***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 McGill consensus statement on overdentures ( 14 ) was published following a symposium held at McGill University in Montreal , Canada in 2002 . A panel of relevant experts in the field stated that : The evidence currently available suggests that the restoration of the edentulous m and ible with a conventional denture is no longer the most appropriate first choice prosthodontic treatment . There is now overwhelming evidence that a two-implant overdenture should become the first choice of treatment for the edentulous m and ible ( 14 ) . In 2009 , a further consensus statement was released as a support and follow-up to the McGill consensus statement . This report was jointly created by members of the BSSPD ( British Society for the Study of Prosthetic Dentistry ) Council and the panel of presenters at the BSSPD conference in York , UK in April 2009 ( 15 ) . This report also highlighted that since the McGill statement in 2002 , uptake by dentists of implant technology for complete denture wearers has been slow . The York statement concluded that ' a substantial body of evidence is now available demonstrating that patients ' satisfaction and quality of life with ISOD m and ibular overdentures is significantly greater than for conventional dentures . Much of this data comes from r and omised controlled trials ( 15 ) . Whilst it is accepted that the two-implant overdenture is not the gold st and ard of implant therapy it is the minimum st and ard that should be sufficient for most people , taking into account performance , patient satisfaction , cost and clinical time PURPOSE This r and omized clinical trial tested hypotheses that there are no differences in patient satisfaction , component costs , or treatment and maintenance times when m and ibular overdentures are retained by one or two implants . MATERIAL S AND METHODS Subjects wearing conventional complete dentures were r and omized to receive either one midline or two bilateral m and ibular implants followed by a m and ibular denture reline to incorporate implant retention . They indicated on a visual analog scale satisfaction with their dentures before implants and at 2 months and 1 year after implant retention . Satisfaction outcomes between the two groups were compared using the Wilcoxon/Mann-Whitney nonparametric rank test , while changes within each group were analyzed using signed-rank tests . Component costs and times for surgery , prosthodontic treatment , and maintenance were compared using nonparametric and t tests . RESULTS Eighty-six subjects enrolled in this study and 85 completed the 1-year follow-up , at which median satisfaction was 93 ( maximum 100 ) in the single-implant group and 94 in the two-implant group ( P > .5 ) . Within each group , median improvement in satisfaction was similarly dramatic ( approximately 44 ) and significant ( P < .001 ) . Prosthodontic maintenance time was similar for both groups ( P > .37 ) , but the single-implant group had significantly lower component costs ( P < .001 ) and lower times for surgery ( P = .002 ) , postsurgical denture maintenance ( P = .021 ) , and denture reline ( P < .001 ) . Five implants failed in four subjects , all in the two-implant group and all before denture reline . CONCLUSION Lower component costs and treatment times , with comparable satisfaction and maintenance time over the first year , indicate that a m and ibular overdenture retained by a single midline implant may be an alternative to the customary two-implant overdenture for maladaptive denture patients Although it has been shown that patients are more satisfied with prostheses supported by implants than with conventional dentures , there have been few direct comparisons of the various design s of implant-supported prostheses . This within-subject crossover clinical trial was design ed to compare two forms of removable prostheses which are frequently prescribed for the edentulous m and ible : a long-bar overdenture supported by 4 implants and a two-implant hybrid overdenture .  Sixteen completely edentulous subjects were given a new maxillary conventional denture : Ten of them received the m and ibular long-bar prosthesis first and six the hybrid . After a two-month adaptation period , psychometric measures of various aspects of the prostheses and physiological tests of masticatory efficiency were carried out over three weeks . The m and ibular prostheses were then changed and the procedures repeated . At the end of the study , subjects were asked to choose the m and ibular prosthesis that they wished to keep , and final psychometric measures were taken . In this paper , the results of the psychometric assessment and patient preference are presented . Subjects assessed factors such as general