***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE The purpose of this prospect i ve clinical study was to evaluate peri-implant soft-tissue conditions and esthetic fulfillment during a 3-year follow-up period following prosthetic rehabilitation . MATERIAL AND METHODS As part of a prospect i ve multi-center study , 152 ITI dental implants were placed in 80 patients in the maxillary anterior region . Fifty-nine crowns ( 38.82 % ) were cement retained , while 93 ( 61.18 % ) crowns were screw retained . At loading and 3 , 6 , 12 and 36 months post-loading , modified plaque index ( MPI ) , sulcus bleeding index ( SBI ) , keratinized mucosa ( KM ) , gingival level ( GL ) , and esthetic fulfillment were recorded . RESULTS All patients completed the study and no complications were reported . While statistically not significant at all time points , cement-retained crowns seemed to present a worsening trend in MPI and SBI scores . Interestingly , screw-retained crowns seemed to present an opposite picture , their MPI and SBI scores improved over time . While plaque accumulation , prophylaxis and depth of crown margin significantly affected levels of sulcus bleeding , prophylaxis alone played a key role in reducing plaque accumulation . No soft tissue recession was observed in either cement- or screw-retained crowns up to 3 years post-loading . Esthetic fulfillment survey revealed that patients did not have a preference for crown types ; however , dentists favored cement-retained over screw-retained crowns . CONCLUSIONS Peri-implant soft tissues responded more favorably to screw-retained crowns when compared with cement-retained crowns . However , no soft-tissue recession was observed in either type of crowns . Cement-retained crowns were preferred by dentists , while patients were equally satisfied with either type of crowns they received The aim of the present study was to identify the peri-implant conditions ( bleeding on probing ( BOP ) , pocket probing depth ( PPD ) , modified plaque index ( mPI ) ) and marginal bone loss ( MBL , marginal bone level change between follow-up and occlusal loading ) around  cemented and screw-retained posterior single crowns on tissue-level implants .  The study was a retrospective cohort study with up to 4 years ( mean 2.5 years ) follow-up . Patients with either cemented or screw-retained crowns in posterior regions were included .  Implant survival , technical complications , BOP , PPD , mPI , MBL , biologic complications ( peri-implant mocositis and peri-implantitis ) were evaluated . Mann-Whitney U test was used to test the difference between the screw-retained group ( SG ) and cemented group ( CG ) . 176 patients ( SG : 94 , CG : 82 ) were included .  The implant survival rates were 100 % in SG and 98.8 % in CG . Prosthetic screw loosening was found in 8 restorations ( 8.7 % ) at follow-up visit . Peri-implant mucositis rate was significantly higher in the SG group ( 42.1 % ) than that in the CG group ( 32.2 % ) ( P = 0.04 ) . Six patients ( 6.38 % ) in the screw-retained group and 5 patients ( 6.10 % ) in the cemented group were diagnosed with peri-implantitis , the difference did not reach statistical significance ( P>0.05 ) . No significant difference of PPD , mPI and MBL were found between two groups ( P = 0.11 , 0.13 and 0.08 , respectively ) . High implant survival rates were achieved in both groups . Cemented single crowns on tissue-level implants showed comparable peri-implant conditions in comparison with two-piece screw-retained crowns . Well- design ed prospect i ve cohort or r and omized controlled clinical trials with longer follow-up are needed to confirm the result PURPOSE The aim of this study was to evaluate the survival and success of screw-retained versus cement-retained implant restorations in immediately loaded implants at 8-year follow-up . MATERIAL S AND METHODS Patients who were scheduled for full-arch ceramic prosthetic restorations were divided into two groups by r and omization : in one group , prosthetic frameworks were screwed onto implants ( screw-retained group , SRG ) , and in the second group , the frameworks were cemented on abutments ( cement-retained group , CRG ) . Dental implants were placed both in post extraction and in healed sites . A temporary full-arch prosthesis was placed immediately after implant placement . Intraoral digital radiographic examinations ( evaluating marginal bone levels ) were made at baseline , 6 months , and each year after implant placement . RESULTS In 28 patients , 24 full arches and 192 implants were placed in the maxilla and 10 full arches and 80 implants in the m and ible ( 17 rehabilitations in each group ) . After an 8-year follow-up period , a survival rate of 99.27 % was reported for all implants . Within the first year after implant placement , bone loss was recorded as follows : the CRG showed mean bone levels of -1.23 ± 0.45 mm , while the SRG showed mean bone levels of -1.01 ± 0.33 mm . After a 3-year follow-up , a slight increase was found ( 0.30 ± 0.25 mm in CRG and 0.45 ± 0.29 mm in SRG ) . After that point , marginal bone levels remained stable over time , up to the 8-year follow-up . No statistically significant differences were found between groups ( P > .05 ) . CONCLUSION Definitive cement- and screw-retained ceramic restorations are highly predictable , biocompatible , and esthetically pleasing , and the two groups presented no statistically significant differences in bone loss PURPOSE The purpose of this controlled prospect i ve clinical study was to compare cemented and screw-retained implant-supported single-tooth crowns followed for 4 years following prosthetic rehabilitation with respect to peri-implant marginal bone levels , peri-implant soft tissue parameters , and prosthetic complications . MATERIAL S AND METHODS Twelve consecutive patients were selected from a patient population attending the Implantology Department at the University of Padova . They all presented with single-tooth bilateral edentulous sites in the canine/premolar/molar region with adequate bone width , similar bone height at the implant sites , and an occlusal scheme that allowed for the establishment of identical occlusal cusp/fossa contacts . Each patient received 2 identical implants ( 1 in each edentulous site ) . One was r and omly selected to be restored with a cemented implant-supported single-tooth crown , and the other was restored with a screw-retained implant-supported single-tooth crown . Data on peri-implant marginal bone levels and on soft tissue parameters were collected 4 years after implant placement and analyzed to determine whether there was a significant difference with respect to the method of retention ( cemented versus screw-retained ) . RESULTS All patients completed the study . All 24 implants survived , result ing in a cumulative implant success rate of 100 % . Statistical analysis revealed no significant differences between the 2 groups with respect to peri-implant marginal bone levels and soft tissue parameters . DISCUSSION The data obtained with this study suggested that the choice of cementation versus screw retention for single-tooth implant restorations is likely not based on clinical results but seems to be based primarily on the clinician 's preference . CONCLUSIONS Within the limitations of this study , the results indicate that there was no evidence of different behavior of the peri-implant marginal bone and of the peri-implant soft tissue when cemented or screw-retained single-tooth implant restorations were provided for this patient population 
    Output:
    
The keywords , such as " Screw versus Cement Retained Fixed Implant Supported Reconstructions , " " Screw Retained Fixed Implant . " "
Results No significant difference was found between the screw-retained and cemented retained implant supported reconstructions .
Dental implants are associated with complications leading to implant failure based on the type of restoration that is being used ; cement-retained restoration and screw-retained restoration .
Conclusion Screw-retained implant-supported reconstructions were found to pose less biological and technological complications .
Retention of the tooth is more stable and functional when implantation is selected based on the efficiency of a treatment procedure