Kiara Serafini Dapieve1, Gabriel Kalil Rocha Pereira2, Andressa Borin Venturini3, Natália Daudt4, André Valcanaia5, Marco Cícero Bottino6, Luiz Felipe Valandro7. 1. Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil. Electronic address: kiara_s_d@hotmail.com. 2. Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil. Electronic address: gabrielkrpereira@hotmail.com. 3. Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil. Electronic address: andressa.venturini@hotmail.com. 4. Post-Graduate Program in Mechanical Engineering, Department of Mechanical Engineering, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil. Electronic address: natalia.daudt@ufsm.br. 5. Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, USA. Electronic address: andrev@umich.edu. 6. Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, USA. Electronic address: mbottino@umich.edu. 7. Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil. Electronic address: valandrolf@gmail.com.
Abstract
OBJECTIVE: To assess the effects of a resin cement in high and low viscosity and distinct conditioning of the intaglio surface of lithium disilicate glass-ceramic crowns on fatigue performance of the crowns. METHODS: Prosthetic preparations (full-crown) in resin epoxy and crowns in lithium disilicate glass-ceramic were machined and allocated considering 2 factors (n = 10): "surface treatment" (HF - 5% hydrofluoric acid etching, followed by silane application; or E&P-self-etching ceramic primer) and "resin cement" (high or low viscosity). The preparations were etched with 10% hydrofluoric acid and an adhesive was applied. The intaglio surfaces of the ceramic crowns were treated as aforementioned (HF or E&P) and luted with high or low viscosity. The bonded sets were subjected to fatigue testing (step-stress approach: initial load of 200 N, step-size of 50 N, 10,000 cycles/step, 20 Hz) and complementary analyses (fractographic, topographic, and cross-sectional bonded interfacial zone analyses) were performed. RESULTS: Treatment with HF and silane with high viscosity resin cement (955 N/156,000 cycles) and E&P with low viscosity resin cement (1090 N/183,000 cycles) showed the best fatigue performance (statistical similarity between them). The failures originated from defects of the cement-ceramic interface, and the HF treatment induced a more pronounced topographical alteration. SIGNIFICANCE: Distinct topographical patterns from the HF and E&P treatments induced better fatigue results for the specific viscosity of the resin cement. Therefore, the fatigue performance depended on the existing topography, type of intaglio surface's defects/irregularities after surface treatment, and how the luting agent filled the irregularities.
OBJECTIVE: To assess the effects of a resin cement in high and low viscosity and distinct conditioning of the intaglio surface of lithium disilicate glass-ceramic crowns on fatigue performance of the crowns. METHODS: Prosthetic preparations (full-crown) in resin epoxy and crowns in lithium disilicate glass-ceramic were machined and allocated considering 2 factors (n = 10): "surface treatment" (HF - 5% hydrofluoric acid etching, followed by silane application; or E&P-self-etching ceramic primer) and "resin cement" (high or low viscosity). The preparations were etched with 10% hydrofluoric acid and an adhesive was applied. The intaglio surfaces of the ceramic crowns were treated as aforementioned (HF or E&P) and luted with high or low viscosity. The bonded sets were subjected to fatigue testing (step-stress approach: initial load of 200 N, step-size of 50 N, 10,000 cycles/step, 20 Hz) and complementary analyses (fractographic, topographic, and cross-sectional bonded interfacial zone analyses) were performed. RESULTS: Treatment with HF and silane with high viscosity resin cement (955 N/156,000 cycles) and E&P with low viscosity resin cement (1090 N/183,000 cycles) showed the best fatigue performance (statistical similarity between them). The failures originated from defects of the cement-ceramic interface, and the HF treatment induced a more pronounced topographical alteration. SIGNIFICANCE: Distinct topographical patterns from the HF and E&P treatments induced better fatigue results for the specific viscosity of the resin cement. Therefore, the fatigue performance depended on the existing topography, type of intaglio surface's defects/irregularities after surface treatment, and how the luting agent filled the irregularities.
Authors: Monika Bjelopavlovic; Michael Weyhrauch; Herbert Scheller; Stefan Wentaschek; Karl Martin Lehmann Journal: Materials (Basel) Date: 2022-10-07 Impact factor: 3.748