Influence of silane and solvated bonding agents on the bond strength to glass‐fibre posts

The combined use of silane and solvated bonding agents on the bond strength to glass‐fibre posts was investigated. A model Bis‐GMA/HEMA adhesive was formulated with no solvent, 30% of ethanol or 80% of acetone. The surfaces of rectangular‐shaped posts were silanated or not and one of the agents was applied, except for the control group. Cylinders of resin cement (RelyX ARC, 3M ESPE, Saint Paul, MN, USA) were built‐up on the surfaces (n = 20) and submitted to shear testing. All groups showed higher bond strengths when the surfaces were silanated. When no silanization was carried out, the use of bonding agents, either solvated or non‐solvated, increased the bond strengths. All groups treated with both silane and bonding agent showed higher bond strengths than the group that was only silanated. Control and ethanol‐based adhesives were similar, whereas the acetone‐based agent yielded higher bond strengths. Adhesive failures were predominant. Combination of silane and adhesive enhanced the bond to fibre posts.     

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目的对比4种充填材料的边缘微渗漏情况,为其临床应用提供合理指导。方法选择2013年1—6月青岛大学医学院附属医院口腔科因牙周病或阻生齿而拔除的健康新鲜后牙60颗,备洞后随机分为6组,每组10颗,分别使用Fihek Z250复合树脂（A1、A2组）、Ketac N100树脂加强型玻璃离子（B1组）、Ketac MolarEasymix型玻璃离子（B2、B3组）、F2000Compomer玻璃离子复合体（B4组）充填窝洞。其中A2组充填后充填体表面涂布AdperSingleBond2粘接剂,B3组充填后充填体表面涂布凡士林,而其他各组充填后表面不做任何处理。经冷热交替实验后,记录各组染料渗入窝洞壁与充填体之间的深度,并进行统计分析。结果A2组微渗漏最小,B2组微渗漏最大,与其他组（A1、B1、B3、B4）相比差异有统计学意义（P〈0．05）;A1、B1、B3、B4组间两两比较差异均无统计学意义（P〉0．05）。结论复合树脂、树脂加强型玻璃离子、玻璃离子复合体的边缘微渗漏均小于传统型玻璃离子;表面涂布隔湿剂后能增强上述材料的边缘封闭性能。     

金属翼板树脂粘接固定义齿的临床应用

金属翼板树脂粘接固定义齿是以铸造金属为支架,金属翼板为固位体,烤瓷熔附金属为桥体的粘接固定桥,是目前应用最多的一种粘接桥修复方法。其主要缺点是远期留存率较低,最常见的失败原因是脱胶,具体表现为脱落或松动,脱落率高成为限制发展的主要因素。影响其成功率的因素众多,本文就病例选择、固位体设计和连接体三个方面对粘接桥的影响作一综述,以供临床参考。     

不同树脂嵌体材料边缘微渗漏的对比研究

目的：通过对比4种树脂嵌体材料的微渗漏大小,为临床树脂嵌体材料的选择提供参考.方法：40颗离体牙按嵌体备洞原则制备近中邻（牙合）Ⅱ类洞,随机分为4组,每组10颗.分别用Z350、P60、Ceramage、Solitaire 2制作嵌体后使用Adper Single Bond 2和Adper Rely X ARC进行粘结.经冷热循环500次品红染色后,金刚砂片平行于牙体长轴沿近远中方向将修复体纵向剖开2次,在体式显微镜下测量染料渗入轴壁、龈壁的深度.结果：4组树脂嵌体材料轴壁和龈壁均出现微渗漏.经单因素方差分析,不同树脂嵌体材料之间的轴壁（F=0.131）及龈壁（F=0.385）微渗漏差异无统计学意义（P＞0.05）;同材料组的龈方渗漏程度均显著高于轴壁,配对t检验显示差异有统计学意义（P＜0.01）.结论：从微渗漏深度大小来进行评价,4种树脂嵌体材料均是临床上制作树脂嵌体理想的材料;树脂嵌体与牙釉质粘结效果比牙本质好.     

