***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: The purpose of the present study was to compare the success of and surgical differences between 1- and 2-stage sinus inlay bone grafts and implants after 1 year in function . The individual risk for implant failure in grafted areas among 1-stage patients was about twice the risk in 2-stage patients ( odds ratio 2.3 , CI 0.6 ; 8.5 ) . The risk for implant failure in non-grafted areas was significantly lower ( P < .05 ) than in grafted areas , regardless of the technique used . Forty edentulous patients , selected according to strict inclusion criteria from consecutive referrals , were allocated to one or other of the 2 sinus-inlay procedures . Twenty patients received bone blocks fixed by implants to the residual alveolar crest in a 1-stage procedure ( group 1 ) . In another 20 patients , particulated bone was condensed against the antral floor and left to heal for 6 months before implants were placed ( group 2 ) . An almost equal number of  implants  was placed in the patients of each group , 76 in the 1-stage procedure and 74 in the 2-stage procedure . Additionally , 72 and 66 implants were placed in the anterior non-grafted regions of group 1 and group 2 patients , respectively . After 1 year in function , a total of 20 implants failed in 1-stage patients , versus 11 in 2-stage patients . Sixteen and 8 implants , respectively , of these were placed in grafted bone . All but one 1-stage patient received the planned fixed prosthetic restorations , but 1 restoration was re design ed after the first year in function because of a functionally unacceptable prosthetic design . At the 1-year follow-up , one 2-stage patient lost her prosthesis as the result of multiple implant failures . Bruxism and postoperative infections were the only parameters that could be related to implant failure , however , depending on the statistical method used Augmentation procedures in the severely resorbed maxilla are st and ard techniques in preprosthetic surgery . Aim of the present study was to compare onlay bone grafting and sinus floor elevation with autogenous bone grafts in edentulous patients in terms of bone resorption of the posterior alveolar crest and implant survival in a 5-year longitudinal study . A total of 100 patients ( 53 female and 47 male patients ) requiring augmentation using autogenous bone due to a severely resorbed maxillae were evaluated . The degree of resorption and bone quality were preoperatively estimated in panoramic radiographs according to Lekholm and Zarb . The overall 5-year success rate of implants placed after augmentation procedures in the posterior maxilla was 93.1 % . Following onlay augmentations 215 out of 235 implant insertions were successful , i.e. a success rate of 91.5 % was achieved . In the sinuslift group , 330 out 349 implants remained successful , i.e. a success rate of 94.6 % was found . The difference between both groups was statistically significant at the end of the evaluation period . Bone resorption , measured as loss of total bone height in panoramic radiographs , was initially more pronounced following onlay augmentations ( > 20 % after 12 months of observation ) . The degree of resorption decreased in the further course of the study . Lower resorption rates and a higher overall success rate were demonstrated for the sinus lift group PURPOSE The aim of this study was to evaluate implants placed according to several methods of sinus floor augmentation . MATERIAL S AND METHODS Forty-eight patients ( median age of 62 years , range 23 to 89 ) had been treated at least 3 years prior to examination with screw-type implants in the posterior maxilla . Depending on the vertical dimension of the residual bone , 1 of 3 surgical procedures had been performed : sinus lift by lateral antrostomy ( SL ) in 13 patients ; osteotome technique ( OT ) in 18 patients ; st and ard implantation in 17 patients ( control ) . In each patient 1 implant was r and omly chosen for analysis ( 48 implants with a mean observation time of 4.6 + /- 1.4 years ) . Examination included probing pocket depth ( PPD ) measurement and radiographic examination . Radiographs were digitized to assess the marginal bone level . Differences between the groups were tested using analysis of variance , the Student t test and the Kruskal-Wallis test . RESULTS Mean PPD was 3.0 mm for the SL , 3.1 mm for OT , and 3.1 mm for control . The mean radiographic bone level was 1.53 mm for SL , 2.40 mm for OT , and 1.96 mm for control . No statistically significant differences were found between the groups for either of these parameters . DISCUSSION AND CONCLUSION Clinical examinations as well as radiographically stable bone levels indicated similar biomechanical conditions for prosthetic restorations when applying the 3 surgical procedures tested The purpose of this clinical investigation was to compare the new resorbable collagen membrane , Bio-Gide , to the conventional exp and ed polytetrafluoroethylene material ( Gore-Tex ) for guided bone regeneration in situations involving exposed implant surfaces . Over a 2-year period , 25 split-mouth patients were treated r and omly : one defect site was treated with Bio-Gide and the other defect site with Gore-Tex ; all 84 defects were filled with Bio-Oss and covered with the respective membrane . The defect types , their dimensions , and their morphology were measured in detail initially and at re-entry to allow for calculation of the exposed implant surface . Changes in defect surface for both types of membranes were statistically significant ( P < .0001 ) ; however , no statistical significance ( P > .94 ) could be detected between the two membranes . The mean average percentage of bone fill was 92 % for Bio-Gide and 78 % for Gore-Tex sites . In the latter group , 44 % wound dehiscences and /or premature membrane removal occurred . The resorbable membrane , Bio-Gide , in combination with a bone graft , can be a useful alternative to the well-established exp and ed polytetrafluoroethylene membranes PURPOSE The aim of this r and omized study was to evaluate and compare the long-term success rates of cylindric , screw-type titanium implants with a larger diameter ( 5.9 mm ) that were placed in fresh extraction sockets in association with resorbable bone substitutes or a resorbable membrane . MATERIAL S AND METHODS Eighty-three partially edentulous adult patients , selected from among those treated in 1997 and 1998 at the San Raffaele Institute in whom 1 or more implants had been placed into fresh posterior m and ibular or maxillary sockets , were included in the study . A total of 111 implants were placed , 36 in m and ibles and 75 in maxillae . Fifty-six implants were placed in combination with resorbable hydroxyapatite ( HA group ) and 55 with a resorbable membrane ( MR group ) . Intraoral radiographs and follow-up examinations , including verification of implant stability via the Periotest , were carried out at second-stage surgery 3 , 6 , 9 , and 12 months later ; and then annually up to 4 years after placement of the definitive restoration . The radiographic examination was conducted by means of a st and ardized procedure to verify osseointegration . RESULTS There was 100 % attendance at the follow-up examination after 4 years . At second-stage surgery , which was performed after 4 to 6 months ' healing time , none of the implants showed any signs of mobility , peri-implantitis , or bone loss . Two implants failed in the MR group , one at 3 months and one at 9 months after placement ; 1 implant failed in the HA group at 4 months after placement . After 4 years , the implant success rate was 97.3 % ( 108 of 111 implants were considered successful ) . The success rate did not differ significantly between the HA group ( 98.2 % ) and the MR group ( 96.4 % ) . DISCUSSION The use of larger-diameter implants served to minimize the anatomic discrepancies that would have evolved when substituting a molar with a st and ard-diameter implant . According to the accepted criteria for success , the 5-year success rate should be at least 85 % ; therefore both methods may be considered satisfactory . CONCLUSION Implants placed in combination with a resorbable allogeneic material or with a resorbable membrane provided predictable long-term results when restored with a fixed partial denture PURPOSE Loss of alveolar bone in the anterior maxilla may preclude implant placement or compromise positioning and thus diminish the final esthetic result of the restoration . Bone augmentation can overcome such difficulties but may affect osseointegration . The aim of this study was to report the outcome of buccal onlay bone grafting in the anterior maxilla in routine dental implant practice . MATERIAL S AND METHODS Seventeen consecutive patients ( 12 men and 5 women , mean age 31.4 years ) received autogenous bone grafts from the m and ibular symphysis to the anterior maxilla . A total of 35 Brånemark System MK II implants were placed in grafted bone . RESULTS Fifteen patients