***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 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 The hypothesis of this 5-y r and omized clinical trial was that there would be no significant difference in the satisfaction of edentulous participants with removable complete overdentures attached to 1 or 2 m and ibular implants .  Secondary aims were to test changes in satisfaction between and within the groups from baseline to 5 y and differences between the groups in implant survival and prosthodontic maintenance over 5 y. Each of the 86 participants ( mean age , 67 y ) was r and omly allocated to receive either 1 implant in the midline ( group 1 ) or 2 implants in the canine areas ( group 2 ) attached to a m and ibular overdenture opposing a maxillary complete denture . Satisfaction was self-assessed by participants on a visual analog scale at baseline prior to implants , as well as at 2 mo and 1 , 3 , and 5 y with implant overdentures , whereas implant survival and prosthodontic maintenance were assessed by clinical examination . After 5 y , 29 participants in group 1 and 33 in group 2 were available , with most dropouts due to death . Satisfaction with the implant denture after 5 y was significantly ( P < 0.001 ) higher than at baseline in both groups and remained with no significant difference ( P = 0.32 ) between the groups . No implants failed in group 1 but 5 failed before loading in 4 participants in group 2 . Most participants required maintenance or occasionally denture replacement , and although differences between the groups were not statistically significant , group 1 experienced almost twice as many fractured dentures usually adjacent to the implant attachment . We conclude that there were no significant differences after 5 y in satisfaction or survival of implants with m and ibular overdentures retained by 1 implant or 2 implants . Additional research is required to confirm long-term treatment effectiveness of single-implant dentures and the implication s of prosthetic maintenance with implant overdentures ( Clinical Trials.gov : NCT02117856 ) PURPOSE The aim of this systematic review is to address treatment outcomes of M and ibular implant overdentures relative to implant survival rate , maintenance and complications , and patient satisfaction . MATERIAL S AND METHODS A systematic literature search was conducted by a PubMed search strategy and h and - search ing of relevant journals from included studies . R and omized  Clinical  Trials ( RCT ) and comparative clinical trial studies on m and ibular implant overdentures until August , 2010 were selected . Eleven studies from 1098 studies were finally selected and data were analyzed relative to number of implants . RESULTS Six studies presented the data of the implant survival rate which ranged from 95 % to 100 % for 2 and 4 implant group and from 81.8 % to 96.1 % for 1 and 2 implant group . One study , which statistically compared implant survival rate showed no significant differences relative to the number of implants . The most common type of prosthetic maintenance and complications were replacement or reattaching of loose clips for 2 and 4 implant group , and denture repair due to the fracture around an implant for 1 and 2 implant groups . Most studies showed no significant differences in the rate of prosthetic maintenance and complication , and patient satisfaction regardless the number of implants . CONCLUSION The implant survival rate of m and ibular overdentures is high regardless of the number of implants . Denture maintenance is likely not inflenced substantially by the number of implants and patient satisfaction is typically high again regardless os the number of implants PURPOSE The purpose of this study was to determine the prosthodontic outcomes of one-piece zirconia implants and their attachment systems in edentulous participants with maxillary and m and ibular overdentures after 1 year of a r and omized controlled trial . MATERIAL S AND METHODS R and om allocation of 24 edentulous participants ( age range : 45 to 86 years ) into titanium ( control ) or zirconia ( test ) groups using onepiece implants and a planned unsplinted prosthodontic design was performed . Four maxillary implants ( one midpalatal ; three anterior crestal ) and three m and ibular implants ( one midsymphyseal ; two bilateral distal ) were conventionally loaded with the overdentures . Similar attachment systems were used throughout : ball abutment-type patrices ( diameter : 2.25 to 3.1 mm as part of the one-piece implants ) and custommade plastic matrices ( with or without metal housings depending on the patrix size ) . Prosthodontic outcomes were documented during the first year of the clinical trial . RESULTS Following three deaths and two dropouts , there were 19 participants who were available at the 1-year recall . Of these participants , 3 had early maxillary implant failure  and had to be converted