satisfaction , quality of life , stability , retention , comfort , esthetics , ease of cleaning , speaking , and chewing , and how well-chewed foods were before being swallowed . Most of the factors except ease of cleaning and speaking were rated significantly better with long-bar overdentures than with hybrid ones . These results are consistent with the fact that all subjects chose long-bar overdentures , reporting stability , ease of chewing , and comfort as the most important factors influencing their choice . These results suggest that , although subjects assign high ratings for most factors to hybrid overdentures , they find long-bar overdentures to be significantly more stable , comfortable , and easier for chewing In a r and omized controlled clinical trial carried out at the Ignatius teaching hospital in Breda , The Netherl and s , 110 edentulous patients with severe m and ibular bone loss were treated with implants of the ITI Dental Implant System using 3 different treatment strategies : a m and ibular overdenture supported by either 2 implants with ball attachments , 2 implants with an interconnecting bar , or by 4 interconnected implants . In this study , results of clinical and radiographic parameters were evaluated and compared over a period of 19 months after implant placement . A total of 283 ITI Dental Implants were placed . Six implants ( 2 % ) were lost during the osseointegration period . No further implant losses occurred after that . At the 19 month evaluation mean values and st and ard deviations for bleeding index were 0.51 + /- 0.5 ( bleeding incidence = 70 % ) and for plaque index they were 0.46 + /- 0.5 ( plaque incidence = 45 % ) . The mean values and st and ard deviations for probing depth and loss of attachment were 2.7 + /- 1.1 mm and 0.26 + /- 0.6 mm respectively . The radiographic evaluation showed a mean bone loss of 1.5 mm + /- 0.26 after 19 months for all the implants . In cases with 4 interconnected implants there was significantly more bone loss around the central 2 implants ( 2.1 + /- 0.31 mm ) in comparison with the lateral 2 ( 1.4 + /- 0.25 mm ) . No significant correlations were found between plaque and bleeding indices and bone loss PURPOSE The aim of the study was to compare the differences in the long-term clinical and radiologic effects for three different treatment strategies with implant-supported overdentures in the edentulous m and ible , with a special emphasis on smoking . MATERIAL S AND METHODS In a r and omized- controlled clinical trial , 110 edentulous patients participated . Thirty-six patients were treated with an overdenture supported by two implants with ball attachments ( 2IBA ) , 37 patients with an overdenture supported by two implants with a bar ( 2ISB ) and 37 patients with an overdenture supported by four implants with a triple bar ( 4ITB ) . After a mean evaluation period of 8.3 years , the clinical and radiographic parameters were evaluated . RESULTS Ninety-four out of the original 110 patients ( = 85 % ) were evaluated . In the 2IBA group , the plaque index was significantly lower ( vs. 2ISB , P=0.013 ; vs. 4ITB , P=0.001 ) than in the other groups , but there was no correlation with the other peri-implant parameters . In the 4ITB group , the marginal bone loss was significantly higher than that in the two implant groups . The maximal probing depth was correlated with peri-implant bone loss ( P=0.011 ) . Smoking almost doubled marginal bone loss irrespective of the treatment strategy chosen . CONCLUSIONS Patients with two implants show less marginal bone loss than those with four implants . Smoking is a risk factor for the survival of dental implants in the long run PURPOSE This r and omized controlled clinical trial aim ed to evaluate the efficacy of splinted implants versus unsplinted implants in overdenture therapy over a 10-year period . MATERIAL S AND METHODS The study sample comprised 36 completely edentulous patients , 17 men and 19 women ( mean age 63.7 years ) . In each patient , 2 implants ( Brånemark System , Nobel Biocare , Göteborg , Sweden ) were placed in the interforaminal area . Three to 5 months after placement , they were connected to st and ard abutments . The patients were then rehabilitated with ball-retained overdentures , magnet-retained overdentures , or bar-retained overdentures ( the control group ) . Patients were followed for 4 , 12 , 60 , and 120 months post-abutment connection . Group means as well as linear regression models were fitted with attachment type and time as classification variables and corrected for simultaneous testing ( Tukey ) . RESULTS After 10 years , 9 patients had died and 1 was severely ill . Over 10 years , no implants failed . Mean Plaque Index , Bleeding Index , change in attachment level , Periotest values , and