能量恒定时不同光密度对不同颜色纳米树脂硬度的影响

Influence of Different Power Density and Shades on the Microhardness of Nano-composite Resins at Different Energy Level.

目的:在2种能量水平下采用3种光密度固化2种纳米复合树脂试片,通过检测比较其硬度值评价不同光密度及不同颜色对纳米树脂固化程度的影响。方法:设定12J及16J两个能量水平,用3盏光固化灯,光密度分别为400mW/cm2、800mW/cm2和1000mW/cm2,固化2种纳米树脂,颜色为A1、A2、A3、A3.5。将固化试片浸泡在蒸馏水中,避光37℃保存24h,测量试片表面和底面的维氏硬度值。结果:所有实验组的底面硬度均能达到有效的硬度百分率。16J的试片底面维氏硬度显著高于12J。采用800mW/cm2光密度固化效果较好,底面硬度随着树脂颜色加深而减小。结论:复合树脂固化的总能量恒定的观点不成立。在相同能量下,光密度800mW/cm2的光固化灯及较浅颜色的树脂可获得更高的转化率。能量为16J的固化效果优于12J,但在本实验条件下都能够满足临床需要。

Objective： To evaluate the performance of different power density at same energy level with different shades in terms of the surface microhardness of resin composites. Methods： When the energy levels were 12J and 16J, three curing lights with power density of 400 mW/cm2 , 800 mW/cm2 , 1000 mW/cm2 were used to cure two kinds of nano--composite resins. The shade of the re stored in the distilled water in a s top and bottom surface were determined higher than those of 1 obtain relatively ideal light pro Results ： sins were A1, A2 of container at 37 Curing with 16J, , A3 and A3.5. After photocuring, the spec- ~C for 24 hours. The VHNs of the specimen＇ the bottom hardness of resin specimens were r the VHNs of specimen＇s bottom surface, the curing light with 800 mW/cm2 could and the values decreased significantly along with the shades changing experimental groups could obtain the valid bottom surface hardness percent values. Conclusion darker The ＇ t level rule＇ is wrong~ Under the same energy level, the light with power density of 800 mW/cm2 and All of the otal energy the lighter shade specimens can get higher VHNs. The composites received energy level of 16J have better degree of conversion than that of 12J, but every group can meet the clinical needs under these experimental conditions.