TiO2纳米管表面对成骨细胞与巨噬细胞黏附、形态及迁移的影响

目的:研究TiO₂纳米管对小鼠成骨细胞和巨噬细胞早期黏附、细胞形态及迁移运动的影响。方法:将小鼠成骨细胞(MC3T3-E1)和巨噬细胞(RAW264.7)分别接种于抛光(P)后的纯钛试样和抛光钛经20 V恒压阳极氧化制备出的纳米管形貌(NT)钛试样表面,扫描电镜观察钛试样的表面形貌以及细胞接种于各组钛试样3、6、12、24、48 h后的细胞形态,Hoechst染色后荧光显微镜统计各组钛试样在接种3、6、12、24 h后的细胞黏附数量,活细胞工作站观察细胞在不同形貌钛表面24 h的迁移运动轨迹。结果:NT组钛试样表面可见均匀排列的纳米管阵列,P组钛表面光滑。与P组相比,NT组表面成骨细胞黏附数量较多,细胞丝状伪足长且丰富,细胞迁移运动缓慢,而巨噬细胞的黏附数量和丝状伪足较少,细胞迁移速率更高。结论:钛表面纳米管形貌可促进成骨细胞黏附,抑制其迁移运动,而对巨噬细胞的影响则相反。     

钛表面微纳层级结构促MC3T3-E1细胞黏附增殖及载药潜力评价

目的 探讨钛表面微纳层级结构对MC3T3-E1细胞黏附增殖的影响和载药潜力的评价,为钛表面选区改性并载药缓释提供参考。方法 根据钛表面处理方式将纯钛样本(直径10 mm,厚2.5 mm)随机分为：抛光组(T)、阳极氧化组(TO)和微纳层级结构组(FTO)。T组仅做抛光处理;TO组采用阳极氧化技术处理;FTO组采用飞秒激光蚀刻联合阳极氧化技术处理。用扫描电镜(scanning electron microscopy,SEM)观察3种表面形貌,接触角测量其表面的润湿性,X射线能谱仪(energy dispersive spectroscopy,EDS)分析表面化学成分;激光共聚焦显微镜(confocal laser scanning microscope,CLSM)测量FTO结构深度和表面粗糙度;免疫荧光染色、CCK-8和茜苏红染色半定量分析评估MC3T3-E1细胞在各组样本表面的黏附增殖分化;应用冷冻干燥法加载重组人源骨形成蛋白-2(recombinant human bone morphogenetic proteins-2,rhBMP-2),酶联免疫吸附反应(enzyme-linke...     

纯钛微弧氧化-壳聚糖-海藻酸钠涂层的细胞相容性研究

目的:通过对不同涂层表面进行成骨细胞生物相容性检测,评价其生物相容性。方法:纯钛微弧氧化组为对照A组、纯钛微弧氧化-碱处理-壳聚糖复合处理为实验B组、纯钛微弧氧化-碱处理-壳聚糖-海藻酸钠复合处理为C组。通过CCK-8实验检测不同时间细胞黏附情况以及增殖情况,激光共聚焦检测早期细胞骨架形态,扫描电镜观察试件表面形貌,ALP检测其不同时间碱性磷酸酶活性。结果:激光共聚焦显示B组和C组表面细胞的生长和黏附均优于A组,C组优于B组。CCK-8和ALP的检测结果显示3组材料表面细胞的增殖、活性的顺序为C组>B组>A组,3组的比较差异均具有统计学意义。结论:3组材料均具有良好的生物相容性,纯钛微弧氧化--碱处理-壳聚糖-海藻酸钠复合处理涂层细胞相容性最佳。[关键词]纯钛成骨细胞壳聚糖海藻酸钠生物相容性     

