***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: AIM The aim of the present prospect i ve study was to evaluate the long-term outcome of implants placed simultaneously with guided bone regeneration ( GBR ) using resorbable and non-resorbable membranes . MATERIAL S AND METHODS The original study population consisted of 72 patients receiving a total of 265 implants . In all GBR-treated sites , demineralized bovine bone mineral ( DBBM ) was used in combination either with a collagen ( CM ) or an Exp and ed polytetrafluoroethylene ( e-PTFE ) membrane . A total of 112 implants was treated with CM , 41 implants were treated with e-PTFE membranes , and 112 served as a control group because implants were entirely surrounded by bone and did not need any GBR procedures . Clinical and radiographic analyses were performed after a period of 12 - 14 years . RESULTS The median follow-up time was 12.5 years ( range 12 - 14 years ) . A total of 58 patients participated in the present investigation , corresponding to 80.5 % of the original study population . The cumulative implant survival rate at the follow-up examination was 93.2 % . For the control group the cumulative survival rate was 94.6 % , for the CM 91.9 % , and for the e-PTFE 92.6 % . Differences among the groups were not statistically significant . The radiographically determined marginal bone level ( MBL ) amounted to : control 2.36 mm ( SD ) , CM 2.4 mm ( SD ) , e-PTFE 2.53 mm ( SD ) . There is no evidence ( P < 0.2 ) that the slope of bone level over time is different for the three treatment groups . CONCLUSION It is concluded that implants placed simultaneously with GBR procedures using resorbable or non-resorbable membranes reveal a high survival rate ranging from 91.9 % to 92.6 % , therefore it is considered to be a safe and predictable therapy . [ Correction added after online publication 30 November 2012 : the marginal bone level of CM , e-PTFE , and control was corrected to ' control 2.36 mm ( SD ) , CM 2.4 mm ( SD ) , e-PTFE 2.53 mm ( SD ) ' in the Results section ] BACKGROUND Guided bone regeneration is considered an effective tool for gaining mineralized tissue either at exposed implant surface or in deficient alveolar ridge areas before implant placement . MATERIAL AND METHODS Customized casts obtained following impression taking at surgery and re-entry allowed for morphometric assessment of alveolar ridge alterations 6 months after one-stage augmentation of bone dehiscences . In a r and omized pilot study using biphasic calcium phosphate tests ( n=17 ) received treatment with ribose cross-linked collagen membranes ( RCLM ) , whereas  controls ( n=20 )  received non-cross-linked membranes . The primary endpoint was to quantify the effect of membrane type on dimensional changes in bone margins at crestal level of endosseous implants . RESULTS Soft tissue dehiscencies occurred at 70.5 % and 55 % frequency for tests and controls , respectively . Gain in clinical ly hard newly mineralized tissue at the crestal level was significantly higher in test group in lateral ( 1.8 versus 0.7 mm ; p=.046 ) and in vertical dimensions ( 1.1 versus 0.2 mm ; p=.035 ) compared with controls . Second measurement obtained at the border of reflected flap revealed no significant difference between groups ( 3.0 versus 2.1 mm ; p=0.57 ) for lateral dimension . CONCLUSIONS Both collagen devices were effective in bone augmentation . RCLMs supported mineralization process and remodelling even in sites showing compromised healing as indicated by morphometric outcome The aim of the present clinical study was to test whether or not the addition of recombinant human bone morphogenetic protein-2 ( rhBMP-2 ) to a xenogenic bone substitute mineral ( Bio-Oss ) will improve guided bone regeneration therapy regarding bone volume , density and maturation . In 11 partially edentulous patients , 34 Brånemark implants were placed at two different sites in the same jaw ( five maxillae , six m and ibles ) requiring lateral ridge augmentation . The bone defects were r and omly assigned to test and control treatments : the test and the control defects were both augmented with the xenogenic bone substitute and a resorbable collagen membrane ( Bio-Gide ) . At the test sites , the xenogenic bone substitute mineral was coated with rhBMP-2 in a lyophilization process . Following implant insertion ( baseline ) , the peri-implant bone defect height was measured from the implant shoulder to the first implant-bone contact . After an average healing period of 6 months ( SD 0.17 , range 5.7 - 6.2 ) , the residual defects were again measured and trephine burs were used to take 22 bone biopsies from the augmented regions . The healing period was uneventful except for one implant site that showed a wound dehiscence , which spontaneously closed after 4 weeks . Later at reentry , all implants were stable . At baseline , the mean defect height was 7.0 mm ( SD 2.67 , range 3 - 12 mm ) at test and 5.8 mm ( SD 1.81 , range 3 - 8 mm ) at control sites . At reentry , the mean defect height decreased to 0.2 mm ( SD 0.35 , range 0 - 1 mm ) at test sites ( corresponding to 96 % vertical defect fill ) and to 0.4 mm ( SD 0.66 , range 0 - 2 mm ) at the control site ( vertical defect fill of 91 % ) . Reduction in defect height from baseline to reentry for both test and control sites was statistically significant ( Wilcoxon P<0.01 ) . Histomorphometric analysis showed an average area density of 37 % ( SD 11.2 , range 23 - 51 % ) newly formed bone at test sites and 30 % ( SD 8.9 , range 18 - 43 % ) at control sites . The fraction of mineralized bone identified as mature lamellar bone amounted to 76 % ( SD 14.4 , range 47.8 - 94 % ) at test compared to 56 % ( SD 18.3 , range 31.6 - 91.4 % ) at control sites ( paired t-test P<0.05 ) . At BMP-treated sites 57 % ( SD 16.2 , range 29 - 81 % ) and at control sites 30 % ( SD 22.6 , range 0 - 66 % ) of the surface of the bone substitute particles were in direct contact with newly formed bone ( paired t-test P<0.05 ) . It is concluded that the combination of the xenogenic bone substitute mineral with rhBMP-2 can enhance the maturation process of bone regeneration and can increase the graft to bone contact in humans . rhBMP-2 has the potential to predictably improve and accelerate guided bone regeneration therapy 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 Two techniques of ridge augmentation using onlay bone graft alone or associated with a non-resorbable membrane have been previously described . This prospect i ve , r and omized study compared these two techniques at 6 months , in terms of bone gain , resorption and quality  obtained at edentulous sites .  