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1.
背景:基于流体动力学说,选择良好的生物材料封闭暴露的牙本质小管口是国际上对治疗牙齿敏感研究的热点。草酸铁溶液可以在牙本质小管内形成结晶样结构。目的:观察草酸铁溶液结合全酸蚀黏结系统处理牙本质后黏结界面的形态学变化。方法:选择无龋人离体智齿12颗,去除牙冠牙釉质,暴露牙本质。随机均分为实验组和对照组,32%磷酸酸蚀剂酸蚀牙本质黏结面,实验组用5.3%草酸铁溶液处理表面1min后充分冲洗10s,两组表面再充填树脂。平行牙长轴方向片切制备扫描电镜试样,在扫描电镜(SEM)下观察黏结界面的微观形态。结果与结论:实验组草酸铁产生的结晶样结构几乎堵塞全部牙本质小管开口,树脂层伸出无数短小树脂突嵌于硬化的牙本质小孔内。对照组局部区域混合层与其下方未脱矿的牙本质间有明显的裂隙出现,树脂突较粗,但长短不均匀,可见树脂突的断裂。提示,5.3%草酸铁溶液能够在牙本质小管内形成结晶,使牙本质小管口封闭良好。对照组可见树脂突的断裂,牙本质小管暴露,封闭不严密。说明5.3%草酸铁溶液结合全酸蚀黏结系统治疗牙本质龋能够提高其临床治愈率。  相似文献   

2.
背景:树脂嵌体修复牙体缺损在一定程度上可减少修复后牙齿的折裂,但嵌体经不同方法黏结处理后对牙体抗力的影响未见报道。目的:了解复合树脂经不同方法处理后修复牙体的抗力特性。方法:将40颗无龋人前磨牙制作近中-面-远中洞型洞,随机分成4组:其中一组备洞后未进行修复作为对照组,其他3组分别以可乐丽菲露光固化复合树脂直接充填,可乐丽菲露光固化复合树脂嵌体直接黏结和酸蚀黏结修复。结果与结论:①力学模型静态力学加载实验结果:树脂直接充填组、树脂嵌体直接黏结和酸蚀黏结组断裂载荷均高于对照组(P〈0.05),前3组断裂载荷比较组间差异无显著性意义(P〉0.05),树脂嵌体酸蚀黏结组断裂载荷最大。②扫描电镜观察结果:树脂直接充填组断裂位于牙本质层和树脂之间,几乎无树脂残留,有较多孔隙;树脂嵌体直接黏结组大量牙本质基体与树脂间断裂,有较少树脂残留;树脂嵌体酸蚀黏结组牙与树脂之间无气泡、无缝隙、相互嵌合、紧密接触;对照组,树脂直接充填、直接黏结、酸蚀黏结组分别出现10,5,3,1个样本树脂内聚破坏断裂。表明经酸蚀处理复合树脂嵌体可提高牙体力学性能。  相似文献   

3.
背景:虽然目前枸橼酸溶液已被逐渐运用于制作牙本质敏感模型方面的研究,但仍未得出一个有效的统一浓度及酸蚀时间。目的:观察不同浓度枸橼酸酸蚀牙本质盘不同时间的效果,以获得研究牙本质敏感症的可靠体外实验模型。方法:选取30颗前磨牙并制作成牙本质盘,经碳化硅水磨砂纸抛光、枸橼酸酸蚀处理,扫描电镜观察牙本质盘表面酸蚀后的形态学特征,测量牙本质小管的直径,比较分析不同浓度枸橼酸溶液(5%,10%,15%)分别酸蚀不同时间(30,60,120,180s)对牙本质样本表面玷污层的去除效果、开放牙本质小管的能力。结果与结论:枸橼酸溶液具有较强的酸蚀作用,其去除玷污层的能力随着酸蚀时间延长及溶液浓度的增加而加强。5%枸橼酸溶液酸蚀各时间组、10%和15%枸橼酸溶液酸蚀30s或60s时去除玷污层能力有限,仍有牙本质小管受到不同程度的玷污层覆盖;10%、15%浓度组各酸蚀120,180s均可使表面玷污层去除,暴露牙本质小管。15%枸橼酸酸蚀120,180s组的牙本质小管直径较10%浓度组大(P<0.05),而10%枸橼酸酸蚀120,180s组的牙本质小管直径差异无显著性意义(P>0.05)。提示10%枸橼酸溶液酸蚀牙本质样本120s是去除玷污层,暴露牙本质小管的最佳方法。  相似文献   

