Clinical Observation On The Cement-retained And Screw-retained Implant-supported Fixed Dental Prostheses In The Complete Edentulism

Objective To evaluate the clinical effect of full-arch cement-retained implant-supported combined crowns and screw-retained implant-supported bridge dentures in complete or half edentulous patients.Methods 25 complete or half edentulous patients received 165 straumann implants and 28 implant-supported full-arch dental prostheses including 11 cases of cemented cobalt-chromium porcelain combined crowns and 17 cases of screw retained cobalt-chromium bridge in our hospital from June 2013 to June 2018.In the cement group,there were 11 cases with 69 implants,and 17 cases with 96 implants in the screw group.During the follow-up of 1,3 and 5 years,the accumulative implant survival rate,accumulative prosthesis survival rate,mechanical complications,biological complications and patient satisfaction were evaluated and compared in both groups.Results 25 complete or half edentulous patients received 165 straumann implants and28 implant-supported fixed dental prostheses.In the cement group,there were 11 cases with 69 implants,and 17 cases with 96 implants in the screw group.The accumulative implant survival rate was 100% in the cement group and 96.9% in the screw group.The accumulative prosthesis survival rate of the two groups was 100%.The cumulative peri-implant mucositis rate was 23.2% in the cement group and 29.2% in the screw group,6.8% of the peri-implantitis rate inthe cement group and 7.3% in the screw group.There was 1 case of porcelain collapse(n= 1/11)and no screw loosening in the cement group and 4 cases of porcelain collapse(n=4/17)and 1 case of screw loosening in the screw group.No fracture of abutment was observed in both groups.No difference of bone loss between the two groups in the first year(P>0.05)and a higher bone loss were found in screw group in the third and fifth years(P<0.05).There was no difference of m SBI between the two groups in the first year and the third year(P>0.05),and a higher value of m SB Iin the cement group in the fifth year(P<0.05).The score of satisfaction in the cement group was 7.91±2.34 and that in the screw group was 8.29±2.52,with no statistically significant difference(P > 0.05).Conclusion When choosing appropriate indications,the survival rate of implant and prosthesis,and patients satisfaction on the cement-retained or screw-retained implant-supported fixed dental prostheses are both high,but the mechanical and biological complications in traditional cobalt-chromium alloy screw-retainer group is higher.We can choose CAD/CAM screw retainer or a milled,titanium framework with retrievable metal ceramic or ceramic crowns if necessary to reduce the mechanical and biological complications.The removal of residual adhesives must be considered when choosing the cement retention method.