Department of Dental Materials Science, The Nippon Dental University, Fujimi, Chiyoda-ku, Tokyo, Japan.
Dent Mater J. 2009 Sep;28(5):544-51. doi: 10.4012/dmj.28.544.
The polymerization shrinkage values of commercial flowable and conventional composites were measured with a newly developed laser displacement sensor. Compressive strength and filler content were also measured. Compared to conventional composites, the flowable composites required a longer time - not exceeding 4 minutes - to reach a constant polymerization shrinkage rate. In terms of shrinkage ratio, it was less than 1.5% for conventional composites at 90 minutes, which was lower than that of flowable composites, i.e. more than 2.0%. The compressive strength of conventional composites was higher than that of flowable composites. A highly significant correlation between filler content and polymerization shrinkage at 90 minutes was observed, and polymerization shrinkage tended to decrease as filler content increased. In light of the results obtained in this study, the newly developed displacement meter with a laser displacement sensor proved to be effective for in-depth investigation of the polymerization shrinkage of dental composites.
采用新型激光位移传感器测量了商用流动复合树脂和常规复合树脂的聚合收缩值。同时还测量了抗压强度和填料含量。与常规复合材料相比，流动复合材料达到恒定聚合收缩率所需的时间更长 - 不超过 4 分钟。在收缩率方面，常规复合材料在 90 分钟时低于 1.5%，低于流动复合材料，即超过 2.0%。常规复合材料的抗压强度高于流动复合材料。在 90 分钟时观察到填料含量与聚合收缩之间存在高度显著的相关性，并且随着填料含量的增加聚合收缩趋于减小。根据本研究的结果，新型激光位移传感器位移计被证明对深入研究牙科复合材料的聚合收缩是有效的。
