不同流动性复合树脂核材料在短时超光强照射下的聚合效果

目的 探讨3种双重固化流动复合树脂核材料在不同光照模式下的聚合效果。方法 将双重固化流动复合树脂核材料A（DC CORE ONE）、B（MultiCore Flow）、C（Rebilda DC）分别充填到有机玻璃圈模具中,使用LED光固化灯以2种光照条件（1 000 mW∕cm2持续照射20 s或以3 200 mW∕cm2持续照射6 s）使其固化,每个实验组6个试件,共36个试件。分别在试件固化后15 min、24 h,测量其表面努氏显微硬度以判断聚合度。测量结束后,试件继续用无水乙醇浸泡24 h,再次测量其表面硬度,并计算浸泡后的硬度降低百分比值以判断聚合的交联密度。采用配对样本t检验和独立样本t检验对数据进行统计学分析。结果 相同光照条件下,3种材料固化后24 h硬度值均高于固化后15 min,除材料A外,材料B、C不同时间段差异具有统计学意义(P＜0.05)。同种材料在相同时间段以3 200 mW∕cm2 × 6 s照射条件所获得的硬度值均高于1 000 mW∕cm2 × 20 s照射条件下所获得硬度值,除材料B、C 固化24 h后两种照射条件下硬度值差异不具有统计学意义外,其余材料在固化后相同时间段不同照射模式下所获得的硬度值之间均存在显著性差异(P＜0.05 )。乙醇浸泡24 h后,材料B和材料C在1 000 mW/cm2×20 s照射条件下的硬度值降低百分比均高于3 200 mW/cm2×6 s照射条件组,而A材料则相反,表现为3 200 mW/cm2×6 s光照强度下的硬度值降低更多。结论 对于双重固化流动复合树脂核材料来说,临床采用短时高强度的照射条件是可行的。     

自粘接树脂水门汀在模拟根管内的硬度变化

目的比较自粘接与通用型树脂水门汀在模拟根管内固化开始后的硬度变化。方法将双重固化自粘接树脂水门汀A（RelyX Unicem）、B（BisCem）和双重固化通用型树脂水门汀C（DUOLINK）注满单端开口、以盖板封闭的半圆柱形不锈钢槽,将光固化灯紧贴开口端持续照射20 s,试件避光保存0.5 h后打开封闭盖板,测量树脂纵断面距照射光源1～10 mm间,以1 mm为间隔共10个深度的努氏显微硬度。试件继续避光保存24、120 h后,重复上述测量。对测量数据进行统计学分析。结果3种材料的硬度值随模拟根管深度的增加而降低（P<0.001）,其中A组在5 mm及以下各深度的硬度值、B和C组在4 mm及以下各深度的硬度值差异无统计学意义。各组的硬度值在固化开始后0.5 h内增长最多,24 h后硬度值达到或接近最大值。光照后120 h,除1 mm深处外,C组在各深度的硬度值均显著高于A和B组（P<0.001）。结论2种类型树脂水门汀双重固化条件下的硬度值差异有统计学意义,但随时间变化的趋势基本一致。     

流动性复合树脂核材料在短时超高光强照射下的聚合效果

目的:评估流动性双重固化复合树脂核材料在短时超高强度照射下的聚合效果.方法:将双重固化流动性复合树脂核材料(regular dentine,Para core)注满单端开口的长方体形不透光硅橡胶模具中,将光固化灯紧贴开口端,以1000 mW/cm2持续照射10、20 s或以3200 mW/cm2持续照射3、6s.试件避光保存1h后取出,测量试件纵断面距照射光源1～10 mm间,以1 mm为间隔共10个深度的努氏显微硬度以判断聚合效果.试件继续避光保存24 h后,重复上述测量.采用SPSS 16.0软件包对数据进行统计学分析.结果:除3200 mW/cm2、3s光照射条件无法引发光固化反应外,在其余光照射条件下,试件在光影响深度内的硬度值在光照后24 h都显著高于单纯化学固化产生的硬度值,但光照射对试件的影响深度有限.在试件的光影响深度内,随着光照射时间的延长,试件的硬度值得到显著提高;而试件在3200 mW/cm2、6 s和1000 mW/em2、20 s条件下光照射后24 h的硬度值无显著差异.结论:3200 mW/cm2光强度照射时间必须延长到6s,才能保证引发流动性复合树脂核材料的光固化反应,并获得合适的聚合效果.     

