Izabela Cristina Maurício Moris1, Yung-Chung Chen2, Adriana Cláudia Lapria Faria3, Ricardo Faria Ribeiro4, Alex Sui-Lun Fok5, Renata Cristina Silveira Rodrigues6. 1. Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Avenida do Café, s/n, Monte Alegre, Ribeirão Preto, SP CEP 14040-904, Brazil. Electronic address: izabelamoris@hotmail.com. 2. Institute of Oral Medicine, College of Medicine, National Cheng Kung University Tainan, No. 1, Daxue Road, East District, Tainan City, Taiwan 701, Taiwan. Electronic address: chen1954@umn.edu. 3. Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Avenida do Café, s/n, Monte Alegre, Ribeirão Preto, SP CEP 14040-904, Brazil. Electronic address: adriclalf@forp.usp.br. 4. Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Avenida do Café, s/n, Monte Alegre, Ribeirão Preto, SP CEP 14040-904, Brazil. Electronic address: rribeiro@forp.usp.br. 5. Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, 16-212 Moos Tower, 515 Delaware St. SE, Minneapolis, MN 55455, United States. Electronic address: alexfok@umn.edu. 6. Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Avenida do Café, s/n, Monte Alegre, Ribeirão Preto, SP CEP 14040-904, Brazil. Electronic address: renata@forp.usp.br.
Abstract
OBJECTIVE: This study aimed to evaluate the fracture load and pattern of customized and non-customized zirconia abutments with Morse-taper connection. METHODS: 18 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. RESULTS: A 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. SIGNIFICANCE: Customization 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.
OBJECTIVE: This study aimed to evaluate the fracture load and pattern of customized and non-customized zirconia abutments with Morse-taper connection. METHODS: 18 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. RESULTS: A 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. SIGNIFICANCE: Customization 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.