1.1. Clinical Studies

1. Groten M, Huttig F:
   The Performance of Zirconium Dioxide Crowns: A Clinical Follow-up.
   Int J Prosthodont; 2010; 23 (5): 429-431
      
2. Nothdurft F, Pospiech P:
   Prefabricated zirconium dioxide implant abutments for single-tooth replacement in the posterior region: evaluation of peri-implant tissues and superstructures after 12 months of function.
   Clin Oral Implants Res; 2010; 21 (8): 857-865
      
3. Nothdurft FP, Pospiech PR:
   Zirconium dioxide implant abutments for posterior single-tooth replacement: first results.
   Journal of periodontology; 2009; 80 (12): 2065-2072

1.2. Randomized Clinical Trials (RCT)

1. Cehreli MC, Kokat AM, Akca K:
   CAD/CAM Zirconia vs. slip-cast glass-infiltrated Alumina/Zirconia all-ceramic crowns: 2-year results of a randomized controlled clinical trial.
   J Appl Oral Sci; 2009; 17 (1): 49-55

1.3. Prospective Studies

1. Larsson C, Vult von Steyern P, Nilner K:
   A prospective study of implant-supported full-arch yttria-stabilized tetragonal zirconia polycrystal mandibular fixed dental prostheses: three-year results.
   Int J Prosthodont; 2010; 23 (4): 364-369
       
2. Tsumita M, Kokubo Y, Ohkubo C, Sakurai S, Fukushima S:
   Clinical evaluation of posterior all-ceramic FPDs (Cercon): a prospective clinical pilot study.
   J Prosthodont Res; 2010; 54 (2): 102-105
        
3. Wolfart S, Harder S, Eschbach S, Lehmann F, Kern M:
   Four-year clinical results of fixed dental prostheses with zirconia substructures (Cercon): end abutments vs. cantilever design.
   Eur J Oral Sci; 2009; 117 (6): 741-749

1.4. Retrospective Studies

1. Redemagni M, Cremonesi S, Garlini G, Maiorana C:
   Soft tissue stability with immediate implants and concave abutments.
   Eur J Esthet Dent; 2009; 4 (4): 328-337

1.5. Literature Overview

1. Pilathadka S, Vahalova D, Vosahlo T:
   The Zirconia: a new dental ceramic material. An overview.
   Prague Med Rep; 2007; 108 (1): 5-12

2.1. In vitro Experiments

1. Baixe S, Fauxpoint G, Arntz Y, Etienne O:
   Microgap between zirconia abutments and titanium implants.
   Int J Oral Maxillofac Implants; 2010; 25 (3): 455-460
            
2. Castillo de Oyague R, Sanchez-Jorge MI, Sanchez Turrion A, Monticelli F, Toledano M, Osorio R:
   Influence of CAM vs. CAD/CAM scanning methods and finish line of tooth preparation in the vertical misfit of zirconia bridge structures.
   Am J Dent; 2009; 22 (2): 79-83
           
3. Gehrke P, Dhom G, Brunner J, Wolf D, Degidi M, Piattelli A:
   Zirconium implant abutments: fracture strength and influence of cyclic loading on retaining-screw loosening.
   Quintessence Int; 2006; 37 (1): 19-26
         
4. Kolbeck C, Behr M, Rosentritt M, Handel G:
   Fracture force of tooth-tooth- and implant-tooth-supported all-ceramic fixed partial dentures using titanium vs. customised zirconia implant abutments.
   Clin Oral Implants Res; 2008; 19 (10): 1049-1053
        
5. Mustafa K, Wennerberg A, Arvidson K, Messelt EB, Haag P, Karlsson S:
   Influence of modifying and veneering the surface of ceramic abutments on cellular attachment and proliferation.
   Clin Oral Implants Res; 2008; 19 (11): 1178-1187
         
6. Nothdurft FP, Merker S, Pospiech PR:
   Fracture behaviour of implant-implant- and implant-tooth-supported all-ceramic fixed dental prostheses utilising zirconium dioxide implant abutments.
   Clin Oral Investig; 2010; published online 05 January 2010

2.2. Finite Element Method (FEM)

1. Dittmer MP, Kohorst P, Borchers L, Stiesch M:
   Influence of the supporting structure on stress distribution in all-ceramic FPDs.
   Int J Prosthodont; 2010; 23 (1): 63-68