纯钛微弧氧化-多巴胺-环型多肽涂层的细胞相容性研究

目的:探讨纯钛种植体表面加载环型多肽对成骨细胞生物行为的影响。方法:微弧氧化组为M组,微弧氧化加载多巴胺组为P组,微弧氧化加载多巴胺接枝环环肽组为R组。扫描电镜对3组钛片进行表面形貌分析,能谱仪分析3组试件元素成分。CCK-8检测成骨细胞不同时间点在3组的增殖黏附能力,激光共聚焦观察成骨细胞在3组涂层表面的铺展情况。结果:扫描电镜及能谱显示涂层加载成功,CCK-8显示R组的A值在各个时间点上都高于M组和P组,且各组比较具有统计学意义(P<0.05)。激光共聚焦观察R组细胞数目最多,伪足较多,细胞联系最为紧密。结论:纯钛表面加载环肽后能有效的促进成骨细胞早期的黏附及增殖。     

抗菌肽生物功能化TiO2纳米管的抗菌性能及其对人角质形成细胞生物学行为的影响

目的探讨抗菌肽生物功能化TiO2纳米管的抗菌性能及其对人角质形成细胞黏附、迁移等生物学行为的影响。方法采用阳极氧化法在光滑钛片(光滑钛组)表面构建TiO2纳米管阵列(纳米管组), 通过物理吸附方式将抗菌肽(LL-37)加载至TiO2纳米管表面(抗菌肽组)。每组采用简单随机抽样法抽取3个试样, 借助场发射扫描电镜、原子力显微镜、接触角测量仪、荧光标记和荧光酶标仪观察各组试样表面形貌、粗糙度、亲水性以及抗菌肽释放特点。将人角质形成细胞分别培养于3组钛试样表面, 每组设置3个重复, 场发射扫描电镜观察细胞黏附形态, 细胞免疫荧光染色观察黏附数量;细胞计数试剂盒检测细胞增殖能力;划痕实验分析细胞迁移特点, 评价各组钛试样对HaCaT细胞生物学行为的影响。将牙龈卟啉单胞菌(Porphyromonas gingivalis, Pg)接种至3组钛试样表面, 每组设置3个重复, 场发射扫描电镜观察细菌形态, 活死细菌染色法测定细菌活力, 评价各组钛试样对Pg的抑制作用。结果抗菌肽组试样表面可见均匀排列的纳米管阵列, 管口处有颗粒状抗菌肽覆盖。纳米管组和抗菌肽组钛试样表面粗糙度[分别为(20.40±3....     

碱酸处理钛基钽涂层对兔骨髓间充质干细胞生物学活性的影响

目的:研究碱酸处理钛基钽涂层对兔骨髓间充质干细胞(rabbit bone marrow mesenchymal stem cells,rBMSCs)黏附、增殖和成骨分化的影响,为钽涂层人工种植体的临床转化研究提供依据.方法:实验分四组:钛基钽涂层(Ta)组、酸处理(HCl)组、碱处理(NaOH)组、碱酸(NaH)组.通过扫描电镜(SEM)、能量色散X射线光谱仪(EDS)、蛋白吸附实验观察不同处理组表面理化性质的变化.将rBMSCs接种在四组材料表面,通过荧光显微镜、CCK-8、碱性磷酸酶(ALP)染色、茜素红染色及RT-qPCR对Runx2和COL-Ⅰ基因表达分析,评估不同处理组对rBMSCs的黏附、增殖和成骨分化的影响.结果 .SEM和EDS显示HCl组涂层表面形貌和元素组成未见明显改变,NaOH组表面孔隙略有增大且表面钠元素含量显著增高.NaH组涂层孔隙均匀,表面钠元素含量明显降低,且较其它三组对蛋白吸附量增多(P＜0.05).免疫荧光及CCK-8结果表明细胞黏附和增殖能力依次为:NaH组＞NaOH组＞HCl组≈Ta组;ALP染色、茜素红染色发现NaH组和NaOH组有更多深染蓝色颗粒和红色钙化结节;RT-qPCR可见细胞在NaH组表面成骨相关基因Runx2和COL-Ⅰ表达量高于其它三组.结论:碱酸处理的钽涂层表面形貌及成分明显改变,能有效促进rBMSCs黏附、增殖及成骨分化,改善钽涂层表面的生物活性并促进成骨,该法是提升钛基钽涂层人工种植体表面生物活性的有效途径.     

