玻璃纤维的表面预处理对纤维增韧树脂基桩力学性能的影响

目的 研究不同表面预处理的高强玻璃纤维对纤维增强光固化树脂复合材料（FRC）桩的力学性能的影响。方法 将玻璃纤维分为4组分别进行以下表面处理：不预处理、450 ℃高温处理、450 ℃高温+10%HCl蚀刻1 h、450 ℃高温+10% HCl蚀刻3 h,然后将4组纤维经过硅烷偶联剂处理后按相同体积比浸入自行配制的光固化树脂基质中,用压挤法制成纤维增强树脂基桩。测试试样的弯曲模量、弯曲强度、弯曲载荷,扫描电子显微镜观察FRC截面和断裂面的形态。结果 不同表面预处理后的玻璃纤维对FRC桩的力学性能有显著差异,其中450℃+KH570组制成的FRC桩性能最佳,弯曲模量、弯曲强度、弯曲载荷分别为（37.70±1.46） GPa、（737.00±25.51） MPa、（196.53±6.80） N,与其余组有显著差异（P＜0.05）。结论 450 ℃高温+KH570处理玻璃纤维对FRC桩的增韧效果最佳。     

不同纳米粒子对纤维增强光固化树脂基桩力学性能的影响

目的研究2种纳米颗粒对自行研制的高强玻璃纤维增强光固化树脂复合材料(FRC)桩的力学性能的影响。方法自行配置光固化树脂基质,将纳米ZrO2和纳米Al2O3分别按1%、3%、4%、5%的比例加入树脂基质,用拉挤法制成纤维增强树脂基牙科桩,用万能力学试验机测试FRC桩的弯曲模量、弯曲强度、弯曲载荷。结果不同含量的纳米粒子对FRC桩的力学性能有影响,含4%纳米ZrO2、Al2O3的光固化树脂制成的FRC桩综合性能最佳,弯曲模量(20.42±0.88)、(19.96±0.69)GPa,弯曲强度(464.89±18.84)、(481.17±24.68)MPa,弯曲载荷(146.05±5.92)、(151.23±7.79)N,与未添加纳米粒子的FRC桩有显著差异(P<0.05)。结论少量纳米粒子对FRC桩有增韧效果。     

玻璃纤维预拉伸对增韧光固化树脂基桩力学性能的影响

目的 研究玻璃纤维预拉伸对自行研制的高强玻璃纤维增韧光固化树脂复合材料（FRC）桩力学性能的影响。方法 利用加载装置将高强玻璃纤维分别拉伸0%、0.5%、1.0%后,按60%体积比浸入自行配置的光固化树脂基质,采用压膜法制成玻璃纤维增韧树脂基齿科桩,三点弯曲测试各试样的弯曲模量、弯曲强度和弯曲载荷,测试结果进行统计学分析。使用扫描电子显微镜观察FRC桩横截面和断裂面的形态。结果 玻璃纤维拉伸率对FRC桩的力学性能影响有显著差异,其中拉伸率为1.0%的玻璃纤维制成的FRC桩综合性能最佳,弯曲模量(20.40±1.40) GPa,弯曲强度(573.38±29.45) MPa,弯曲载荷(180.42±5.88) N,与未预拉伸的玻璃纤维增韧的FRC桩有显著差异(P<0.05)。结论 玻璃纤维预拉伸对FRC桩有增韧效果。     

核壳纳米纤维增强牙科树脂基体的力学性能与界面研究

目的研究PAN—PMMA核壳纳米纤维对牙科光固化树脂基体力学性能的增强效果。方法通过静电纺丝法制备PAN—PMMA核壳纳米纤维,同时将纳米纤维分别按1wt％、2wt％、3wt％和5wt％的质量比直接纺入Bis—GMA／TEGDMA光固化树脂单体制成纳米纤维树脂复合物。空白组是Bis—GMA／TEGDMA纯光固化树脂。在万能力学测试机上用三点弯曲法测试各组的弯曲强度、模量及断裂功,用SPSS软件进行统计学分析。SEM观察各组样条断面纤维与树脂界面及纤维分散状态。结果2wt％纳米纤维增强组弯曲强度和模量及断裂功较空白组分别增加了25％、74％、47％,统计学分析有显著性差异（P〈0．05）;SEM结果显示断面拔出的纤维表面粗糙,纤维分散均匀,有较好的界面形成。结论2wt％质量比的PAN—PMMA核壳纳米纤维可以提高光固化树脂基质的力学性能。     

