温度循环老化对复合树脂表面粗糙度的影响

目的 了解复合树脂经温度循环老化作用后表面粗糙度的变化,分析复合树脂组成成分和工艺对其表面粗糙度的影响,为临床选择和应用复合树脂材料提供指导.方法 选用复合树脂A(Clearfil AP-X,Kurary)、B(Filtek P60,3M ESPE)、C(Filtek P90,3M ESPE)和D(Clearfil MAJESTY,Kurary)制成试样,每组5个样本,在抛光即刻和经10000次及20000次温度循环(55℃和5℃,30s)处理后,用表面粗糙度仪检测试样,获得表面粗糙度Ra值,并进行统计学分析.结果 抛光即刻树脂A的Ra值[(0.16±0.03)μm]显著高于树脂B[(0.09±0.01)μm]、树脂C[(0.09±0.02)μm]和树脂D[(0.08±0.02)μm](P＜0.05),树脂B、C、D的Ra值差异无统计学意义(P＞0.05);4种树脂在温度循环10 000次后的Ra值均无变化(P ＞0.05);20 000次温度循环后,树脂A的Ra值显著增高[(0.20±0.02) μm]较抛光后即刻[(0.16±0.03)μm]和10000次温度循环后[(0.17±0.03) μm]显著增高(P＜0.05),其他3种树脂Ra值仍无显著变化(P＞0.05).结论 短期温度循环老化作用不会导致复合树脂表面粗糙度变化,延长老化时间后大颗粒玻璃填料树脂表面粗糙度增加;纳米工艺可显著改善树脂表面粗糙度;新型硅氧烷类树脂的表面粗糙性表现良好.     

含氟复合树脂释氟对材料挠曲强度的影响

目的：研究含氟复合树脂释氟对材料本身机械性能的影响。方法：选择不同氟含量的含氟树脂,以氟电极法连续30d测定含氟复合树脂体外释氟量。万能试验机测定含氟复合树脂释氟30d前后的挠曲强度。结果：含氟树脂氟含量越高（重量比分别为0％、0．3％、0．6％和1．2％）,初期释氟量越大（分别为0、21．98、43．98和99．91μg.cm^-2),相应挠曲强度越低（分别为101．70、94．29、82．03和79．84MPa）。随着含氟复合树脂释氟量的增加,材料的挠曲强度相应降低。结论：含氟树脂释氟对其机械性能有一定影响。     

冷热循环对龋坏内层和正常牙本质粘接强度的影响

目的评价冷热循环对正常和龋坏内层牙本质粘接强度的影响.方法18个近中(牙合)面中龋人离体磨牙,在龋检液监控下用慢速牙钻去龋,在远中(牙合)面健康牙本质上制备相同深度窝洞作为对照.随机分成3组用粘接剂粘接(Prime&Bond NT、Adper Prompt、Contax Bond),复合树脂(Chrisma A2)充填.制备测试微拉伸粘接强度的正常牙本质和龋坏内层牙本质条状试件,再随机分成3组,分别冷热循环0次、2000次、5000次,在拉力试验机上测定粘接强度.结果冷热循环0次、2000次、5000次时两种牙本质的粘接强度为正常牙本质Prime&BondNT(23.47±5.27 Mpa,25.69±4.52 Mpa,24.54±4.71 Mpa);Adper Prompt(21.29±5.05 Mpa,21.30±2.30Mpa,20.68±6.63 Mpa);Contax(25.78±4.70 Mpa,27.15±5.33 Mpa,24.40±5.93 Mpa);龋坏内层牙本质Prime&BondNT(19.55±3.28 Mpa,18.67±5.52 Mpa,16.07±6.96 Mpa);AdperPrompt(18.40±3.41 Mpa,18.23±3.42 Mpa,16.63±3.42 Mpa);Contax(23.98±3.55 Mpa,21.58±2.69 Mpa,15.34±6.03Mpa).结论冷热循环5000次对正常牙本质的粘接强度无显著影响;对龋坏内层牙本质有显著影响,Adper Prompt除外.未进行冷热循环时,龋坏内层牙本质的粘接强度与正常牙本质没有显著差异.冷热循环5000次后,龋坏内层牙本质的粘接强度显著小于正常牙本质.     

