烧结次数对牙科全瓷开放性总孔体积、透明度和色度的影响

The effects of firing numbers on the opening total pore volume,translucency parameter and color of dental all-ceramic systems

目的评价烧结次数对牙科全瓷开放性总孔体积(TPV)、透明度(TP)和色度的影响。方法采用热压全瓷(IPS EmpressⅡ)、氧化铝全瓷(In-Cream alumina blanks)和氧化锆全瓷(Cercon CAD/CAM zirconia)3种材料制作试样,使用分光光谱仪与表面积和孔隙率仪测量计算试样经过1、3、5次烧结后的TP、明度(ΔL)、彩度(ΔC)和TPV变化。应用SAS 8.0软件对数据进行统计分析。结果相同烧结次数下,3种全瓷试件的TPV、TP、ΔL和ΔC间均存在统计学差异(P<0.05),其中TPV为热压全瓷大于氧化铝全瓷和氧化锆全瓷(P<0.05);TP和ΔL均为热压全瓷最高,氧化锆全瓷其次,氧化铝全瓷最低(P<0.05);ΔC为热压全瓷和氧化铝全瓷大于氧化锆全瓷(P<0.05)。不同烧结次数下,同一全瓷试件TPV、TP、ΔL和ΔC间也存在统计学差异(P<0.05)。随着烧结次数的增加,TPV逐渐减小,TP、ΔL和ΔC逐渐增加。烧结次数与TPV、TPV与TP和ΔL均呈负相关(P<0.05)。结论重复烧结可通过TPV变化影响全瓷修复体的TP和ΔL的稳定性。

Objective To evaluate the effects of firing numbers on the total opening pore volume（TPV）,translucency parameter（TP） and color of dental all-ceramic systems.Methods Specimens of three kinds of all-ceramics systems were made,i.e.heat pressed all-ceramic（IPS Empress Ⅱ）,alumina all-ceramic（In-Cream alumina blanks） and zirconia all-ceramic（Cercon CAD/CAM zirconia）.The specimens＇ TP,lightness（ΔL）,chroma（ΔC） and TPV after 1,3 and 5 firings were measured and calculated by spectrophotometer and surface area/porosity system.The data were analyzed statistically using SAS 8.0 software.Results There were significant differences in TPV,TP,ΔL and ΔC for all-ceramic specimens at same number of firings（P0.05）,i.e.IPSalumina and zirconia for TPV（P0.05）;IPSzirconiaalumina for TP and ΔL（P0.05）;IPS and aluminazirconia for ΔC（P0.05）.The significant differences also presented in TPV,TP,ΔL and ΔC for a same specimen at different number of firings（P0.05）.With increasing number of firings,TPV decreased,and TP,ΔL and ΔC increased gradually.There were negative linear correlation between number of firings and TPV,TP,ΔL and ΔC（P0.05）.Conclusion Repeated firings will affect TP and ΔL of all-ceramic restorations via the change of TPV.