碱酸处理钛基钽涂层对兔骨髓间充质干细胞生物学活性的影响

目的:研究碱酸处理钛基钽涂层对兔骨髓间充质干细胞(rabbit bone marrow mesenchymal stem cells,rBMSCs)黏附、增殖和成骨分化的影响,为钽涂层人工种植体的临床转化研究提供依据.方法:实验分四组:钛基钽涂层(Ta)组、酸处理(HCl)组、碱处理(NaOH)组、碱酸(NaH)组.通过扫描电镜(SEM)、能量色散X射线光谱仪(EDS)、蛋白吸附实验观察不同处理组表面理化性质的变化.将rBMSCs接种在四组材料表面,通过荧光显微镜、CCK-8、碱性磷酸酶(ALP)染色、茜素红染色及RT-qPCR对Runx2和COL-Ⅰ基因表达分析,评估不同处理组对rBMSCs的黏附、增殖和成骨分化的影响.结果 .SEM和EDS显示HCl组涂层表面形貌和元素组成未见明显改变,NaOH组表面孔隙略有增大且表面钠元素含量显著增高.NaH组涂层孔隙均匀,表面钠元素含量明显降低,且较其它三组对蛋白吸附量增多(P＜0.05).免疫荧光及CCK-8结果表明细胞黏附和增殖能力依次为:NaH组＞NaOH组＞HCl组≈Ta组;ALP染色、茜素红染色发现NaH组和NaOH组有更多深染蓝色颗粒和红色钙化结节;RT-qPCR可见细胞在NaH组表面成骨相关基因Runx2和COL-Ⅰ表达量高于其它三组.结论:碱酸处理的钽涂层表面形貌及成分明显改变,能有效促进rBMSCs黏附、增殖及成骨分化,改善钽涂层表面的生物活性并促进成骨,该法是提升钛基钽涂层人工种植体表面生物活性的有效途径.     

不同纳米尺度钛膜表面蛋白黏附的研究

目的：比较蛋白黏附在磁控溅射法形成不同纳米尺度的钛膜是否存在差异性,从而了解经改性后的钛片材料表面与骨之间的生物活性状况。方法：按照溅射处理温度的不同,将钛片分为5组,形成了不同纳米粒径的钛膜。采用BCA（bicinchoninic acid）法蛋白浓度定量测定,计算牛血清白蛋白在不同温度处理组与对照组材料表面黏附蛋白浓度。结果：常温组与其它四组测量值之间存在显著性差异（P〈0.05）,100℃组与常温组及对照组之间差异最大,材料表面黏附白蛋白数量最多,380℃组与常温组及对照组之间差异最小。其他各组之间无显著性差异。结论：利用直流磁控溅射技术在纯钛表面形成的纳米粒度的钛膜,可以改善钛表面的性能,提高其生物相容性。     

细菌脂多糖诱导人牙龈上皮细胞β防御素-4表达的实验研究

目的观察不同浓度细菌脂多糖(BLPS)作用下原代培养的人牙龈上皮细胞(HGECs)β防御素-4(BD-4)的表达。方法体外原代培养HGECs,经免疫细胞化学鉴定,加入10、20、40、80、160μg/m L的BLPS,采用免疫组织化学和Western blotting检测BD-4蛋白在HGECs中的定位和表达变化。结果 HGECs组织块法原代细胞生长状态好,第3代细胞进行鉴定,Ck(AE1/AE3)(+)/Vimentin(-)。HGECs免疫细胞化学染色结果显示,HGECs胞浆可见棕黄色颗粒状着色,阳性染色弥漫分布于胞浆,随着BLPS浓度的增加表达更为强烈。Western Blotting结果显示,BD-4表达水平随BLPS浓度增加而增高。BD-4蛋白在BLPS浓度为160μg/m L表达的值最高,组间比较差异有统计学意义(P<0.01)。结论随着BLPS对牙龈上皮炎症刺激加重,BD-4表达增强,提示了BD-4在牙周炎症进程中的作用。     

