光照时间对自制光固化型牙科玻璃纤维桩弯曲强度影响的实验研究

目的：研究光照时间对自制光固化型牙科玻璃纤维桩弯曲强度的影响。方法：自行合成制作光固化型牙科玻璃纤维桩三点弯曲试件20个，随机分为4组（5个／组），分别进行20s、40s、60s、80s光照固化，测三点弯曲强度，进行单因素方差分析和LSD—t检验。结果：各组弯曲强度为525．76MPa、568．27MPa、602．93MPa和604．12MPa；统计学分析显示，60s组与80s组无显著性差异（P〉O．05），20s组、40s组和60s组或80s组两两间有显著性差异（P〈0．05）。结论：自制光固化型牙科玻璃纤维桩的弯曲强度随光照时间的延长而提高，60s后趋于平稳，综合考虑材料固化后的弯曲强度和临床操作效率，其理想光照时间为60s。

Effects of light duration on flexural strength of self-manufactured light-cure dental glass-fiber reinforced-composite post

Objective To study the effects of light duration on fiexural strength of self-manufactured light-cure dental glass-fiber-reinforced-composite （GFRC） post. Methods Twenty specimens for three-point bending test were manufactured by self-manufactured light-cure dental GFRC post. They were divided into four groups with five specimens in every group, were cured by light for 20s,40s,60s,80s respectively. Then, the flexural strengths of specimens were measured by three-point bending test and the data were analyzed by statistical methods, One-way ANOVA and LSD-t. Results The flexural strengths of four groups were 525.76MPa, 568.27MPa, 602.93MPa and 604.12MPa respectively. There was no significant difference between 60s-group and 80s-group （P〉0.05）, there was significant difference between every two groups of 20s-group, 40s-group and 60s-group or 80s-group （P〈0.05）. Conclusion The flexural strength of the self-manufactured light-cure dental GFRC post was enhanced following the extension of light duration, and kept stable after 60s. Considering flexural strength and efficiency, the ideal light duration was 60s.