***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: PURPOSE The aim of this study was to analyze and compare the survival rates of endosseous implants placed in the edentulous maxillae of patients in whom bone augmentation was undertaken prior to or in conjunction with implant placement with survival rates in patients who did not undergo bone augmentation . MATERIAL S AND METHODS This study included 2 retrospective patient groups : the graft group , which included 64 patients with 437 implants , and the nongraft group , which included 118 patients with 683 implants . The patients were treated consecutively between 1990 and 1996 . In addition , the retrospective patient groups were also followed prospect ively using a st and ardized clinical and radiographic study design . RESULTS The implant survival rate was 75.1 % for the graft group and 84.0 % for the nongraft group after a mean follow-up of 5 to 6 years , a statistically significant difference . However , there was no difference with regard to the prosthesis survival rate , and after reoperation , more grafted patients had a fixed prosthesis at the end of the study ( 87.5 % versus 85.3 % ) . Implant failure appeared to be related to the original jawbone volume in the anterior regions . In the premolar region , where the inlay graft technique was used , the implant survival rate for the graft group was comparable to that of the nongraft group . The graft group had significantly more failures than the nongraft group in the incisor region , but not in the canine , premolar , or molar regions . DISCUSSION The majority of implant failures occurred before loading . Occlusal overload during the healing period may have been a causative factor . CONCLUSIONS The overall implant survival rate was lower in grafted maxillae than in nongrafted maxillae after a mean of 5 to 6 years of follow-up . Analysis revealed that jawbone volume in the anterior regions at the start of treatment was directly related to implant survival rates in both groups : the greater the volume , the higher the survival rate . Moreover , the implant survival rate was similar in grafted posterior edentulous maxillae of classes V and VI and in nongrafted posterior edentulous maxillae of classes III and IV 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 Treatment of the atrophic edentulous maxilla is challenging especially when bone graft procedures are necessary . In this study an onlay bone graft , a saddle or veneer , with or without maxillary sinus floor inlay graft , harvested from the anterior iliac crest , in combination with implants was used in the reconstruction of patients with extreme atrophy in their maxillae . The aim was to investigate treatment outcome , and the impact of gender and smoking , in 44 patients in a prospect i ve , long-term , follow-up study concerning implant survival rate and marginal bone loss adjacent to the surfaces of the implant . Mean follow-up time was 11 years . Of 334 inserted Brånemark implants  , with machined surface , 27 failed . Estimated implant survival rate was 90 % . Marginal bone loss was 1.8 mm 1 year after implant surgery ; 2.3 mm after 5 years ; and 2.4 mm after 10 years . There was a significant difference between genders in implant survival . Marginal bone loss differed significantly between smokers and non-smokers up to the 5-year examination and between genders after the 4-year examination . The onlay bone graft , with or without a maxillary inlay graft , results in high implant survival rate , good oral function and stabilised marginal bone . All patients are still wearing their original fixed bridges PURPOSE To perform a preliminary validation with cone beam computed tomography ( CBCT ) of the combined use of intraoral bone blocks and bio material s for total reconstruction of the atrophic maxilla . MATERIAL S AND METHODS Consecutive cases of total edentulism of the maxilla ( Cawood and Howell classes IV or V ) treated with bilateral sinus floor elevation , m and ibular bone block grafts , and bio material s were evaluated prospect ively . Implants were placed 14 to 16 weeks after grafting . Each patient received a CBCT scan preoperatively , immediately after bone augmentation , and at reentry . A three-dimensional reconstruction of the maxilla with volumetric calculations was obtained at each stage . RESULTS Fourteen patients participated .  Successful graft integration occurred in all cases , with no major complications . Mean preoperative volume was 11,312 mm3 . Mean postoperative volume was 19,997 mm3 immediately after surgery and 19,042 mm3 before implant insertion . The average percentage volumetric increase between the preoperative condition and the situation at reentry was 71.99 % . One hundred eight implants were inserted . Immediate loading was possible with 81 implants in 10 patients . CONCLUSIONS The rehabilitation of the severely resorbed maxilla remains a formidable challenge . The results of this study suggest that the use of m and ibular bone blocks in combination with bio material s is an effective , reliable procedure for the rehabilitation of the severely resorbed maxilla . Significant volume increases and adequate stability of the augmented areas at reentry were found with CBCT analysis . The grafted bone provided sufficient mechanical support to permit provisionalization and immediate loading . This technique enabled the restoration of function and esthetics with a fixed rehabilitation at 4 months Thirty patients with extremely resorbed maxillae had reconstructive bone grafts from the ala iliaca and endosseous implants in a one-stage procedure . The first ten patients constituted a development group and the following 20 patients a routine group . The marginal bone level and implants success rate was evaluated in a prospect i ve long-term follow-up for a minimum of 10 years ( 10 - 13 years ) . Clinical and radiographic examinations were performed at 6 months and then annually up to 5 years . The final examinations were performed at the 10-year follow-up . The bridges were removed at every clinical examination . Marginal bone loss was seen up to the 3-year examination , where it averaged 4.6 mm in the routine group . Between the 3- and 10-year follow-up no significant change was registered . The initial bone loss was probably due to the design of the 3.6 mm conical unthreaded marginal part of the implant . The implant success rate was 