Physicomechanical properties of different nanohybrid composites after aging: color stability, flexural strength, and microhardness

• Main Authors: Rafaella Caramori Saab (Author), Adriana Osten Costacurta (Author), Marina Samara Baechtold (Author), Rafaella Ronchi Zinelli (Author), Ana Beatriz Franco Fernandes (Author), Gisele Maria Correr (Author), Leonardo Fernandes da Cunha (Author), Carla Castiglia Gonzaga (Author)
• Format: Book
• Published: Universidade Estadual de Campinas, 2019-04-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.20396/bjos.v18i0.8655276; 1677-3225
• Keywords: Mechanical phenomena; Hardness; Flexural strength; Color.; Dentistry; RK1-715
• Source: Brazilian Journal of Oral Sciences, Vol 18 (2019)

Aim: To evaluate the physicomechanical properties of different hybrid composites (Charisma Diamond - CD, Aura - AU, NT Premium - NT, Opallis - OP, Filtek Z250 - Z250) after 6 months of aging in distilled water. Methods: Discs were fabricated and color measurements were performed after 24 hours and at 7, 30, and 180 days. Flexural strength was determined using the three-point bending test. For the microhardness test, the specimens were flattened to obtain polished and flat surfaces and indentations. The results for ∆E and microhardness were analyzed by two-way repeated-measures ANOVA and Tukey's HSD test. The flexural strength results were analyzed by two-way ANOVA and Tukey's test (α=0.05). Results: The ∆E values for composite resins varied in the following order: CD (3.54)a < Z250 (4.70)ab < AU (4.95)ab < OP (5.20)ab < NT (6.23)b. ∆E values were lower for 24 h (3.84)a < 7 days (4.43)ab < 30 days (4.93)b. The highest values were observed after 180 days (ΔE = 6.54)c. The flexural strength of composite resins varied in the following order: CD (89.17 MPa)a < Z250 (73.06 MPa)b < OP (60.30 MPa)c < NT (51.28 MPa)c < AU (23.77 MPa)d. Flexural strength values were significantly higher for 24 h (68.62 MPa)a < 180 days (51.40 MPa)b. The microhardness of composite resins varied in the following order: Z250 (112.05)a < CD (102.15)ab < OP (92.04)bc < NT (87.77)d < AU (87.68)d. Microhardness was significantly higher for 180 days (113.44)a < 24 h (78.21)b. Conclusion: The microhybrid (Z250) and one of the nanohybrid composites (CD) performed better. The color stability and flexural strength of all tested composites decreased with storage time.