***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: This paper describes the 5-year results of a comparative study between Astra Tech and Brånemark system implants . The aim was to compare the systems primarily with regard to bone level changes , and also with regard to other variables of interest . Sixty-six patients with edentulous jaws were included in the study . R and omisation schedules were used to allocate the patients to the two implant systems . 184 Astra Tech implants with a titanium-blasted surface and 187 Brånemark implants with a turned surface were used . The implants were inserted with a two-stage technique and the insertion followed the routines for the respective implant system . All patients were provided with full-arch fixed bridges . All patients were followed up with clinical and radiographic examinations from fixture insertion to the 5-year follow-up . The total mean bone level change in the upper jaw between fixture insertion and the 5-year examination was -1.74+/-0.45 mm at the Astra implants and -1.98+/-0.21 at the Brånemark implants . The corresponding values for the lower jaw were -1.06+/-0.19 for Astra and -1.38+/-0.17 for Brånemark . The major postoperative changes of the marginal bone level took place between fixture insertion and baseline . During this period , there was also a different pattern of bone remodelling between the implant systems . Between baseline ( prosthesis connection ) and the 5-year examination , the marginal bone level changes were small , with no difference between the implant systems . The implant stability was examined with the supraconstructions removed . At the 5-year examination , the survival rate for Astra Tech implants was 98.4 % and for the Brånemark implants it was 94.6 % . The difference was not statistically significant PURPOSE To compare implants with machined vs roughened surfaces placed flapless in totally edentulous jaws and immediately restored with metal-resin screw-retained cross-arch prostheses . M and ibles were rehabilitated with two implants ( Fixed-on-2 or Fo2 ) and maxillae with three implants ( Fixed-on-3 or Fo3 ) . MATERIAL S AND METHODS Forty edentulous or to be rendered edentulous patients ( 20 in the m and ible and 20 in the maxilla ) were r and omised to the machined group  ( 20 patients : 10 m and ibles and 10 maxillae ) and to the roughened group  ( 20 patients : 10 m and ibles and 10 maxillae ) according to a parallel group design . To be immediately loaded implants had to be inserted with a minimum torque of 60 Ncm . Outcome measures were prosthesis and implant failures , complications and peri-implant marginal bone level changes evaluated up to 1 year post-loading . RESULTS Flaps were raised in four patients from the machined group . Four prostheses on machined implants and three on roughened implants were delayed for loading because a sufficient insertion torque was not obtained . There were no dropouts 1 year after loading . Two maxillary machined implants were lost in two patients ( difference in proportions = 0.10 ; 95 % CI = -0.03 to 0.23 ; P ( Fisher 's exact test ) = 0.487 ) ; one maxillary Fo3 prosthesis on machined implants and one m and ibular Fo2 prosthesis on roughened implants had to be remade ( difference in proportions = 0 ; 95 % CI = -0.14 to 0.14 ; P ( Fisher 's exact test ) = 1.000 ) . Five patients with machined implants had six complications vs seven patients who had eight complications at roughened implants ( difference in proportions = -0.10 ; 95 % CI = -0.38 to 0.18 ; P ( Fisher 's exact test ) = 0.731 ) . There were no statistically significant differences for implant failures , prosthetic failures or complications between groups . There were no statistically significant differences for marginal peri-implant bone levels between the two groups ( estimate of the difference = -0.06 mm ; 95 % CI = -0.23 to 0.10 ; P ( ANCOVA ) = 0.445 ) , with both groups losing marginal bone in a statistically significant way ( 0.35 ± 0.23 mm for machined and 0.42 ± 0.27 mm for roughened surface ) . CONCLUSIONS These preliminary results suggest that immediately loaded cross-arch prostheses can be supported by only two m and ibular or three maxillary dental implants at least up to 1 year post-loading , independently of the type of implant surface used . Longer follow-ups are needed to underst and whether one of the two-implant surfaces is preferable OBJECTIVE This report is a 20-year follow-up of a r and omized controlled clinical trial evaluating the potential long-term effect of a modified implant surface on the preservation of the peri-implant marginal bone level . MATERIAL & METHODS In each of 51 patients and for each fixed partial denture ( FPD ) , by r and omization at least one implant installed had a non-modified turned surface and one a modified and roughened surface ( TiOblast ® ) . Clinical and radiological examinations were performed at various follow-up intervals . Primary outcome variables were peri-implant marginal bone level change from time of loading and proportion of implants with no bone loss at 20 years . Multilevel analysis followed by nonparametric and Pearson 's Chi-Square tests were applied for statistical analysis . RESULTS At the 20-year follow-up , 25 patients carrying 64 implants were available for evaluation .  Turned and TiOblast implants presented with a mean bone level change from the time of FDP delivery amounting to -0.41 mm ( 95 % CI -0.84/0.02 ) and -0.83 mm ( 95 % CI -1.38/-0.28 ) respectively ( inter-group comparison p > .05 ) . 