4.
背景:目前国内外对全酸蚀、自酸蚀及自黏结树脂黏结剂对纤维桩的冠向微渗漏及黏结强度影响的研究仍存在差异。 目的:评价全酸蚀、自酸蚀及自黏结3种树脂黏结剂对纤维桩黏固后冠向微渗漏及黏结强度影响。 方法:将32颗人离体上前牙随机分成5组,其中3组为实验组,2组为对照组。实验组离体牙经根管预备后,选用全酸蚀、自酸蚀及自黏结3种树脂黏结剂分别黏结直径为1.4 mm的玻璃纤维桩。体视显微镜下观察试件各剖面的微渗漏情况,再将实验组试件沿垂直牙长轴方向切成厚度为2 mm的薄片,万能材料测试机进行微推出实验,并观察试件断裂方式。阳性对照组不进行根管预备,根部涂布指甲油,冠部直接暴露于染色剂中;阴性对照组不进行根管预备,树脂覆盖根管口,将牙体整体涂布指甲油后黏蜡包埋至截面下1 mm。 结果与结论:各种树脂黏结剂均存在微渗漏现象,其中全酸蚀树脂黏结剂的微渗漏程度最轻,自酸蚀树脂黏结剂的微渗漏程度最重。3种树脂黏结剂间的微渗漏程度差异有显著性意义(P〈0.05)。黏结剂间的黏结强度由高到低分别为全酸蚀树脂黏结剂、自酸蚀树脂黏结剂、自黏结树脂黏结剂,3种黏结剂的黏结强度差异有显著性意义(P〈0.05)。试件的主要断裂方式为黏结剂/纤维桩间断裂及混合破坏。说明全酸蚀树脂黏结剂与牙本质结合紧密,与自酸蚀树脂黏结剂、自黏结树脂黏结剂比较在微渗漏程度及黏结性能方面显示出优越性。  相似文献   

5.
背景:研究发现表没食子儿茶素浸食子酸酯具有抑制免疫炎症反应、抗菌、抗氧化、抗突变和抗癌等多种功效。目的:通过体外实验探讨表没食子儿茶素浸食子酸酯对牙本质龋再矿化方面的影响。方法:将30颗正畸拔除的人离体牙按照随机数字表均分为实验组、对照组及空白对照组,在乳酸脱矿系统制成牙本质龋后,分别置于2 g/L表没食子儿茶素浸食子酸酯溶液、饱和Ca(OH)2溶液、人工唾液中12 d进行再矿化实验,测定3种溶液中牙本质块表面显微硬度,扫描电镜观察牙本质块表面再矿化结果。结果与结论:按照再矿化后牙本质表面显微硬度从高到低的顺序依次排列为:对照组、实验组、空白对照组,组间两两比较差异均有显著性意义(P<0.05),结果表明表没食子儿茶素浸食子酸酯与Ca(OH)2在牙本质再矿化方面的作用好于人工唾液,两者均能促进牙本质龋的再矿化,且表没食子儿茶素浸食子酸酯促进牙本质龋再矿化效果低于Ca(OH)2。扫描电镜显示,对照组牙本质表面附着有大量沉积物,未见牙本质小管开口;实验组也可见沉积物附着牙本质表面,但较平整;空白对照组牙本质表面沉积物较少,可见有未覆盖沉积物的牙本质小管口。扫描电镜结果定性证明了表没食子儿茶素浸食子酸酯能促进脱矿牙本质的再矿化。  相似文献   

