关键词: 含氟树脂, 机械性能, 挠曲强度, 弹性模量, 微拉伸, 粘结强度

Abstract:

Objective To study the effects of fluoride level on the mechanical properties,such as flexural strength,elastic modulus and micro-tensile bond strength(μTBS),of new nano-fluoride-containing resin.Methods Z350 and four composite resins (containing 0%,10%,20% and 30% fluoride)were selected. Five kinds of resins were used to make standard samples with the size of (25.0±2.0)mm×(2.0±0.1)mm×(2.0±0.1)mm,and there were 5 specimens in each group. The flexural strength and elastic modulus of the specimens were assessed using a three-point bending test on a universal test machine. Twenty five human molars were randomly divided into five groups,and there were 5 molars in each group. The teeth were sectioned with a cross-section of (1.0±0.2)mm²,and there were ten specimens in each group,and the μTBS of specimens were detected by Micro Tensile Tester. The fracture modes of specimens were observed under low magnification microscope.Results The flexural test results showed that there was no significant difference of the flexural strength of specimen among all groups(P>0.05);the elastic modulus of specimens in 20%F group was higher than those in the other groups(P<0.05).The micro-tensile test results showed that the μTBS of the specimens in 30%F group was lower than those in 0%F group,10%F group and 20%F group(P<0.05);but there were no significant differences of μTBS between 0%F group and 10%F or 20% F groups (P>0.05).Compared with Z350 group,the μTBS of the specimens in 20% and 30%F groups were significantly decreased (P<0.05),but there were no significant differences of μTBS between 0%, 10% F groups and Z350 group (P>0.05).All specimens were broken from the adhesive surface.Conclusion When the fluoride level is lower than 20%,it has no effect on μTBS;when the fluoride level is above 20%,the μTBS is significantly decreased.

Key words: flexural strength, elastic modulus, micro-tensile, bond strength, fluoride-containing resin, mechanical property