粘接处理剂对自粘接树脂水门汀和RMGIC的牙本质粘接强度的影响

目的:实验评价牙本质粘接处理剂对自粘接树脂水门汀和树脂加强型玻璃离子水门汀(RMGIC)的牙本质微拉伸粘接强度的影响.方法:选用离体人无龋第三恒磨牙24颗,用低速切片机垂直于牙体长轴方向将磨牙冠(牙合)中1/3交界线处切开待用.实验组牙本质表面涂布牙本质粘接处理剂,对照组不涂粘接处理剂.后将试样分别用自粘接树脂水门汀(Unicem,3M ESPE;seT PP,SDI)或树脂加强型玻璃离子水门汀(Fuji CEM,GC)原位对位粘接.水浴中储存24h后,用低速切片机把样本切割成约1mm×1mm×8mm条状,随后进行微拉伸测试.用扫描电镜观察粘接界面形貌.结果:无论是否使用粘接处理剂,Unicem的牙本质粘接强度显著高于seT PP 和Fuji CEM(P <0.01).与对照组相比,实验组的粘接强度显著提高(P <0.05).结论:粘接处理剂表面处理增强自粘接树脂水门汀及树脂加强型玻璃离子水门汀的牙本质粘接强度.     

GIC衬垫对复合树脂粘接强度的影响

本实验应用玻璃离子粘固剂和光敏固化氢氧化钙作衬垫材料，观察其对复合树脂与牙本质间粘接强度的影响。结果表明采用ＧＩＳ衬垫后，能明显增强复合树脂与牙本质间的粘接强度，而光敏固化氢氧化钙反而降低其粘接强度。各组间差异均极显著。采用ＧＩＳ衬垫方法，以距充填体表面０．５毫米组粘接强度最大，明显高于其它组。     

POSS纳米填料对复合树脂与牙本质粘接强度的影响

目的：评价自制POSS纳米填料复合树脂经冷热循环后粘接强度的变化,为新型树脂的研发和应用提供参考依据。方法：160颗人类离体前磨牙随机分为5组,牙体近中面牙本质预备后选用Prime＆BondNT粘接剂分别粘接5种复合树脂（自制POSS纳米复合树脂、未添加POSS填料复合树脂、FiltekTMZ250、FiltekTMZ350、DU-RAFILLVS）。80个试件经10000次冷热循环后,万能材料试验机测试所有试件粘接强度。结果：冷热循环前后粘接强度测试结果分别为：POSS纳米树脂组（27.84±2.19,27.01±2.19）MPa,无POSS填料树脂组（26.73±3.37,20.28±3.30）MPa,FiltekTMZ250（27.56±1.95,26.77±2.74）MPa,FiltekTMZ350（27.68±2.28,24.47±3.04）MPa,DURAFILL○RVS（27.40±1.83,21.49±2.92）MPa。冷热循环前五组树脂粘接强度差异无显著性,经冷热循环各组材料粘接强度差异有显著性（P〈0.05）。结论：5种复合树脂牙本质粘接强度差异显著,添入POSS纳米树脂组冷热循环前后粘接强度均优于未添入组,其耐温度老化性能优于部分临床常用复合树脂。     

负压对多晶颗粒表面改性氧化锆与树脂粘接强度的影响

目的:探讨负压对多晶颗粒表面改性氧化锆陶瓷与树脂粘接强度的影响。方法:制备120个预烧结氧化锆圆片,用随机数字表法随机分成对照组和喷砂组以及30、50、70 s酸蚀组（每组24个）。对照组、喷砂组试件致密烧结前无额外处理;30、50、70 s酸蚀组分别浸入氢氟酸溶液30、50、70 s,再置于CaCl 2溶...     

