Department of Crown and Bridge Dentistry, Medical University of South Carolina, School of Medicine, Charleston, SC 29401, USA.
J Prosthet Dent. 1975 Sep;34(3):314-9. doi: 10.1016/0022-3913(75)90109-2.
Thirty-six specimens of porcelain, including 18 vacuum-fired and 18 air-fired specimens, were brought to a high bisque bake under like conditions. Both types were divided into six groups to identify the dependent variables, while employing the usual procedures for "polishing" porcelain. These specimens were studied with a scanning electron microscope with the following results: (1) An unpolished, highly fired porcelain surface has a rather smooth appearance. (2) Treating the porcelain surface with sandpaper creates a rough surface with exposed bubbles. (3) The roughness of the porcelain surface after sanding is greatly improved with the use of polishing mediums. (4) A good smooth surface is not obtained unless the procedures are followed by a final glaze. (5) In each stage of polishing, the vacuum-fired porcelain has a smoother surface than the air-fired porcelain. Therefore, our conclusions are that vacuum-fired porcelain will tend to have a smoother surface, as viewed microscopically, than air-fired porcelain. The relative absence of bubbles in the former apparently allows the porcelain to be sanded and polished to a significantly superior finish. However, this study shows that, regardless of the usual polishing techniques, a final glaze presents the most acceptable surface.
三十六件瓷器标本，包括十八件真空烧制和十八件空气烧制的标本，在相同条件下被带到高温素烧阶段。两种类型的瓷器都被分为六组来确定因变量，同时采用通常的“抛光”瓷器的程序。这些标本用扫描电子显微镜进行了研究，结果如下：（1）未经抛光的高火瓷器表面具有相当光滑的外观。（2）用砂纸处理瓷器表面会产生带有暴露气泡的粗糙表面。（3）用抛光介质处理后，瓷器表面的粗糙度大大提高。（4）除非最后上釉，否则无法获得良好的光滑表面。（5）在抛光的每个阶段，真空烧制的瓷器表面都比空气烧制的瓷器更光滑。因此，我们的结论是，从微观上看，真空烧制的瓷器表面会比空气烧制的瓷器更光滑。前者气泡相对较少，显然可以使瓷器经过打磨和抛光，达到明显更好的效果。然而，这项研究表明，无论采用通常的抛光技术，最终上釉都会呈现出最令人满意的表面。
