喷砂技术对牙釉质和正畸托槽间黏结强度的影响

目的 观察牙釉质和托槽底板用喷砂技术表面处理后与复合树脂黏结的效果.方法 80颗人类前磨牙随机分为4组,均采用复合树脂黏结托槽.对照组(A组)根据产品使用说明黏结;喷砂组对托槽底部(B组)、釉质表面(C组)分别喷砂或同时(D组)进行喷砂处理后再做常规黏结.记录抗剪切强度和残留黏合剂指数(ARI).结果 酸蚀前用喷砂机对牙釉质和托槽底板表面分别进行喷砂处理的D组与A组、B组、C组之间的总体剪切强度和ARI记分差异有统计学意义. A组与B组、C组; B组与D组两两比较的剪切强度差异没有统计学意义.托槽底板和牙釉质表面同时经喷砂处理后获得了较高的黏结强度和较低的ARI记分.结论 对托槽底板和牙釉质表面同时喷吵处理可提高两者间黏结强度.     

瓷表面不同处理方法及粘结剂对全瓷剪切强度的影响

目的:观察喷砂、酸蚀及硅烷偶联剂等表面处理方法对热压铸陶瓷,玻璃渗透陶瓷和氧化锆陶瓷与不同种粘结剂的粘结强度的影响。方法:样本分为热压铸陶瓷组,渗透陶瓷组和氧化锆陶瓷组。分别应用不同表面处理方法和粘结剂,测其剪切强度。结果:方差分析表明,热压铸陶瓷组中酸蚀涂硅烷树脂粘结组粘结强度最高,渗透陶瓷组中喷砂玻璃离子粘结组粘结强度最高,氧化锆陶瓷组中喷砂玻璃离子粘结组粘结强度最高。结论:应用常规树脂粘结剂粘固热压铸陶瓷修复体取得较好的粘固效果,采用酸蚀和硅烷偶联剂的表面处理,可取得最大粘结强度。     

酸蚀处理对新型自粘结树脂水门汀粘结强度的影响

目的:评价酸蚀处理对新型自粘结树脂水门汀Unicem与牙本质和牙釉质之间粘结强度的影响。方法:选取新鲜拔除的无龋坏人第三磨牙36个,制备颊侧牙本质粘结面和近、远中牙釉质粘结面,随机分为3组,每组12个牙,分别选用Unicem、磷酸酸蚀配合Unicem和Panavia F(对照组)进行粘结处理,分别测试牙本质、牙釉质粘结强度,并通过扫描电镜观察粘结界面。结果:在牙本质粘结强度上,Unicem组(12.84±2.29 MPa)与Panavia F组(14.93±3.73 MPa)之间无显著性差异(P>0.05),但均显著高于磷酸酸蚀配合Unicem组(9.12±1.54 MPa)(P<0.05);牙釉质粘结强度上,磷酸酸蚀配合Unicem组(17.24±7.62 MPa)和Panavia F组(17.99±3.66 MPa)无显著性差异(P>0.05),但均显著高于Unicem组(6.47±1.54MPa)(P<0.05)。结论:酸蚀处理可以显著提高自粘结树脂水门汀Unicem牙釉质粘结强度,却降低了牙本质粘结效果。     

Hydrolytic stability of composite repair bond

The hydrolytic stability of composite repairs is a desirable property. In the present study, the composite repair microtensile bond strength, failure mode distribution, and nanoleakage occurrence before and after thermocycling were evaluated. Standardized, 1-month-old composite substrates were roughened, cleaned, and randomly assigned to seven groups according to the intermediate agent applied. Resin-based, silane-based, and combined silane/adhesive coupling agents were investigated. The same resin composite as the substrate was used for repair. For each group, repaired samples were wet stored for 24 h (37 degrees C) or thermocycled (5,000 cycles, 5-55 degrees C). Failure mode and silver nitrate penetration were examined by stereomicroscopy. Intermediate agent, experimental condition, and their interaction were significant factors. Hydrophobic flowable composites resulted in statistically higher repair strengths, lower occurrence of adhesive failures, and good quality interfacial coupling without any silver uptake in both conditions. Light-curing, hydrophilic resin monomer-based intermediate agents, although not affected by thermocycling, showed a more pronounced silver penetration. The composite repair strength of a self-curing silane/adhesive agent was significantly affected by thermal stresses, despite the absence of silver uptake. A prehydrolized silane agent recorded the lowest repair strength, with minimal or no evidence of interfacial silver impregnation after thermocycling. In conclusion, flowability and hydrophobic nature can be considered important properties when selecting intermediate agents for composite repair.     