复合树脂直接与间接修复的粘接微拉伸强度测试研究

目的对复合树脂直接与间接修复的粘接微拉伸强度进行测试。方法新鲜拔除的完好无龋、人下颌第三磨牙15颗,随机分成3组,用Isomet低速切割机流水冲洗下磨去咬合面釉质,暴露牙本质,A组为Renew树脂用One Step Plus直接粘接在牙本质面上,B组为预成的Renew树脂＂冠＂用One Step Plus和C＆B cement间接粘接修复,C组为预成的Renew树脂＂冠＂用One Step Plus和Duo-link间接粘接修复,贮存于室温水中24h,测试微拉伸强度,检查断裂界面。结果A组微拉伸强度（33.38±6.24）MPa高于B组（20.06±4.96）MPa和C组（21.08±4.60）MPa,且差异有显著性,BC两组的微拉伸强度无统计差异。结论树脂直接充填粘接的微拉伸强度要高于树脂间接修复。     

照射时间对复合树脂粘接强度及机械性能的影响

本文考察了光照时间对ＫｕｌｚｅｒＤｕｆａｆｉｌ Ａ１０可见光固化复合树脂粘接强度和机械性能的影响。结果表明，光照时间对Ｄｕｒａｆｉｌ Ａ１０的粘接强度和机械性能有明显影响。随着光照时间的延长，树脂与牛牙釉质的剪切粘度强度及树脂的径向抗张强度不断提高。但当光照时间长至一定限度，树脂的剪切粘接强度及径向抗张强度达最高值，不因光照时间的延长而有明显变化。本研究的结果对临床实际工作具有一定的指导意义。     

Constic自粘接流动树脂拉伸强度及与牙釉质粘接的剪切强度的检测

目的比较Constic自粘接流动树脂、Filtek^TM Supreme Ultra树脂及Spectrum TPH3树脂三种材料的拉伸强度及剪切粘接强度,为Constic树脂的临床应用提供理论依据。方法制备Constic自粘接流动树脂(A组)、Filtek^TM Supreme Ultra树脂(B组)及Spectrum TPH3树脂(C组)试件,使用电子式万能试验机测试三组材料的拉伸强度值。其次制备Constic自粘接流动树脂(A组)、Constic自粘接流动树脂加粘接剂(B组)、Filtek^TM Supreme Ultra树脂(C组)、Spectrum TPH3树脂(D组)试件,使用电子式万能试验机测试四组的剪切粘接强度值,并在显微镜下观察试件断裂面的破坏形式。结果在拉伸强度试验中:A、B、C三组的拉伸强度值分别为31.10±8.35MPa,35.10±6.65MPa,30.00±7.08MPa,A组的强度值与B、C两组相近,三组间无统计学差异(P>0.05)。在剪切粘接强度实验中:强度值分别为A(19.48±1.5...     

Effect of time on tensile bond strength of resin cement bonded to dentine and low-viscosity composite

OBJECTIVES: The purpose of this study was to evaluate the tensile bond strength (TBS) of Panavia F resin cement (PF) applied on dentine pre-treated with ED Primer (ED) and Clearfil Liner Bond 2V (CLB) coated with a layer of low-viscosity composite Protect Liner F (PLF) at 10 min, 24 h and 12 months after curing. METHODS: The labial surfaces of 60 bovine lower incisors were ground to obtain a flat dentine surface, allowing a demarcation of a 4.0 mm-diameter area with adhesive tape. The teeth were randomly divided in six groups; ED was applied in groups A I, A II and A III and CLB was applied, followed by PLF, in groups B I, B II and B III. A resin composite rod with a wire loop was luted directly to the prepared surface of each group with PF. The specimens of groups A I and B I were submitted to TBS test after 10 min. Groups A II and B II were submitted to TBS test after 24 h storage and groups A III and B III were submitted to TBS test after 12 months storage. Each specimen was inspected by SEM and classified according to the failure mode. Additionally, two representative specimens of each failure mode were sectioned for a composite/dentine interface SEM evaluation. RESULTS: No significant statistical differences were observed among the groups at 10 min and 24 h. Groups A III and B III presented the lowest TBS values (p<0.05) after 12 months storage. PF on resin-coated dentin (PLF) showed the highest TBS values and was statistically different to PF on dentine for all the groups. The fracture pattern was generally cohesive on the adhesive/hybrid layer for groups A I, A II and A III and cohesive on composite resin for B I, B II and B III. SIGNIFICANCE: The use of a less hydrophilic self-etching system to pre-treat dentine, coating with a low-viscosity composite layer prior luting with resin cement, may provide a protection of the hybridised complex, allowing a dentine seal during the 12 months storage period.     

