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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, WalterThe 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.Item Effects of blood and root-dentin cleaning on the porosity and bond strength of a collagen bioceramic material(Fundação Odontológica de Ribeirão Preto) Saltareli, Fernanda Mara; Raucci, Larissa Moreira Spinola de Castro; Miranda, Carlos Eduardo Saraiva; Silva, Nathalia Cristina Tavella; Oliveira, Ivone Regina de; Raucci Neto, WalterTo assess the effect of cleaning protocols on dentin contaminated with blood in reparative endodontic materials, bovine root samples were divided: no contamination (N); contamination (P); contamination and cleaning with saline (S), 2.5% NaOCl+saline (Na) or 2.5% NaOCl+17% EDTA+saline (NaE) and filled with: mineral trioxide aggregate (MTA), calcium-aluminate-cement (C), or C+collagen (Ccol) (n=13). The samples were evaluated for porosity, chemical composition, and bond strength. MTA porosity was lower than C (p=0.02) and higher than Ccol (p<0.001). P and NaE were similar (p=1.00), but higher than the other groups (p<0.001). MTA bond strength was similar to Ccol (p=0.777) and lower than C (p=0.028). P presented lower bond strength than the N (p<0.001); S and Na were similar to each other (p=0.969), but higher than P and lower than N (p<0.001). It was observed a predominance of mixed and cohesive failures. None of the samples showed Ca/P ratio values similar to human hydroxyapatite. This study showed that contamination with blood increased the materials porosity, but dentin cleaning with 2.5% NaOCl reduced this effect, and the collagen additive reduced the material porosity. Furthermore, blood contamination reduced the materials bond strength, and cleaning with saline or 2.5% NaOCl diminished this effect.