瓷块厚度及透光性对树脂水门汀固化硬度的影响

目的 研究瓷块的厚度和透光性对不同类型树脂水门汀固化硬度的影响,为临床的全瓷粘接提供参考。方法 选择三种树脂水门汀Choice2,Duolink,RelyX Ultimate Clicker,分别通过不同厚度(0.5 mm、1.0 mm、1.5 mm、2.0 mm)的高透(HT)和低透(LT)的IPS e.max Presss瓷块,用800 mw/cm²高强度LED灯进行光照固化。三种树脂水门汀透过盖玻片照射的试件作为对照组。在固化后30 min和24 h通过显微硬度仪测量固化后树脂的表面努氏硬度值。评价瓷块厚度和透光性对树脂水门汀固化硬度的影响。结果 Choice 2固化后的努氏硬度值在各个厚度及透光度下与对照组相比均显著降低。Duolink和RelyX Ultimate固化后的努氏硬度值在HT瓷块厚度达到2.0mm时,实验组与对照组相比显著降低。在LT瓷块中,当厚度达到1.5 mm时,实验组硬度值即显著降低。结论 当IPS e.max Presss低透瓷块达到1.5 mm厚度,高透瓷块达到2.0 mm厚度时,树脂水门汀的固化硬度会显著降低,从...     

颜色及光照射条件对复合树脂核材料聚合的影响

目的:评估材料颜色和光照射条件对流动性双重固化复合树脂核材料聚合的影响.方法:将双重固化流动性复合树脂核材料(牙本质色和白色,Para Core)注满单端开口的长方体不透光硅橡胶模具中,将光固化灯紧贴开口端以1000 mW/cm2持续照射20 s或以3 200 mW/cm2持续照射6 s获得4组试件(n=5).试件避光保存1h后,测量试件纵断面距光源1、2、3mm深度的努氏显微硬度.试件继续避光保存24 h后,重复上述测量.采用单因素方差分析对数据进行统计学分析.结果:4组试件随测量深度的增加试件的硬度值显著降低.光照后24 h,牙本质色试件每个测量深度的硬度值在1 000 mW/cm2×20 s和3 200 mW/cm2×6 s条件间无显著差异,但白色试件每个测量深度的1 000 mW/cm2×20 s的硬度值要显著高于3 200 mW/cm2 × 6 s的硬度值.结论:不同颜色的复合树脂核材料需要选择合适的光照射条件来获得最佳的聚合效果.     

2种树脂黏固剂产品与人牙本质黏结性能的研究

目的探讨2种树脂黏固剂对进行和不进行处理的人牙本质是否具有相同的黏结效果。方法将30枚人牙本质试件分为6组,分别施以不同表面的处理（A、B组不处理 C、D组磷酸酸蚀15s E、F组磷酸酸蚀15s后使用One-step通用型黏结剂）。A、C、E组使用RelyX Unicem双固化树脂黏固剂,B、D、F组使用Bis-cem双固化树脂黏固剂,制作牙本质/树脂黏固剂黏结试件,测试剪切黏结强度,扫描电镜观察黏结界面形态。结果统计分析可知组A和组B的黏结强度值分别低于组C、E和组D、F,组C与组E间以及组D与组F间无统计学差别。RelyX Unicem树脂黏固剂除对于磷酸酸蚀牙本质的黏结强度高于Biscem树脂黏固剂外,牙本质进行其他表面处理或不处理时,2种树脂黏固剂间的黏结强度无明显差别。结论磷酸酸蚀能够提高RelyX Unicem和Biscem2种自黏结树脂黏固剂对牙本质的黏结强度。     

