***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: 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 ) OBJECTIVE The purpose of this prospect i ve , r and omized , controlled , multicenter clinical study was to analyze the optical effects of an anodized pink colored implant shoulder/abutment system in the peri-implant mucosa of immediately placed dental implants . MATERIAL S AND METHOD Forty subjects with a restoratively hopeless tooth in the maxillary esthetic zone , were recruited and r and omized to receive either a pink-neck implant , or a conventional gray implant . All patients received an immediate implant and immediate provisional and two identical CAD/CAM titanium abutments with different surface colors : pink and gray , and one zirconia all-ceramic crown . The color of the peri-implant mucosa was measured using a dental spectrophotometer and analyzed using CIELAB color system . RESULTS The overall color difference between the peri-implant mucosa with a pink abutment and a gray abutment was ΔE = 4.22 . Patients with gray implants presented a color change of ΔE = 3.86 - 4.17 with this abutment change , while patients with pink implants had a color change of ΔE = 3.84 - 4.69 . The peri-implant mucosa with a pink abutment was significantly more red when compared with a gray abutment ( P ≤ .01 ) . CONCLUSIONS When a pink abutment was used , there is a significant color change of the peri-implant mucosa that is above the detectable color threshold . CLINICAL SIGNIFICANCE Esthetic outcomes are important for the success of implant treatment of maxillary anterior implants . The phenomenon of the gray color of a dental implant and abutment shining through the peri-implant mucosa has been documented in the literature . The objective of this study was to assess the optical effect of an anodized pink-neck implant and a pink abutment on the color of peri-implant mucosa . This study demonstrates that using pink-neck implant and a pink abutment would contribute positively to the overall esthetic outcome for an anterior implant AIM The purpose of this prospect i ve study was to evaluate radiographic , clinical and aesthetic outcomes and patient satisfaction of cases treated with  platform-switched single implant restorations in the aesthetic region of the maxilla . Furthermore , the influence of an augmentation procedure 3 months before implant placement and the type of restoration ( screw-retained vs. cement-retained ) was evaluated . MATERIAL AND METHODS Sixty patients with a missing anterior tooth in the maxilla were treated with a Straumann Bone Level Implant . Bone augmentation was performed in 29 patients at 3 months before implant placement . Implants were loaded after 3 months of submerged healing . Follow-up was conducted at 7 and 18 months after implant placement . Peri-implant mucosa and implant crown aesthetic outcomes were determined using the Implant Crown Aesthetic Index ( ICAI ) and the Pink Esthetic Score-White Esthetic Score ( PES-WES ) . RESULTS No implants were lost . At 18 months after implant placement , mean bone level change was -0.10 ± 0.27 mm and mean probing pocket depth was 2.57 mm . No differences were found between augmented and nonaugmented sites ( P = 0.28 ) . The ICAI indicated satisfactory mucosa and crown aesthetics in 67 % and 75 % of the cases , respectively , while the PES score was 14.4 . ICAI mucosa ( P = 0.004 ) and PES ( P = 0.02 ) scores were significantly less favourable for augmented sites compared with nonaugmented sites . Patient satisfaction was high ( 8.9 ± 1.1 on VAS-score ) . CONCLUSIONS From the present prospect i ve , clinical study , it can be concluded that the Straumann Bone Level Implant shows an excellent survival rate , marginal bone stability and good clinical and aesthetic results . Bone augmentation before implant placement does not lead to more marginal bone loss . However , less favourable pink aesthetic outcomes were found in augmented sites compared with nonaugmented sites , while no differences were found between cement-retained and screw-retained restorations PURPOSE This study aims to test whether or not veneering of the submucosal part of zirconia abutments with pink dental ceramic affects radiographic and technical outcomes of implant-supported single crowns ( ISSC ) . MATERIAL S AND METHODS Single tooth implants were r and omly restored with either pink-veneered zirconia abutments ( test ; n = 10 ) or non-veneered zirconia abutments ( control group ; n = 10 ) and all-ceramic crowns .  At baseline ( crown insertion ) , and 6- and 12-month radiographic and technical evaluations were performed including st and ardized x-rays and modified United States Public Health Service criteria ( technical ) . Survival and complication rates were assessed for implants and restorations . Robust linear mixed model analysis was performed to investigate the effect of group and time-point on radiographic outcomes . RESULTS At 1 year , the survival rate for implants was 100 % and 95 % for ISSC . Most of the implants were placed subcrestally . Therefore , mean marginal bone levels decreased in both groups between implant insertion and baseline ( p < .05 ) , but then remained stable up to 1 year ( test : 0.15 mm ± 0.42 mm ; control 0.23 mm ± 0.63 mm ) ( p > .005 ) . At 6 months , one minor chipping occurred in the test group . At 1 year , three crowns ( control ) exhibited occlusal roughness . In addition , one abutment fracture