低温氩氧等离子体处理的无机牛骨对MC3T3-E1细胞黏附、增殖及分化的影响

目的研究小鼠胚胎成骨细胞MC3T3-E1在低温氩氧等离子体处理的无机牛骨上的黏附、增殖及分化特征。方法使用低温氩氧等离子体对无机牛骨进行表面活化(实验组)后,使用扫描电子显微镜(SEM)观察无机牛骨表面形貌的变化,X射线光电子能谱分析(XPS)检测表面元素的组成。将MC3T3-E1细胞接种于低温氩氧等离子体处理的无机牛骨表面,使用SEM观察细胞的黏附形态,CCK-8法检测细胞1、3、5 d的增殖变化,碱性磷酸酶(ALP)法检测细胞7、14 d的分化状态。以不作处理的无机牛骨作为对照。结果对照组与实验组的表面形貌无明显改变;在表面材料的元素组成上,实验组表面碳元素减少,氧、钙、磷元素均增高。实验组MC3T3-E1细胞的黏附更充分,细胞伸出伪足;培养1、3、5 d时,实验组细胞增殖数量明显高于对照组;培养14 d时,实验组ALP活性明显高于对照组(P<0.05)。结论低温氩氧等离子体处理对无机牛骨表面小鼠胚胎成骨细胞的黏附、增殖及分化具有一定的促进作用。     

Effects of Delta12-prostaglandin J2 on bone regeneration and growth factor expression in rats

OBJECTIVES: Cyclopentenone prostaglandins have been shown to promote osteoblast differentiation in vitro. The aim of this study was to examine in a rat model the effects of local delivery of Delta(12)-prostaglandin J(2) (Delta(12)-PGJ(2)) on new bone formation and growth factor expression in (i) cortical defects and (ii) around titanium implants. MATERIAL AND METHODS: Standardized transcortical defects were prepared bilaterally in the femur of 28 male Wistar rats. Ten microliters of Delta(12)-PGJ(2) at 4 concentrations (10(-9), 10(-7), 10(-5) and 10(-3) mol/l) in a collagen vehicle were delivered inside a half-cylindrical titanium chamber fixed over the defect. Contralateral defects served as vehicle controls. Ten days after surgery, the amount of new bone formation in the cortical defect area was determined by histomorphometry and expression of platelet-derived growth factor (PDGF)-A and -B, insulin-like growth factor (IGF)-I/II, bone morphogenetic protein (BMP)-2 and -6 was examined by immunohistochemistry. In an additional six rats, 24 titanium implants were inserted into the femur. Five microliters of carboxymethylcellulose alone (control) or with Delta(12)-PGJ(2) (10(-5) and 10(-3) mol/l) were delivered into surgically prepared beds prior to implant installation. RESULTS: Delta(12)-PGJ(2) (10(-5) and 10(-3) mol/l) significantly enhanced new bone formation (33%, P<0.05) compared with control cortical defects. Delivery of Delta(12)-PGJ(2) at 10(-3) mol/l significantly increased PDGF-A and -B and BMP-2 and -6 protein expression (P<0.05) compared with control defects. No significant difference was found in IGF-I/II expression compared with controls. Administration of Delta(12)-PGJ(2) also significantly increased endosteal new bone formation around implants compared with controls. CONCLUSION: Local delivery of Delta(12)-PGJ(2) promoted new bone formation in the cortical defect area and around titanium implants. Enhanced expression of BMP-2 and -6 as well as PDGF-A and -B may be involved in Delta(12)-PGJ(2)-induced new bone formation.     

