Le Bell Anna-Maria, Tanner Johanna, Lassila Lippo V J, Kangasniemi Ilkka, Vallittu Pekka K
Department of Prosthetic Dentistry and Biomaterials Research, Institute of Dentistry, University of Turku, Finland.
Int J Prosthodont. 2003 Jul-Aug;16(4):403-8.
The possibility of polymerizing glass fiber-reinforced composite (FRC) material into the root canal was preliminarily evaluated by determining the depth of light-initiated polymerization of FRC.
The material used was polymer-preimpregnated E-glass fiber reinforcement, which was further impregnated with light-polymerizable dimethacrylate monomer resin. The same resin without fiber reinforcement was used as a control. Six different lengths (range 4 to 24 mm) of light-protected cylinders filled with the test materials were light polymerized from one end. The degree of monomer conversion was determined from the other end by FT-IR spectrometry. Infrared spectra were recorded at six time points from the beginning of polymerization. The microhardness of the test materials was measured from the light-exposure surface toward the other end of the cylinder.
Both groups showed a reduction in the degree of conversion with increased lengths of the cylinder. The FRC group showed a higher degree of conversion in the longest sample group compared to the resin group. Microhardness measurement confirmed the constant reduction of the degree of conversion by the reduced Vickers hardness values with increased cylinder length of the FRC.
Generally, the glass FRC showed an almost equal degree of conversion after light curing as monomer resin without fibers. However, in the longest cylinders, FRC showed a slightly higher degree of conversion compared to resin only; this might be due to the fibers' ability to conduct light.
通过测定玻璃纤维增强复合材料（FRC）光引发聚合的深度，初步评估将该材料聚合到根管内的可能性。
所用材料为预浸渍聚合物的E玻璃纤维增强材料，其进一步用可光聚合的二甲基丙烯酸酯单体树脂浸渍。将不含纤维增强的相同树脂用作对照。将六个不同长度（范围为4至24毫米）装有测试材料的光保护圆柱体从一端进行光聚合。通过傅里叶变换红外光谱法从另一端测定单体转化率。在聚合开始后的六个时间点记录红外光谱。从圆柱体的光暴露表面朝向另一端测量测试材料的显微硬度。
两组均显示随着圆柱体长度增加转化率降低。与树脂组相比，FRC组在最长样本组中显示出更高的转化率。显微硬度测量通过FRC圆柱体长度增加时维氏硬度值降低证实了转化率的持续降低。
一般来说，玻璃FRC光固化后的转化率与无纤维的单体树脂几乎相等。然而，在最长的圆柱体中，FRC的转化率比仅树脂略高；这可能是由于纤维传导光的能力。