to conventional maxillary complete dentures opposing m and ibular implant overdentures . There were 79 maintenance events , 34 in the titanium ( control ) group and 45 in the zirconia ( test ) group . Patrix loss occurred as a result of three zirconia implant fractures ( one m and ibular and two crestal maxillary implants ) . Maintenance events were principally the replacement of matrices and overdenture fracture . Although relines and replacement overdentures also occurred , overall there were no significant differences in prosthodontic maintenance between the control and test groups . A six-field prosthodontic-success analysis table showed no statistically significant difference between the two groups ; however , 50 % of participants in each group were allocated to the retreatment ( repair ) field , which produced a low prosthodontic success rate . CONCLUSIONS Removable overdentures can be used on both one-piece titanium and zirconia implants with these attachment systems , due to no difference in prosthodontic maintenance and success . Before recommending routine use of a " metal-free " overdenture treatment option in clinical practice , consideration must be given to the success of the implants themselves OBJECTIVE The aim of this long-term study was to compare the need for prosthetic aftercare of direct vs. indirect attachment incorporation techniques to m and ibular implant-supported overdenture . MATERIAL S AND METHODS Forty-five consecutive patients were included ( 130 implants were placed ) . Treatment was r and omly allocated , result ing in 22 patients ( group A ) to be treated with direct ball attachment incorporation and 23 patients ( group B ) to be treated with indirect ball attachment incorporation .  All patients were treated by experienced oral-maxillofacial surgeons/periodontists and experienced prosthodontists/residents . From the first day that the patients visited the clinic up to 20 years after the first treatment session , all surgical or prosthetic therapeutic interventions were recorded . The recorded data for the present study included the number of aftercare visits and dental treatment received ( pressure sores relieve , liner changes due to loss of retention and attachment replacement due to wear ) . RESULTS The mean follow-up was 93±57 months . No implants were lost . Statistical analysis revealed a statistically significantly ( P<0.001 ) greater need for prosthetic interventions in group B vs. group A. The mean number of visits dedicated to - pressure sores relieve ( 7.04±1.4 vs. 3.63±0.84 ) ; liner exchange due to loss of retention ( 3.6±1.3 vs. 1.09±1.06 ) was significantly higher in group B. Attachment replacement due to wear occurred only in group B ( 11/23 - 47.8 % ) . CONCLUSION The direct technique for attachment incorporation in m and ibular implant-supported overdentures using ball attachments is superior to the indirect technique from the aftercare perspective during a long-term evaluation period The CONSORT ( Consoli date d St and ards of Reporting Trials ) statement is used worldwide to improve the reporting of r and omized , controlled trials . Schulz and colleagues describe the latest version , CONSORT 2010 , which up date s the reporting guideline based on new method ological evidence and accumulating experience . 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 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 Few long-term studies on overdentures report both implant and prosthodontic outcomes . The aim of this prospect i ve study was to report long-term prosthodontic- and implant-related treatment outcomes of patients treated with design -specific implant-supported overdentures .  MATERIAL S AND METHODS Between 1982 and 1992 , 45 consecutively treated patients received a total of 47 overdentures ( 42 m and ibular and 5 maxillary ) supported by Brånemark implants .  Prospect i ve clinical and radiographic data were collected over the observation period ; this study presents the most recent treatment outcomes . RESULTS Thirty patients ( mean age 70 years ) with 32 prostheses attended the final recall visit , with 67 % of patients followed for 15.53 years ( range 10 to 19 years ) . Six implants failed , and the prosthetic plan and implant cumulative survival rates were both in excess of 90 % . Mean marginal bone loss around implants after the first year of loading was 
    Output:
    
These articles provided evidence that a mean complication rate was impossible to determine because of the multiplicity of contributing factors .
No clear identification of the causes of mechanical complications was found , nor was there any clear evidence of superiority of one implant and /or attachment design over another .
Prosthetic complications with IODs are unavoidable .
However , they can be reduced to an expected level if a close follow‐up protocol is implemented aim ing at anticipating risks of unexpected complications .