纤维表面沉积二氧化硅薄膜对纤维树脂复合物性能的影响

目的 探究纤维表面原子层沉积二氧化硅薄膜对牙科纤维树脂复合物性能的影响。方法 利用原子层沉积技术(atomic layer deposition, ALD)在石英纤维表面沉积二氧化硅薄膜，制作纤维树脂复合物，分为A(未去除浸润剂)、B(去除浸润剂)、C(去除浸润剂+硅烷化)、D(去除浸润剂+ALD 600循环+硅烷化)4组，通过扫描电子显微镜、水接触角实验、吸湿性测试、CCK8实验、三点弯曲实验等检测纤维树脂复合物相关性能。结果 原子层沉积二氧化硅薄膜后，石英纤维表面形态光滑，较处理前无明显改变；经ALD处理的石英纤维在硅烷化后呈疏水性。三点弯曲实验结果表明，经ALD改性的纤维树脂复合物力学性能显著提高(P<0.05)。电镜图像显示D组石英纤维与树脂基质之间具有良好的界面结合；此外，D组纤维树脂复合物表现出低吸附性、低溶解性与良好的生物相容性。结论 原子层沉积技术在石英纤维表面沉积二氧化硅薄膜可显著提高牙科纤维增强树脂复合物的力学性能。     

不同弯曲度对牙科纤维增强复合材料桩钉性能的影响

目的研制一套具有不同弯曲角度的牙科纤维增强复合材料(FRC)桩钉,探讨弯曲角度对FRC桩钉性能的影响。方法自行设计一套金属模具,利用该模具制作一套弯曲角度分别为5°、10°、15°的FRC弯钉。三点挠曲实验比较不同弯曲度的FRC弯钉与FRC直钉的挠曲强度和挠曲模量。结果15°FRC弯钉的挠曲性能低于5°、10°及直钉,差异均有统计学意义(P<0.05),其余各组FRC桩钉的挠曲性能,差异无统计学意义(P>0.05)。结论自制FRC桩钉的弯曲角度在0°、5°、10°时,其对材料力学性能影响较小。     

6种表面处理法对纤维桩树脂核黏结力影响的实验研究

目的:研究纤维桩不同表面处理方法对树脂核材料与纤维桩黏结性能的影响.方法:纤维桩表面用6种方法处理(Contax、Clearfil SE Bond、Single Bond 2、Prime&Bond NT、Silane、Silane+Contax)后,用2种树脂类核材料分别制作桩核试件,万能力学试验机上测试桩核黏结力.结果:表面处理方法对纤维桩核的黏结力有显著影响(P＜0.05),Silane+Contax组黏结力均值最大(589.50±68.85)N,与除了Silane组以外的所有组差异均有显著性(P＜0.05).电镜结果显示,双固化树脂核材料Muhieore Heavy Body与Silane+Contax处理后纤维桩表面结合紧密,结合界面未见裂纹;对照组双固化树脂核材料Muhicore Heavy Body与未做表面处理的纤维桩表面结合较差,结合界面有裂隙存在.结论:表面处理方法对纤维桩树脂核黏结力有显著影响,硅烷偶联剂可显著提高纤维桩树脂核黏结力.     

