***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 This multicenter investigation is an interim 3-year survival report of a 5-year prospect i ve study using Brånemark osseointegrated implants in partially edentulous patients . MATERIAL S AND METHODS Previously defined patient characteristics and clinical parameters were related to implant survival using lifetable analysis . RESULTS Three years after prosthesis insertion , 460 implants placed in 139 patients remained in the study .  Cumulative success rates for maxillary implants ( 92.5 % ) were less than for m and ibular implants ( 94.8 % ) , with an overall cumulative success rate of 93.9 % . CONCLUSION Failures were associated with poor bone quality , smaller implant sizes , and a higher plaque index , and were more likely to occur before loading . A 4 % incidence of residual long-term inferior alveolar nerve paresthesia was higher than previously reported PURPOSE Bone resorption following tooth loss often limits the quantity of bone available for implant placement . The purpose of the present study was to evaluate the clinical outcome of 10-mm or shorter machined-surface implants when used exclusively in the treatment of various forms of edentulism . MATERIAL S AND METHODS Two hundred sixty-nine screw-type Brånemark System implants ( Nobel Biocare ) , 10 mm or shorter , were placed in 111 consecutively treated patients . Of the total , 88.8 % were placed in the m and ible and 11.2 % were placed in the maxilla ; 95.2 % were used to treat partially edentulous situations , including single-tooth losses , of which 96.6 % were in the premolar and molar regions . The patients were followed for periods of 12 to 92 months . RESULTS Of the 269 placed implants , 12 were lost . The overall survival rate was 95.5 % . Bone quality 2 and 3 ( Lekholm-Zarb classification of 1985 ) was found in 88.8 % of the treated sites . There was no statistical difference in the survival rate of the 10-mm implants when compared to the shorter series ( P > .05 ) or between the various implant diameters . The mean marginal bone loss was 0.71 + /- 0.65 mm . DISCUSSION The failure rate of 4.5 % compares favorably with that of implants of different shape , surface characteristics , and length . Bone quality appeared to be the critical factor in implant survival , rather than bone quantity , in this patient series . CONCLUSIONS This study supports the survival of short , machined-surface implants when used for the treatment of partial edentulism in bone of good quality BACKGROUND In cases of reduced alveolar bone height , implants of short length ( 10 mm or less ) may be employed although there is a perceived risk that because of their small stature they will be unable to tolerate occlusal loads and will fail to osseointegrate . PURPOSE This report describes an analysis of prospect i ve multicenter clinical studies evaluating the risk for failure of short-length implants , comparing dual acid-etched ( DAE ) Osseotite implants ( Implant Innovations , Inc. , Palm Beach Gardens , FL , USA ) to machined-surfaced implants . MATERIAL S AND METHODS Admission criteria were the same for both data sets . Baseline variables of demographics including age , gender and smoking status , bone quality , location , implant dimensions , and types of prostheses were compared to ensure balance among groups . Cumulative survival rates ( CSRs ) were calculated with the Kaplan-Meier estimator . RESULTS The implant data included 2294 implants for the DAE series and 2597 implants for the machined-surfaced series . Patient demographics showed similar percentages of occurrence for all variables . The distributions of implants between short- and st and ard-length data sets for baseline variables including width , location , and restorative type were similar , qualifying these data sets for comparison of the independent variable of length . Overall , there was a 2.2 % difference in 5-year CSRs between the machined-surfaced short- and the st and ard-length implants . For these implants a 7.1 % difference was observed in the posterior maxilla and an 8.5 % difference in the anterior maxilla . For DAE implants the overall difference between " st and ards " and " shorts " was 0.7 % , which is not statistically significant . CONCLUSION In this analysis the difference in CSRs between  short- and st and ard-length implants  was greater for machined-surfaced implants than for DAE implants Limited bone height restricts the use of long dental implants , so short implants may be selected in these situations . Recent reports on clinical results with short implants have been negative , however , and have suggested that indications for the use of these implants are limited . To verify these findings , a multicenter study of short ITI implants was carried out . In a 6-year period 253 short implants with a length of 6 mm were placed into 126 patients , who were followed up from 1 to 7 years . Altogether 7 implants were removed ; 6 of these were located in the maxilla and 1 in the m and ible . The quality of survival was comparable with the clinical results of longer implants from the same implant system . Although the clinical results of these short implants were favorable , it is recommended that they be used in combination with longer implants , especially when used in the less dense bone that is often seen in the maxilla One hundred and eight-seven ITI implants were prospect ively followed from November 1992 to July 2000 , in order to evaluate the clinical efficiency and the long-term prognosis in 109 partially edentulous patients ( 69 women and 40 men ; average age 41.3 years ) . Of these 187 implants , 69.5 % were placed in the m and ible and 30.5 % in the maxilla . After a healing period that ranged from three to six months , the osseointegrated implants ( n = 184 ) were restored with single crowns . Three implants were extracted prior to loading the fixture and were considered early failures . Each implant was reassessed on a yearly basis , both clinical ly and radiographically . The results of the investigation , which were evaluated according to predefined success criteria , were review ed in accordance with a life table method . During the follow-up , six cases were deemed to be late failures . In each of these cases , a suppurative infection of the peri-implant tissue was diagnosed : in one implant , the infection could not be eradicated and the implant was removed . When 11 drop-outs were included in the analysis , the cumulative survival and success rates for the whole sample group were 96.77 % and 93.6 % , respectively . When only prosthetically loaded implants were considered , the results increased to 99.35 % for the cumulative survival rate and 96.18 % for the cumulative success rate . The analysis on disaggregated data showed better results for maxillary restorations ( survival rate 100 % ) in comparison to m and ible restorations ( survival rate 95.11 % ) . It was concluded that , under st and ard anatomic conditions ( bone site height > 8 mm , thickness > 6 mm ) , prosthetic restoration of partially edentulous patients with the ITI system can be described as a reliable and efficient therapy in the long term The purpose of this study was to determine implant survival rates by means of life table analyses for a cohort of patients not part of a prospect i ve efficacy trial and treated by practitioners at varying experience levels . Prognostic variables associated with implant failure were identified by means of proportional hazards models and advanced statistical methods that account for patient effects . Ninety-nine consecutive patients treated from 1987 to 1991 with follow-up to 1994 were included in this retrospective study . A total of 384 dental implants ( 79.7 % Brånemark , 19.3 % IMZ plasma-sprayed , 1 % IMZ hydroxyapatite-coated )  were placed and subsequently supported 108 prostheses . Survival and proportional hazards modeling were used to generate Kaplan-Meier survival curves and to identify variables associated with implant failure . Survey data analysis was used to adjust for any patient effects for variables identified as significant through the proportional hazards models . Thirty-four implants failed over the follow-up period ( median follow-up time 3.6 years ) , result ing in an overall failure rate of 8.9 % . Seventeen of 99 patients experienced an implant failure . When prosthesis type was excluded from the modeling process , survey data analysis identified posterior location and an implant width of less than 4.0 mm as being associated with implant failure ( all P < .05 ) Forty-eight Endopore dental implants were placed in the posterior m and ibles of 24 partially edentulous patients . Seventeen of these implants replaced premolar teeth , while 31 replaced molars . Only 7-mm and 9-mm implants were used , and the majority of prosthetic restorations ( 83 % ) were single crowns . After a mean functional time of 32.6 months ( range , 8.2 to 50.3 months ) , the implant survival rate was 100 % and assessment of available radiographic data showed minimal to no crestal bone loss In this prospect i ve study , the clinical outcome of 2-months loaded implants placed in the posterior jaws was evaluated after up to 3 years of functional loading . 405 Osseotite implants  with microtextured acid-etched surface were consecutively placed in 11 fully and 164 partially edentulous patients ( mean age 53.5 + /- 15.3 ( S.D. ) years ) using a one-stage technique . 282 implants , supporting 154 restorations , were placed in the m and ible , while 123 implants , supporting 75 restorations , were placed in the maxilla . A total of 99 single-tooth restorations , 119 short-span fixed bridges and 11 full-arch prostheses were applied . The mean time interval from surgery to connection of provisional restoration was 2.0 + /- 0.7 months . 9 failures were reported up to 3 years of follow-up ; of these , 4 m and ibular and 2 maxillary implants  failed during the initial healing period ( before prosthesis connection ) , while 3 m and ibular implants failed after loading . No other complications occurred throughout the study . Life table analysis showed a cumulative survival rate of 97.5 % for the m and ible and 98.4 % for the maxilla . Post-loading implant survival rate was 98.9 % for the m and ible and 100 % for the maxilla . The excellent outcome of this interim report suggests that microtextured Osseotite implants in the posterior jaws may safely bear a functional load applied 2 months after insertion . The results of the present study are particularly encouraging for implants placed in the maxilla , since both a significant reduction of the healing period compared to the 6 months suggested by the classical Brånemark protocol , and an excellent post-loading function may be achieved also in low quality bone PURPOSE The use of implants for prosthetic rehabilitation of partially edentulous patients is increasing . However , the possibilities of placing implants in the posterior part of the m and ible are often limited . The purpose of this longitudinal study with 10 years of follow-up was to evaluate the use of short implants supporting fixed partial dentures ( FPD ) in the posterior part of the m and ible , and to compare implant supported FPDs to tooth-implant supported FPDs . MATERIAL S AND METHODS The patient material comprised 23 patients with residual m and ibular anterior teeth , and each patient received FPDs unilaterally . On one side the FPD was supported by two implants , and on the other side by one implant and one tooth , thus permitting intraindividual comparison . The distribution of the two types of FPDs in each jaw was r and omized . Implant success rates , marginal bone changes , and mechanical complications were studied . RESULTS The tooth-implant connection did not demonstrate any negative influences on the overall success rates for the 10-year period , nor were the shorter implants found to be less favorable . CONCLUSION It is suggested that a prosthetic construction supported by both a tooth and an implant may be recommended as a predictable and reliable treatment alternative in the posterior m and ible In the present multi-center study , non-submerged ITI implants were prospect ively followed to evaluate their long-term prognosis in fully and partially edentulous patients . In a total of 1003 patients , 2359 implants were consecutively inserted . Following a healing period of 3 - 6 months , the successfully integrated implants were restored with 393 removable and 758 fixed restorations . Subsequently , all consecutive implants were documented annually up to 8 years . At each examination , the clinical status of all implants was evaluated according to predefined criteria of success . Therefore , the data base allowed the evaluation of 8-year cumulative survival and success rates for 2359 implants . In addition , cumulative success rates were calculated for implant subgroups divided per implant type , implant length , and implant location . Furthermore , the actual 5-year survival and success rates could be determined for 488 implants . During the healing period , 13 implants did not successfully integrate , whereas 2346 implants fulfilled the predefined criteria of success . This corresponds with an early failure rate of 0.55 % . During follow-up , 19 implants were classified as failures due to several reasons . In addition , 17 implants ( approximately 0.8 % ) demonstrated at the last annual examination a suppurative periimplant infection . Including 127 drop out implants (= 5.4 % drop out rate ) into the calculation , the 8-year cumulative survival and success rates result ed in 96.7 % and 93.3 % , 
    Output:
    
There was a tendency toward higher failure rates for the maxilla and for dental implants with a machined surface compared with the m and ible and dental implants with a rough surface , respectively .
Among the risk factors examined , most failures of short implants can be attributed to poor bone quality in the maxilla and a machined surface .