Lithium-disilicate bars and crowns (IPS e.max CAD, Ivoclar-Vivadent) were divided into four groups (n = 30): WG/F (WG=with glaze/F=fast crystallization), NG/F (NG=no glaze), WG/C (C=conventional crystallization), and NG/C. A liquid/powder glaze system was used (IPS Ivocolor®, Ivoclar-Vivadent). Specimens were crystallized (Programat P310, Ivoclar-Vivadent) using the P161 program for C (approx. 20-25 min), and P165 for F (approx. 14-16 min). Bars (n = 30) underwent three-point bending tests (flexural strength-FS in MPa and modulus of elasticity-E in GPa) using a universal testing machine. Crowns were analyzed via scanning electron microscopy (SEM) after selective etching, and to Raman, FTIR-ATR, and X-ray diffraction (XRD) spectroscopies to assess chemical composition.
For FS, both factors/interaction were statistically significant. C (427.48±42.41 MPa) showed significantly higher values than F (409.82±38.82 MPa). WG (398.32±29.80 MPa) exhibited significantly lower FS than NG (438.21±41.77 MPa). For E data, both factors/interaction were significant. NG (90.28±14.71 GPa) displayed higher E than WG (83.07±5.69 GPa), while C (90.08±12.98 GPa) exhibited higher E than F (83.46±9.40 GPa). NG/C showed the best results for both variables. F groups showed (SEM) porous surfaces and crack-like marks on crystals. FTIR, Raman and XRD spectra confirmed the typical composition of a lithium-disilicate glass ceramic, and some attenuated signals and structural variations (XRD) in WG.
\"Fast\" crystallization and simultaneous-glazing produced weaker/less-rigid structures with irregular crystals and glassy phases. Simultaneous glazing may have hindered proper thermal distribution during crystallization.
\"Fast\" crystallization and simultaneous glazing with non-recommended systems, can adversely affect the final properties of lithium disilicate restorations.
方法:二硅酸锂棒和冠(IPSe.maxCAD,Ivoclar-Vivadent)分为四组(n=30):WG/F(WG=有釉/F=快速结晶),NG/F(NG=无釉),WG/C(C=常规结晶),和NG/C。使用液体/粉末釉系统(IPSIvocolor®,Ivoclar-Vivadent)。使用用于C的P161程序将样品结晶(ProgramatP310,Ivoclar-Vivadent)(约20-25分钟),和P165为F(约14-16分钟)。使用万能试验机对棒材(n=30)进行了三点弯曲测试(抗弯强度-FS,以MPa为单位,弹性模量-E,以GPa为单位)。选择蚀刻后通过扫描电子显微镜(SEM)分析牙冠,还有拉曼,FTIR-ATR,和X射线衍射(XRD)光谱来评估化学成分。
结果:对于FS,这两个因素/交互作用均有统计学意义.C(427.48±42.41MPa)明显高于F(409.82±38.82MPa)。WG(398.32±29.80MPa)的FS明显低于NG(438.21±41.77MPa)。对于E数据,这两个因素/交互作用是显著的。NG(90.28±14.71GPa)显示E高于WG(83.07±5.69GPa),而C(90.08±12.98GPa)的E高于F(83.46±9.40GPa)。NG/C显示了两个变量的最佳结果。F组显示(SEM)多孔表面和晶体上的裂纹样痕迹。FTIR,拉曼光谱和XRD光谱证实了二硅酸锂玻璃陶瓷的典型组成,以及WG中一些衰减的信号和结构变化(XRD)。
结论:“快速”结晶和同时上釉产生了具有不规则晶体和玻璃相的较弱/刚性较低的结构。同时的玻璃窗可能阻碍了结晶过程中的适当热分布。
结论:“快速”结晶和同时使用非推荐系统的玻璃,会对焦硅酸锂修复体的最终性能产生不利影响。