Polymerization Shrinkage, Hygroscopic Expansion, Elastic Modulus and Degree of Conversion of Different Composites for Dental Application

Author(s)

Borges, Alexandre Luiz Souto ^[1] ; Dal Piva, Amanda Maria de Oliveira ^{[2, 3]} ; Moecke, Sabrina Elise ^[1] ; de Morais, Raquel Coutinho ^[1] ; Tribst, Joao Paulo Mendes ^{[2, 3]}

Affiliation

^[1] Sao Paulo State Univ Unesp, Inst Sci & Technol, BR-12245000 Sao Jose Dos Campos - Brazil

^[2] Univ Amsterdam, Acad Ctr Dent Amsterdam ACTA, NL-1081 LA Amsterdam - Netherlands

^[3] Vrije Univ Amsterdam, NL-1081 LA Amsterdam - Netherlands

• Document type: Journal article
• Source: JOURNAL OF COMPOSITES SCIENCE; v. 5, n. 12 DEC 2021.
• Web of Science Citations: 0

Abstract

Objectives: To characterize the mechanical properties of different resin-composites for dental application. Methods: Thirteen universal dentin shade composites (n = 10) from different manufacturers were evaluated (4 Seasons, Grandio, Venus, Amelogen Plus, P90, Z350, Esthet-X, Amaris, Vita-l-escence, Natural-Look, Charisma, Z250 and Opallis). The polymerization shrinkage percentage was calculated using a video-image recording device (ACUVOL-Bisco Dental) and the hygroscopic expansion was measured after thermocycling aging in the same equipment. Equal volumes of material were used and, after 5 min of relaxation, baseline measurements were calculated with 18 J of energy delivered from the light-curing unit. Specimens were stored in a dry-dark environment for 24 h then thermocycled in distilled water (5-55 degrees C for 20,000 cycles) with volume measurement at each 5000 cycles. In addition, the pulse-excitatory method was applied to calculate the elastic modulus and Poisson ratio for each resin material and the degree of conversion was evaluated using Fourier transform infrared spectroscopy. Results: The ANOVA showed that all composite volumes were influenced by the number of cycles (alpha = 0.05). Volumes at 5 min post-polymerization (12.47 +/- 0.08 cm(3)) were significantly lower than those at baseline (12.80 +/- 0.09 cm(3)). With regard to the impact of aging, all resin materials showed a statistically significant increase in volume after 5000 cycles (13.04 +/- 0.22 cm(3)). There was no statistical difference between volumes measured at the other cycle steps. The elastic modulus ranged from 22.15 to 10.06 GPa and the Poisson ratio from 0.54 to 0.22 with a significant difference between the evaluated materials (alpha = 0.05). The degree of conversion was higher than 60% for all evaluated resin composites. (AU)