不同表面处理对纤维桩粘结强度的影响及电镜观察

目的 比较研究不同表面处理对纤维桩剪切粘结强度的影响及各自的粘结面超微结构。方法 20根纤维桩分为4组（n=5）：表面无处理组（A）、椅旁硅烷化处理组（B）、厂家预处理组（C）、厂家预处理+椅旁硅烷化处理组（D）。分别用树脂核材料置于纤维桩周围制成圆柱形标准试件,包埋,切割成1 mm薄片。每根纤维桩可获得10个薄片。每组5个薄片用于电镜观察纤维桩与树脂核材料粘结界面的超微结构;45个薄片在万能实验机上进行微推出实验,记录数值并进行统计学分析。结果 各组的剪切粘结强度依次为（13.46±1.78）、（18.39±1.60）、（24.54±1.34）、（24.39±1.65） MPa。表面处理组均高于A组,C组高于B组,D组与C组之间无差异。电镜观察各组纤维桩与树脂核材料粘结界面结合良好。C组和D组的纤维桩粘结界面可见微机械固位结构。结论 纤维桩表面由厂家预处理有效提高了纤维桩剪切粘结强度,表面预处理形成的微机械固位和化学粘结固位是增强纤维桩粘结强度的重要因素。     

四种加工方式对基托树脂力学性能的影响

目的 探讨不同混合和热加工方式对义齿基托树脂力学性能的影响,探讨捏炼混合+电烤箱加热的固化方式可否提高基托树脂的力学性能.方法 制作4组基托树脂试件,第1组:常规混合+水浴加热;第2组:捏炼混合+水浴加热;第3组:常规混合+电烤箱加热;第4组:捏炼混合+电烤箱加热.测定树脂的表面硬度、弯曲强度和弯曲模量、冲击强度.结果 第1～4组试件表面硬度分别为19.4、21.2、22.3、23.2 N/mm2,弯曲强度分别为58.58、63.32、66.73、63.76 MPa,冲击强度分别为1.42、1.53、1.77、1.78 KJ/m2,弯曲模量分别为2311.38、2417.82、2566.36、2400.37 MPa.结论 与常规混合+水浴加热方式相比,捏炼混合+电烤箱加热方式制作的树脂有较高的表面硬度和冲击强度,综合力学性能较佳.     

纤维桩核材料及预备时机对粘接界面密合性影响的实验研究

目的 研究不同桩核预备时机对FRC纤维桩核和预成石英纤维桩核与牙体组织粘接界面密合性的影响.方法 40颗人离体前磨牙按桩核预备时机和纤维桩材料分为A、B、C、D 4组(n=10)(A组:FRC纤维桩+即刻预备组;B组:FRC纤维桩+延迟预备组;C组:预成纤维桩+即刻预备组;D组:预成纤维桩+延迟预备组).使用扫描电镜(SEM)分别在纤维桩核冠完成后、冷热循环5000次后和循环加载24万次后,观察测量每组试件桩核与牙体组织粘接界面的裂隙宽度,并进行统计学分析.结果 试件经冷热循环后,B组的裂隙宽度小于D组,有统计学差异,其余各组无统计学差异.试件经循环加载后,A组的裂隙宽度小于C组,有统计学差异,B组裂隙宽度小于D组,有统计学差异,其余各组的裂隙宽度相近无统计学差异.结论 对于同一种纤维桩材料,不同桩核预备时机可以达到相近的边缘密合性.FRC纤维桩核冠的边缘密合性优于预成石英纤维桩核冠的边缘密合性.     

A simple etching technique for improving the retention of fiber posts to resin composites

Coupling of fiber posts to composites is hampered by absence of chemical union between epoxy resins and methacrylate-based resins. This study examined a clinically feasible protocol for creating micromechanical retention on the surface of fiber posts, using hydrogen peroxide etching to remove the surface layer of epoxy resin. This was followed by silanization of the exposed quartz fibers to enhance their chemical bonding to composites. Etching with 24% H2O2 for 10 min or 10% H2O2 for 20 min produced a 50 microm thick surface zone that is depleted of epoxy resin, leaving intact, undamaged quartz fibers for silanization. Low viscosity flowable composites were employed to infiltrate this zone, to simulate the creation of hybrid layers in acid-etched dentin by dentin adhesives. Interfacial strengths were enhanced with the adjunctive use of H2O2 etching and silanization, and were probably dependent on the ability of the flowable composites to completely infiltrate this interdiffusion zone.     

