Metal-ceramic Bond Mechanism of the Co-Cr Alloy Denture with Original Rough Surface Produced by Selective Laser Melting

作     者：ZHANG Sheng LI Yong HAO Liang XU Tian WEI Qingsong SHI Yusheng 

作者机构：State Key Lab of Materials Processing and Die&Mold Technology Huazhong University of Science and Technology Hospital of Stomatology WuHan University School of Engineering Computing and Mathematics University of Exeter 

出 版 物：《Chinese Journal of Mechanical Engineering》 (中国机械工程学报（英文版）)

年 卷 期：2014年第27卷第1期

页      面：69-78页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 

基　　金：supported by the Royal Academy of Engineering Research Exchanges with China and UK(Grant No.2012-P02) National Key Technology R&D Program of Ministry of Science and Technology of China(Grant No.2012BAF08B03) National Natural Science Foundation of China(Grant No.51375189) 

主　　题：selective laser melting(SLM) Co-Cr alloy metal-ceramic bond strength 

摘      要：The porcelain fracture caused by low metal-ceramic bond strength is a critical issue in porcelain fused to metal（PFM） restorations. Surface roughening methods, such as sand blasting, acid etching and alkaline degreasing for the metal matrix are used to increase bond strength. However, the metal matrix of PFM processed by selective laser melting（SLM） has natural rough surface. To explore the effect of the original roughness on metal-ceramic bond strength, two groups of specimen are fabricated by SLM. One group of specimen surface is polished smooth while another group remains the original rough surface. The dental porcelain is fused to the specimens＇ surfaces according to the ISO 9693：1999 standard. To gain the bond strength, a three-point bending test is carried out and X ray energy spectrum analysis（EDS）, scanning electron microscope（SEM） are used to show fracture mode. The results show that the mean bond strength is 116.5 16 MPa of the group with rough surface（Ra= 17.2）, and the fracture mode is cohesive. However, when the surface is smooth （Ra =3.8）, the mean bond strength is 74.5 MPa _＋ 5 MPa and the fracture mode is mixed. The original surface with prominent structures formed by the partly melted powder particles, not only increases surface roughness but also significantly improves the bond strength by forming strong mechanical lock effect. Statistical analysis （Student＇s t-test） demonstrates a significant difference （p〈0.05） of the mean value of bond strength between the two groups. The experiments indicate the natural rough surface can enhance the metal-ceramic bond strength to over four times the minimum value （25 MPa） of the ISO 9693：1999 standard. It is found that the natural rough surface of SLM-made PFM can eliminate the porcelain collapse defect produced by traditional casting method in PFM restorations.