ARTÍCULO
Saliva influence on the mechanical properties of advanced CAD/CAM composites for indirect dental restorations
Fecha
2021Registro en:
2073-4360
10.3390/polym13050808
Autor
Palacios, Teresa
Pastor, José Ygnacio
Abad Coronel, Cristian Gustavo
Tarancón, Sandra
Institución
Resumen
This study aims to evaluate the microstructural and mechanical properties of three commercial resin-based materials available for computer-aid design and manufacturing (CAD/CAM)-
processed indirect dental restoration: LavaTM Ultimate Restorative (LU), 3M ESPE; Brilliant Crios
(BC), COLTENE and CerasmartTM (CS), GC Dental Product. The three types of resin-based composite
CAD/CAM materials were physically and mechanically tested under two conditions: directly as
received by the manufacturer (AR) and after storage under immersion in artificial saliva (AS) for
30 days. A global approximation to microstructure and mechanical behaviour was evaluated: density,
hardness and nanohardness, nanoelastic modulus, flexural strength, fracture toughness, fracture
surfaces, and microstructures and fractography. Moreover, their structural and chemical composition
using X-ray fluorescence analysis (XRF) and field emission scanning electron microscopy (FESEM)
were investigated. As a result, LU exhibited slightly higher mechanical properties, while the decrease
of its mechanical performance after immersion in AS was doubled compared to BC and CS. Tests
of pristine material showed 13 GPa elastic modulus, 150 MPa flexural strength, 1.0 MPa·m1/2 fracture toughness, and 1.0 GPa hardness for LU, 11.4 GPa elastic modulus; 140 MPa flexural strength,
1.1 MPa·m1/2 fracture toughness, and 0.8 GPa hardness for BC; and 8.3 GPa elastic modulus, 140 MPa
flexural strength, 0.9 MPa·m1/2 fracture toughness, and 0.7 GPa hardness for CS. These values were
significantly reduced after one month of immersion in saliva. The interpretation of the mechanical
results could suggest, in general, a better behaviour of LU compared with the other two despite
it having the coarsest microstructure of the three studied materials. The saliva effect in the three
materials was critically relevant for clinical use and must be considered when choosing the best
solution for the restoration to be used