不同材料及厚度椅旁CAD/CAM瓷贴面的边缘特征

Marginal features of CAD/CAM laminate veneers with different materials and thicknesses

目的:评价不同材料及厚度椅旁计算机辅助设计和计算机辅助制作(computer-aided design and computer-aided manufacturing,CAD/CAM)瓷贴面的边缘粗糙度和边缘密合度,旨在为瓷贴面的临床应用提供参考。方法:在树脂人工牙上进行对接型瓷贴面牙体预备,利用扫描仪扫描预备体,利用椅旁切削设备CAD/CAM瓷贴面。根据陶瓷材料类型(玻璃基陶瓷和树脂基陶瓷)及贴面厚度(0.3 mm和0.5 mm)将贴面分为4组(n=9),共36个。利用体式显微镜拍摄瓷贴面边缘形貌的数码照片,在软件内测量边缘粗糙度;利用间隙检查剂和数字化扫描与测量方法评价瓷贴面的边缘密合度;同时利用万能力学试验机测试玻璃基陶瓷和树脂基陶瓷条形试件(n=20)的力学性能。结果:厚度为0.3 mm和0.5 mm玻璃基陶瓷贴面的边缘粗糙度分别为(24.48±5.55)μm和(19.06±5.75)μm,差异有统计学意义(P<0.001);厚度为0.3 mm和0.5 mm树脂基陶瓷贴面的边缘粗糙度分别为(6.13±1.27)μm和(6.84±2.19)μm,差异无统计学意义(P>0.05);玻璃基陶瓷贴面的边缘粗糙度大于树脂基陶瓷,差异有统计学意义(P<0.001)。厚度为0.3 mm和0.5 mm玻璃基陶瓷贴面的边缘密合度分别为(66.30±26.71)μm和(85.48±30.44)μm,厚度为0.3 mm和0.5 mm树脂基陶瓷贴面的边缘密合度分别为(56.42±19.27)μm和(58.36±8.33)μm,4组间差异均无统计学意义(P>0.05)。玻璃基陶瓷的弯曲强度为(327.40±54.25)MPa,弯曲模量为(44.40±4.39)GPa,回弹模量为(1.24±0.37)MPa;树脂基陶瓷的弯曲强度为(173.71±16.61)MPa,弯曲模量为(11.88±0.51)GPa,回弹模量为(1.29±0.27)MPa;玻璃基陶瓷的弯曲强度和弯曲模量大于树脂基陶瓷,差异有统计学意义(P<0.001),但两种材料的回弹模量差异无统计学意义(P>0.05)。结论:椅旁CAD/CAM玻璃基陶瓷贴面的边缘粗糙度大于树脂基陶瓷贴面,但二者的边缘密合度无显著差异。增加贴面厚度可降低玻璃基陶瓷贴面的边缘粗糙度,但对树脂基陶瓷贴面的边缘粗糙度无影响。

Objective:To analyze the marginal roughness and marginal fitness of chairside computer-aided design and computer-aided manufacturing(CAD/CAM)laminate veneers with different materials and thicknesses,and to provide a reference for the clinical application of laminate veneers.Methods:The butt-to-butt type laminate veneers were prepared on resin typodonts,the preparations were scanned,and the laminate veneers were manufactured by chairside CAD/CAM equipment.The laminate veneers were divided into four groups(n=9)according to the materials(glass-matrix ceramics and resin-matrix ceramics)and thickness(0.3 mm and 0.5 mm)of the veneers,with a total of 36.The marginal topo-graphies of each laminate veneer were digitally recorded by stereomicroscope,and the marginal rough-nesses of the laminate veneers were determined by ImageJ software.The marginal fitness of the laminate veneers was measured by a fit checker and digital scanning and measuring method.At the same time,the mechanical properties of glass-matrix ceramic and resin-matrix ceramic bars(n=20)were tested by a universal testing device.Results:The marginal roughness of 0.3 mm and 0.5 mm glass-matrix ceramic laminate veneers was(24.48±5.55)μm and(19.06±5.75)μm,respectively,with a statistically significant difference(P<0.001).The marginal roughness of 0.3 mm and 0.5 mm resin-matrix ceramic laminate veneers was(6.13±1.27)μm and(6.84±2.19)μm,respectively,without a statistically significant difference(P>0.05).The marginal roughness of the glass-matrix ceramic laminate veneers was higher than that of the resin-matrix ceramic laminate veneers with a statistically significant difference(P<0.001).The marginal fitness of 0.3 mm and 0.5 mm glass-matrix ceramic laminate veneers were(66.30±26.71)μm and(85.48±30.44)μm,respectively.The marginal fitness of 0.3 mm and 0.5 mm resin-matrix ceramic laminate veneers were(56.42±19.27)μm and(58.36±8.33)μm,respectively.There was no statistically significant difference among the 4 groups(P>0.05).For glass-matrix ceramics,the flexural strength was(327.40±54.25)MPa,the flexural modulus was(44.40±4.39)GPa,and the modulus of resilience was(1.24±0.37)MPa.For resin-matrix ceramics,the flexural strength was(173.71±16.61)MPa,the flexural modulus was(11.88±0.51)GPa,and the modulus of resilience was(1.29±0.27)MPa.The flexural strength and modulus of glass-matrix ceramics were significantly higher than those of resin-matrix ceramics(P<0.001),but there was no statistically significant difference in the modulus of resilience between the two materials(P>0.05).Conclusion:The marginal roughness of CAD/CAM glass-matrix ceramic laminate veneers is greater than that of resin-matrix ceramic laminate veneers,but there was no statistically significant difference in marginal fitness among them.Increasing the thickness can reduce the marginal roughness of glass-matrix ceramic laminate veneers,but has no effect on the marginal roughness of resin-matrix ceramic laminate veneers.