Fracture resistance and the mode of failure produced in metal-free crowns cemented onto zirconia abutments in dental implants

• Published in: PloS one Vol. 14; no. 8; p. e0220551
• Main Authors: Agustín-Panadero, Rubén, Serra-Pastor, Blanca, Roig-Vanaclocha, Ana, Fons-Font, Antonio, Solá-Ruiz, María Fernanda
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 08.08.2019; Public Library of Science (PLoS)
• Subjects: Aluminum; Analysis; Biocompatibility; Biology and Life Sciences; Ceramics; Cermets; Composite materials; Crowns; Dental Cementum - chemistry; Dental Implants; Dental materials; Dental Porcelain - chemistry; Dental prosthetics; Dental Restoration Failure; Dental restorative materials; Dentistry; Design; Dynamic loads; Engineering and Technology; Failure analysis; Fixing; Fracture (Materials); Fracture toughness; Fractures; Humans; Internal fixation; Lithium; Materials; Materials Testing; Mechanical loading; Mechanical properties; Medicine; Medicine and Health Sciences; Metals; Morphology; Physical Sciences; Prostheses; Prostheses and implants; Resins; Restoration; Surgical implants; Teeth; Thermal cycling; Titanium; Young adults; Zirconia; Zirconium; Zirconium - chemistry; Zirconium dioxide; Zirconium oxide; Zirconium oxides; Italy; Monaco; Sweden; Spain
• DOI: 10.1371/journal.pone.0220551
• ISSN: 1932-6203

The purpose of the investigation was to analyze fracture resistance and mode of failure of zirconium oxide (zirconia) abutments placed on dental implants bearing crowns of different esthetic materials: zirconia, lithium disilicate (LDS), and nano-ceramic resin, for replacing single teeth in the anterior sector. Eighty implant-abutment-crown units were divided into four groups: Group T-MC (control): 20 metal-ceramic crowns cemented onto titanium abutments; Group Z-Z: 20 zirconia crowns on zirconia abutments; Group Z-LD: 20 lithium disilicate crowns on zirconia abutments; and Group Z-NCR: 20 nano-ceramic resin crowns on zirconia abutments. Specimens underwent a fatiguing process (dynamic loading and thermocycling), followed by static loading to evaluate mechanical fracture resistance, and the mode of failure produced. Mean fracture resistance values were: Control Group T-MC, 575.85±120.01 N; Group Z-Z 459.64±66.52 N; Group Z-LD, 531.77±34.10 N; and Group Z-NCR, 587.05±59.27 N. In Group T-MC, fracture occurred in the prosthetic fixing screw in 100% of specimens. In Group Z-Z, 80% of fractures occurred in the fixing screw, 15% in the abutment, and 5% in the abutment and crown. In Group Z-LD, 60% of fractures were produced in the fixing screw and 40% in the abutment. In Group Z-NCR, 70% of fractures were produced in the fixing screw and 30% in the abutment. All the abutments and crowns analyzed have the potential to withstand the physiological occlusal forces to which they would be subject in the anterior region. Lithium disilicate and nano-ceramic resin crowns cemented onto zirconia abutments are a good restoration alternative for single implants in the anterior sector.