47 % of the Turned and 34 % TiOblast implants ( p > .05 ) showed no bone loss . All but one of these implants were free of bacterial plaque and inflammation as well as presented with probing pocket depths ≤5 mm at both the 5- and 20-year follow-up examinations . CONCLUSION It is suggested that a moderate increase of implant surface roughness has no beneficial effect on long-term preservation of the peri-implant marginal bone level Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more OBJECTIVE The aim of this study was to evaluate the change in marginal bone level radiographically around two different implant systems after 7 years of use . MATERIAL AND METHODS Twenty fully edentulous patients were included in the study and r and omly assigned to two treatment groups of machined surface implants ( Brånemark , n = 40 ) and rough-surface implants ( Xive , n = 40 ) . The implants were early loaded with individual bar-retained overdentures . All patients were treated by the same surgeon and the same prosthodontist . Clinical and radiographic examinations were conducted at the time of implant loading ( baseline ) and annually for up to 7 years of use . Measurements to the nearest 0.1 mm were taken at the mesial and distal site , and the average values were calculated for each implant . A three-level mixed-effect analysis of covariance ( ANOVA ) was used to test the significance of the mean marginal bone change in the two implant groups . RESULTS The study population consisted of 15 women ( 75 % ) and five men ( 25 % ) with an average age of 61.6 years . A total of 79 of 80 implants integrated successfully . n = 1 Brånemark implant failed after 3 weeks . There was a significant difference ( P < 0.001 ) between the two implant systems at the baseline measurements ( 0.14 mm Brånemark vs. 0.39 mm Xive ) and a highly significant difference for the annual bone loss ( 0.07 mm [ Brånemark ] vs. 0.18 mm [ Xive ] , P < 0.001 ) . CONCLUSION Both the implant systems are clinical ly satisfying . Nevertheless , the Brånemark group showed a better radiological performance than the Xive group BACKGROUND Dental implants with moderately rough surfaces are commonly used in the treatment of edentulous patients . However , long-term data on survival rates and marginal bone conditions are lacking . PURPOSE This prospect i ve study evaluated the cumulative survival rate of the TiOblast implant ( Astra Tech AB , Mölndal , Sweden ) after 10 years of prosthetic loading . MATERIAL S AND METHODS A total of 199 TiOblast implants were placed in 36 consecutive edentulous patients ( 23 males and 13 females ) . All patients were treated at one clinic and by the same team . The patients were edentulous in either the maxilla ( n = 16 ) or the m and ible ( n = 20 ) . The average age of the patients at the start of the trial was 64 years ( range , 59 - 82 years ) . Of the 199 implants inserted 108 were in the m and ible and 91 were in the maxilla . Clinical evaluations were undertaken after completion of the prosthetic superstructure ( baseline ) and after 6 months , 1 year , 3 years , 5 years , 7 years , and 10 years . Mean marginal bone level was evaluated for the first 100 placed implants for up to 7 years . RESULTS Six implants failed during the study ( 3 in the m and ible and 3 in the maxilla ) . All failures occurred within the first year , giving a cumulative survival rate of 96.9 % ( 96.6 % in the maxilla and 97.2 % in the m and ible ) after 10 years of follow-up . The survival rate for the superstructures was 100 % . The mean marginal bone level in the measured sample was 0.2 mm ( st and ard deviation [ SD ] , 0.31 ) below the reference point at baseline , 0.28 mm ( SD , 0.20 ) and 1.27 mm ( SD , 1.15 ) below the same point 7 years later ( mean , 0.15 mm per year ) . CONCLUSION This study showed that titanium dioxide-blasted implants offer predictable long-term results as supports for fixed prostheses in both the maxilla and m and ible BACKGROUND Step-wise reduction in loading protocol s is necessary to evaluate early loading of implants with m and ibular overdentures . PURPOSE To compare the success rates of two different dental implant systems following conventional or early loading protocol s in patients being rehabilitated with m and ibular overdentures . MATERIAL S AND METHODS Forty-eight edentulous participants were r and omly allocated to two different implant systems : one with a machined titanium implant surface ( Sterioss , Nobel Biocare , Yorba Linda , California , USA ) and the other with a roughened titanium surface ( Southern Implants , Irene , South Africa ) . For each system , the participants were further divided into control groups , in whom m and ibular implant overdentures and their respective matrices were inserted following a st and ard 12-week healing period , and test groups , in whom a 6-week healing period was followed prior to identical loading . Two unsplinted implants to support implant overdentures were placed in the anterior m and ible of all participants , using a st and ardized one-stage surgical procedure . Mobility tests and marginal bone levels , as well as peri-implant parameters , were evaluated at each baseline and 52 and 104 weeks after surgery . RESULTS There was no statistically significant difference in the success rates of the two systems in either control or test groups . At the 2-year evaluation , a success rate was found of 87.5 % and 70.8 % for the control and test Sterioss groups , respectively , and 83.3 % and 100 % for the control and test Southern Implants groups were observed . For the Sterioss groups , eight implants were lost at an early stage : seven in the test group and one in the control group . For the Southern Implants control and test groups , no failures were seen at any time interval . There were no significant differences in marginal bone loss , Periotest values , and peri-implant parameters between implant systems or between any of the control or test groups . CONCLUSIONS Early loading , with step-wise reductions in loading protocol s , of unsplinted machined Sterioss and roughened Southern Implants fixtures with m and ibular overdentures is possible for up to 2 years BACKGROUND Evidence -based reports are needed to support the application of a one-stage surgical protocol for  unsplinted implants supporting m and ibular overdentures . PURPOSE To examine the feasibility and success of using two different dental implant systems ( originally design ed for two-stage operative technique ) using a one-stage operative procedure in patients being rehabilitated with implant m and ibular overdentures . MATERIAL S AND METHODS The study sample involved 24 edentulous subjects ( aged 55 - 80 yr ) r and omly allocated to two different implant systems , one with a machined titanium implant surface ( Steri-Oss , Nobel Biocare , Göteborg , Sweden ) and the other with a roughened titanium surface ( Southern Implants , Ltd. , Irene , South Africa ) . Two unsplinted implants to support implant overdentures were placed in the anterior m and ible of all patients , using a st and ardized one-stage surgical and prosthodontic procedure . Primary stability and 
    Output:
    
This meta- analysis reveals that s and blasting is superior over machined surface in implant failure but not in marginal bone level in healthy subjects .