Marina D S Chiari1, Marcela C Rodrigues1, Tathy A Xavier1, Eugen M N de Souza1, Victor E Arana-Chavez1, Roberto R Braga2. 1. Department of Biomaterials and Oral Biology, Univ. of São Paulo School of Dentistry, Av. Prof. Lineu Prestes, 2227, São Paulo, SP 05508-000, Brazil. 2. Department of Biomaterials and Oral Biology, Univ. of São Paulo School of Dentistry, Av. Prof. Lineu Prestes, 2227, São Paulo, SP 05508-000, Brazil. Electronic address: rrbraga@usp.br.
Abstract
OBJECTIVE: To evaluate the effect of the replacement of barium glass by dicalcium phosphate dihydrate (DCPD) particles on the mechanical properties and degree of conversion (DC) of composites. Additionally, calcium and hydrogen phosphate (HPO4(2-)) release were followed for 28 days. METHODS: Nine composites containing equal parts (in mols) of BisGMA and TEGDMA and 40, 50 or 60 vol% of total filler were manipulated. Filler phase was constituted by silanated barium glass and 0%, 10% or 20% of DCPD particles. DC was determined by near-FTIR. Biaxial flexural strength (BFS) and modulus (E) were tested using the "piston on three balls" method, while fracture toughness (KIc) used the "single edge notched beam" method. Specimens were tested after 24h and 28 days in water. Ion release was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Data were analyzed by ANOVA/Tukey (DC and ion release) or Kruskal-Wallis/Mann-Whitney (mechanical properties; alpha: 5%). RESULTS: DC was not affected by DCPD. The presence of DCPD reduced BFS for both storage times, while differences in E became evident after 28 days. After 24h, KIc increased with the addition of DCPD; after 28 days, however, KIc decreased only for DCPD-containing composites. Calcium release was similar for both DCPD contents and remained fairly constant during the 28-day period. Overall, HPO4(2-) release was higher at 7 days and did not decrease after 14 days. SIGNIFICANCE: The composite with the highest filler level and 10% DCPD represented the best compromise between mechanical properties after aging in water and ion release.
OBJECTIVE: To evaluate the effect of the replacement of barium glass by dicalcium phosphate dihydrate (DCPD) particles on the mechanical properties and degree of conversion (DC) of composites. Additionally, calcium and hydrogen phosphate (HPO4(2-)) release were followed for 28 days. METHODS: Nine composites containing equal parts (in mols) of BisGMA and TEGDMA and 40, 50 or 60 vol% of total filler were manipulated. Filler phase was constituted by silanated barium glass and 0%, 10% or 20% of DCPD particles. DC was determined by near-FTIR. Biaxial flexural strength (BFS) and modulus (E) were tested using the "piston on three balls" method, while fracture toughness (KIc) used the "single edge notched beam" method. Specimens were tested after 24h and 28 days in water. Ion release was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Data were analyzed by ANOVA/Tukey (DC and ion release) or Kruskal-Wallis/Mann-Whitney (mechanical properties; alpha: 5%). RESULTS: DC was not affected by DCPD. The presence of DCPD reduced BFS for both storage times, while differences in E became evident after 28 days. After 24h, KIc increased with the addition of DCPD; after 28 days, however, KIc decreased only for DCPD-containing composites. Calcium release was similar for both DCPD contents and remained fairly constant during the 28-day period. Overall, HPO4(2-) release was higher at 7 days and did not decrease after 14 days. SIGNIFICANCE: The composite with the highest filler level and 10% DCPD represented the best compromise between mechanical properties after aging in water and ion release.
Authors: Matias Mederos; Carlos Enrique Cuevas-Suarez; Walter Sanchez; Pablo Miranda; Alejandro Francia; Helena Pardo; Juan Pablo Villanueva-Stark; Marcelo Kreiner; Guillermo Grazioli Journal: Odontology Date: 2021-06-10 Impact factor: 2.634
Authors: Abdulrahman A Balhaddad; Anmar A Kansara; Denise Hidan; Michael D Weir; Hockin H K Xu; Mary Anne S Melo Journal: Bioact Mater Date: 2018-12-18