Objective To investigate the effect of different inner metal materials of porcelain-fused-to-metal（PFM） crown on periodontal tissue by means of measuring the level of soluble intercellular adhesion molecule-1（sICAM-1） and interleukin-1β（IL-1β） in gingival crevicular fluid（GCF） after PFM restorations. Methods 30 teeth were divided into three groups（Ni-Cr alloy group, Co-Cr alloy group and Au-Pt alloy group, 10 teeth each group）, and restored by Ni-Cr alloy, Co-Cr alloy and Au-Pt alloy PFM crown according grouping. At the point of pre-restoration, 6-month and 12- month after cementation, the clinical parameters including plaque index（PLI）, gingival index（GI） and gingival crevice depth（GCD） were detected, and GCF was collected from labial and lingual of mesial site and distal site. The level of sICAM-1 and IL-1β were detected. Results At the point of 6-month and 12-month after cementation, Ni-Cr alloy group showed significant difference for GI, GCD and all GCF indexes when compared to pre-restoration, Co-Cr alloy group and Au-Pt alloy group（P＜0.05）. At the point of 12-month after cementation, Co-Cr alloy group showed significant difference for GI, GCD and all GCF indexes when compared to pre-restoration and Au-Pt alloy group（P＜0.05）. All indexes have no significant difference for Au-Pt alloy group during the 12-month experiment times when compared to pre-restoration（P＞0.05）. Conclusion Non-noble metal has bad effect on the periodontal tissue.
