Evaluation Of Cement-retained Versus Screw-retained Implant-supported Restorations In The Maxillary Anterior Zone

ObjectivePatients with maxillary anterior missing teeth were treated with implant-supported fixed dental prostheses?ISFDP?by screw-retained?SR?prostheses and cement-retained?CR?prostheses.The effect of implantation was compared,providing certain reference for the selection of suitable fixation method for dental implant and repair of the maxillary anterior area in clinic.MethodsSeventy-four patients with maxillary anterior missing teeth undergoing ISFDP in the Implant Center of the Stomatologic Hospital&College,Anhui Medical University between July 2015 and October 2016 were selected,including 53 males and 21 females aging from 18 to 66 years?mean,31.22±10.77 years?.A total of 90 missing teeth undergoing ISFDP were included,with single missing tooth in the maxillary anterior area of 58 patients and 2 missing teeth of 16 patients.All patients received routine implant and repair using Nobel replace^?implants.Fifty-one teeth were treated with SR prostheses?SR group?and 39 tooth with CR prostheses?CR group?.After treatment,the patients re-visited our hospital 1 d,3 m,6 m and 12 m postoperatively.Clinical examinations were conducted by the same doctor,and cone bean CT was taken,with indexes including marginal bone loss of the implant,modified plaque index?MPI?,modified sulcus bleeding index?mSBI?,the width of keratinized mucosa?wKM?and gingival level?GL?.At the 12^th month in re-visit,patients'satisfaction was evaluated using the visual analogue scale?VAS?.ResultsAt 3 m,6 m and 12 m postoperatively,mean bone resorption was 0.72 mm,0.65mm and 0.61 mm in the SR group and 0.65 mm,0.63 mm and 0.57 mm in the CR group,respectively,suggesting a higher mean bone resorption in the SR group than the CR group at 3 m,6 m and 12 m postoperatively.Analysis of variance for repeated measurements indicated statistically significant differences in bone resorption between the 2 groups?F=14.644,P<0.001?.MPI showed no statistically significant differences between the SR group and the CR group 1 d,3 m,6 m and 12 m postoperatively?F=1.525,P=0.220?.Comparison of mSBI,wKM and GL between the 2 groups presented statistically significant differences?F=7.563,11.489,6.407,P=0.007,0.001,0.013,respectively?,suggesting that mean mSBI,wKM and GL in the SR group were lower compared with the CR group at 3 m,6 m and 12 m postoperatively.As for patients'satisfaction,satisfaction in good appearance and bleeding when brushing teeth showed statistically significant differences between the SR group and the CR group(t_SR=-3.359,P_SR<0.05;t_CR=3.022,P_CR<0.05).Overall satisfaction and satisfaction in other dimensions demonstrated no statistically significant differences between the 2 groups.Score of satisfaction in good appearance was higher in the CR group,while score of satisfaction in bleeding when brushing teeth was higher in the SR group.ConclusionThis study suggests that the clinical effects of difference indexes are different in SR prostheses and CR prostheses.They have own advantages and disadvantages in bone resorption around the implant,mSBI,GL and patients'satisfaction in different dimensions.In the aesthetic aspect,the repair effect of ISFDP can meet the requirements of the patients.However,the sample size is small and the follow-up time is short in this study.Therefore,the long-term clinical effect of CR and SR prostheses and their differences in different implant systems still need to be further observed.