浸泡时间对5种水门汀黏结强度的影响

目的研究浸泡时间对水门汀黏结强度的影响。方法用5种不同水门汀对金属合金进行黏结,保存在37℃人工唾液中24 h、3周、6周后分别测其黏结强度的变化。结果增强型玻璃离子水门汀、增强型磷酸锌水门汀、松风玻璃离子水门汀、松风聚羧酸锌水门汀在浸泡24 h、3周、6周三个时间段后的黏结强度未发生明显改变(P>0.05);增强型聚羧酸锌水门汀浸泡3周与浸泡24 h其黏结强度有统计学差异(0.01相似文献   

固化模式对双固化树脂水门汀微观机械性能及聚合程度的影响

目的研究不同固化模式对临床常用的两种双固化树脂水门汀表面纳米硬度、弹性模量、压入蠕变等微观机械性能及聚合程度的影响。 方法采用即刻光照、间歇光照、延迟光照和无光照四种不同的固化模式,分别对RelyX Unicem、PermaCem 2.0两种双固化树脂水门汀进行固化,制备厚度为0.5 mm、直径5 mm的圆形测试试件。室温避光保存24 h后,使用纳米压痕法对表面纳米硬度、弹性模量、压入蠕变等微观机械性能进行测量,使用傅立叶变换红外光谱-衰减全发射法测试材料的转化率。利用SPSS 16.0软件对数据进行分析（α= 0.05）。 结果固化模式对本实验选用的两种双固化树脂水门汀的表面纳米硬度、弹性模量有显著影响（P<0.001）。对于RelyX Unicem,无光照组的表面纳米硬度、弹性模量最低,分别为（153.1 ± 14.6）MPa和（7.6 ± 0.7）GPa,即刻、间歇、延迟光照组差异无统计学意义。对于PermaCem 2.0,无光照组的表面纳米硬度、弹性模量最低,分别为（244.8 ± 21.1）MPa和（7.3 ± 0.5）GPa,即刻、间歇、延迟光照组差异无统计学意义。固化模式对RelyX Unicem的压入蠕变有显著影响（F= 135.41,P<0.001）,对PermaCem 2.0也有显著影响（F= 148.94,P<0.001）,其由高到低依次为：无光照组>延迟光照组>即刻、间歇光照组。固化模式对PermaCem 2.0的转化率有显著影响（F= 20.76,P= 0.004）,但对RelyX Unicem的转化率无显著影响（F= 0.899,P= 0.447）。 结论双固化树脂水门汀在无光照时容易固化不全,降低其微观机械性能。即刻、间歇光照比延迟光照更有利于降低树脂水门汀的压入蠕变。固化模式对不同种类的双固化树脂水门汀聚合程度及微观机械性能的影响程度不同。     

Nd:YAG激光对自黏结树脂水门汀与牙本质黏结强度的影响

目的:采用剪切强度实验和扫描电镜,评价脉冲Nd:YAG激光对自黏结树脂水门汀与牙本质之间黏结强度的影响。方法:选择新鲜、无龋、无裂纹的人离体前磨牙10颗,分为颊、舌2部分,暴露牙本质黏结面,形成20个测试试件,随机分为激光组和对照组(n=10)。激光组以0.8W、10Hz脉冲Nd:YAG激光作用于涂墨汁的牙本质表面25s,联合自黏结树脂水门汀RelyX Unicem充填;对照组直接使用自黏结树脂水门汀RelyX Unicem充填于牙本质表面,放置在37℃生理盐水中24h后,测试剪切强度,在牙科显微镜下观察断裂模式并分类。采用SPSS 17.0软件包对数据进行统计学处理。最后,扫描电镜下观察试件的树脂水门汀-牙本质的纵剖面。结果:对照组和激光组的剪切强度分别为(9.48±1.80)MPa和(11.15±1.71)MPa,有显著差异(P<0.05)。牙科显微镜下观察,2组试件断裂大部分发生在树脂水门汀-牙本质界面。扫描电镜观察,2组自黏结树脂水门汀RelyX Unicem与牙本质之间结合较紧密,但均未见树脂突。结论:Nd:YAG激光(0.8W、10Hz)处理牙本质,能提高自黏结树脂水门汀RelyX Unicem与牙本质之间的黏结强度。     

