Abstract:

Abstract:Objective To analyze the reason of dyeing and inflammation of gum caused by the non- precious metal porcelain crown,make improvements on the methods of gold-plated and provide a reference for the clinical application of gold-plated porcelain crown.Methods 240 patients who needed porcelain-fused-to-metal crown(PFM) repair from June,2005 to December,2006 were selected.The differences of nickel-chromium alloy,gilded nickel-chromium alloy,and aurum alloy  (PFM) were introduced to patientsThe patients were divided into three groups according to their voluntary choice of PFM.Gilded Ni-Cr alloy PFM group: 80 cases of gilded Ni-Cr alloy PFM; Ni-Cr alloy PFM group: 80 cases of Ni-Cr alloy PFM; Aurum alloy PFM group: 80 cases of aurum alloy PFM.Then  the gum discoloration and gingival health in these groups were observed and compared.Results After the first wearing of PFM,three cases of gum discoloration occurred in Ni-Cr alloy group while no cases occurred in other two groups;but there was no significant difference between Ni-Cr alloy PFM and gilded Ni-Cr alloy PFM and aurum alloy PFM groups(P>0.05)；and there was no gingival inflammation in the three groups.One year later,there were twelve cases of gum discoloration in Ni-Cr alloy PFM group,while no cases occurred in gilded Ni-Cr alloy PFM and  aurum alloy PFM groups,there was  significant difference between them(P<0.01).　Thirteen cases of gingival redness and swelling symptoms appeared in Ni-Cr alloy group and three cases occurred in gilded Ni-Cr alloy PFM group;by means of rank sum test,the difference between them was significant (P<0.01);there was no cases occurred in in aurum alloy PFM group;the difference between Ni-Cr alloy group and aurum alloy PFM group was significant,too(P<0.01),but the  difference between gilded Ni-Cr alloy PFM group and aurum alloy PFM group was not significant(P>0.05).Conclusion  In view of the esthetic effects of gingival margin and moderate price,highly gilded Ni-Cr alloy PFM is an ideal choice in clinical rehabilitation.

Key words: porcelain-fused-to-metal crown;gilded Ni-Cr alloy；Ni-Cr alloy；aurum alloy；gingival margin