Regina Furbino Villefort1, Marina Amaral2, Gabriel Kalil Rocha Pereira3, Tiago Moreira Bastos Campos4, Yu Zhang5, Marco Antonio Bottino6, Luiz Felipe Valandro7, Renata Marques de Melo8. 1. PhD Graduate Program in Restorative Dentistry, Prosthetic Dentistry Unit, School of Dentistry, São Paulo State University, Av. Eng Franscisco José Longo, 777, São José dos Campos, SP 12245-000, Brazil. Electronic address: reginavillefort@gmail.com. 2. PhD Graduate Program in Restorative Dentistry, Prosthetic Dentistry Unit, School of Dentistry, São Paulo State University, Av. Eng Franscisco José Longo, 777, São José dos Campos, SP 12245-000, Brazil. Electronic address: marinamaral_85@yahoo.com.br. 3. PhD Graduate Program in Oral Science, Prosthetic Dentistry Unit, Federal University of Santa Maria, R. Floriano Peixoto, 1184, Santa Maria, RS 97015-372, Brazil. Electronic address: gabrielkrpereira@hotmail.com. 4. Department of Physics, Technological Institute of Aeronautics, São José dos Campos, São Paulo, Brazil. Electronic address: moreiratiago22@gmail.com. 5. Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY 10010, USA. Electronic address: yz21@nyu.edu. 6. PhD Graduate Program in Restorative Dentistry, Prosthetic Dentistry Unit, School of Dentistry, São Paulo State University, Av. Eng Franscisco José Longo, 777, São José dos Campos, SP 12245-000, Brazil. Electronic address: mmbottino@uol.com.br. 7. PhD Graduate Program in Restorative Dentistry, Prosthetic Dentistry Unit, School of Dentistry, São Paulo State University, Av. Eng Franscisco José Longo, 777, São José dos Campos, SP 12245-000, Brazil; PhD Graduate Program in Oral Science, Prosthetic Dentistry Unit, Federal University of Santa Maria, R. Floriano Peixoto, 1184, Santa Maria, RS 97015-372, Brazil. Electronic address: lfvalandro@hotmail.com. 8. PhD Graduate Program in Restorative Dentistry, Prosthetic Dentistry Unit, School of Dentistry, São Paulo State University, Av. Eng Franscisco José Longo, 777, São José dos Campos, SP 12245-000, Brazil. Electronic address: marquesdemelo@gmail.com.
Abstract
OBJECTIVE: This study evaluated the effects of two grading techniques of zirconia material on the fatigue limit of full-contour 3-unit fixed dental prostheses (FDPs). METHODS: Presintered blocks of 3Y-TZP were milled to obtain sixty-nine 3-unit FDPs, which were divided into three groups (n=23). The control group (CTL) was sintered and glazed following manufacturer's instructions. In the two experimental groups presintered FDPs received a surface silica/glass infiltration treatment before the sintering process. Silica sol-gel group (SSG) was graded by the sol-gel processing route, while the glass-zirconia-glass group (GZG) was graded by an enameling technique. Graded groups did not receive a glaze layer after sintering. All FDPs were then luted with a dual-curing resin cement on composite abutments, embedded in polyurethane and stored in water for five days. The initial load of the fatigue test was calculated based on the results of the monotonic testing applied on three specimens of each group. To determine the fatigue limit, 20 samples of each group were subjected to staircase testing (100,000 cycles/5Hz). RESULTS: The fatigue limits (in Newtons) were CTL=1607.27, SSG=1824.31, and GZG=2006.57, and the Dixon and Mood test indicated statistically significant differences among groups (95% confidence interval) (GZG > SSG > CTL). SIGNIFICANCE: The infiltration of silica and glass on bulk zirconia, by two different grading methods, increased the fatigue limits of monolithic zirconia FDPs.
OBJECTIVE: This study evaluated the effects of two grading techniques of zirconia material on the fatigue limit of full-contour 3-unit fixed dental prostheses (FDPs). METHODS: Presintered blocks of 3Y-TZP were milled to obtain sixty-nine 3-unit FDPs, which were divided into three groups (n=23). The control group (CTL) was sintered and glazed following manufacturer's instructions. In the two experimental groups presintered FDPs received a surface silica/glass infiltration treatment before the sintering process. Silica sol-gel group (SSG) was graded by the sol-gel processing route, while the glass-zirconia-glass group (GZG) was graded by an enameling technique. Graded groups did not receive a glaze layer after sintering. All FDPs were then luted with a dual-curing resin cement on composite abutments, embedded in polyurethane and stored in water for five days. The initial load of the fatigue test was calculated based on the results of the monotonic testing applied on three specimens of each group. To determine the fatigue limit, 20 samples of each group were subjected to staircase testing (100,000 cycles/5Hz). RESULTS: The fatigue limits (in Newtons) were CTL=1607.27, SSG=1824.31, and GZG=2006.57, and the Dixon and Mood test indicated statistically significant differences among groups (95% confidence interval) (GZG > SSG > CTL). SIGNIFICANCE: The infiltration of silica and glass on bulk zirconia, by two different grading methods, increased the fatigue limits of monolithic zirconia FDPs.
Authors: F Campos; L F Valandro; S A Feitosa; C J Kleverlaan; A J Feilzer; N de Jager; M A Bottino Journal: Oper Dent Date: 2016-11-28 Impact factor: 2.440
Authors: Marina Amaral; Regina F Villefort; Renata Marques Melo; Gabriel K R Pereira; Yu Zhang; Luiz Felipe Valandro; Marco Antonio Bottino Journal: J Mech Behav Biomed Mater Date: 2017-03-07