Heintze S D, Forjanic M, Rousson V
R&D, Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein.
Dent Mater. 2006 Feb;22(2):146-65. doi: 10.1016/j.dental.2005.04.013. Epub 2005 Aug 9.
The purpose of this study was (1) to analyze the influence of polishing time and press-on force on the surface gloss and roughness of dental materials by using a three-component rubber-based polishing system and to compare the results with those obtained in conjunction with an optimal polishing procedure and application of the specimens to a metal matrix, (2) to estimate the correlation between surface gloss and surface roughness.
Eight flat specimens were made of each dental material (Tetric Ceram [TC], Tetric EvoCeram [TE], Heliomolar [HM], Compoglass [CO] and Amalcap [AM]) and polished with 4000-grit SiC and a polishing liquid. Subsequently, the mean surface roughness (Ra) was measured with an optical sensor (FRT MicroProf) and the gloss (Gl) with a glossmeter (Novocurve). Prior to polishing the specimens with the polishing system, the surface was pre-roughened with 320-grit SiC paper and polishing was performed under water cooling at 10,000rpm, applying a controlled force of 2N. Each component of the Astropol system (F/P/HP) was used for 30s and Ra and Gl were measured at 5-second intervals. Other specimens of the same materials were polished with a controlled force of 4N or they were applied to a metal matrix and, subsequently, Ra and Gl were measured. To measure the influence of the polishing time on the surface gloss and roughness, repeated ANOVA with post-hoc paired t-tests was carried out in log-transformed Ra and gloss values. To estimate the correlation between Ra and Gl, the Spearman and Pearson correlation was calculated.
(1) Surface gloss and surface roughness were time-dependent, showing the greatest improvement already after 5s of polishing with each of the polishing components, with the exception of AM, for which HP was not effective. The patterns of improvement varied considerably from material to material, but they were more consistent with regard to Gl than to Ra. (2) Ra was statistically significantly higher only in TC, TE and CO when 4N of force was applied instead of 2N. (3) Polishing the surface with a polishing machine resulted in a significantly better surface gloss in all materials. (4) After applying the specimens to a metal matrix, the surface roughness of all dental materials was significantly higher when compared to polished specimens except for TC. (5) Correlations between gloss and roughness were in general negative but they were higher for individual measurements compared to the differences between two consecutive measurements.
Both surface gloss and surface roughness were material-dependent and influenced by the polishing time and applied force. As gloss and roughness proved to be closely associated with each other, gloss assessment may be a sufficient method to screen materials with regard to their polishability.
本研究的目的是：（1）使用基于三元橡胶的抛光系统分析抛光时间和压接力对牙科材料表面光泽度和粗糙度的影响，并将结果与采用最佳抛光程序并将试样应用于金属基体时获得的结果进行比较；（2）估计表面光泽度与表面粗糙度之间的相关性。
每种牙科材料（Tetric Ceram [TC]、Tetric EvoCeram [TE]、Heliomolar [HM]、Compoglass [CO] 和 Amalcap [AM]）制作8个扁平试样，并用4000目碳化硅砂纸和抛光液进行抛光。随后，使用光学传感器（FRT MicroProf）测量平均表面粗糙度（Ra），使用光泽度仪（Novocurve）测量光泽度（Gl）。在用抛光系统对试样进行抛光之前，先用320目碳化硅砂纸对表面进行预粗化，并在水冷条件下以10000转/分钟的转速、施加2N的控制力进行抛光。Astropol系统的每个组件（F/P/HP）使用30秒，并每隔5秒测量一次Ra和Gl。相同材料的其他试样以4N的控制力进行抛光，或将它们应用于金属基体，随后测量Ra和Gl。为了测量抛光时间对表面光泽度和粗糙度的影响，对经对数转换的Ra和光泽度值进行重复方差分析及事后配对t检验。为了估计Ra和Gl之间的相关性，计算斯皮尔曼和皮尔逊相关性。
（1）表面光泽度和表面粗糙度与时间有关，除AM外，每种抛光组件抛光5秒后就已显示出最大改善，AM材料中HP组件无效。改善模式因材料而异，但就Gl而言比Ra更一致。（2）当施加4N力而非2N力时，仅TC、TE和CO的Ra在统计学上显著更高。（3）用抛光机对表面进行抛光后，所有材料的表面光泽度均显著提高。（4）将试样应用于金属基体后，除TC外，所有牙科材料的表面粗糙度与抛光试样相比均显著更高。（5）光泽度与粗糙度之间的相关性总体上为负，但与连续两次测量之间的差异相比，单次测量的相关性更高。
表面光泽度和表面粗糙度均取决于材料，并受抛光时间和施加力的影响。由于光泽度和粗糙度被证明彼此密切相关，光泽度评估可能是筛选材料可抛光性的一种充分方法。
