Leina Nakanishi1, Marina R Kaizer2, Suzane Brandeburski3, Sergio S Cava4, Alvaro Della Bona3, Yu Zhang5, Rafael R Moraes6. 1. Graduate Program in Dentistry, Federal University of Pelotas, Brazil. 2. Graduate Program in Dentistry, Positivo University, Brazil. 3. Graduate Program in Dentistry, University of Passo Fundo, Brazil. 4. School of Materials Engineering, Federal University of Pelotas, Brazil. 5. College of Dentistry, New York University, USA. 6. Graduate Program in Dentistry, Federal University of Pelotas, Brazil. Electronic address: rafael.moraes@ufpel.edu.br.
Abstract
OBJECTIVE: Zirconia and alumina nanoparticles were coated with a silica-rich layer (ALSI and ZRSI) and used to prepare experimental nanohybrid resin composites, which were characterized and compared to a control commercial resin composite (Filtek Z350 XT). METHODS: Silica nanoparticles with sizes compatible to ALSI (Aerosil 150) and ZRSI (Aerosil OX 50) were tested as references. The volume of nanoparticles was equivalent across the composites, which also had consistent content of glass microparticles. CC conversion, viscosity, depth of cure, surface topography, hardness, opacity, radio-opacity, and edge chipping resistance (ReA) were tested after 24 h. Flexural strength (σf) and fracture toughness (KIC) were also tested after 15 K thermal cycles. Data were analyzed using one-way or two-way ANOVA and Tukey's test (α = 0.05). RESULTS: ALSI and ZRSI yielded resin composites with lower viscosity and more irregular nanoagglomerates compared to nanosilica-based composites. CC conversion and depth of cure were lower for ZRSI composite, which had higher opacity, radio-opacity, and hardness. ReA was higher for ALSI composite. Composites with ALSI and ZRSI showed stable σf after aging, whereas the control and Aerosil 150 resin composites showed significant degradation. The commercial and nanosilica-based composites showed up to 42% reduction in KIC after aging, whereas resin composites with ZRSI and ALSI showed a more stable KIC. SIGNIFICANCE: ALSI and ZRSI generated nanohybrid resin composites with improved and/or more stable physical properties compared with nanosilica-based and commercial composites. This study suggests that changing the composition of nanofillers is a simple method to enhance the performance of nanohybrid composites.
OBJECTIVE:Zirconia and alumina nanoparticles were coated with a silica-rich layer (ALSI and ZRSI) and used to prepare experimental nanohybrid resin composites, which were characterized and compared to a control commercial resin composite (Filtek Z350 XT). METHODS:Silica nanoparticles with sizes compatible to ALSI (Aerosil 150) and ZRSI (Aerosil OX 50) were tested as references. The volume of nanoparticles was equivalent across the composites, which also had consistent content of glass microparticles. CC conversion, viscosity, depth of cure, surface topography, hardness, opacity, radio-opacity, and edge chipping resistance (ReA) were tested after 24 h. Flexural strength (σf) and fracture toughness (KIC) were also tested after 15 K thermal cycles. Data were analyzed using one-way or two-way ANOVA and Tukey's test (α = 0.05). RESULTS:ALSI and ZRSI yielded resin composites with lower viscosity and more irregular nanoagglomerates compared to nanosilica-based composites. CC conversion and depth of cure were lower for ZRSI composite, which had higher opacity, radio-opacity, and hardness. ReA was higher for ALSI composite. Composites with ALSI and ZRSI showed stable σf after aging, whereas the control and Aerosil 150 resin composites showed significant degradation. The commercial and nanosilica-based composites showed up to 42% reduction in KIC after aging, whereas resin composites with ZRSI and ALSI showed a more stable KIC. SIGNIFICANCE: ALSI and ZRSI generated nanohybrid resin composites with improved and/or more stable physical properties compared with nanosilica-based and commercial composites. This study suggests that changing the composition of nanofillers is a simple method to enhance the performance of nanohybrid composites.
Authors: Flávio F Demarco; Kauê Collares; Fabio H Coelho-de-Souza; Marcos B Correa; Maximiliano S Cenci; Rafael R Moraes; Niek J M Opdam Journal: Dent Mater Date: 2015-08-21 Impact factor: 5.304
Authors: C Domingo; R W Arcís; A López-Macipe; R Osorio; R Rodríguez-Clemente; J Murtra; M A Fanovich; M Toledano Journal: J Biomed Mater Res Date: 2001-08
Authors: Flávio Fernando Demarco; Kauê Collares; Marcos Britto Correa; Maximiliano Sergio Cenci; Rafael Ratto de Moraes; Niek Johannes Opdam Journal: Braz Oral Res Date: 2017-08-28