两种双固化树脂水门汀粘接性能及聚合度的比较研究

目的:对传统双固化树脂水门汀与氧化锆在缺乏光照条件下的粘接强度、粘接耐久性以及聚合度进行比较,为新型树脂水门汀粘接全锆修复体的临床应用提供实验参考.方法:选用传统双固化树脂水门汀RelyX Ultimate(RUL)作为对照,分别使用新型双固化树脂水门汀Panavia V5(PV5)与RUL在自固化模式下氧化锆瓷片制作粘接试件,24h水储及人工老化处理后分别进行剪切强度(SBS)测试.自固化24h后的两种树脂水门汀以傅里叶红外分析(FTIR)测试,进行聚合度分析.结果:无论老化前后,PV5的氧化锆粘接强度均显著高于RUL.老化处理对RUL和PV5的氧化锆粘接处理均会产生不利影响,但老化后PV5的粘接强度值存在优势.24h红外聚合度与24h的SBS测试结果相匹配.结论:PV5在修复体过厚导致缺乏光照的极限情况下具有可靠的粘接性能.     

光照模式对双固化树脂粘接剂聚合程度的影响

目的研究不同光照模式对两种双固化树脂粘接剂聚合程度的影响。方法采用间歇光照、即刻光照、延迟光照和无光照4种不同固化方式,分别制备3MRelyXUnicem和DMGPermaCem2．0双固化树脂试件．24h避光保存后使用显微硬度仪测定样本表面硬度．三点弯曲试验测量挠曲强度．差示扫描量热仪进行玻璃化转变温度测量。数据采用协方差分析进行统计。结果两种树脂粘接剂各组表面硬度和挠曲强度由高到低依次为：间歇光照模式、即刻光照模式〉延迟光照模式〉无光照模式（P〈0．05）。差示扫描量热分析未检测到明显吸热峰,不能确定玻璃化转变温度。除无光照组外．3MRelvX Unicem表面硬度均显著高于DMG PermaCem2．0（P〈0．05）;DMG PermaCem2．0挠曲强度显著高于3MRelyX Unicem（P〈0．05）。结论间歇光照模式比延迟光照模式更有利于提高双固化树脂粘接剂聚合程度：双固化树脂粘接剂在无光照情况下聚合不全;与3MRelyX Unicem相比．DMGPernlaCem2．0抗压性能较差．但韧性较好．且无光照条件下聚合程度更高。     

Effect of different light curing methods on mechanical and physical properties of resin-cements polymerized through ceramic discs

Objective

The aim of this study was to compare the polimerization ability of three different light-curing units (quartz tungsten halogen, light-emitting diodes and plasma arc) and their exposure modes (high-intensity and soft-start) by determination of microhardness, water sorption and solubility, and diametral tensile strength of 5 dual-curing resin cements.

Material and methods

A total of 720 disc-shaped samples (1 mm height and 5 mm diameter) were prepared from different dual-curing resin cements (Duolink, Nexus, Bifix-QM, Panavia F and RelyX Unicem). Photoactivation was performed by using quartz tungsten halogen (high-power and soft-up modes), light-emitting diode (standard and exponential modes) and plasma arc (normal and ramp-curing modes) curing units through ceramic discs. Then the samples (n=8/per group) were stored dry in the dark at 37ºC for 24 h. The Vickers hardness test was performed on the resin cement layer with a microhardness tester (Shimadzu HMV). For sorption and solubility tests; the samples were stored in a desiccator at 37ºC and weighed to a constant mass. The samples were weighed both before and after being immersed in deionized water for different periods of time (24 h and 7 days) and being desiccated. The diametral tensile strength of the samples was tested in a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by nonparametric Kruskal Wallis and Mann-Whitney U tests at 5% significance level.

