Division of Applied Prosthodontics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
J Adhes Dent. 2011 Feb;13(1):79-84. doi: 10.3290/j.jad.a18239.
The aim of the present study was to assess the influence of pre-treatments of zirconia by sandblasting and/or heat treatment on the flexural strength of zirconia and debonding/crack-initiation strength of porcelain-veneered zirconia ceramic.
Zirconia ceramic specimens were divided into four groups according to treatment (grinding as controls, sandblasting, heat treatment at 1000°C for 10 min, and heat treatment after sandblasting). The porcelain- veneered zirconia specimens were also prepared. The zirconia specimens were subjected to three-point bending tests, and flexural strength was calculated. The debonding/crack-initiation strength of porcelain-veneered zirconia ceramic was measured according to ISO 9693. X-ray diffractometry (XRD) was used to estimate the relative amount of monoclinic phase.
There was no significant difference in flexural strength between the four treatments (p > 0.05). The highest amount of monoclinic phase was found after sandblasting. No monoclinic phase was obtained from heat treatment and heat treatment after sandblasting groups, and these two groups showed significantly higher debonding/crack-initiation strength than other two groups (p < 0.05). All specimens failed within the veneering porcelain. No elements of veneering porcelain were detected on the zirconia side at the interface using EPMA (electron probe microanalyzer).
The present study suggests that the pre-treatment of zirconia with heat treatment after sandblasting prior to firing porcelain does not affect the debonding/crack-initiation strength of porcelain-veneered zirconia ceramic.
本研究旨在评估对氧化锆进行喷砂和/或热处理预处理对氧化锆的弯曲强度和烤瓷氧化锆陶瓷的脱粘/裂纹起始强度的影响。
根据处理方法（研磨作为对照、喷砂、1000°C 热处理 10 分钟、喷砂后热处理）将氧化锆陶瓷试件分为四组。还制备了烤瓷氧化锆试件。将氧化锆试件进行三点弯曲试验，并计算弯曲强度。根据 ISO 9693 测量烤瓷氧化锆陶瓷的脱粘/裂纹起始强度。X 射线衍射仪（XRD）用于估计单斜相的相对量。
四种处理方法之间的弯曲强度没有显著差异（p＞0.05）。喷砂后单斜相含量最高。热处理和喷砂后热处理组未获得单斜相，这两组的脱粘/裂纹起始强度明显高于其他两组（p＜0.05）。所有试件均在烤瓷层内失效。在界面处使用电子探针微分析仪（EPMA）未在氧化锆侧检测到烤瓷层的任何元素。
本研究表明，在烧制烤瓷之前，对氧化锆进行喷砂后热处理预处理不会影响烤瓷氧化锆陶瓷的脱粘/裂纹起始强度。