occurred ( test ) . The differences between test and control group were not statistically significantly different for any of the evaluated outcome measures ( p > .05 ) . CONCLUSIONS Veneering of the submucosal part of zirconia abutments did not affect biological and technical outcomes of ISSCs . Technical complications of the reconstructions , however , were frequent , result ing in a rate of 75 % of the crowns being complication free Statement of problem . Two‐piece abutments consisting of a prefabricated titanium luting base and a zirconia abutment are used widely in implant restorations . Straightforward and reliable procedures for bonding titanium and zirconia are necessary for ensuring low failure rates in such restorations . Purpose . The purpose of this in vitro study was to evaluate the tensile load of zirconia copings on prefabricated titanium abutments using 4 different self‐adhesive resin cements . Material and methods . A total of 128 industrially manufactured partially yttria‐stabilized zirconia ceramic copings were bonded to titanium abutments with a luting space of about 60 & mgr;m or 100 & mgr;m . The bonding surfaces were airborne‐particle abraded with 50 & mgr;m alumina and cleaned ultrasonically . The zirconia copings were bonded with Panavia SA Cement Automix ( SA ) , RelyX Unicem 2 Automix ( RU ) , MaxCem Elite ( ME ) , or SmartCem 2 ( SC ) . Specimens from each cement group were r and omly assigned to be stored either in distilled water ( 37 ° C ) for 3 days or subjected to 37 500 thermocycles over 150 days . After debonding in tension , failure modes ( adhesive or cohesive ) were analyzed , and basic fuchsin dye penetration tests were performed using optical microscopy and scanning electron microscopy . Three‐way ANOVA and Tukey HSD tests were used for statistical analysis ( & agr;=.05 ) . Results . Three‐way ANOVA results determined that the luting resin used and the luting space had a significant effect ( P≤.002 ) , while the storage time did not have an overall effect ( P>.05 ) . The interaction between the luting resin used and storage time was significant ( P<.001 ) . After storage for 3 days , the retentive force of SA ( 1002 N ) was highest , followed by that for RU ( 614 N ) , ME ( 550 N ) , and SC ( 346 N ) ( P≤.05 ) ; the forces for RU and ME were not significantly different ( P>.05 ) . However , after thermocycling , RU had the highest retentive force ( 848 N ) , followed by SA ( 646 N ) , ME ( 475 N ) , and SC ( 364 N ) ( P≤.05 ) . Retentive forces for ME and SC were not significantly different ( P>.05 ) . The failure modes of the zirconia abutment surfaces were predominantly adhesive , while those of the titanium surfaces were mainly cohesive . The SA specimens showed the lowest dye penetration , followed by the RU , ME , and SC specimens . Conclusions . The greatest mean retention was found with Panavia SA Cement Automix and RelyX Unicem 2 Automix with a luting space of 60 & mgr;m when bonding zirconia copings to titanium PURPOSE The purpose s of this study were to test whether or not veneering of the submucosal part of zirconia abutments can positively influence the esthetic outcome compared with nonveneered zirconia abutments ; to evaluate the influence of the mucosal thickness on the esthetic outcomes of the veneered and nonveneered abutments ; and to evaluate the thickness of the peri-implant mucosa compared with the thickness of the gingiva of contralateral tooth sites . MATERIAL S AND METHODS Forty-four single-tooth implants in 44 patients were r and omly restored with either cemented ( CR ) or screw-retained ( SR ) reconstructions  based on white zirconia abutments ( CR-W , SR-W ) or pink-veneered zirconia abutments ( CR-P , SR-P ) .  Esthetic outcome measurements were performed based on a spectrophotometric evaluation of the peri-implant mucosal color . In addition , the thickness of the mucosa was measured . A two-way analysis of variance was conducted to test the effect of veneering ( pink vs white ) and mucosa thickness ( < 2 mm vs ≥2 mm ) on the calculated color difference ΔE for pooled data of CR and SR reconstructions ( p < .05 ) . RESULTS Analyses grouping the sites according to veneering of the abutments and mucosal thickness demonstrated less discoloration for sites with a veneered abutment irrespective of the mucosal thickness : ΔE 4.50 ± 1.93 ( < 2 mm ) and ΔE 6.88 ± 2.45 ( ≥2 mm ) ; CR-P , SR-P ) compared with sites without veneering ΔE 9.72 ± 3.82 ( < 2 mm ; CR-W , SR-W ) and ΔE 8.31 ± 2.98 ( ≥2 mm ) . The differences between veneered and nonveneered abutments were significant ( p = .032 ) . CONCLUSIONS Veneering of zirconia abutments with pink veneering ceramic positively influenced the peri-implant mucosal color OBJECTIVES To test the survival rates , and the technical and biological complication rates of customized zirconia and tit 
    Output:
    
No difference was found between prefabricated and custom abutments or internal and external implant connections regarding fractures or screw loosening .
All authors reported “ good to excellent ” esthetic integration in terms of restorations and soft‐tissue color and the presence and height of papillae .
The most difficult esthetic parameters to achieve were root convexity , soft‐tissue color , and texture and level of mucosa .
Esthetics remain the major advantage of zirconia abutment when compared with titanium , despite reservations concerning the risk of mechanical complications .