Results

Resin cement and light-curing unit had significant effects (p<0.05) on microhardness, diametral tensile strength, water solubility and sorption. However, no significant differences (p>0.05) were obtained with different modes of LCUs.

Conclusion

The study indicates that polymerization of resin cements with different light-curing units may result in various polymer structures, and consequently different mechanical and physical properties.     

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??Abstract: Objective To investigate the influence of light and chemical curing mode on polymerization capability (degree of polymerization and cross-link density) of dual cured flowable resin composites. Methods The plexiglas circles ( inner diameter: 5mm?? height:2mm ) were respectively injected and filled by dual cured flowable resin composite core build-up materials [ A ( Luxa Core ) ??B ( Clearfil DC Core )] and dual cured resin cement [ C ( DUOLINK )]?? then specimens for chemical curing mode were stored untreated at 37?? in the dark ??while specimens for light curing mode were immediately light-irradiated for 20 seconds before storage. Surface hardness numbers were detected at 0.5??24 and 120 hours post-curing time to compare degree of polymerization indirectly .After that the specimens were soaked in 100% ethanol for 24 hours and percentage of reduction of hardness was recorded to compare cross-link density indirectly. Data were analyzed by One-way ANOVA and independent T test. Results For the 3 materials hardness of both curing mode increased with the post-curing time (P<0.05) and attained to the maximum values at 120 hours post-curing time. Hardness of light-curing mode at 120 hours post-curing time was greater than that of chemical-curing mode [material A: light-cured mode (61.27 ± 2.14) MPa?? chemical-cured mode(39.26 ± 0.89) MPa?? P<0.05;material B: light-cured mode (66.94 ± 0.97)MPa?? chemical-cured mode( 44.18 ± 1.84) MPa?? P<0.05;material C??light-cured mode(64.21 ± 1.07)MPa?? chemical-cured mode(51.39 ± 1.22)MPa??P<0.05]. After soaking significant difference of percentage of reduction of hardness were detected between the 2 modes[material A: light-cured mode (19.58 ± 1.72)%?? chemical-cured mode (25.18 ± 2.82)%?? P<0.05;material B: light-cured mode (17.74 ± 1.75)%?? chemical-cured mode(24.56 ± 1.78)%?? P<0.05 ); material C : light-cured mode (23.10 ± 2.50)%?? chemical-cured mode(23.72 ± 1.65)%?? P = 0.658]. Conclusion For dual cured flowable resin composites?? curing mode exerts distinct influence on the degree of polymerization and cross-link density.     

Effect of veneering materials and curing methods on resin cement knoop hardness

This study evaluated the Knoop hardness of Enforce resin cement activated by the either chemical/physical or physical mode, and light cured directly and through ceramic (HeraCeram) or composite resin (Artglass). Light curing were performed with either conventional halogen light (QTH; XL2500) for 40 s or xenon plasma arc (PAC; Apollo 95E) for 3 s. Bovine incisors had their buccal surfaces flattened and hybridized. On these surfaces a mold was seated and filled with cement. A 1.5-mm-thick disc of the veneering material was seated over this set for light curing. After storage (24 h/37 masculineC), specimens (n=10) were sectioned for hardness (KHN) measurements in a micro-hardness tester (50 gf load/ 15 s). Data were submitted to ANOVA and Tukey's test (alpha=0.05). It was observed that the dual cure mode yielded higher hardness compared to the physical mode alone, except for direct light curing with the QTH unit and through Artglass. Higher hardness was observed with QTH compared to PAC, except for Artglass/dual groups, in which similar hardness means were obtained. Low KHN means were obtained with PAC for both Artglass and HeraCeram. It may be concluded that the hardness of resin cements may be influenced by the presence of an indirect restorative material and the type of light-curing unit.     