The adhesion between fibre posts and composite resin cores: the evaluation of microtensile bond strength following various surface chemical treatments to posts

AIM: To evaluate the influence of various surface treatments to fibre posts on the microtensile bond strength with different composite resins. METHODOLOGY: A total of 110 fibre posts were randomly divided into five groups, according to the surface pre-treatment performed. Group 1: immersion in 24% H(2)O(2) for 10 min and silanization for 60 s; group 2: immersion in 10% H(2)O(2) for 20 min and silanization for 60 s; group 3: immersion in 4% hydrofluoric acid gel for 60 s and silanization for 60 s; group 4: silanization of the post surface for 60 s and application of the bonding agent G-Bond; group 5: silanization of the post surface for 60 s (control group). After treatment, two posts were randomly selected from each group to evaluate the morphological aspect of the post surface with scanning electron microscopy. The remaining posts in each group were divided into five subgroups of five posts each, which differed in the type of composite resin used for the core build-up. Post-core strength were calculated and the differences among experimental groups were analysed with two-way anova and the Tukey test (alpha = 0.05). RESULTS: The post-core strengths achieved in groups 1 and 2 were significantly higher (P < 0.05), than those of groups 3, 4 and 5. The post-core strength in the control group was significantly lower (P < 0.05) than all other groups. CONCLUSIONS: Hydrogen peroxide and hydrofluoric acid both modified the surface morphology of fibre posts and with silane, significantly enhanced the interfacial strength between them and core materials.     

Effects of mechanical cycling on the bonding of zirconia and fiber posts to human root dentin

PURPOSE: To evaluate the effect of cyclical mechanical loading on the bond strength of a fiber and a zirconia post bonded to root dentin. MATERIALS AND METHODS: Forty single-rooted human teeth (maxillary incisors and canines) were sectioned, and the root canals were prepared at 12 mm. Twenty randomly seleced specimens received a quartz fiber post (FRC) (D.T. Light-Post) and 20 others received a zirconia post (ZR) (Cosmopost). The posts were resin luted (All Bond 2 + resin cement Duo-link) and each specimen was embedded in epoxy resin inside a PVC cylinder. Ten specimens with FRC post and 10 specimens with ZR post were submitted to fatigue testing (2,000,000 cycles; load: 50 N; angle of 45 degrees; frequency: 8 Hz), while the other 20 specimens were not fatigued. Thus, 4 groups were formed: G1: FRC+O cycles; G2: FRC+2,000,000 cycles; G3: ZR+O cycles; G4: ZR+2,000,000 cycles. Later, the specimens were cut perpendicular to their long axis to form 2-mm-thick disk-shaped samples (4 sections/specimen), which were submitted to the push-out test (1 mm/min). The mean bond strength values (MPa) were calculated for each tooth (n = 10) and data were submitted to statistical analysis (alpha = 0.05). RESULTS: Two-way ANOVA revealed that the bond strength was significantly affected by mechanical cycling (p = 0.0014) and root post (p = 0.0325). The interaction was also statistically significant (p = 0.0010). Tukey's test showed that the mechanical cycling did not affect the bonding of FRC to root dentin, while fatigue impaired the bonding of zirconium to root dentin. CONCLUSION: (1) The bond strength of the FRC postto root dentin was not reduced after fatigue testing, whereas the bonding of the zirconia post was significantly affected by the fatigue. (2) Cyclical mechanical loading appears to damage the bond strength of the rigid post only.     

