***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: OBJECTIVES the aim of this r and omized-controlled clinical trial was to compare the objective and subjective esthetic outcomes of two types of  screwed-retained single-implant crowns .  MATERIAL S AND METHODS participants were r and omly assigned to the test ( all-ceramic ) and control [ porcelain-fused-to-ceramic ( PFM ) ] groups and were seen under investigation at baseline ( B ) , crown insertion ( CI ) , 1-year follow-up ( 1Y ) , and 2-year follow-up ( 2Y ) . Objective parameters were assessed by an intra-oral digital photograph ( 1:1 ratio ) , a study cast , a st and ardized radiograph , periodontal/peri-implant measurements , and question naires were obtained for the subjective parameters . In addition , pink esthetic score ( PES ) and white esthetic score ( WES ) were calculated for both groups . For the subjective evaluation , a visual analogue scale ( VAS ) question naire was used to assess the level of patient satisfaction regarding the esthetic outcome . Then , nine expert clinicians visually inspected and assessed subjective evaluation at the professional level . Statistical analysis was used to compare between groups and investigational appointments . RESULTS twenty patients were included in the study , 10 allocated to the all-ceramic group and 10 to the PFM group . No statistically significant differences were observed for the objective measurements comparing the test and control groups . Minor chipping of the ceramic veneering material was observed in the two patients of control group . The mean difference for all groups comparing objective parameters revealed an increase of papilla height between time points . A slight recession ( 0.26 mm ) of the peri-implant mucosal margin at the implant site was observed between 1Y and 2Y . Mean values for PES and WES were 13.9 and 13.1 for the PFM group and for the all-ceramic group , respectively . These values were not statistically significant . Implant crown volume , outline , translucency , and characterization showed major discrepancies with the contra-lateral natural teeth . As for subjective parameters , VAS patients ' responses regarding their perceptions of the esthetic outcome showed no statistical differences between groups and clinicians ' accuracy scores were 50 % and 47 % for PFM and all-ceramic crowns , respectively . CONCLUSION PFM and all-ceramic single-implant restorations may be indistinguishable from each other regarding the objective /subjective assessment of esthetic integration . The material chosen for fabricating an implant crown per se does not ensure an optimal esthetic outcome if other esthetic parameters are not present OBJECTIVE The aim of this uncontrolled prospect i ve multicenter study was to determine the success and survival rate of posterior single crowns composed of zirconia frameworks h and -layered with a leucite-reinforced feldspathic ceramic supported by one-piece zirconia oral implants . MATERIAL AND METHODS In two centers , sixty patients received 71 zirconia oral implants .  To obtain a clear indication of posterior implant-supported single crowns ( ISSCs ) , 14 patients ( 25 implants ) were excluded from the analysis ( 11 bridges , three anterior crowns ) . The remaining patients were provided with single implants in posterior regions . As one patient lost his implant and another refused further participation after final prosthesis insertion , 44 ISSCs/ patients ( 19 females , 25 males ) were available for evaluation . Of these patients , all were seen at prosthetic delivery and the 6- and 12-month follow-up appointments . Evaluations were performed using modified United States Public Health Service ( USPHS ) criteria . Restorations within Alpha and Bravo ratings were regarded as success . This included minor chippings , a slight roughness , slightly soundable restoration margins and minimal contour deficiencies . In case of more distinct defects that could , however , be repaired to a clinical ly acceptable level , restorations were regarded as surviving . Kaplan-Meier plots and log-rank tests were used for the success/survival analyses and the calculation of potential group differences ( gender , jaw and center ) . RESULTS After a mean observation period of 12.5 months ( SD : 0.8 months ) , no ISSC had to be replaced , result ing in a Kaplan-Meier survival rate of 100 % . The Kaplan-Meier success rate was 90.9 % ( one major chipping , one obvious roughness , one significant crevice and one pronounced over-contouring ) . Minor chippings and