复合树脂、玻璃离子对人巨噬细胞的增殖活性和功能的影响

目的：研究常用复合树脂、玻璃离子对体外培养的人单核-巨噬细胞增殖活性和功能的影响。方法：体外诱导培养人的单核血细胞株THP-1,获得巨噬细胞,MTT 法测定2种常用复合树脂材料Filtek Z350(3M)、Filtek P60(3M)和玻璃离子材料的24 h浸渍液对体外培养的人单核-巨噬细胞增殖活性的影响,ELISA试验检测各组材料浸渍液对细胞分泌 IL-1细胞因子活性的影响。采用SPSS 17. 0 软件包对数据进行统计学分析。结果：与对照组相比,2种复合树脂材料浸渍培养液对体外培养的人单核-巨噬细胞的增殖活性有促进作用,与对照组相比差异有显著性(P<0.05) ;检测各材料对巨噬细胞分泌IL-1的影响,2种复合树脂材料与对照组相比,差异没有显著性(P>0.05);玻璃离子与对照组相比,差异有显著性(P<0.05)。结论：复合树脂对人巨噬细胞的增殖和功能活性有显著影响,可能与复合树脂充填产生牙本质敏感症状有关。玻璃离子对人巨噬细胞的增殖活性无明显影响,但可能会促进炎症发展。     

Influence of curing lights and modes on cross-link density of dental composites

This study investigated the influence of curing lights and modes on the cross-link density of dental composites. Four LED/halogen curing lights (LED-Elipar Freelight [FL], 3M-ESPE and GC e-light [EL], GC; high intensity halogen-Elipar Trilight [TL], 3M-ESPE; very high intensity halogen-Astralis 10 [AS], Ivoclar Vivadent) were selected for this study. Pulse (EL1), continuous (FL1, EL2, TL1), turbo (EL3, AS) and soft-start (FL2, EL4, TL2) curing modes of the various lights were examined. A conventional, continuous cure halogen light (Max [MX], Dentsply-Caulk) was used for comparison. Six composite (Z100, 3M-ESPE) specimens were made for each light-curing mode combination. After polymerization, the specimens were stored in air at 37 degrees C for 24 hours and subjected to hardness testing using a digital microhardness tester (load=500 g; dwell time=15 seconds). The specimens were then placed in 75% ethanol-water solution at 37 degrees C for 24 hours and post-conditioning hardness was determined. Mean hardness (HK)/change in hardness (deltaHK) was computed and the data subjected to analysis using one-way ANOVA/Scheffe's test and Independent Samples t-test (p<0.05). Softening upon storage in ethanol (deltaHK) was used as a relative indication of cross-link density. Specimens polymerized with AS, TL2 and all modes of both LED lights were significantly more susceptible to softening in ethanol than specimens cured with MX. No significant difference in cross-link density was observed among the various modes of EL and FL. For TL, curing with continuous mode resulted in specimens with significantly higher cross-link density than curing with the soft-start mode.     

Post-irradiation hardening of dual-cured and light-cured resin cements through machinable ceramics

PURPOSE: To evaluate the surface hardness (Knoop Hardness Number) of the thin layer in three light-cured and dual-cured resin cements irradiated through or not through 2.0 mm thick machinable ceramics. METHODS: A piece of adhesive polyethylene tape with a circular hole was positioned on the surface of the ceramic plate to control the cement layer (approximately 50 microm). The cement paste was placed on the ceramic surface within the circle. The ceramic plate with resin cement paste was placed on a clear micro cover glass over a zirconia ceramic block to obtain a flat surface, and the material was polymerized using a visible-light-curing unit. The surface hardness was recorded at a series of time intervals up to 5 days, starting from the end of a light-irradiation period. RESULTS: The hardness steadily increased with post-irradiation time and tended towards a maximum, usually reached after 1 or 2 days. In all cases, the increase in hardness was relatively rapid over the first 30 minutes and continued at a lower rate thereafter. The dual-cured resin cement for each material showed a significantly higher hardness value than the light-cured resin cement irradiated either through or not through ceramics at all post-irradiation times. The resin cements cured through ceramic for each material were significantly less hard compared with those cured not through ceramics at all post-irradiation times.