Protein free diet feeding: effects on sympathetic activity and salivary evoked secretion in the submandibular gland of the rat

Protein restriction impairs the salivary flow rate and composition in human and rats. The aim of the present work was to establish the effect of low protein (casein 5%) and protein free (casein 0%) isocaloric diets on sympathetic activity and salivary evoked secretion in the submandibular gland (SMG) of the rat. After 21 days, rats fed casein 0% presented: (a) a significant shift to the left of the dose-response curves (DRC) to the autonomic agonists-norepinephrine (NE), methoxamine, isoproterenol (ISO) and methacholine; (b) increased food consumption (p<0.001); (c) decreased body (p<0.001) and SMG (p<0.001) weights maintaining SMG/body (w/w) relation; (d) enhanced submandibular alpha1-adrenoceptor number without changes in the apparent dissociation constant (Kd); (e) increased submandibular NE content (p<0.05) and phosphoinositoside hydrolysis (p<0.001); (f) decreased submandibular tyrosine hydroxylase activity (TH) (p<0.01). Casein 5% feeding increased food consumption (p<0.01) and reduced body weight (p<0.05). This protein restriction increased metacholine-evoked salivation, but it altered neither submandibular sympathetic activity nor sympathetic-induced salivary secretion as compared to the Control group (C) fed a similar diet containing 25.5% protein. Present results suggest that in the adult rat, a protein free diet during 21 days lowers SMG sympathetic and cholinergic activity leading to supersensitivity as revealed by up-regulation of alpha1-adrenergic receptor number and increased autonomic-evoked salivation.     

Protection of short-time enamel erosion by different tetrafluoride compounds

OBJECTIVE: This in vitro study aimed to analyse the protective effect of differently concentrated titanium (TiF(4)), zirconium (ZrF(4)) and hafnium (HfF(4)) tetrafluoride on enamel erosion. METHODS: Polished enamel surfaces of 36 bovine crowns were covered with tape leaving 4 enamel windows each 3mm in diameter exposed. The crowns were randomly assigned to six groups (each n=6) and pretreated with 4% TiF(4), 10% TiF(4), 4% ZrF(4), 10% ZrF(4), 4% HfF(4) or 10% HfF(4) for 4 min (first window), 10 min (second window) or 15 min (third window). The fourth window of each crown was not pretreated and served as control. Erosion was performed stepwise with 1% HCl (pH 2) in five consecutive intervals of each 15 s (total 75 s). Enamel dissolution was quantified by colorimetric determination of phosphate release into the acid. For each tooth, cumulative phosphate loss of enamel pretreated with one of the tetrafluoride compounds was calculated as percentage of the respective control and statistically analysed using two-way ANOVA. RESULTS: Enamel erosion was significantly reduced by TiF(4), ZrF(4) and HfF(4) application. Cumulative phosphate loss (mean % of control, 75s erosion) after 4-15 min application was significantly lower for 4% ZrF(4) (7-11%), 10% ZrF(4) (2-6%), 4% HfF(4) (11-9%) and 10% HfF(4) (12-16%) compared to 4% TiF(4) (42-27%) and 10% TiF(4) (54-33%). Only for 4% and 10% TiF(4), phosphate loss decreased with increasing duration of application, but also increased with increasing acid intervals. CONCLUSION: TiF(4), ZrF(4) and HfF(4) might protect enamel against short-time erosion, but protection was more enhanced by ZrF(4) and HfF(4) compared to TiF(4) application overtime.     

