饰瓷温度烧结对氧化锆陶瓷与树脂黏结剂剪切强度的影响

背景：研究已证实硅烷偶联剂和喷砂等表面处理方式,以及增加氧化锆陶瓷表面的微裂纹可提高氧化锆陶瓷与树脂黏结剂间的黏结强度,但有关多次反复烧结是否会对氧化锆陶瓷黏结剪切强度产生影响尚缺少相关研究。目的：测试饰瓷温度烧结对牙科氧化锆陶瓷与树脂黏结剂黏结剪切强度的影响。方法：从40片氧化锆瓷片随机选择20片,分成5组,按照常规烧结程序分别烧结0（对照组）,2,4,6,8次,热处理起始温度为500℃,最终温度1 000℃,升温速率55℃/min,抽真空时间7 min。每次烧结最终温度恒定不变。将各组分别用树脂黏结剂与剩余未烧结的陶瓷片对位黏结,用万能材料试验机测黏结界面的剪切强度;使用扫描电镜观察剪切后的试件断面形貌。结果与结论：烧结4,6,8次组试件剪切强度高于对照组（P〈0.05）;烧结2次组试件剪切强度稍高于对照组,但差异无显著性意义（P〉0.05）;烧结8次组试件剪切强度高于烧结4,6次组（P〈0.05）。未烧结氧化锆陶瓷表面未见裂纹;经过2次烧结后表面可见细微裂纹;经过4次烧结后表面可见裂纹增多;经过6次烧结后表面已经开始有明显变化,裂纹增多并伴有细微空隙产生,少量黏结剂残留;经过8次烧结后表面可见裂纹与空隙明显增多并有黏结剂残留。表明经过4,6,8次烧结后的氧化锆陶瓷对树脂黏结剂有较好的黏结剪切强度,烧结8次后的黏结剪切强度最强。

Decorative porcelain temperature firing affects the shear bond strength between zirconia ceramics and resin binder

BACKGROUND： Studies have confirmed that the surface treatment methods such as silane coupling agent and sand blasting could improve bonding strength of zirconia ceramics and resin binder. In addition, the increase of micro cracks on the surface of zirconia ceramics can also improve the bonding strength of zirconia ceramics and resin binder. But there is a lack of related studies addressing whether repeatedly sintering would have an impact on shear bond strength of zirconia ceramics. OBJECTIVE： To determine the effect of decorative porcelain temperature firing on the shear bond strength between dental zirconia ceramics and resin binder. METHODS： Twenty pieces of zirconia ceramics specimens were selected from 40 tablets, and then randomly divided into five groups according to the number of sintered times： control group （without sintering）, sintering groups for 2, 4, 6, 8 times. Heat starting temperature was 500 ~C, and final temperature was 1 000 ~C with a heating rate of 55 ~C/min. The vacuum time was 7 minutes. During the sintering, the final temperature was constant. Unsintered ceramic pieces were bonded using resin binder. Universal testing machine was used to test the shear strength of the interface between the two pieces of zirconia ceramics. The interface after shearing was characterized by scanning electron microscope. RESULTS AND CONCLUSION： The shear strength of sintering groups for 4, 6, 8 times was significantly higher than that of the control group （P 〈 0.05）. Shear strength of specimens sintered twice was slightly higher than that of specimens without sintering, but the difference was not significant （P 〉 0.05）. Shear strength of specimens sintered 8 times was slightly higher than that sintered 4 and 6 times （P ~ 0.05）. Under the scanning electron microscope, there was no crack on the surface of non-sintered zirconia ceramics. After 2 times sintering, the surface appeared to have fine cracks. After sintering 4 times, visible cracks were increased. After six rounds of sintering, the surface began to have significant changes; cracks rose along with slight gaps and a small amount of adhesive residues were found. After sintering for 8 times, cracks and voids were obviously increased on the sintered surface and adhesive residues were found. It indicated that after sintering for 4, 6 and 8 times, zirconia ceramics could have a good shear strength binding to resin adhesives; with the increasing of sintering times, the shear bond strength could be increased.