83.1 % in the routine group . Failures mostly occurred during the first 2 years ( 14 out of 20 ) . A substantial amount of bone can be gained in patients with extremely resorbed maxillae , when treated with bone graft according to the procedure described in this study INTRODUCTION Edentulism causes progressive bone resorption of the maxillae , which can lead to altered maxillo-m and ibular relationships . The aim of the study was to evaluate the applicability of guided bone regeneration ( GBR ) to Le Fort I osteotomies with interpositional bone grafts for treatment of patients with severe maxillary atrophy . MATERIAL S AND METHODS Twenty consecutive patients characterized by severely atrophic maxillae were treated from January 2003 to January 2006 in order to resolve maxillary edentulism . All patients underwent  pre-prosthetic surgery  , including a Le Fort I osteotomy associated with autologous interpositional bone grafts to move the alveolar arch forward and to resolve the maxillary atrophy . Barrier membranes were also used to cover the bone grafts and the osteotomy line , favoring the healing process according to GBR principles . Maxilla advancement and alveolar crest augmentation were measured to assess the degree of reconstruction . A total of 154 implants were inserted in reconstructed maxillae 4 months after surgery and were restored with fixed full-arch dentures after another 4 months . Surgical and prosthetic complications were recorded and previously established implant success criteria were used to assess the success of this treatment protocol . RESULTS The outcome of pre-prosthetic surgery and implant-supported rehabilitation was prospect ively evaluated every year . All Le Fort I osteotomies were successfully carried out , with a mean maxilla advancement of 4.2 cm ( range : 3.1 - 5 cm ) , which appeared to be stable during the follow-up . After a mean follow-up of 66.4 ± 18.4 months , only four implants failed according to the success criteria , yielding a cumulative success rate of 95.8 % . DISCUSSION AND CONCLUSIONS Le Fort I osteotomies with the use of barrier membranes to cover the interpositional bone grafts can be a predictable treatment for edentulous patients with severely resorbed maxillae . The study data suggest that this approach makes it possible to compensate for both sagittal and vertical discrepancies due to maxilla atrophy , with a minimum resorption of advanced maxillae and grafted bone . A GBR-based protocol seems to lead to high implant success rates , although further r and omized controlled studies are needed to demonstrate the usefulness and advantageousness of GBR BACKGROUND Prosthetic treatment of the edentulous maxilla may require bone augmentation to enable placement and integration of dental implants . This constitutes a complex healing situation , and resorption of the grafted bone and failure of the implants often occur . The application of autogenous platelet-rich plasma ( PRP ) has been suggested to improve incorporation and preservation of bone grafts . PURPOSE The aim of this controlled clinical study was to evaluate whether PRP in conjunction with grafting of particulated autogenous bone to the maxilla could improve the integration and clinical function of dental implants . An additional aim was to compare block bone grafts without PRP with PRP-treated particulated bone . MATERIAL AND METHODS Nineteen consecutive patients were included in the study and treated with iliac bone grafts and dental implants in the maxilla according to a split-mouth design . In the anterior maxilla , particulated bone mixed with PRP ( test ) was compared with onlay block grafts without additional PRP ( control ) . In the posterior maxilla , particulated bone grafts with ( test ) or without ( control ) PRP were placed as sinus inlay grafts . After 6 months of healing , 152 implants ( 8 implants/patient ) ( TiOblast , Astra Tech AB , Mölndal , Sweden ) were placed . Test ( PRP ; 76 implants ) and non-PRP ( 76 implants ) sides were evaluated and compared by implant survival rate , marginal bone level , and implant stability using resonance frequency analysis ( RFA ) during 1 year in function . RESULTS Two control implants in control sites in two patients were lost at abutment connection . After 1 year in function , no further implants were lost , giving an overall survival rate of 98.7 % . The marginal bone level measurements showed no significant differences , although there was a tendency toward less resorption on PRP sides . RFA measurements showed statistically significantly higher implant stability quotient values for PRP sites at abutment connection in the anterior but not in the posterior regions . CONCLUSIONS The present clinical study showed that a high implant survival rate and stable marginal bone conditions can be achieved after 1 year of loading in the maxilla following autogenous bone grafting whether or not PRP is used . RFA measurements revealed differences at abutment connection , which could be explained by the type of graft rather than as an effect of PRP . Although no obvious positive effects of PRP on bone graft healing could be demonstrated , the h and ling of the particulated bone grafts was improved BACKGROUND Immediate implant placement into fresh extraction sockets is generally considered a reliable procedure that offers several clinical advantages . PURPOSE The primary aim of this study was to evaluate and compare the overall clinical outcomes of immediate and delayed restoration procedures for  implants placed in fresh extraction sockets by means of a flapless technique and resorbable membrane stabilizing a xenograft . Total costs and operating times were also compared . MATERIAL S AND METHODS In this prospect i ve cohort study , changes of marginal bone level , facial soft tissue ( ΔFST ) , and width of keratinized gingiva ( ΔWKG ) , in addition to the papilla index , underwent a pairwise comparison ; correlations with pristine buccal bone thickness were also investigated . RESULTS Although similar results were recorded for the two procedures , with a bone loss of -1.0 ± 0.5 mm and - 
    Output:
    
All five treatment modalities discussed-onlay bone grafting , GBR , Le Fort I interpositional grafting , maxillary sinus augmentation , and /or nasal floor inlay grafting or the combination approach-can be successfully used to augment edentulous maxillary ridge with high implant SRs