树脂水门汀与氧化锆陶瓷剪切粘接强度的研究

目的评估不同实验条件下树脂水门汀与氧化锆瓷之间的剪切粘接强度（SBS）。 方法使用计算机辅助设计与制作（CAD/CAM）设备切割并烧结制作6个边长为2 cm的正方体氧化锆试件。按不同实验条件将8种双固化树脂水门汀分为13组（n = 20）：（1）Monobond N + Multilink N（MMN组）;（2）Ivoclean + Monobond N + Multilink N（IMM组）;（3）Ivoclean + Monobond N + Multilink N[无喷砂,IMM（ns）组];（4）Tetric N-Bond Universal + Multilink Speed（TUM组）;（5）Multilink Speed（MLS组）;（6）Z-Prime Plus + TheraCem（ZPT组）;（7）Z-Prime Plus + Duo-Link（ZPD组）;（8）Single Bond Universal + RelyX U200（SRU组）;（9）RelyX U200（RXU组）;（10）Single Bond Universal + RelyX Ultimate Clicker（SRU组）;（11）OptiBond Versa + Kerr NX3（OVK组）;（12）Clearfil Universal Bond + Clearfil SAC（CUS组）;（13）Clearfil SAC（SAC组）。将每组树脂水门汀自混合注入透明模具并将其无压力置于氧化锆面后进行光照固化。所有试件在37 ℃水中存储24 h后进行SBS测试。采用SPSS 19.0软件One-Way ANOVA（P<0.05）对SBS进行统计学分析。利用电子体视显微镜观察氧化锆端断裂界面。 结果本实验中13组树脂水门汀的SBS（单位：MPa）降序排列依次为：OVK（27.51 ± 3.65）>IMM（27.28 ± 3.79）>SRC（26.77 ± 3.62）>CUS（25.36 ± 3.10）>TUM（25.22 ± 4.88）>ZPD（23.96 ± 6.25）>MLS（23.13 ± 2.74）>MMN（23.07 ± 3.71）>SAC（22.20 ± 3.59）>IMM（ns）（21.99 ± 3.50）>SRU（19.19 ± 2.27）>ZPT（18.62 ± 2.08）>RXU（15.04 ± 4.02）。 结论（1）不同树脂水门汀的SBS具有材料依赖性;（2）在氧化锆表面进行喷砂处理、使用专用清洗剂或将通用型粘接剂作为底漆使用有利于提高树脂水门汀的SBS。     

Effect of relining, water storage and cyclic loading on the flexural strength of a denture base acrylic resin

OBJECTIVES: This study investigated the effect of relining, water storage and cyclic loading on the ultimate flexural strength (FS(U)) and on the flexural strength at the proportional limit (FS(Pl)) of a denture base acrylic resin (Lucitone 550-L). METHODS: Rectangular bars of L were made (64 mm x 10 mm x 2 mm) and relined (1.3mm) with four relining resins (Kooliner-K, Ufi Gel Hard-UGH, Tokuso Rebase Fast-TR and New Truliner-NT). In addition, specimens relined with L and intact L specimens were made (64 mm x 10 mm x 3.3 mm). A three-point flexural test was applied on the specimens (n=10) after (1) polymerization; (2) water storage (30 days); (3) cyclic loading (10,000 cycles at 5 Hz) and (4) water storage (30 days)+cyclic loading. Data (MPa) were analyzed with three-way ANOVA and Tukey's HSD tests (alpha=0.05). To test for a possible correlation between FS(U) and FS(Pl), a linear regression coefficient "r" was calculated. RESULTS: After water storage, L-UGH and L-TR demonstrated an increased FS(U) (41.49-50.64 MPa and 49.95-57.36 MPa, respectively) (P<0.05). Only L-TR demonstrated an increased FS(Pl) (20.58-24.21 MPa) after water storage (P<0.05). L-L had the highest FS(U) (between 78.57 and 85.09 MPa) and FS(Pl) (between 31.30 and 34.17 MPa) (P<0.05). The cyclic loading decreased the FS(U) and FS(Pl) of all materials (P<0.05). Regression analysis showed a strong linear correlation between the two variables (r=0.941). CONCLUSIONS: Water storage improved the FS(U) of L-UGH and L-TR and the FS(Pl) of L-TR. L-L produced the highest FS(U) and FS(Pl). The FS(U) and FS(Pl) of all materials were detrimentally influenced by cyclic loading.     

