***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: In a r and omized , controlled clinical trial , 110 edentulous patients with atrophic m and ibles were treated with International Team for Oral Implantology-dental implants using three different treatment strategies : a m and ibular overdenture supported by two implants with ball attachments , two implants with an interconnecting bar , or four interconnected implants . The patients ' opinions and their social functioning were evaluated by means of a question naire directly before and 16 months after treatment . Before treatment most patients had complaints about the retention of their m and ibular denture . Sixteen months after treatment almost all patients were generally satisfied with their dentures . Since no significant difference was found between the three treatment strategies , it was concluded that simple implant treatment such as an overdenture retained by two ball attachments is sufficient 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 A prospect i ve study on m and ibular implant-supported overdentures using more than 2 Brånemark implants splinted with multiple round bars evaluated a hypothesis that unnecessary prosthodontic maintenance would result from the contravention of accepted biomechanical principles . MATERIAL S AND METHODS A r and omized prospect i ve trial on 59 edentulous patients details prosthodontic maintenance and complications of 52 m and ibular overdentures ( 11 unsplinted , 41 splinted ) over a 3-year period . RESULTS Prosthodontic maintenance was greater in the first year than in subsequent years , regardless of design . Comparison between the splinted design s with round bars revealed no statistically significant difference with either retentive clip activation or fractures . More than 70 % of the retention clips in the 2-implant ( single round bar ) design needed activation , as compared to 44 % of those with the 3-implant ( double round bar ) or 4-implant ( triple round bar ) design . Retention clip fracture occurred in 30 % of patients with 3 or 4 implants and 16 % of those with 2 implants . Relining the overdentures , regardless of design , revealed an excessive maintenance burden in 40 % of overdentures . Remaking of overdentures was necessary in 21 % of patients . CONCLUSION Multiple round bars splinting 3 or 4 implants can still be a treatment concept in m and ibular overdenture treatment . Results from prospect i ve evaluation of this design indicate less prosthodontic maintenance of clip activation but more clip fractures than with 2 implants splinted with single round bars , although not at statistically significant levels 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 PURPOSE The aim of this study was to evaluate long-term marginal bone levels for two unsplinted implants supporting m and ibular overdentures using conventional and early loading protocol s with different implant surfaces and attachment systems . MATERIAL S AND METHODS A cohort of 106 edentulous participants ( mean age : 65 years ) was treated with m and ibular two-implant overdentures opposing complete maxillary dentures . Participants were r and omly allocated into three loading protocol groups using four implant systems ; single-stage surgery was performed for all participants , followed by an unsplinted prosthesis using six different attachment systems . St and ardized intraoral radiographs taken at baseline ( loading ) and over 10 years appraised marginal bone levels mesially and distally from reference points under magnification . Three calibrated examiners repeated measurements , diminishing intra- and interobserver variability . Progressive attrition of participants occurred as a result of deaths , dropouts , and emigration . Seventy-nine participants ( 74.5 % , mean age : 72 years ) were available at the 10-year recall . Differences in bone loss among different loading protocol s , implant surfaces , and attachment systems were tested using chi-square and one-way analysis of variance tests . RESULTS Minimal , time-dependent , long-term marginal bone loss occurred with all loading protocol s. Annual marginal bone loss progressed at low levels after the first year with episodes of bone loss and gain . There was stability in marginal bone levels over the long term , with the majority of remodeling occurring during the first year of function . Roughened implant surfaces may be beneficial during the early remodeling period . The amount of marginal bone loss in the first year of loading differed significantly by loading protocol and implant surface , whereas attachment system had a minor influence . Differences were not reflected in the success rates calculated using st and ard criteria . The remaining participants at 10 years were classified as successful related to the criterion of marginal bone loss , irrespective of the determining criteria for success . CONCLUSIONS Either a 2- , 6- , or 12-week loading protocol for m and ibular two-implant overdentures is possible in the long term , irrespective of the attachment system used . Minimal marginal bone loss may be attributed primarily to m and ibular basal bone remaining from long-term edentulism . Revision of the current implant success criteria to offer a stricter limit is desirable Prosthetic outcome and patient satisfaction were evaluated in order to investigate whether there is a need or advantage to splint two implants in the m and ible retaining a hinging overdenture . This study included 36 fully edentulous patients r and omly divided into three groups according to the attachment system they received : magnets , ball attachments or straight bars ( reference group ) . None of the implants failed during the whole observation period in any of the groups . After 5 years of observation , the Bar group presented the highest retention capacity and the least prosthetic complications but revealed more mucositis and gingival hyperplasia . Patient satisfaction rated similar for all groups although the Magnet