钇稳定氧化锆基底材料与饰面瓷结合性能的实验研究

目的考察国产氧化钇稳定四方晶体氧化锆（3Y-TZP）与4种氧化锆专用饰面瓷界面的结合性能。方法粉浆涂塑方法分别将VITA VM9、SHOFU VINTAGE ZR、IPS e.max Ceram、Cercon ceram kiss 4种氧化锆专用饰面瓷烧结在15 mm×5 mm×5 mm的3Y-TZP核瓷试件上,另外制作相同尺寸镍铬合金烤瓷试件作为对照,测试界面剪切强度。制作氧化锆基底与饰面瓷双层瓷试件,扫描电镜（SEM）观察结合界面微观形貌;能谱分析（EDS）检测界面元素分布。结果氧化锆与VITA VM9、SHOFU VINTAGE ZR、IPS e.max Ceram、Cercon ceram kiss 4种氧化锆专用饰面瓷的剪切强度分别为（18.83±1.77）MPa、（23.83±7.05）MPa、（17.87±2.30）MPa、（22.26±7.45）MPa,各组与金属烤瓷对照组比较,差异均无统计学意义（P＞0.05）。各3Y-TZP烤瓷组试件破坏模式以界面破坏为主。扫描电镜观察氧化锆和饰面瓷结合界面结合紧密;能谱分析结果显示二者存在化学元素渗透。结论国产3Y-TZP与饰面瓷材料界面结合良好,可以满足临床需要。     

模拟髓室压力对中层牙本质树脂微拉伸粘结强度的影响

目的评价髓室压力对中层牙本质树脂粘结强度的影响。方法32颗第三磨牙随机分组,实验组以15cm水柱模拟髓室压力。Clearfil S~3 Bond粘结剂作树脂光固化后微拉伸力学测试。结果实验组粘结剂应用时间为300 s时,微拉伸粘结强度明显下降。实验组和对照组相比较,150 s组和300 s组的微拉伸粘结强度差异均有统计学意义。结论模拟髓室压力会影响中层牙本质树脂微拉伸粘结强度。     

不同方法处理脱落托槽后其抗剪切强度对比研究

目的 观察正畸托槽脱落后再次黏结时托槽底板的不同处理方法对抗剪切强度的影响。方法 选择40颗离体人前磨牙,随机分成4组,每组10个样本,托槽均使用3M UNITEK transbond XT光敏树脂正畸黏结剂黏结。处理方法分别为更换新托槽组（简称更新组）;磨除底板残胶组（简称磨除组）;托槽底板喷砂处理组（简称喷砂组）;氯仿溶液浸泡溶解托槽底板上的黏结剂组（简称氯仿浸润组）。各样本均采用万能测试机进行剪切强度试验,记录每组抗剪切强度数值的变化并观察ARI指数（牙面残留黏结剂指数）。结果 磨除组、喷砂组抗剪切强度增强,氯仿浸泡组抗剪切强度则减弱,三者间均有统计学差异。结论 黏结脱落托槽时可采用磨除法或喷砂法对脱落托槽底板进行处理。     

ADHESION OF AN ENDODONTIC SEALER TO DENTIN AND GUTTA-PERCHA: SHEAR AND PUSH-OUT BOND STRENGTH MEASUREMENTS AND SEM ANALYSIS