marginal bone level at the end of the follow-up period were not significantly different among the groups . DISCUSSION The annual marginal bone loss , excluding the first months of remodeling , was comparable with that found around healthy natural teeth . CONCLUSION The fact that no implants failed and that overall marginal bone loss after the first year of bone remodeling was limited suggested that implants in a 2-implant m and ibular overdenture concept have an excellent prognosis in this patient population , irrespective of the attachment system used Objectives : The objective of this clinical study was to evaluate the prosthetic complications of patients with 2 to 4 implants splinted with a round bar or with 2 to 4 unsplinted implants with ball attachments during the follow-up period . Methods : A total of 26 patients were included in this study . Patients were r and omly provided with a round bar or with ball attachments that were used to retain overdentures . During follow-up visits , the following prosthetic complications were recorded : round bar fracture , fractured overdenture , hygiene complications , abutment screw loose , worn O-ring or replacement of O-ring attachment , and fractured retention clip . The functioning period of overdentures in the round bar group ranged from 12 to 72 months ( mean 49 ) , and from 12 to 40 months ( mean 23 ) in the ball attachment group . Results : A total of 20 prosthetic complications were recorded in both groups . No differences in prosthetic complications were observed for 2 attachment systems . Conclusion : Implant-supported overdentures with bar or ball attachments may be considered to be reliable methods in the treatment of the edentulous individuals PURPOSE The present study evaluated implant and peri-implant outcomes as well as prosthodontic  maintenance efforts for implant/bar-supported m and ibular prostheses with different prosthesis anchorage systems . MATERIAL S AND METHODS Seventy-six patients who received two or four interforaminal implants  were assigned to one of three different bar design s and subsequently to different prosthesis supporting systems . Forty-nine patients received implants and a mucosa-supported implant-retained overdenture ( OD ) with an ovoid bar ( two implants ; design 1 ) or multiple ovoid bars ( four implants ; design 2 ) . Twenty-seven patients received four implants and a rigid implant-supported prosthesis ( ISP ) with a milled bar ( design 3 ) . Implant survival , peri-implant parameters ( marginal bone resorption , pocket depth , and plaque , bleeding , gingival , and calculus indices ) , and postinsertion prosthodontic maintenance were followed over a 5-year period and compared among the different retention modalities . At the most recent follow-up examination , subjective patient satisfaction was additionally evaluated using a simplified scoring system ( ranging from 1 = not satisfactory to 5 = excellent ) . RESULTS Implant survival rates ( 100 % ) and all peri-implant parameters evaluated showed no differences among the three design s used for implant prosthesis anchorage . Prosthodontic maintenance did not differ between the different ODs ( OD design 1 : average of 1.04 maintenance visits/year/patient ; OD design 2 : 1.2 maintenance visits/year/patient ) , but it was significantly lower for the dentures that were rigidly stabilized with milled bars ( ISP : 0.37 maintenance visits/year/patient ) . A high subjective satisfaction rate ( range : 4.5 to 5.0 ) was registered at the final examination , without any differences among the design s used . CONCLUSIONS Rigid anchorage with milled bars on four-implant prostheses combined with a metal-reinforced framework showed a lower extent of prosthodontic maintenance issues than round bars on two- or four-implant overdentures with resilient denture stabilization . Nevertheless , implants and peri-implant structures were not negatively affected by either resilient or rigid anchorage mechanisms STATEMENT OF PROBLEM M and ibular  implant overdentures  provide improved treatment outcome than conventional denture therapy , but there is controversy as to which overdenture treatment is the best choice . PURPOSE This study evaluated 3 different m and ibular implant overdenture treatments with respect to prosthesis retention and stability , tissue response , patient satisfaction and preference , and complications to determine treatment outcomes . MATERIAL AND METHODS In a prospect i ve , r and omized clinical trial , using a cros 
    Output:
    
For the m and ible , it can not be concluded that bone loss , patient satisfaction , or number of complications is significantly related to the number of implants supporting the overdenture .
Furthermore , splinting two implants does not seem to offer additional value .