Osseous measurements were taken using stents , callipers and CT-scans . Membrane exposure occurred at one site , 4 weeks after placement .  Endosseous implants  were successfully placed at all grafted sites . The mean graft thickness for all subjects was 4.7 mm ( range : 2.3 - 6.2 mm ) . Overall mean resorption was 1.5 mm ( range : 0 - 4.6 mm ) whereas overall mean width gain was 3.2 mm ( range : 0.8 - 6.2 mm ) . Six months following surgery , the membrane group experienced significantly less bone resorption than the graft alone group ( P<0.01 ) . Width augmentation did not differ significantly between the two groups . In conclusion , combining a membrane with an onlay graft demonstrates less bone resorption with a minimal risk of complications . Longer follow-up is needed to confirm the benefits of using a non-resorbable membrane OBJECTIVE The aim of this r and omized-controlled clinical trial was to evaluate the long-term outcome of implants placed in bone augmented with a xenogenic bone substitute material and a collagen membrane with or without the addition of recombinant human bone morphogenetic protein-2 ( rhBMP-2 ) . MATERIAL AND METHODS Eleven patients received a total of 34 implants placed into sites exhibiting lateral bone defects . In a split mouth design , the defects were r and omly treated with the graft material and the collagen membrane either with ( test ) or without ( control ) rhBMP-2 . The patients were examined 3 and 5 years after insertion of the prosthetic restoration . Student 's paired t-test was performed to detect differences between the two groups . RESULTS The survival rate at 3 and 5 years was 100 % for both groups . The peri-implant soft tissues were stable and healthy without any difference between the two groups . The prosthetic reevaluation demonstrated four loose prosthetic screws during the first 3 years and seven ceramic chippings after 3 and 5 years . The mean distance between the first bone to implant contact to implant abutment junction at 3 years was 1.37 mm ( test ) , 1.22 mm ( control ) , and 1.38 mm ( test ) , and 1.23 mm ( control ) at 5 years . The difference of < 0.2 mm between test and control implants was not statistically significant . The mean change of the marginal bone level between baseline and 5 years ranged from -0.07 mm ( mesial , test ) , -0.11 mm ( distal , test ) , -0.03 mm ( mesial , control ) , to + 0.13 mm ( distal , control ) . No statistically significant differences were observed between test and control sites . CONCLUSION Implants placed in bone augmented with and without rhBMP-2 revealed excellent clinical and radiological outcomes after 3 and 5 years PURPOSE This study evaluated predictability and treatment outcome of the combined application of autografts and exp and ed-polytetrafluoroethylene ( e-PTFE ) membranes for lateral ridge augmentation in partially edentulous patients using a staged approach . MATERIAL S AND METHODS Forty partially edentulous patients were consecutively treated . Emphasis was given to a lateral incision technique , perforation of the cortex to open the marrow cavity , stable placement of corticocancellous autografts and bone chips , precise adaptation of the e-PTFE membranes and stabilization with miniscrews , and a tension-free primary soft tissue closure . After 7 to 13 months , the sites were reopened for membrane removal and implant placement . RESULTS All but one patient showed complication-free soft tissue healing . After reopening , 38 patients exhibited excellent ridge augmentation , whereas two had compromised results , with soft tissue encapsulation of some bone chips . None of the applied block grafts showed clinical signs of resorption . Preaugmentation and postaugmentation measurements showed an enlargement of the crest width from a mean of 3.5 mm to 7.1 mm . This allowed the placement of nonsubmerged titanium implants in all 40 patients . CONCLUSIONS The current study demonstrates that the combined application of autografts and e-PTFE membranes is a predictable surgical procedure for lateral ridge augmentation that results in an enlargement of the alveolar crest in partially edentulous patients . The autografts support the membrane and activate bone formation with their osteoconductive and osteoinductive properties . The membrane acts as a physical barrier to nonosteogenic soft tissue cells , and protects the autografts against resorption during healing The aim of this prospect i ve 5-year longitudinal study was to follow endosteal implants in which guided bone regeneration ( GBR ) was applied during implant placement . In 75 patients , defects around implants ( Branemark System ) were treated with Bio-Oss and Bio-Gide ( 112 implants ) . In split-mouth patients in this group , Bio-Oss and Gore-Tex were used in the second defect site ( 41 implants ) . All 7 
    Output:
    
The intervention combining bone replacement grafts with barrier membranes was associated with superior outcomes The most frequently used intervention was the combination of xenograft and bioabsorbable membrane .
The most frequently used intervention was the use of  autogenous bone blocks .
Both treatment strategies led to high survival and success rates ( > 95 % ) for the implants placed on the regenerated sites .