 15, 30, and 60 days after the implantation procedure. The presence of inflammation, predominant cell types, and the thickness of fibrous connective tissue adjacent to each inserted sample were recorded. There were no differences in tissue reaction between Resilon cone material and gutta-percha cone groups for first three observation periods (p > 0.05). However, there were highly significant differences among observation periods within both groups (7, 15, 30, and 60 days) (p < 0.01). The tissues showed high tolerance to Resilon and gutta-percha at the 60th day. Resilon may serve as an alternative to gutta-percha in terms of biocompatibility.     

Microbial leakage of Gutta-Percha and Resilon root canal filling material: a comparative study using a new homogeneous assay for sequence detection

The sealing ability of gutta-percha/sealer root canal filling was compared to a new thermoplastic synthetic polymer-based obturation material (Resilon), using a microleakage model and a new sequence detection assay One Cut Event AmplificatioN (OCEAN). Eighty-eight extracted human teeth, shaped with K-Files and the ProTaper Technique, were randomly assigned to four groups (n = 22) and obturated in the apical 5 mm. Group R were obturated with the Resilon/Epiphany technique; group GP were obturated with gutta-percha and Zinc oxide eugenoe sealer; group RCH and GPCH received calcium hydroxide intracanal medication before being obturated. Sterilized specimens were inoculated with Enterococcus faecalis and incubated in sterile medium for 47 days. DNA extracted from the specimens was amplified by PCR and then identified by the OCEAN technique. Samples obturated with Resilon root canal filling material showed a greater number of microleakage events than the other groups (p = 0.036). Calcium hydroxide medication did not have a relevant impact on the quality of the apical seal (p = 0.044).     

不同pH值纳米羟基磷灰石复合根充糊剂的体外抑菌性

背景：目前临床应用的根管充填糊剂抗菌作用有限,存在组织刺激性强、成形困难、根管封闭性较差及易降解等缺点。 目的：比较不同pH值纳米羟基磷灰石复合根充糊剂对感染根管常见菌的体外抑菌作用。 方法：建立体外根管粪肠球菌、白色念球菌感染模型,评价pH 8纳米羟基磷灰石糊剂、pH 9纳米羟基磷灰石糊剂、pH 10纳米羟基磷灰石糊剂在离体牙根管内的抗菌作用,并以氧化锌丁香油做对照。 结果与结论：所有根充糊剂均具有抑菌作用。各pH值纳米羟基磷灰石糊剂对粪肠球菌抑制作用实验组优于氧化锌丁香油组(P < 0.05),不同pH值纳米羟基磷灰石组组间比较差异无显著性意义(P > 0.05)。而对白色念珠菌抑制作用各pH值纳米羟基磷灰石组不及氧化锌丁香油组(P < 0.05),各pH值纳米羟基磷灰石组组间比较,pH10纳米羟基磷灰石组>pH 9纳米羟基磷灰石组>pH 8纳米羟基磷灰石组(P < 0.05)。结果表明,感染根管模型中,纳米羟基磷灰石根充糊剂对粪肠球菌的抑制作用好于氧化锌丁香油(P < 0.05),而对白色念珠菌的抑制作用不及氧化锌丁香油(P < 0.05)。pH=10纳米羟基磷灰石复合根充糊剂的抑菌作用最佳。     

New endodontic obturation systems and their interfacial bond strength with intraradicular dentine - ex vivo studies

PurposeTo comparatively evaluate adhesive properties of selected root canal fillings through the measurement of the material-dentine interfacial bond strength.Material and MethodsFifty extracted single-rooted human teeth with one canal each were prepared using Hero instruments to size 30.04. Teeth were divided into four subgroups depending on the root canal filling material and the method of obturation: Resilon/Epiphany - a thermoplastic method (IA), Resilon/Epiphany - a matching single-point method (IB), gutta-percha/Roeko Seal Automix - a thermoplastic method (IIA) and gutta-percha/Roeko Seal Automix - a matching single-point method (IIB). The obturated roots were cut perpendicular to the long axis to create 1.7 mm thick slices. The bond strength was measured for each test slice with push –out testing machine.ResultsThe highest push-out bond strength was registered in subgroup IB (3.98 ± 1.33 MPa). Significantly lower bond strength was observed in subgroups IA (0.50 ± 0.24 MPa), IIA (0.33 ± 0.18 MPa) and IIB (0.08 ± 0.03 MPa) (p<0.001). No statistically significant differences in material-dentine interfacial bond strength values were observed between IA and IIA, IA and IIB, IIA and IIB subgroups (p > 0.05).ConclusionsThe push-out bond strength of the material-dentine interface was dependent on the type of material used and the root canal filling technique. The R/E system exhibited better adhesion ability to intraradicular dentine than G/RSA. The highest bond strength was observed for Resilon/Epiphany introduced with the single-cone technique.     

磷酸钙牙根管材料的封闭性能研究

以自行研制的磷酸钙（α-TCP/TTCP）水泥作为牙根管充填材料，为了评价该材料的封闭性能，以六只成年狗作为实验对象，人为造成根端开放后，在根管内充填磷酸钙水泥，并同时以Ca(OH)2糊剂，HA糊剂作为对照组，动态观察根尖孔闭合情况及根尖周组织修复过程，进行组织学及SEM分析。结果表明，磷酸钙水泥比Ca（OH）2糊剂和HA糊剂的封闭性能更为优异，在根管内与牙本质壁适合性好，具有优良的生物相容性，能引导根尖钙化组织沉积，完全封闭根尖孔，促进根尖周组织愈合，适用于根端开放，根尖周组织有破坏的无髓牙根管充填。     

杜仲提取物对运动后小鼠血清尿素氮、肝糖原和血乳酸含量的影响

目的:研究杜仲醇提水溶部位(DT)对小鼠运动及运动后代谢变化的影响。方法:对小鼠负重游泳时间、运动后血清尿素氮、肝糖原、血乳酸含量进行测定。结果:杜仲醇提水溶部位不影响小鼠正常体重。延长负重游泳时间、降低运动后血清尿素氮含量,增加肝糖原含量,降低血乳酸含量。结论:杜仲醇提水溶部位具有抗疲劳作用。     

Tooth fracture risk analysis based on a new finite element dental structure models using micro-CT data

The finite element (FE) analysis is an effective method to study the strength and predict the fracture risk of endodontically-treated teeth. This paper presents a rapid method developed to generate a comprehensive tooth FE model using data retrieved from micro-computed tomography (μCT). With this method, the inhomogeneity of material properties of teeth was included into the model without dividing the tooth model into different regions. The material properties of the tooth were assumed to be related to the mineral density. The fracture risk at different tooth portions was assessed for root canal treatments. The micro-CT images of a tooth were processed by a Matlab software programme and the CT numbers were retrieved. The tooth contours were obtained with thresholding segmentation using Amira. The inner and outer surfaces of the tooth were imported into Solidworks and a three-dimensional (3D) tooth model was constructed. An assembly of the tooth model with the periodontal ligament (PDL) layer and surrounding bone was imported into ABAQUS. The material properties of the tooth were calculated from the retrieved CT numbers via ABAQUS user's subroutines. Three root canal geometries (original and two enlargements) were investigated. The proposed method in this study can generate detailed 3D finite element models of a tooth with different root canal enlargements and filling materials, and would be very useful for the assessment of the fracture risk at different tooth portions after root canal treatments.