occlusal roughness were frequent complications . No significantly different survival/success rates could be observed between the mentioned groups . CONCLUSION The frequent incidence of minor chippings suggests a high technique sensitivity when providing zirconia implants with veneered zirconia-based crowns question ing its suitability for this indication OBJECTIVES To prospect ively evaluate the clinical long-term outcome of  tooth-supported crowns ( SCs ) , implant-supported crowns ( ISCs ) , and fixed dental prostheses ( FDPs )  made of a lithium-disilicate glass-ceramic framework material ( IPS Empress 2 ) . MATERIAL S AND METHODS Between 1997 and 1999 , a total of 184 restorations ( 106 SCs , 32 ISCs , 33 FDPs , and 13 diverse restorations ) were placed in 73 patients .  Kaplan-Meier estimation was applied for survival and chipping-free rates . Inter-group comparison of both rates was realized by a log rank test and a 2 × 2 contingency table . Also , SCs and FDPs were compared regarding adhesive vs. conventional cementation , and anterior vs. posterior positioning , for impact on survival . RESULTS Due to 14 dropouts ( 34 restorations ) and reasonable exclusion of 19 other restorations , the final data set included : i ) 87 SCs [ 37 patients , mean observation time 11.4 (±3.8)years ] ; ii ) 17 ISCs [ 12 patients , mean observation time 13.3 (±2.3)years ; and iii ) 27 FDPs [ 19 patients , mean observation time 8.9 (±5.4)years ] . The 10-year survival rate/chipping-free rate for SCs were 86.1%/83.4 % , for ISCs 93.8%/94.1 % , and for FDPs were 51.9%/90.8 % . Both ISCs and SCs had a significantly higher survival than FDPs ( ISCs vs. FDPs : both tests p=0.001 ; SCs vs. FDPs : p=0.001 and p=0.005 ) . Differences in the chipping-free rates did not reach significance . Also , neither the cementation mode nor positioning of the restoration had an impact on survival . CONCLUSIONS SCs had a slightly lower outcome than can generally be expected from single crowns . In contrast , ICSs had a favorable outcome and the FDPs predominantly failed . CLINICAL SIGNIFICANCE The practitioner 's choice of dental material s is based ( at best ) on long-term experience . The present 10-year results are based on comprehensive data analyses and show the high potential of lithium-disilicate as a reliable material , especially for single-unit restoration In aesthetic sites , the integrity of the facial bone wall dimension in the anterior maxilla is jeopardized by physiologic and structural changes post extraction . An effective regenerative protocol is key to reestablish and maintain the hard and soft tissue dimensions over time . The present prospect i ve case series study examined the effectiveness of early implant placement with simultaneous contour augmentation through guided bone regeneration with a 2-layer composite graft in post extraction single-tooth sites over an observation period of 10 y among 20 patients . The median peri-implant bone loss was 0.35 mm between the 1- and 10-y examination . A success rate of 95 % was obtained , with pleasing aesthetic outcomes and a high median Pink Esthetic Score ( 8) . Implant crowns ( ICs ) revealed significant median facial recession between IC10y and IC1y ( 0.17 mm ) . The facial bone wall dimensions were assessed by preoperative cone beam computed tomography and 2 subsequent scans taken at 6 and 10 y. The median facial bone wall thickness increased significantly from 0 mm at surgery to 1.67 mm at the 10-y examination . The facial vertical bone wall peak ( DIC ) was located at a median distance of 0.16 mm coronal to the implant shoulder . The facial vertical bone loss of DIC amounted to 0.02 mm between 6 and 10 y. Equivalence testing was performed for the null hypothesis of a difference of > 0.2 mm per year between 2 respective time points , showing stable bone conditions . Modulating factors influencing the regenerative outcomes at 10 y were the preoperative proximal crest width and soft tissue thickness . In conclusion , the present study confirmed the long-term effectiveness of early implant placement with simultaneous contour augmentation through guided bone regeneration with a 2-layer composite graft in post extraction single-tooth sites offering stable bone conditions with low risks of mucosal recessions over an observation period of 10 y ( Clinical Trials.gov NCT03252106 ) Patients ’ esthetic expectations are increasing , and the options of the prosthetic pathways are currently evolving . The objective of this r and omized multicenter clinical trial was to assess