安氏Ⅱ类错(骀)合并下颌后缩青少年吞咽运动研究

目的 通过对安氏Ⅱ类下颌后缩青少年吞咽时肌肉肌电图和下颌运动描记图进行研究,探索下颌后缩对患者吞咽功能的影响.方法 对29名安氏Ⅱ类下颌后缩青少年(安氏Ⅱ类组)与28名安氏Ⅰ类青少年(对照组)进行吞咽时颞肌前束、咬肌、颏肌肌电幅值及下颌运动范围进行测量,对比两组差异.结果 研究所得的计量数据以(中位数M上(Q25),下(Q75)四分位数)表示.1.安氏Ⅱ类组右侧颞肌前束肌电幅值(3.2(1.7,4.4) μV)小于对照组(5.0(2.7,12.9)μV),双侧咬肌肌电幅值(右3.2(2.2,5.7) μV/左3.1(1.9,4.8)μV)小于对照组(右5.6(3.1,9.7)μV/左4.7(2.6,9.8)μV),双侧颏肌肌电幅值(右22.1(15.2,40.1)μV/左21.9(13.1,36.9) μV)大于对照组(右13.7(7.3,20.7)μV/左10.8(7.0,22.8) μV).2.安氏Ⅱ类组吞咽颌位垂直向偏离(1.2(0.3,2.0)mm)大于对照组(0.5(0.2,1.0) mm)、冠状向偏离(0.4(0.2,0.7)mm)大于对照组(0.2(0.1,0.3)mm),矢状向偏离(-0.4(-1.1,0.3)mm)比对照组(0.1(-0.1,0.4)mm)更为偏前.吞咽过程中下颌垂直向位移(1.6(1.1,3.0) mm)大于对照组(1.0(0.5,1.6) mm),冠状向位移(0.3(0.1,0.8) mm)大于对照组(0.1(0.0,0.2) mm),矢状向位移(-0.4(-1.8,0.5)mm)比对照组(0.0(-0.3,0.4)mm)向前更多.结论 相比于安氏Ⅰ类患者,安氏Ⅱ类下颌后缩青少年中异常吞咽及唇功能不全比例更高.     

Silensor阻鼾器治疗前后阻塞性睡眠呼吸暂停综合征患者上气道结构改变的分析

目的 探讨Silensor阻鼾器治疗前后阻塞性睡眠呼吸暂停综合征(OSAS)患者上气道结构的改变。方法 采用X线头影测量法对42例OSAS患者Silensor阻鼾器治疗前后的上气道及其周围结构的形态进行测量,并对测量的42项结果进行配对t检验。结果 经阻鼾器治疗后,OSAS患者的软腭后气道增大最显著,软腭后-软腭后咽壁距由（9.10±2.25） mm 增加到（12.24±2.61） mm,舌根后气道间隙由（8.99±3.20） mm增至（11.24±3.79） mm,软腭与舌体接触长度由（26.26±6.04） mm 减小至（14.37±8.14） mm,舌骨-下颌平面距由（21.27±6.12） mm减小为（12.14±5.89） mm,会厌谷与颏后点间的距离由（55.15±5.61） mm减小为（51.63±5.87） mm。口咽气道面积和喉咽气道面积分别由（7.01±1.54） mm2和（3.02±0.89） mm2增大为（7.85±1.61） mm2和（3.61±1.61） mm2。结论 Silensor阻鼾器治疗后OSAS患者的上气道间隙明显增大。     

氧化锆增韧纳米复合陶瓷粉体粒度与基体强度的关系

目的　探讨氧化锆 (ZrO2 )粉体微观粒度、级配与材料增韧补强效果之间的关系。方法以采用包裹共沉淀法与湿法球磨方法合成的Al2 O3 nZrO2 纳米复合陶瓷粉体为研究对象 ,改变所添加ZrO2 粉体的粒度 ,对粉体形貌进行扫描电镜观察与粉体粒径的测定分析 ;以注浆法将粉体制成样本生坯 ,经 1 4 50℃烧结后 ,测定样本的抗弯强度与断裂韧性。结果　①添加等量、不同粒度ZrO2 的Al2 O3 nZrO2 纳米复合渗透陶瓷材料 ,其基体抗弯强度与断裂韧性差异有显著性 (P <0 0 5) ;②添加粒度分布范围在 0 0 2～ 3 5μm ,包含粒径小于 0 5μm超细颗粒的ZrO2 组 ,增韧增强效果最显著 ,抗弯强度与断裂韧性分别达 (1 1 5 434± 5 31 9)MPa和 (2 0 4± 0 1 0 )MPam1 /2 。结论　添加ZrO2 的粉体粒度与级配是影响Al2 O3 nZrO2 纳米复合渗透陶瓷材料基体强度的重要因素     