丙酮及甲基丙烯酸甲酯表面处理对基托树脂与软衬材料粘接效果的影响

目的 研究丙酮及甲基丙烯酸甲酯表面处理对基托树脂与软衬材料间微渗漏、粘接强度及基托树脂抗弯强度的影响.方法 制备30 mm×30 mm×2 mm树脂块36块,根据随机数字表随机均分为3组,每组12块,丙酮组:树脂块粘接面浸泡于丙酮溶液中30 s;甲基丙烯酸甲酯组:树脂块粘接面浸泡于甲基丙烯酸甲酯溶液中180 s;对照组:不进行表面处理.两树脂块间衬以2 mm软衬材料后粘接,冷热循环5000次,浸泡于131Ⅰ溶液中24h后计数γ射线,即微渗漏数.制备36块30 mm×10 mm ×7.5 mm树脂块,分组及表面处理同上.两树脂块间衬以3 mm软衬材料后粘接,冷热循环5000次后,测试拉伸强度,即粘接强度.制备18块65 mm× 10 mm×3.3 mm树脂块,分组及表面处理同上,涂布软衬材料粘接剂后测试抗弯强度.结果 丙酮组和甲基丙烯酸甲酯组的微渗漏数(520.0±562.2和493.5±447.9)均小于对照组(1369.5±590.2,P＜0.05);丙酮组和甲基丙烯酸甲酯组粘接强度[(1.5±0.4)和(1.4±0.5) MPa]均大于对照组[(0.9±0.2) MPa,P＜0.05];两实验组间微渗漏数和粘接强度差异均无统计学意义(P＞0.05);3组抗弯强度差异均无统计学意义(P＞0.05).结论 丙酮及甲基丙烯酸甲酯表面处理可减少软衬材料与基托树脂间微渗漏,增加两者间粘接强度,未导致基托树脂抗弯强度下降.     

Effects of post surface conditioning before silanization on bond strength between fiber post and resin cement

PURPOSE

Post surface conditioning is necessary to expose the glass fibers to enable bonding between fiber post and resin cement. The purpose of the present study was to evaluate the effect of different surface conditioning on tensile bond strength (TBS) of a glass fiber reinforced post to resin cement.

MATERIALS AND METHODS

In this in vitro study, 40 extracted single canal central incisors were endodontically treated and post spaces were prepared. The teeth were divided into four groups according to the methods of post surface treatment (n=10): 1) Silanization after etching with 20% H₂O₂, 2) Silanization after airborne-particle abrasion, 3) Silanization, and 4) No conditioning (Control). Adhesive resin cement (Panavia F 2.0) was used for cementation of the fiber posts to the root canal dentin. Three slices of 3 mm thick were obtained from each root. A universal testing machine was used with a cross-head speed of 1 mm/minute for performing the push-out tests. Two-way ANOVA and Tukey post hoc tests were used for analyzing data (α=0.05).

RESULTS

It is revealed that different surface treatments and root dentin regions had significant effects on TBS, but the interaction between surface treatments and root canal regions had no significant effect on TBS. There was significant difference among H₂O₂ + Silane Group and other three groups.

CONCLUSION

There were significant differences among the mean TBS values of different surface treatments. Application of hydrogen peroxide before silanization increased the bond strength between resin cements and fiber posts. The mean TBS mean values was significantly greater in the coronal region of root canal than the middle and apical thirds.     

Evaluation of bond strength of silorane and methacrylate based restorative systems to dentin using different cavity models

Objective

The aim of this in vitro study was to evaluate the microtensile bond strength (µTBS) to dentin of two different restorative systems: silorane-based (P90), and methacrylate-based (P60), using two cavity models.