H2O2溶液表面处理对纤维桩和树脂水门汀粘接强度的影响

目的 评价不同浓度H2O2溶液表面处理对玻璃纤维桩与树脂水门汀粘接强度的影响。方法 将25支POPO纤维桩随机分成5组：A组（对照组）,B组（硅烷组）,C组（10% H2O2+硅烷组）,D组（20% H2O2+硅烷组）,E组（30% H2O2+硅烷组）。将纤维桩与树脂水门汀粘接制作树脂块及薄片试件,将试件放在万能试验机上加载后算出粘接强度,体视显微镜观察破坏模式,统计学分析。结果 各组粘接强度值为：A组 （12.36±1.66）MPa,B组（12.76±1.59）MPa,C组（16.10±2.55）MPa,D组（19.19±2.81）MPa,E组（21.95±2.95） MPa。5组数据两两比较,除AB组比较无统计学意义（P>0.05）,其余均有统计学意义（P<0.05）。结论 仅用硅烷偶联剂对玻璃纤维桩进行表面处理的粘接强度并未提高;H2O2溶液处理后再涂硅烷偶联剂可提高玻璃纤维桩与树脂水门汀的粘接强度,随H2O2溶液浓度的增加,粘接强度增加增多。     

不同浓度H2O2的桩表面处理对玻璃纤维桩与树脂水门汀黏结强度的影响

目的：研究不同浓度的H2O2表面处理对纤维桩与树脂水门汀之间黏结强度的影响。方法：选择2种不同种类的玻璃纤维桩各18支,随机分为6组,A组(对照组)、B组(单纯硅烷化处理)、C组(3%H2O2+硅烷化处理)、D组(10%H2O2+硅烷化处理)、E组(20%H2O2+硅烷化处理)和F组(30%H2O2+硅烷化处理)。将各组纤维桩与树脂水门汀进行黏结,形成圆柱状树脂块,将每个树脂块切割成7个1.0 mm厚的薄片进行推出实验,记录数据并采用SPSS13.0软件包对数据进行统计学分析。测试后的试件置于光学显微镜下,观察其破坏模式。结果：Tenax玻璃纤维桩黏结强度值A1-F1组分别为 (22.35±3.43) MPa 、(22.75±1.92) MPa、(27.21±3.60) MPa、(32.32±2.19) MPa、(36.15±2.32) MPa和(40.51±2.37) MPa,Macthpost玻璃纤维桩黏结强度值A2-F2组分别为(17.29±3.23) MPa、(17.01±3.18) MPa、(20.48±2.11) MPa 、(23.60±2.60) MPa 、(27.65±3.77) MPa和(30.52±2.99) MPa。Tenax及Matchpost组中,除了A组和B组无显著差异(P>0.05)外,其余每2组间相比,差异均有显著性(P<0.05)。结论：使用H2O2溶液处理Tenax及Matchpost玻璃纤维桩表面再涂以硅烷偶联剂,可明显提高2种玻璃纤维桩与树脂水门汀之间的黏结强度。30%H2O2溶液处理玻璃纤维桩表面的黏结强度最高,可使其更利于黏结。     

Bond strengths of resin cements to fiber-reinforced composite posts

PURPOSE: To evaluate the bond strengths of six different luting cements to fiber-reinforced composite (FRC) posts after various pre-treatment procedures. METHODS: 180 FRC posts were divided into three groups (n=60) and received the following surface treatments. Group 1: untreated control; Group 2: silane treatment; Group 3: CoJet treatment. The posts of each group were fixed with six different luting cements. Push-out tests were performed to determine the bond strengths between the cements and the fiber posts. RESULTS: The observed bond strengths (MPa) of the different resin cements to the posts were significantly affected by the type of cement (P< 0.001), but not by the pre-treatment chosen (P> 0.05; 2-way-ANOVA). Without consideration of the pre-treatment procedures, Clearfil showed the highest bond strengths, followed by Panavia F and RelyX, whereas Multilink, Variolink and PermaFlo showed significantly lower bond strength values (P< 0.05; Tukey's B).     