and compare the esthetic outcome and clinical performance of anterior maxillary all-ceramic implant crowns ( ICs ) based either on prefabricated zirconia abutments veneered with pressed ceramics or on CAD/CAM zirconia abutments veneered with h and buildup technique . The null hypothesis was that there is no statistically significant difference between the 2 groups . Forty implants were inserted in sites 14 to 24 ( FDI ) in 40 patients in 2 centers , the Universities of Bern and Geneva , Switzerl and . After final impression , 20 patients were r and omized into group A , restored with a 1-piece screw-retained single crown made of a prefabricated zirconia abutment with pressed ceramic as the veneering material using the cut-back technique , or group B using an individualized CAD/CAM zirconia abutment ( CARES abutment ; Institut Straumann AG ) with a h and buildup technique . At baseline , 6 mo , and 1 y clinical , esthetic and radiographic parameters were assessed . Group A exhibited 1 dropout patient and 1 failure , result ing in a survival rate of 94.7 % after 1 y , in comparison to 100 % for group B. No other complications occurred . Clinical parameters presented stable and healthy peri-implant soft tissues . Overall , no or only minimal crestal bone changes were observed with a mean DIB ( distance from the implant shoulder to the first bone-to-implant contact ) of −0.15 mm ( group A ) and 0.12 mm ( group B ) at 1 y. There were no significant differences at baseline , 6 mo , and 1 y for DIB values between the 2 groups . Pink esthetic score ( PES ) and white esthetic score ( WES ) values at all 3 examinations indicated stability over time for both groups and pleasing esthetic outcomes . Both implant-supported prosthetic pathways represent a valuable treatment option for the restoration of single ICs in the anterior maxilla ( Clinical Trials.gov NCT02905838 ) Background Supporting 21st century health care and the practice of evidence -based medicine ( EBM ) requires ubiquitous access to clinical information and to knowledge-based re sources to answer clinical questions . Many questions go unanswered , however , due to lack of skills in formulating questions , crafting effective search strategies , and accessing data bases to identify best levels of evidence . Methods This r and omized trial was design ed as a pilot study to measure the relevancy of search results using three different interfaces for the PubMed search system . Two of the search interfaces utilized a specific framework called PICO , which was design ed to focus clinical questions and to prompt for publication type or type of question asked . The third interface was the st and ard PubMed interface readily available on the Web . Study subjects were recruited from interns and residents on an inpatient general medicine rotation at an academic medical center in the US . Thirty-one subjects were r and omized to one of the three interfaces , given 3 clinical questions , and asked to search PubMed for a set of relevant articles that would provide an answer for each question . The success of the search results was determined by a precision score , which compared the number of relevant or gold st and ard articles retrieved in a result set to the total number of articles retrieved in that set . Results Participants using the PICO templates ( Protocol A or Protocol B ) had higher precision scores for each question than the participants who used Protocol C , the st and ard PubMed Web interface . ( Question 1 : A = 35 % , B = 28 % , C = 20 % ; Question 2 : A = 5 % , B = 6 % , C = 4 % ; Question 3 : A = 1 % , B = 0 % , C = 0 % ) 95 % confidence intervals were calculated for the precision for each question using a lower boundary of zero . However , the 95 % confidence limits were overlapping , suggesting no statistical difference between the groups . Conclusion Due to the small number of search es for each arm , this pilot study could not demonstrate a statistically significant difference between the search protocol s. However there was a trend towards higher precision that needs to be investigated in a larger study to determine if PICO can improve the relevancy of search results BACKGROUND New dental material s are introduced and promoted in the field without extensive clinical testing . Using those material s in a clinical setting might result in unacceptable early failure rates . PURPOSE The purpose of this paper was to 
    Output:
    
CONCLUSIONS All-ceramic implant-supported SCs showed-with the exception of a RNC material -high survival rates .