6.
目的:酸性较弱的多元羧酸对牙体硬组织具有化学吸附作用,故部分牙体黏接材料采用多元羧酸及其衍生物作为预处理剂.比较苹果酸、酒石酸、柠檬酸和传统酸蚀剂磷酸对牙本质的脱钙作用,分析多元羧酸的酸蚀能力.方法:实验于2006-10/2007-04在上海交通大学医学院附属第九人民医院和浙江大学医学院附属第一医院口腔科完成.采用150 g/L苹果酸、150 g/L酒石酸、150 g/L柠檬酸溶液分别酸蚀牙本质60 s,360 g/L磷酸酸蚀牙本质15 s,扫描电镜下观察牙本质处理前后表面形貌及牙本质小管直径,方差分析比较不同酸处理对牙本质小管直径大小的影响差异.结果:①扫描电镜下见未酸蚀样本的牙本质小管开口狭小.酸蚀处理后牙本质表面平坦、清晰,覆盖的玷污层基本去除,管周牙本质脱矿明显,牙质小管开口扩大、敞开.②不同种类酸溶液处理后牙本质脱矿,牙本质小管直径明显增大(P < 0.01).磷酸酸蚀15 s、柠檬酸、酒石酸酸蚀60 s的牙本质小管直径大小无差异(P > 0.05),明显大于苹果酸酸蚀60 s的小管直径(P < 0.01).结论:苹果酸的脱矿作用较弱,适当延长酒石酸、柠檬酸的处理时间可获得与磷酸酸蚀相当的牙本质脱矿效果.  相似文献   

7.
目的:酸性较弱的多元羧酸对牙体硬组织具有化学吸附作用,故部分牙体黏接材料采用多元羧酸及其衍生物作为预处理剂。比较苹果酸、酒石酸、柠檬酸和传统酸蚀剂磷酸对牙本质的脱钙作用,分析多元羧酸的酸蚀能力。方法:实验于2006-10/2007-04在上海交通大学医学院附属第九人民医院和浙江大学医学院附属第一医院口腔科完成。采用150g/L苹果酸、150g/L酒石酸、150g/L柠檬酸溶液分别酸蚀牙本质60s,360g/L磷酸酸蚀牙本质15s,扫描电镜下观察牙本质处理前后表面形貌及牙本质小管直径,方差分析比较不同酸处理对牙本质小管直径大小的影响差异。结果:①扫描电镜下见未酸蚀样本的牙本质小管开口狭小。酸蚀处理后牙本质表面平坦、清晰,覆盖的玷污层基本去除,管周牙本质脱矿明显,牙质小管开口扩大、敞开。②不同种类酸溶液处理后牙本质脱矿,牙本质小管直径明显增大(P〈0.01)。磷酸酸蚀15s、柠檬酸、酒石酸酸蚀60s的牙本质小管直径大小无差异(P〉0.05),明显大于苹果酸酸蚀60s的小管直径(P〈0.01)。结论:苹果酸的脱矿作用较弱,适当延长酒石酸、柠檬酸的处理时间可获得与磷酸酸蚀相当的牙本质脱矿效果。  相似文献   

8.
背景:多项体外实验证实硅酸三钙不仅可以通过自固化过程与牙本质紧密结合,而且在生理环境下能诱导牙本质再矿化,有效阻塞牙本质小管。 目的:进一步验证硅酸三钙对牙本质小管的封闭作用。 方法:选择正畸患者拔除的第一前磨牙制作离体牙本质盘36块,分别经0.29 mol/L EDTA 内浸置2 min,6%柠檬酸蚀1 min 后冲洗,蒸馏水超声清洗20 min 3种方法预处理,模拟具有牙本质小管不同开放程度的牙本质敏感症。以上每组随机分为3个亚组,即硅酸三钙组、氟化钠对照组、空白对照组,前2组每天早晚分别用对应材料涂刷表面,2 min/次,空白对照组不处理,其余时间全部置于人工唾液37℃恒温箱中保存。14 d后通过扫描电镜观察各组处理前后牙本质形态,并计算开放牙本质小管直径和面积。 结果与结论:经不同预处理后牙本质小管都呈开放状态,但柠檬酸和EDTA预处理溶液较蒸馏水有更强的脱矿作用,牙本质小管更加清晰。各组经氟化钠或硅酸三钙涂擦后,牙本质小管口有不同程度沉积物,且开放牙本质小管面积及平均直径较空白对照组小(P〈0.05);经硅酸三钙涂擦的牙本质小管几乎完全均质封闭,偶见有单个孤立开放的牙本质小管口,开放牙本质小管面积及平均直径都明显低于氟化钠对照组(P〈0.05)。证实硅酸三钙可有效封闭牙本质小管,且效果优于氟化钠;在治疗牙本质过敏时,如果先用EDTA或酸蚀剂处理,脱敏效果会更完善。  相似文献   