“劲润”牙本质保护膜的牙本质粘结性能探讨

目的：探讨“劲润”牙本质保护膜（Hybrid Coat,HyC）的牙本质粘结性能。方法：选取A组（HyC）和其他3组不同类型的牙本质粘结剂：B组（G-Bond）、C组（MegaBond）和D组（single Bond）,比较其对牛牙牙本质的剪切粘结强度,并用实体显微镜观察粘结界面断裂模式。各组试料数分别为n=10,结果通过Tukey-Kramer（P〈0．05）进行统计学分析。结果：B、C、D组均显示了较大的粘结强度,3组之间无统计学差异。A组（HyC）显示了较低的粘结强度,约10．08MPa,与其他3组之间存在显著性差异。断裂模式显示,A组（HyC）以界面破坏为主,而其他3组以凝集破坏和混合破坏为主。结论：本研究结果提示,“劲润”牙本质保护膜（HyC）的粘结强度弱于其他3组牙本质粘结剂。为了保证HyC长期稳定的防过敏效果及粘结性能,在今后的研究中有必要进一步探讨如何提高HyC的牙本质粘结性能。     

不同清洁方式处理义齿树脂基托后的SEM观察

目的:采用扫描电子显微镜对不同清洁方式处理后的义齿树脂基托表面进行观察以分析不同清洁方式对义齿树脂基托的影响。方法:制作圆形树脂基托样本(14mm×14mm×3mm)16个,随机分为4组,A组为对照组置于清水中,B、C、D组为实验组,其处理方式及时间分别为:牙刷+清水组/30s、牙刷+牙膏组/30s、义齿清洁片溶液浸泡组/5min,重复该处理过程1080次。结果:结果显示B、C组树脂基托表面呈现条纹状摩擦沟及划痕结构改变,C组变化尤为明显,A组及D组无明显改变。结论:牙刷+牙膏清洁方式对义齿基托表面形态改变较为明显,义齿清洁片溶液浸泡对基托表面影响较小,几乎不会对其表面造成明显裂纹及划痕。     

复合树脂多色分层美学修复用于Ⅳ类洞的美学探讨

目的:应用多色分层复合树脂修复前牙Ⅳ类洞,观察其美学修复效果。方法:选取40颗Ⅳ类洞患牙,先经牙体预备,而后制备硅橡胶背板,比色,粘结,多色分层树脂修复,最后进行咬合调整,精细抛光,分别于术后1周、3、6、12、24月复查修复体充填效果。结果:36例充填体在24个月内的各项评价指标均达到临床满意的美学效果。结论:多色分层复合树脂修复前牙牙体,在较少磨除牙体组织的同时取得较好的临床美学效果。     

The effect of acrylamide incorporation on the thermal and physical properties of denture resins

PURPOSE

Polymethyl methacrylate (PMMA) is the most commonly used denture base material despite typically low in strength. The purpose of this study was to improve the physical properties of the PMMA based denture base resins (QC-20, Dentsply Ltd., Addlestone, UK; Stellon, AD International Ltd, Dentsply, Switzerland; Acron MC; GC Lab Technologies Inc., Alsip, Japan) by copolymerization mechanism.

MATERIALS AND METHODS

Control group specimens were prepared according to the manufacturer recommendations. In the copolymer groups; resins were prepared with 5%, 10%, 15% and 20% acrylamide (AAm) (Merck, Hohenbrunn, Germany) content according to the moleculer weight ratio, respectively. Chemical structure was characterized by a Bruker Vertex-70 Fourier transform infrared spectroscopy (FTIR) (Bruker Optics Inc., Ettlingen, Germany). Hardness was determined using an universal hardness tester (Struers Duramin, Struers A/S, Ballerup, Denmark) equipped with a Vickers diamond penetrator. The glass transition temperature (T_g) of control and copolymers were evaluated by Perkin Elmer Diamond DSC (Perkin Elmer, Massachusetts,USA). Statistical analyses were carried out using the statistical package SPSS for Windows, version 15.0 (SPSS, Chicago, IL, USA). The results were tested regarding the normality of distribution with the Shapiro Wilk test. Data were analyzed using ANOVA with post-hoc Tukey test (P<.01).

RESULTS

The copolymer synthesis was confirmed by FTIR spectroscopy. Glass transition temperature of the copolymer groups were higher than the control groups of the resins. The 10%, 15% and 20% copolymer groups of Stellon presented significantly higher than the control group in terms of hardness. 15% and 20% copolymer groups of Acron MC showed significantly higher hardness values when compared to the control group of the resin. Acrylamide addition did not affect the hardness of the QC-20 resin significantly.

CONCLUSION

Within the limitation of this study, it can be concluded that copolymerization of PMMA with AAm increased the hardness value and glass transition temperature of PMMA denture base resins.