had a mean period of graft consolidation of 19.7 weeks ( range 13 to 32 weeks ) . Two patients had simultaneous graft and implant placement ; 1 implant failed to Integrate in this group . This represents a survival rate of 97.1 % of implants in functional loading after a mean follow-up period of 153.6 weeks from occlusal loading ( range 74 to 283 weeks ) . DISCUSSION AND CONCLUSION M and ibular block onlay grafts appear to be a predictable method for augmenting the width of the  anterior maxilla  prior to implant placement The efficacy of combinations of membranes and autogenous bone grafts at immediate implants were compared in a prospect i ve study . Sixty-two consecutively treated patients each received an immediate implant for a single tooth replacement at a maxillary anterior or premolar site . Dimensions of the peri-implant defect at the implant collar were measured as follows : vertical defect height ( VDH ) , horizontal defect depth ( HDD ) and horizontal defect width ( HDW ) . Each implant r and omly received one of five augmentation treatments and were submerged with connective tissue grafts : Group 1 (n=12)--exp and ed polytetrafluoroethylene membrane only , Group 2 (n=11)--resorbable polylactide/polyglycolide copolymer membrane only , Group 3 (n=13)--resorbable membrane and autogenous bone graft ; Group 4 (n=14)--autogenous bone graft only , and Group 5 (n=12)--no membrane and no bone graft control . At re-entry , all groups showed significant reduction in VDH , HDD and HDW . Comparisons between groups showed no significant differences for VDH ( mean 75.4 % ) and HDD ( mean 77 % ) reduction . Significant differences were observed between groups for HDW reduction ( range , 34.1 - 67.3 % ) , with membrane-treated Groups 1 , 2 and 3 showing the greatest reduction . In the presence of dehiscence defects of the labial plate , HDW reduction of 66.6 % was achieved with membrane use compared with 37.7 % without membranes . Over 50 % more labial plate resorption occurred in the presence of a dehiscence defect irrespective of the augmentation treatment used . The results indicate that VDH and HDD reduction at defects adjacent to immediate implants may be achieved without the use of membranes and /or bone grafts One of the key factors for attaining osseointegration is the presence of an adequate osseous volume . In patients with inadequate osseous width or height , a bone augmentation using the guided bone regeneration ( GBR ) concept may be applied either with a simultaneous or a staged approach . The aim of this multicenter prospect i ve case series study was to evaluate the efficacy and predictability of the GBR technique ( simultaneous approach ) in patients with peri-implant osseous defects , both dehiscences and fenestrations . Results 5 years post-treatment ( survival rates and marginal bone level ) were assessed . A total of 19 consecutive patients with 26 peri-implant osseous defects ( 20 dehiscences and six fenestrations ) were treated during the period from September 1992 to June 1993 with a simultaneous GBR approach using non-resorbable membranes combined with autogenous bone grafts or decalcified freeze-dried bone allograft . The mean osseous augmentation was 94.8 % . Marginal bone levels at re-entry and 5 years after surgery were calculated from st and ardized periapical radiographs . One implant was lost 3 months after loading . Thus , the cumulative survival rate was 96.1 % after 5 years . The mean marginal bone level after 5 years was 2.03 mm ( SD=+/-0.5 ) , without a difference between mesial and distal sites . This study demonstrates that implants with peri-implant defects that are treated with GBR had similar survival rates and crestal bone levels compared with implants in native bone This prospect i ve clinical analysis reports on the use of coral granules in alveolar ridge preservation procedures in a population of young , growing patients . The sample consisted of 21 patients , 12 females and 9 males , with a mean age of 13.6 years . These 21 patients had 48 dento-alveolar defects suitable for augmentation with coral granules  , and were followed clinical ly and radiographically 
    Output:
    
However , studies that met the inclusion criteria seemed to be comparable and yielded favorable results in supporting dental implants .
The alveolar ridge augmentation procedures may be more technique- and operator-experience-sensitive , and implant survival may be a function of residual bone supporting the dental implant rather than grafted bone .