9.
目的:探讨根管预备后牙本质内表面处理方法对纤维桩黏结强度的影响。方法:选用30颗完整离体成人上颌中切牙,随机分为A,B,C 3组,每组各10牙,完善根管治疗后,于釉牙骨质界上方2 mm水平截断并预备桩道。A,B,C组分别用体积分数14%乙二胺四乙酸溶液、体积分数3%双氧水和质量分数0.9%生理盐水溶液处理1 min,自酸蚀黏结把纤维桩黏结于桩道内。用万能材料试验机测试其固位力。结果:A组纤维桩黏结固位力大于B,C组,差异有统计学意义(P<0.05);B,C组纤维桩黏固位力比较差异无统计学意义(P>0.05)。结论:使用乙二胺四乙酸溶液处理桩道预备后的根管牙本质,可提高纤维桩黏结固位力。  相似文献   

10.
背景:有临床研究报道牙本质保护膜在用于烤瓷全冠牙体预备后牙本质面的保护处理后,能有效降低基牙敏感度。目的:体外实验观察牙本质保护膜封闭牙本质小管的效果。方法:将20颗完好离体人前磨牙分为3组:空白对照组牙本质表面不作任何处理,对照组牙本质表面涂布格鲁玛脱敏剂,实验组牙本质表面涂布牙本质保护膜,在扫描电镜下观察牙本质小管口封闭情况。结果与结论:扫描式电子显微镜观察显示,实验组牙本质小管口密度和直径均明显低于对照组与空白对照组(P〈0.05),牙本质小管口相对面积明显低于空白对照组(P〈0.01)。表明牙本质保护膜在减小牙本质小管的密度和直径方面的作用优于格鲁玛脱敏剂。  相似文献   

11.
OBJECTIVE: This study was conducted to analyze microleakage in Class V cavity preparation, using rewetting (or not) just after burr or Er:YAG laser preparation of enamel and dentin walls in permanent teeth. Background Data: Several studies reported microleakage around composite restorations when cavity preparation was done or treated by Er:YAG laser. As the hybridized laser is removed when this laser is used to cut dental hard tissue, there is a need for new materials or techniques to minimize gaps and microleakage. RESULTS: Primer solution showed significant effect in enamel and dentin, at the level of 5%, when Er:YAG laser was used as a cutting tool. Using primer solution after phosphoric acid in preparations with the laser, microleakage was similar in degree to when cavities were prepared with the burr. CONCLUSION: Re-wetting surface just after Er:YAG irradiation and chemical treatment with phosphoric acid using HEMA aqueous solution seems to improve the quality of bioattachment between the adhesive system and enamel/dentin, showing similarities between restoration behaviors independently of the cutting tool, whether burr or laser.  相似文献   

12.
OBJECTIVE: The purpose of this study was to investigate the acquired acid resistance of human dental enamel and dentin treated by 38% diamine silver fluoride [Ag(NH3)2F] solution and semiconductor (diode) laser irradiation in vitro. BACKGROUND DATA: There have been no reports on the acid-resistant effect by combined use of fluoride and semiconductor laser. METHODS: Sixty crowns of extracted human molars were divided into two groups for enamel and dentin samples, and each group was subdivided into three subgroups of 10 each. Each subgroup of enamel and dentin samples served as a control; one was treated with Ag(NH3)2F and the other was treated with Ag(NH3)2F and semiconductor laser irradiation at 2 W for 30 sec. Then all samples were immersed in 5 ml of 0.1 M lactic acid (pH 4.8) at 37 degrees C for 24 h. The concentration of calcium ion (Ca2+) dissolved in the solution was measured by atomic absorption spectrophotometry, and the samples were observed by stereoscopy and scanning electron microscopy (SEM). RESULTS: In both enamel and dentin samples, dissolved Ca2+ concentration in Ag(NH3)2F- or Ag(NH3)2F- and laser-treated group was significantly decreased compared with that in the control (p < 0.01). SEM findings showed that numerous cubic particles ranging from 0.1 to 0.5 mcirom were observed only in the combined treated groups of both enamel and dentin samples. CONCLUSIONS: A significantly decreased solubility of human enamel and dentin was acquired after treatment by Ag(NH3)2F and semiconductor laser irradiation, which suggested that this combined use has the capability of a more efficient acid-resistant effect on human dental hard tissues.  相似文献   