group showed lower retention forces . All patients would repeat the same treatment even though the majority of the Magnet group would prefer a more retentive solution because of limited denture stability PURPOSE This clinical trial tested the null hypothesis that there would be no difference in prosthetic maintenance for two-implant m and ibular overdentures retained by either a bar-clip mechanism or ball attachments . Prosthetic outcomes are reported over 3 years using a six-field protocol . MATERIAL S AND METHODS One hundred edentulous participants received new maxillary complete dentures and a m and ibular two-implant overdenture ( IOD )  , with r and om assignment to either a bar and metal clip or two ball attachments ( titanium alloy matrix and spring ) for retention . Eighty-seven subjects were available for follow-up after 3 years . RESULTS Almost three times as many bar-clip dentures ( 63 % ) were rated successful compared to the ball attachment design . Two percent of the participants in each group died over the course of the study , while 15 % of the bar-clip and 8 % of the ball IOD subjects were lost to follow-up . More than three times as many ball attachment IODs ( 60 % ) required retreatment in the form of excessive repairs , and twice as many of the ball attachment design ( 8 % ) required replacement . The ball attachment IOD was significantly more likely to require patrix tightening or matrix replacement , while the bar-clip design was more likely to require activation of the matrix . CONCLUSION Using the criteria of a six-field protocol for implant overdenture outcomes , the bar-clip IOD was a significantly more successful prosthesis , requiring less maintenance than the titanium alloy matrix and spring ball attachment IOD employed in this study . The null hypothesis was therefore defeated OBJECTIVES Astra Tech implants have been used to provide implant supported overdentures for 25 people , 13 with paired stud retention , 10 with paired magnetic retention and two with magnetic retention on three fixtures . RESULTS The first case was completed in June 1990 and the last in May 1992 . Of the 52 fixtures which were used initially , one became loose after 6 months and one fractured after 12 months . Healing following Stage I surgery was classified as good for 14 people , moderate for eight and poor for three . Healing following Stage II surgery was problem-free in 14 people , with problems encountered in 11 people in six of whom the problem was caused by selecting healing abutments which were too short . There were 58 events of post-insertion care for the magnet group , which result ed in 104 visits and 60 events of post-insertion care for the stud group , which result ed in 89 visits . The need for post-insertion care was greatest during the first year with the magnet group having 33 events and the stud group 36 events . Twenty four of the participants rated treatment success as good and one as moderate . CONCLUSIONS Implant supported overdentures in the m and ible using two isolated abutments are a successful treatment option by they can be dem and ing in continuing care PURPOSE This study aim ed to compare the prosthetic aspects and patient satisfaction with prosthetic care in two-implant-retained m and ibular overdentures , whether implants were splinted with a bar or left with magnets or ball attachments . MATERIAL S AND METHODS Thirty-six completely edentulous patients had two Brånemark implants placed in the m and ibular canine area . A r and omized procedure allocated patients into three groups of equal size , each with a different attachment system : bars , magnets , or balls .  Prosthesis retention and mechanical as well as soft tissue complications were recorded in addition to patient satisfaction . A linear mixed model was fitted with attachment type and time as classification variables and adjusted by Turkey 's multiple range test . RESULTS Ball-retained overdentures showed at year 10 the greatest vertical retention force ( 1,327 g ) , followed by bars ( 1,067 g ) and magnets ( 219 g ) . In the ball group , need for tightening of abutment screws was the most common mechanical complication ; in the magnet and bar groups , respectively , the most common complications were wear and corrosion , and the need for clip activation . Prosthesis stability and chewing comfort for the overdenture were rated significantly lower for the magnet group compared to the ball and bar groups . Prosthesis stability of the maxillary denture was rated significantly lower in the bar group compared to ball and magnet groups . CONCLUSION The ball group scored best in relation to retention of the overdenture , soft tissue complications , and patient satisfaction at year 10 . The bar group scored lower for comfort and stability of the maxillary denture . Magnets offered patients the least comfort PURPOSE The aim of this research was to determine the long-term prosthodontic maintenance requirements of m and ibular two-implant overdentures using different loading protocol s and attachment systems . MATERIAL S AND METHODS A total of 106 participants were allocated r and omly to one of  four  different implant systems ( Steri-Oss , Southern , Straumann , or Branemark ) . Three different loading protocol s ( 2 , 6 , and 12 weeks ) were used with six different ball abutment patrices and their respective matrices ( Steri-Oss rubber , Straumann gold , 
    Output:
    
Prosthetic maintenance and complications most commonly occurred in the magnet groups .
Conflicting findings were found on the rate of prosthetic maintenance and complications comparing ball and bar attachments .
Most studies showed no significant differences in patient satisfaction depending upon attachment systems .
The implant survival rate of m and ibular overdentures seemed to be high regardless attachment systems .
The prosthetic maintenance and complications may be influenced by attachment systems .
However patient satisfaction may be independent of the attachment system