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Purpose The purpose of this study is to obtain an effective implant with porous structures on its surface, named porous-surfaced implant, which helps to improve the overall stability of the implant and promote the combination of implant and alveolar bone. Design/methodology/approach Porous-surfaced implants with a porosity of 16%, 21%and 32% were designed and the effect of porosity on the strength of the implant was analyzed by ABAQUS software. Porous-surfaced implants with different porosity were printed by selective laser melting and the surface morphology was observed. Animal experiments of implants with porous structures and coating were carried out in healthy beagle dogs. The experimental group was treated with hydroxyapatite coating and the control group was not treated. Bone volume (BV) and total volume (TV) of the implant surface of the experimental group and control group were calculated by Skyscan CTvol software. Findings With the increase of porosity of porous-surfaced implants, the neck stress of the porous-surfaced implants increased and their strength decreased. In addition, in animal vivo experiments, the ratio value of BV to TV of the porous-surfaced implants was between 55.38% and 79.86%, which was the largest when the porosity of porous-surfaced implants was 16%. The internal and surrounding bone formation content of porous-surfaced implants with hydroxyapatite coating was higher than porous-surfaced implants without coating. Originality/value The results of this study show that the pores on the surface of implants can be filled with the new bone and porous-surfaced implants with 16% porosity provide better space for the growth of new bone. The porous structures with hydroxyapatite coating are beneficial to the growth of new bone around implants. The results of this study are helpful to improve the overall stability of implants and to promote the combination of implant and alveolar bone.

Diamond wire sawing technology is widely used in polysilicon cutting. The poor lubrication performance of the common water-based cutting fluid results in many cutting grooves and kerfs on wafer surface, which increases the difficulty of subsequent processing. In this paper, the application of nanoparticles water-based cutting fluid in polysilicon diamond wire sawing was proposed to further improve surface quality of wafers. A novel water-based cutting fluid was prepared with nano silicon carbide (N–SiC), polyethylene glycol (PEG2000) and sodium carboxymethylcellulose (CMC-Na). The dispersibility and friction performance of N–SiC cutting fluid were studied. And then the cutting performance of cutting fluid with different N–SiC content was investigated. Research results show that the dispersibility and friction performance of cutting fluid with 0.2 wt% N–SiC, 0.5 wt% CMC-Na and 6 wt% PEG2000 are the best. N–SiC particles can effectively reduce the width of edge breakage and the surface roughness of polysilicon wafers. The width of edge breakage and the surface roughness reach the lowest value when the N–SiC content in the cutting fluid is 0.2 wt%.