The use of an adequate method for evaluation of the adhesion of root canal filling materials provides more reliable results to allow comparison of the materials and substantiate their clinical choice. The aims of this study were to compare the shear bond strength (SBS) test and push-out test for evaluation of the adhesion of an epoxy-based endodontic sealer (AH Plus) to dentin and guttapercha, and to assess the failure modes on the debonded surfaces by means of scanning electron microscopy (SEM). Three groups were established (n=7): in group 1, root cylinders obtained from human canines were embedded in acrylic resin and had their canals prepared and filled with sealer; in group 2, longitudinal sections of dentin cylinders were embedded in resin with the canal surface smoothed and turned upwards; in group 3, gutta-percha cylinders were embedded in resin. Polyethylene tubes filled with sealer were positioned on the polished surface of the specimens (groups 2 and 3). The push-out test (group 1) and the SBS test (groups 2 and 3) were performed in an Instron universal testing machine running at crosshead speed of 1 mm/min. Means (±SD) in MPa were: G1 (8.8±1.13), G2 (5.9±1.05) and G3 (3.8±0.55). Statistical analysis by ANOVA and Student''s t-test (α=0.05) revealed statistically significant differences (p<0.01) among the groups. SEM analysis showed a predominance of adhesive and mixed failures of AH Plus sealer. The tested surface affected significantly the results with the sealer reaching higher bond strength to dentin than to guttapercha with the SBS test. The comparison of the employed methodologies showed that the SBS test produced significantly lower bond strength values than the push-out test, was skilful in determining the adhesion of AH Plus sealer to dentin and gutta-percha, and required specimens that could be easily prepared for SEM, presenting as a viable alternative for further experiments.     

Er,Cr:YSGG激光制备对牙体抗剪切强度影响的实验研究

目的　比较Er,Cr:YSGG激光与传统高速手机两种切割方法对牙体抗剪切强度的影响 ,分析Er,Cr:YSGG激光是否可以提高牙面的黏结强度。方法　选取新鲜离体牛上中切牙 4 6颗 ,分为两组 ,分别采用Er,Cr :YSGG激光和高速手机切割牙体。通过分组对照 ,进行抗剪切强度实验、扫描电镜观察、能谱分析及X线衍射分析。结果　Er,Cr:YSGG激光组的抗剪切强度高于高速手机组 (P <0 .0 0 1) .扫描电镜下观察 ,激光组的牙体表面清洁、粗糙 ,无玷污层存在 ,牙本质小管口开放 ,无裂化、熔融等热损伤迹象 ;能谱分析与X线衍射分析结果表明 ,两组样本在表面成分、结构上无明显差异。结论　Er,Cr:YSGG激光制备牙体不会引起牙体组织成分及结构的改变 ;Er,Cr:YSGG激光制备后的牙体抗剪切强度高于高速手机制备后的牙体 ,Er,Cr:YSGG激光制备牙体可以提高牙体的黏接强度。     

四种牙本质粘接系统的微拉伸强度测试评价

目的:评价四种牙本质粘接系统(SingleBond;Bond-1;Prime&BondNT;One-Step)在口内、外环境下粘接处理后的粘接强度。方法:将15名志愿者口内18颗无龋坏活髓磨牙,于局麻下用高速涡轮机金钢砂车针在喷水降温下磨切咬合面,暴露牙本质。随机选择四种牙本质粘接系统之一,按使用说明粘接处理其咬合面牙本质一半。即刻拔除。贮存于37℃生理盐水中24h后,使用同一粘接系统处理其咬合面牙本质另一半。二者分别制备成沙漏状试件。试件粘接界面面积控制在1mm2左右;测试同一颗牙齿标本上口内、外粘接处理的试件拉伸强度,并作统计学处理。结果:四种牙本质粘接系统在口内粘接处理的微拉伸强度分别为:26.09±3.78MPa(SingleBond),30.18±2.77MPa(Bond-1),29.10±3.03MPa(Prime&BondNT),29.95±3.81MPa(One-Step);在口外粘接处理的微拉伸强度为:25.80±2.41MPa(SingleBond),29.92±3.04MPa(Bond-1),28.97±2.73MPa(Prime&BondNT),30.03±2.96MPa(One-Step)。结论:四种牙本质粘接系统在口内与口外环境下粘接处理的微拉伸强度比较,无显著性差异。离体牙的体外粘接实验测试结果可以客观、真实地反映各粘接系统在口腔内的实际粘接强度。