Effects of chemical surface treatments of quartz and glass fiber posts on the retention of a composite resin

STATEMENT OF PROBLEM: Failure of a fiber post and composite resin core often occurs at the junction between the 2 materials. This failure process requires better characterization. PURPOSE: The purpose of this study was to evaluate the effect of 2 chemical solvents, hydrogen peroxide and methylene chloride, on the shear bond strength of quartz and glass fiber posts to a composite resin. MATERIAL AND METHODS: Twenty-four posts (3 +/-0.1 mm in length) were prepared for each quartz (LIGHT-POST (LP)) and glass fiber (Cytec blanco (CB)) post. Posts were horizontally embedded in acrylic resin with half of the post diameter exposed. The exposed surfaces were successively ground with 400-, 800-, and 1200-grit silicon carbide papers, to ensure uniform smoothness. The specimens were divided into 3 subgroups (n=8) representing different surface treatment techniques, including application of silane for 60 seconds (S), etching with hydrogen peroxide for 20 minutes (H), and etching with methylene chloride for 5 seconds (M). Silane-treated specimens served as controls. A dual-polymerized composite resin (Tetric EvoCeram) was placed in a polytetrafluoroethylene mold (30 x 2 mm) positioned upon the post specimens and polymerized for 20 seconds with a light-emitting diode (LED) polymerization unit. The specimens were stored in water at 37 degrees C for 24 hours. Shear bond strength values (MPa) of posts and composite resin cores were measured using a universal testing machine with a crosshead speed of 0.5 mm/min. Data were analyzed by 2-way analysis of variance (ANOVA). Post hoc Tukey intervals for comparison among the 2 post materials and 3 surface treatment techniques were calculated (alpha =.05). The effect of the chemical surface treatments on glass and quartz fiber post surfaces were examined with a scanning electron microscope (SEM). RESULTS: There were significant differences between the shear bond strength for LP and CB (P<.001). For all groups, the application of H showed the highest bond strength values. There was no significant difference between the S and M groups (P>.05). The SEM observations demonstrated that the fiber post surfaces were modified after chemical surface treatment techniques. CONCLUSIONS: The surface treatment of quartz and glass fiber posts with hydrogen peroxide significantly enhanced the shear bond strength of the composite resin tested due to its ability to dissolve the epoxy resin matrix used in each post. The lowest bond strength was obtained with M and S groups. Application of methylene chloride to the fiber post surfaces for 5 seconds was not effective in increasing the shear bond strength of the fiber post to composite resin.     

Adhesion between fiber posts and resin luting agents: a microtensile bond strength test and an SEM investigation following different treatments of the post surface

PURPOSE: (1) To evaluate the interfacial strength between FRC Postec posts and three luting agents (Multilink, Variolink II, and MultiCore Flow) following different surface treatments, and (2) to observe the effect of sandblasting (Rocatec Pre) on the surface morphology of methacrylate-based fiber posts. MATERIALS AND METHODS: The posts received one of the following surface treatments: (1) sandblasting, (2) sandblasting + silanization, (3) silanization or (4) no treatment. The three luting agents were bonded to the post and the post-cement bond strength was evaluated with the microtensile test. SEM observation of sandblasted and nontreated posts was performed. Post-cement interfaces were also evaluated. Data were statistically analyzed with two-Way ANOVA with post treatment and luting agent as factors. Tukey's test was applied for post-hoc comparisons. RESULTS: Post treatment and the interaction between type of luting agent and type of post treatment were significant factors for bond strength (p < 0.001). The type of luting agent did not significantly influence bond strength (p = 0.07). Sandblasting + silanization performed better than sandblasting or no treatment (p < 0.001). Silanization resulted in significantly higher bond strengths than no treatment (p = 0.045). No differences were detected between sandblasting + silanization and silanization. SEM observation revealed an increased surface roughness and exposure of fibers in sandblasted posts. CONCLUSION: Silanization was confirmed to be a reliable method for improving the bond strength of resin luting agents to fiber posts. Bond strength of resin luting agents to fiber posts was not influenced by the type of luting agent. The sandblasting procedure modified the methacrylate-based post surface texture.