13.
OBJECTIVE: The aim of this in vitro study was to assess tensile bond strength of dentin-resinous system interfaces conditioned with Er:YAG laser irradiation. BACKGROUND DATA: There are different results reported in the literature which relate to laser Er:YAG effects on dentin surface as a pretreatment during adhesives procedures. MATERIALS AND METHODS: Forty-two surfaces of human dentin from third upper molar were used after being extracted and kept in the refrigerator in 0.5% chloramines aqueous solution and then divided into three experimental groups and three control groups. The chosen restorative systems were Alert (Jeneric/Penton), Prodigy (Kerr Co.), and Z-100 (3M Co.), with correspondent dental adhesives Bond 1, Optibond Solo, and Single Bond, respectively. To conduct tensile tests, a special system of pairs of rods aligned in a specific apparatus was used, in accordance with ISO/TR 11405 standard (1994). RESULTS: By means of statistical analysis, the Kruskal Wallis test, it was noticed that group IE (laser + acid + Alert), 18.89 MPa, differed considerably from group IC (acid + Alert), 8.03 MPa (p < 0.10), but did not differ from the other groups. Group IIC (acid + Prodigy), 19.88 MPa, differed from group IIE (laser + acid + Prodigy), 12.57 MPa (p < 0.05), but did not differ from groups IIIE (laser + acid + Z-100), 14.11 MPa, and IIIC (acid + Z-100), 19.58 MPa. Group IIIE did not differ statistically from group IIIC. CONCLUSION: It was concluded that previous Er:YAG laser treatment on the dentinal structure only improved the tensile bond resistance of the Alert restorative system.  相似文献   

14.
OBJECTIVE: The purpose of the present study was to investigate the effects of ND:YLF laser irradiation (1.31 J/cm2; 250 mJ per pulse), acid etching, and hypermineralization on the shear bond strength (SBS) of the Scotchbond Multi-Purpose Plus (3M Dental Products) bonding system. SUMMARY BACKGROUND DATA: Previous studies had shown that the pretreatment of the dentin substrate with laser irradiation can influence the SBS. METHODS: Sixty bovine incisors were selected and stored at -18 degrees C. Dentinal buccal surface was exposed and radiographs were taken to control dentin thickness. The specimens were separated into 2 groups: (1) the control, which was kept in distilled water at 4 degrees C; (2) the hypermineralized, which was kept in hypermineralizing solution at 4 degrees C for 14 days. Each group was divided into 3 subgroups according to the type of dentin pretreatment used: M (acid etching + primer + bond); AL (acid etching + primer + bond + laser); and LA (laser + acid etching + primer + bond). A standard composite resin cylinder (Z100-3M) was bonded to the dentinal surface and the SBS performed on an Instron machine (500 Kg load cell at 0.5 mm/min), followed by scanning electron microscopy (SEM) and x-ray diffraction analysis. RESULTS: Analysis of variance (ANOVA) determined that the pretreatments influenced the SBS values (p < 0.05): AL (9.96 MPa), M (7.28 MPa), and LA (4.87 MPa). The interaction between the group and pretreatment factors also influenced the SBS (p < 0.05). The highest values were obtained for the interaction control/AL (11.64 MPa). CONCLUSION: The results suggested that dentin treatment with laser after the application of the adhesive system is efficient in achieving higher bond strength and is promising as a possible new adhesive substrate.  相似文献   

