Fracture loads and failure modes of customized and non-customized zirconia abutments

Publication date: Available online 5 May 2018
Source:Dental Materials
Author(s): Izabela Cristina Maurício Moris, Yung-Chung Chen, Adriana Cláudia Lapria Faria, Ricardo Faria Ribeiro, Alex Sui-Lun Fok, Renata Cristina Silveira Rodrigues
ObjectiveThis study aimed to evaluate the fracture load and pattern of customized and non-customized zirconia abutments with Morse-taper connection.Methods18 implants were divided into 3 groups according to the abutments used: Zr — with non-customized zirconia abutments; Zrc — with customized zirconia abutments; and Ti — with titanium abutments. To test their load capacity, a universal test machine with a 500-kgf load cell and a 0.5-mm/min speed were used. After, one implant-abutment assembly from each group was analyzed by Scanning Electron Microscopy (SEM). For fractographic analysis, the specimens were transversely sectioned above the threads of the abutment screw in order to examine their fracture surfaces using SEM.ResultsA significant difference was noted between the groups (Zr=573.7±11.66N, Zrc=768.0±8.72N and Ti=659.1±7.70N). Also, the zirconia abutments fractured while the titanium abutments deformed plastically. Zrc presented fracture loads significantly higher than Zr (p=0.009). All the zirconia abutments fractured below the implant platform, starting from the area of contact between the abutment and implant and propagating to the internal surface of the abutment. All the zirconia abutments presented complete cleavage in the mechanical test. Fractography detected differences in the position and pattern of fracture between the two groups with zirconia abutments, probably because of the different diameters in the transmucosal region.SignificanceCustomization of zirconia abutments did not affect their fracture loads, which were comparable to that of titanium and much higher than the maximum physiological limit for the anterior region of the maxilla.



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