Material and Methods

Occlusal enamel of 40 human third molars was removed to expose flat dentin surface. Class I cavities with 4 mm mesial-distal width, 3 mm buccal-lingual width and 3 mm depth (C-factor=4.5) were prepared in 20 teeth, which were divided into two groups (n=10) restored with P60 and P90, bulk-filled after dentin treatment according to manufacturer''s instructions. Flat buccal dentin surfaces were prepared in the 20 remaining teeth (C-factor=0.2) and restored with resin blocks measuring 4x3x3 mm using the two restorative systems (n=10). The teeth were sectioned into samples with area between 0.85 and 1.25 mm² that were submitted to µTBS testing, using a universal testing machine (EMIC) at speed of 0.5 mm/min. Fractured specimens were analyzed under stereomicroscope and categorized according to fracture pattern. Data were analyzed using ANOVA and Tukey Kramer tests.

Results

For flat surfaces, P60 obtained higher bond strength values compared with P90. However, for Class I cavities, P60 showed significant reduction in bond strength (p<0.05). No statistical difference between restorative systems was shown for Class I cavity model (p>0.05), or between Class I Cavity and Flat Surface group, considering P90 restorative system (p>0.05). Regarding fracture pattern, there was no statistical difference among groups (p=0.0713) and 56.3% of the fractures were adhesive.

Conclusion

It was concluded that methacrylate-based composite µTBS was influenced by cavity models, and the use of silorane-based composite led to similar bond strength values compared to the methacrylate-based composite in cavities with high C-factor.     

不同方向剪切力作用下两种树脂粘结剂与人牙釉质的剪切粘结强度研究

目的：考察不同施力方向上树脂粘结剂与人牙釉质的剪切粘结强度。方法：使用树脂类粘结剂A（Clearfil SE BOND）和B（Prime＆Bond NT），将各自配套的复合树脂粘结在离体人牙釉质面上，当剪切力沿根尖、骀面、近中和远中方向作用时测量其剪切粘结强度。结果：粘结剂A和B与牙釉质的剪切粘结强度值显示，根尖方向[分别为（44．38±3．68）Pa和（45．50±2．88）Pa]〉近中方向[分别为（37．81±7．56）Pa和（40．15±2．59）Pa]和远中方向[分别为（35．71±3．34）Pa和（35．75±4．15）Pa]〉[牙合]面方向[分别为（29．19±3．75）Pa和（33．44±3．79）Pa]，近中方向和远中方向间差异无统计学意义（P〉0．05），根尖方向与[牙合]面方向间差异有统计学意义（P〈0．05）。结论：树脂粘结剂与人牙釉质剪切粘结强度的大小与剪切力作用的方向相关。     

一步法自酸蚀粘接剂微拉伸粘接强度的研究

目的评价一步法白酸蚀粘接剂的牙本质微拉伸粘接强度，观察并分析样本断裂类型。方法选择新拔除的人无龋下颌第三磨牙12颗，分别用3种一步法、1种两步法的白酸蚀粘接剂进行牙本质粘接。用微拉伸测力仪测试粘接强度，并用体视显微镜和扫描电镜观察样本断裂类型。结果3种一步法白酸蚀粘接剂的微拉伸强度分别为：材料A（Adper Prompt）（23．36±2．55）MPa；材料B（Clearfil S^3 Bond）（30．46±3．82）MPa；材料C（Xenon Ⅲ）（34．59±3．46）MPa；1种两步法自酸蚀粘接剂材料D（Clearfil SE Bond）的微拉伸粘接强度为（45．06±5．29）MPa。材料D微拉伸粘接强度最高，与其他3组相比，差异具有统计学意义（P〈0．01）。样本断裂均发生于粘接界面，未观察到复合树脂或牙本质内聚破坏。结论一步法白酸蚀粘接剂的牙本质粘接强度低于两步法白酸蚀粘接剂，但多数仍可满足临床对树脂粘接强度的要求。     

Effect of physicochemical aging conditions on the composite-composite repair bond strength

