Daou Elie E, Özcan Mutlu, Salameh Pascale, Salameh Ziad
Department of Prosthodontics, Faculty of Dentistry, Lebanese university, Beirut, Lebanon.
Department of Fixed Prosthodontics, Faculty of Dentistry, Saint Joseph university, Beirut, Lebanaon.
Front Dent. 2024 Aug 11;21:32. doi: 10.18502/fid.v21i32.16362. eCollection 2024.
We aimed to evaluate ceramic-alloy interface and emphasize the alteration of alloy microstructure after ceramic layering. Thirty-two discs made from a ceramic-alloy combination of pre-sintered cobalt-chromium (CoCr), cast CoCr, cast nickel-chromium (NiCr), or pre-sintered zirconia were prepared with eight discs in each group. Four specimens were examined as manufactured and four were ceramic-layered. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-Ray diffractometer (XRD), and an atomic force microscope were used for analysis. Non-layered specimens received ceramic fire-heating without adding any ceramic. Alloy microstructure was compared before and after ceramic veneering or heating within the same group. Mean differences in grain size and surface roughness were compared among groups. P<0.05 was considered significant. SEM showed a close bonding interface between alloys and ceramics. EDX demonstrated differences compared to the manufacturer's composition. Ceramic-layering reduced grain size for both milled alloys (P<0.05), whereas grain size increased in cast groups (P=0.011). Heat treatment did the same for the CoCr groups (P=0.013). Ceramic veneering increased the surface roughness of the cast CoCr (Gi) (P=0.029) and NiCr (Wi) (P=0.005) groups, whereas zirconia roughness average (Ra) showed a slight decrease (P=0.282). XRD showed no differences among zirconia, NiCr, and milled CoCr groups before and after veneering. Crystallite size differed between monoclinic and tetragonal phases in zirconia. The study highlights that ceramic-layering induces significant microstructural changes in alloys, enhancing bonding potential and mechanical stability. Pre-sintered materials show a fine homogeneous surface, optimizing ceramic adherence and potentially improving clinical outcomes.
我们旨在评估陶瓷 - 合金界面，并强调陶瓷堆塑后合金微观结构的变化。制备了32个由预烧结钴铬合金（CoCr）、铸造CoCr、铸造镍铬合金（NiCr）或预烧结氧化锆的陶瓷 - 合金组合制成的圆盘，每组8个圆盘。4个样本按原样进行检查，另外4个进行陶瓷堆塑。使用扫描电子显微镜（SEM）、能量色散X射线光谱仪（EDS）、X射线衍射仪（XRD）和原子力显微镜进行分析。未堆塑的样本在不添加任何陶瓷的情况下进行陶瓷加热。在同一组中比较陶瓷贴面或加热前后的合金微观结构。比较各组晶粒尺寸和表面粗糙度的平均差异。P<0.05被认为具有统计学意义。SEM显示合金与陶瓷之间有紧密的结合界面。EDX显示与制造商提供的成分相比存在差异。陶瓷堆塑使两种研磨合金的晶粒尺寸减小（P<0.05），而铸造组的晶粒尺寸增加（P = 0.011）。热处理对CoCr组也有同样的效果（P = 0.013）。陶瓷贴面增加了铸造CoCr（Gi）组（P = 0.029）和NiCr（Wi）组（P = 0.005）的表面粗糙度，而氧化锆的粗糙度平均值（Ra）略有下降（P = 0.282）。XRD显示贴面前后氧化锆、NiCr和研磨CoCr组之间没有差异。氧化锆中单斜相和四方相的微晶尺寸不同。该研究强调，陶瓷堆塑会在合金中引起显著的微观结构变化，增强结合潜力和机械稳定性。预烧结材料显示出精细均匀的表面，优化了陶瓷的附着力，并可能改善临床效果。
