Navegando por Autor "Raucci Neto, Walter"

Agora exibindo 1 - 2 de 2
  • Imagem de Miniatura
    Item
    Apatite‐like forming ability, porosity, and bond strength of calcium aluminate cement with chitosan, zirconium oxide, and hydroxyapatite additives
    (Wiley) Saltareli, Fernanda Mara; Leoni, Graziela Bianchi; Aguiar, Nayara de Lima Ferraz; Faria, Natália Spadini de; Oliveira, Ivone Regina de; Bachmann, Luciano; Raucci Neto, Walter
    This study evaluated the effect of chitosan, zirconium oxide, and hydroxyapatite on the apatite-like forming ability, porosity, and bond-strength of calcium-aluminate cements (C). Three hundred bovine root-slices were assigned to one of five groups, according to the material: MTA, C, C + chitosan (Cchi), C + zirconium oxide (Czio),and C + hydroxyapatite (Chap), and within each group, two subgroups, according to the immersion: deionized water or phosphate-buffered saline (PBS) up to 14 days.Assessments (n = 10) of apatite-like forming ability were performed using scanning-electron microscopy, energy-dispersive x-ray spectroscopy, Fourier-transform infra-red spectroscopy, and x-ray diffraction. PBS was evaluated for pH and Ca 2+ release(n = 10). Bond-strength was analyzed by push-out test (n = 10) and porosity bymicro-CT (n = 10). Chemical and push-out data were analyzed by ANOVA and Tukey's tests (α = .05). Porosity data were analyzed by the Kruskal-Wallis and SNK tests (α = .05). Similar Ca/P ratios were observed between all groups (p > .05). The pH of MTA and Cchi were higher than that of other cements at d 3 and 6 (p < .05).Cchi had a higher release of Ca 2+ up to 6 days (p < .05). All cements had lower poros-ity after PBS (p < .05). Cchi and Chap had similar porosity reduction (p > .05), and were higher than MTA, C, and Czio (p < .05). Cchi had higher bond-strength than the other groups (p < .05). PBS samples had higher bond-strength (p < .05). All cements had hydroxyapatite deposition and the chitosan blend had the lowest porosity and the highest bond-strength
  • Imagem de Miniatura
    Item
    Strontium- and bioactive glass-enriched dentin repair cement: Mechanical performance and physicochemical characteristics
    (Elsevier) Tavella-Silva, Nathalia Cristina; Raucci, Larissa Moreira Spinola Castro; Polizeli, Victor Miguel; Miranda, Carlos Eduardo Saraiva; Oliveira, Ivone Regina de; Raucci Neto, Walter
    The aim of this study was to evaluate the effect of strontium (Sr2+) and varying concentrations of bioactive glass (BG) on the physicochemical and mechanical properties of calcium aluminate cement (CAC). The experimental groups included: control (CAC); CAC with 5 wt% BG (CAC5); CAC with 10 wt% BG (CAC10); CAC with 1 wt% Sr2+ (CAC-Sr); CAC5 with 1 wt% Sr2+ (CAC5-Sr); and CAC10 with 1 wt% Sr2+ (CAC10-Sr). Setting time (ST), solubility (SL), pH, electrical conductivity (CON), total dissolved solids (TDS), calcium ion release (Ca2+), radiopacity (RAD), surface roughness (SR), and bond strength (BS) were evaluated using cement discs. ST and RAD were assessed in freshly prepared samples. SL was determined by measuring the weight change of the specimens after seven days of water immersion. pH, CON, TDS, and Ca2+ were quantified in the immersion solutions. SR was measured after 7 and 28 days in water and phosphate-buffered saline (PBS), and BS was evaluated using the push-out test. Data were analyzed using one-way ANOVA and Tukey’s post hoc test (α = 0.05). BG incorporation significantly reduced ST, whereas Sr2+ had no effect. All groups showed mass gain. No significant differences in pH were observed among groups. CAC and CAC5 exhibited higher Ca2+ release than CAC-Sr and CAC5-Sr (p < 0.05). No differences in RAD were found. BS increased with the addition of BG and Sr2+, except in the CAC10-Sr group. Sr2+ enhanced BS in CAC (p < 0.001), but not in CAC5. Failure modes were predominantly mixed and cohesive. In conclusion, BG improved bond strength and reduced setting time, while Sr2+ had no significant effect on the physicochemical properties of the cement.