Comparison of using calcium hydroxide or a dentine primer for reducing dentinal pain following crown preparation: a randomized clinical trial with an observation time up to 30 months

The purpose of this study was to evaluate effect of a calcium hydroxide suspension [Ca(OH)2] or glutaraldehyde based dentine primer (GDP) to reduce tooth sensitivity after full crown preparation. Thirty-six patients were treated with Ca(OH)(2) on one tooth and with GDP on another. Patients completed a questionnaire regarding sensitivity during crown preparation, when the not-anaesthetized abutments were irritated [cotton pellet (20 degrees C)]. The teeth were tested before (T(0)) and after using the desensitizer (T(1)), again after 7 days (T(2)), 6 months (T(3)) and 30 months (T(4)). The results were registered on a visual analogue scale [0 (no pain)-100 (severe pain)]. The changes of tooth sensitivity between different testing times were analysed. The median and the (interquartile range) for the different time intervals for Ca(OH)(2) were DeltaT(0)-T(1): 5 (6-17), DeltaT(0)-T(2): 17 (14-32), and for GDP, DeltaT(0)-T(1): 9 (7-18) DeltaT(0)-T(2): 18 (16-33), the decreases in sensitivity were lower for DeltaT(0)-T(1) than for DeltaT(0)-T(2) for both desensitizers (P < 0.001). There was no statistical difference (P > 0.05) between the agents (DeltaT(0)-T(1), DeltaT(0)-T(2), DeltaT(3)-T(4)). Both substances might be useful in reducing tooth sensitivity after crown preparation, but no differences in the efficacy were found when comparing the materials.     

Longitudinal study of the influence of removable partial denture and chemical control on the levels of Streptococcus mutans in saliva

Some studies have evaluated the salivary levels of mutans streptococci (MS) in removable partial denture (RPD) users. Saliva samples (2.0 mL) were obtained from 31 patients in six periods: (T0): immediately before installation of RPD; (T8): 8 days after T0; (T48): 48 days after T0; (T92): 92 days after T0; (T140): 140 days after T0 and (T189): 189 days after T0. The samples were vortexed and serially diluted from 10(-1) to 10(-6) in 0.05 m phosphate buffer (pH 7.4). From each dilution, 0.025 mL was plated on Mitis Salivarius Bacitracin (MSB). The plates were incubated in 5% CO2 at 37 degrees C for 72 h. There was an increase (t-test, P < 0.05) in the number of MS between periods T0 and T48 (mean/s.d., CFU mL(-1) of saliva): T0: 2.26/4.43 x 10(6) and T48: 0.47/1.48 x 10(8). After this, intensive treatment with CHX was accomplished in 29 patients. Saliva samples were obtained after treatment in four periods: (T24 h): 24 h after T0; (T14): 14 days after T24 h; (T28): 28 days after T24 h, and (T63): 63 days after T24 h. The number of MS in saliva did not decrease (t-test, P > 0.05). A new CHX formulation was applied in 15 patients. Saliva samples were obtained in periods: (T0): before new CHX application; (T24 h): 24 h after T0 and (T82): 82 days after T0. The new CHX reduced MS levels in saliva: (mean/s.d., CFU mL(-1) of saliva): T0: 6.64/8.47 x 10(6) and T24 h: 3.2/4.27 x 10(5) (sign rank, P < 0.05). In conclusion, there was a significant increase in the number of MS in saliva after the installation of RPD. The intensive treatment with a properly formulated CHX was effective in the reduction of MS, between 24 h and 82 days after its application.