RESUMO
OBJECTIVE: The study aims to evaluate the effect of a glass ionomer cement (GIC; Fuji 9 Gold Label, GC) with added calcium orthophosphate particles and a calcium silicate cement (CSC; Biodentine, Septodont) regarding ion release, degradation in water, mineral content, and mechanical properties of demineralized dentin samples. METHODS: GIC, GIC + 5% DCPD (dicalcium phosphate dihydrate), GIC + 15% DCPD, GIC + 5% ß-TCP (tricalcium phosphate), GIC + 15% ß-TCP (by mass), and CSC were evaluated for Ca2+/Sr2+/F- release in water for 56 days. Cement mass loss was evaluated after 7-day immersion in water. Partially demineralized dentin disks were kept in contact with materials while immersed in simulated body fluid (SBF) at 37 °C for 56 days. The "mineral-to-matrix ratio" (MMR) was determined by ATR-FTIR spectroscopy. Dentin hardness and elastic modulus were obtained by nanoindentation. Samples were observed under scanning and transmission electron microscopy. Data were analyzed by ANOVA/Tukey test (α = 0.05). RESULTS: Ca2+ release from CSC and GIC (µg/cm2) were 4737.0 ± 735.9 and 13.6 ± 1.6, respectively. In relation to the unmodified GIC, the addition of DCPD or ß-TCP increased ion release (p < 0.001). Only the dentin disks in contact with CSC presented higher MMR (p < 0.05) and mechanical properties than those restored with a resin composite used as control (p < 0.05). Mass loss was similar for GIC and CSC; however, the addition of DCPD or ß-TCP increased GIC degradation (p < 0.05). CONCLUSION: Despite the increase in ion release, the additional Ca2+ sources did not impart remineralizing capability to GIC. Both unmodified GIC and CSC showed similar degradation in water. CLINICAL RELEVANCE: CSC was able to promote dentin remineralization.
Assuntos
Compostos de Cálcio , Fosfatos de Cálcio , Cálcio , Cimentos de Ionômeros de Vidro , Silicatos , Cimentos de Ionômeros de Vidro/farmacologia , Cimentos de Ionômeros de Vidro/química , Cálcio/análise , Fosfatos/análise , Cimento de Silicato/análise , Cimento de Silicato/farmacologia , Dentina , Água/química , Teste de MateriaisRESUMO
OBJECTIVE: to evaluate the effect a glass ionomer cement (GIC) containing hydroxyapatite (HAp) or calcium silicate (CaSi) particles on mineral content and mechanical properties of demineralized dentin. Ion release and compressive strength (CS) of the cements were also evaluated. METHODS: GIC (Fuji 9 Gold Label, GC), GIC+ 5%HAp and GIC+ 5%CaSi (by mass) were evaluated. Ion release was determined by induced coupled plasma optical emission spectroscopy (Ca2+/Sr2+) or ion-specific electrode (F-) (n = 3). A composite (Filtek Z250, 3 M ESPE) was used as control in remineralization tests. Demineralized dentin discs were kept in contact with materials in simulated body fluid (SBF) at 37 °C for eight weeks. Mineral:matrix ratio (MMR) was determined by ATR-FTIR spectroscopy (n = 5). Dentin hardness (H) and elastic modulus (E) were determined by nanoindentation (n = 10). CS was tested after 24 h and 7d in deionized water (n = 12). Data were analyzed by ANOVA/Tukey test (α = 0.05). RESULTS: Ca2+ and Sr2+ release was higher for the modified materials (p < 0.05). Only GIC+ 5%HAp showed higher F- release than the control (p < 0.05). All groups showed statistically significant increases in MMR, with no differences among them after 8 weeks (p > 0.05). No differences in dentin H or E were observed among groups (p > 0.05). HAp-modified GIC showed increased initial CS, while adding CaSi had the opposite effect (p < 0.05). After 7 days, GIC+ 5%CaSi presented lower CS in relation to control and GIC+ 5%HAp (p < 0.05). SIGNIFICANCE: GIC modification with HAp or CaSi affected CS and increased ion release; however, none of the groups showed evidence of dentin remineralization in comparison to the negative control.