15.
OBJECTIVE: The purpose of this study was to investigate the effect of Nd:YAG laser irradiation on the acid demineralization of enamel and dentin by spectrophotometry. A mechanism of acquired acid resistance is also proposed. SUMMARY BACKGROUND DATA: The ability of Nd:YAG laser irradiation to the enhanced resistance to artificial caries formation is still controversial. METHODS: A pulsed Nd:YAG laser at 1.064-micron wavelength was used to irradiate the human enamel and dentin samples from 20 extracted human molars at the parameters of 1, 2, and 3 W and 20 pps for a total of 9 sec after painting with black ink. Samples were then subjected to 2 microliters of 0.1 M lactic acid solution (pH 4.8) for 24 h at 36 degrees C. The parts per million (ppm) of calcium ion (Ca2+) dissolved in each solution was determined by atomic absorption spectrophotometry and the morphological changes were also investigated by scanning electron microscopy (SEM). RESULTS: The lowest mean Ca2+ ppm was recorded in the samples irradiated at 3 W, in those by irradiated at 2 W and 1 W. The unlased samples showed the highest Ca2+ ppm. SEM observation showed that in the lased areas, the smear layer was partially melted and the underlying primary enamel or dentin seemed to be thermally degenerated. CONCLUSIONS: The results of this study suggested that melted smear layer and underlying enamel or dentin degenerated thermally by the heat treatment of Nd:YAG laser might play a major role to enhance resistance to artificial caries-like formation.  相似文献   

16.
OBJECTIVE: The purpose of this study was to investigate the caries-preventive effect of CO2 laser irradiation with or without sodium fluoride (NaF) solution at human dental enamel and dentin in vitro. BACKGROUND DATA: The capability of caries prevention with CO2 laser irradiation has been reported in many previous studies, but few studies have been performed with regard to the combined effect of fluoride and laser. MATERIALS AND METHODS: Forty extracted human incisor teeth were used for the enamel study, and 40 molar teeth were used for the dentin study. Samples were then divided into four categories: control (no treatment); CO2 laser irradiation only; NaF treatment only; and NaF treatment followed by CO2 laser irradiation. Each sample was immersed in 2 mL of lactic acid (0.1 M, pH 4.8) solution for 24 h at 37 degrees C in 100% humidity. The parts per million (ppm) of calcium ion (Ca2+) dissolved in each solution was determined by atomic absorption spectrophotometry. The samples were also observed by stereoscopy and scanning electron microscopy (SEM). RESULTS: The lowest mean Ca2+ ppm was recorded at the enamel or dentin samples treated with NaF and laser. Statistical analysis of the data was considered significant (p < 0.01). SEM observation showed that surfaces were changed to melted, smooth, and mirror-like appearances when CO2 laser irradiation was applied with NaF solution. CONCLUSION: It can be concluded that CO2 laser irradiation with NaF solution has more caries-preventive effect than CO2 laser irradiation only at the enamel and dentin surfaces.  相似文献   

17.
BACKGROUND: To compare efficacy between recombinant human erythropoietin (rhEPO) plus parenteral iron vs. iron alone (parenteral vs. oral) in postpartum anaemia. METHODS: Sixty patients (haemoglobin 8.6 +/- 1.1 g dL-1) were randomized to rhEPO plus intravenous (i.v.) iron sucrose (group 1), rhEPO placebo plus i.v. iron sucrose (group 2), or oral iron alone (group 3), daily for 4 days beginning 48-72 h postpartum. Erythropoiesis and iron status were assessed before, and on 4, 7 and 14 days after, starting therapy. RESULTS: On day 7 the group 1 haematocrit increase was 7.7 +/- 3.1% vs. 5.3 +/- 1.9% (group 2, P < 0.01) and 4.4 +/- 3.2% (group 3, P < 0.01), and on day 14, 11.3 +/- 2.9% vs. 9.2 +/- 3.4% (group 2, P < 0.05) and 8 +/- 2.8% (group 3, P < 0.01). The odds of achieving a target haematocrit > 32% on day 7 and > 35% on day 14 were higher on rhEPO (1.5-2.7) than on either iron regimen alone. Group 1 reticulocyte counts were also higher on days 4 (P < 0.05 vs. oral iron) and 7 (P < 0.01 vs. oral and parenteral iron). CONCLUSION: All three regimens were effective in postpartum anaemia, but the haematocrit and reticulocyte responses to rhEPO plus parenteral iron were significantly greater than to iron alone. Benefit was greatest in the blunted erythropoiesis subgroup with elevated post-Caesarean section C-reactive protein levels.  相似文献   

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