PURPOSE: This study evaluated the effect of different physicochemical aging methods and surface conditioning techniques on the repair bond strength of composite. It was hypothesized that the aging conditions would decrease the repair bond strength and surface conditioning methods would perform similarly for the repair of resin composites. MATERIALS AND METHODS: Disk-shaped resin composite specimens (Clearfil Photo Bright, Kuraray) were randomly assigned to one of the three aging conditions (N=120, n = 12/per group): (1) immersion in deionized water (37 degrees C, 1 week), (2) immersion in citric acid (pH: 3.0, 1 week), (3) boiling in water (8 h), (4) thermocycling (5000 times, 5 degrees C to 55 degreesC), (5) immersion in water (37 degrees C, 2 months). After aging procedures, the specimens were subjected to one of the following surface conditioning methods: (1) chairside silica coating (30-microm SiOx) (CoJet, 3M ESPE) + silane (ESPE-Sil) (SC method), (2) silane (Clearfil SE Bond Primer and Clearfil Porcelain Bond Activator) + bonding agent (Clearfil SE Bond) (SB method). The fresh and aged composite surfaces were also examined using SEM (n=6, 1/group). Resin composite (Quadrant Anterior Shine) was bonded to the conditioned substrates using polyethylene molds and then light polymerized. Shear force was applied to the adhesive interface in a universal testing machine (1 mm/min). The failure types were categorized as: (A) cohesive in the substrate, (B) adhesive at the interface, or C) cohesive in the adherend. Bond strength values were statistically analyzed using two-way ANOVA and Tukey's test (alpha < 0.05). RESULTS: A significant influence of the conditioning method (p < 0.0001) and aging method was observed (p < 0.01) (two-way ANOVA, Tukey-Kramer). The SC method showed significantly higher bond values (7.8 +/- 1.2 to 11.6 +/- 5 MPa) than those of SB method (4.6 +/- 2.3 to 7.6 +/- 3.9 MPa) in all groups (p < 0.0001). While the SC method showed 96% cohesive (A type), the SB method demonstrated 92% adhesive failures (B type). SEM images showed distinct pattern of microcracks in the boiled specimens and filler dissolution with disorganized matrix resin in the other aged specimens. Aging the composite substrates through water storage for 2 months produced significantly lower bond strengths than those of water or acid storage for 1 week (p = 0.011). CONCLUSION: Chairside silica coating and silanization provided the highest bond strength values with almost exclusively cohesive failures on aged composites. Aging methods showed significant differences on the composite-composite repair strength.     

热循环和机械循环对切削Ti2448和纯钛金瓷结合强度的影响

目的 研究热循环和机械循环对切削Ti2448和纯钛金瓷结合强度的影响。方法 按照ISO 9693的标准分别制作纯钛和Ti2448烤瓷试件各30个,每种试件均随机分为3组,A组为对照组,在37 ℃水浴中保存24 h;B组和C组在5~55 ℃水浴中热循环3 000次,在每一个温度下保持60 s,然后采用载荷50 N、频率4 Hz,机械循环20 000次（B组）或40 000次（C组）。采用三点弯曲实验测试试件的金瓷结合强度,通过扫描电镜和能谱分析金瓷剥脱面和金瓷结合界面的显微结构和成分组成,对结果进行两因素方差分析和Tukey检验。结果 A组中,纯钛试件的金瓷结合强度（29.21 MPa±2.20 MPa）明显小于Ti2448试件（44.86 MPa±1.75 MPa）（P<0.01）;纯钛试件和Ti2448试件中,C组与A组之间均有统计学差异（P<0.01）。扫描电镜和能谱分析结果显示,Ti2448瓷剥脱面有明显的瓷残留,而纯钛瓷剥脱面无明显瓷残留。结论 热循环和机械循环处理降低了Ti2448和纯钛的金瓷结合强度。     

四种核树脂冷热循环前后机械性能的比较

目的通过体外冷热循环模拟老化核树脂材料,比较不同核树脂的机械性能。方法将A、B、C、D四种核树脂分别制备成25mm×2mm×2mm的6个棱柱状挠曲试样和高6mm,直径4mm的10个圆柱状抗压试样,通过万能试验机测试冷热循环前后试样的挠曲强度和抗压强度;用单因素方差分析和t检验进行统计分析。结果未冷热循环的四组核树脂挠曲强度值和抗压强度值差异均没有统计学意义。经过5000次冷热循环后,自制核树脂与三种成品核树脂相比较,在挠曲强度和抗压强度上差异均没有统计学意义。A、B、C三组核树脂挠曲强度和抗压强度在循环后均有显著下降(P<0.05)。结论自制核树脂的挠曲强度和抗压强度良好,冷热循环对核树脂材料的老化作用明显。