RESUMO
AIM: To compare the surface microhardness, compressive strength, and antimicrobial activity of white Portland nanoparticle and microparticle Peruvian cement, mineral trioxide aggregate (MTA), and neomineral trioxide aggregate (NeoMTA) at 24 hours and 28 days. MATERIALS AND METHODS: Twenty specimens were prepared for each group of cement microparticulated powder (PCm), nanoparticulated cement (PCn), MTA, and NeoMTA to be evaluated at two different times, 24 hours and 28 days for the surface microhardness test and compressive strength. For the antimicrobial activity tests, another 20 specimens were prepared for each group of cement where they were subdivided into two subgroups according to the different periods at 24 hours and 48 hours. For the surface microhardness and compressive strength, the specimens, and the cement groups were mixed according to the manufacturer's instructions and transferred to a cylindrical polyethylene mold of 6-mm diameter and 4-mm height. The compressive strength test was conducted using a universal testing machine. Moreover, the agar diffusion technique was to evaluate the antibacterial and antifungal activity of the American Type Culture Collection (ATCC) Enterococcus faecalis and Candida albicans. Finally, the data were statistically analyzed. RESULTS: The highest microhardness values for the 24-hour subgroup were recorded for NeoMTA cement (16.99 ± 2.02), followed by MTA, PCn, and PCm, respectively. As for the 28-day subgroup, PCn cement (41.64 ± 3.20) presented the highest microhardness, followed by NeoMTA, PCm, and MTA, respectively, with statistically significant differences among them. The compressive strength of both subgroups 24 hours and 28 days exhibited the highest mean for PCn (41.3 ± 4.29, 65.74 ± 3.06), followed by PCm, NeoMTA, and the lowest value for MTA cement. Finally, for the antimicrobial activity, the highest mean for the 24-hours and 48-hours subgroup was recorded for NeoMTA cement (17.6 ± 1.26, 17.8 ± 1.44), followed by PCn, PCm, and the lowest value for MTA, with significant differences between them. CLINICAL SIGNIFICANCE: It is highly recommended, Portland cement (PC) as a viable substitute since it has very similar components and properties, but at a lower cost. CONCLUSION: Regardless of the evaluation time, PCn produced higher surface microhardness and compressive strength; however, NeoMTA showed higher antimicrobial activity.
Assuntos
Materiais Restauradores do Canal Radicular , Peru , Materiais Restauradores do Canal Radicular/farmacologia , Compostos de Cálcio/farmacologia , Óxidos/farmacologia , Silicatos/farmacologia , Compostos de Alumínio/farmacologia , Cimentos Dentários/farmacologia , Combinação de Medicamentos , Cimentos de Ionômeros de Vidro , AntibacterianosRESUMO
OBJECTIVE: To fabricate and characterize dental composites with calcium type pre-reacted glass-ionomer (PRG-Ca) fillers. METHODS: PRG-Ca fillers were prepared by the reaction of calcium fluoroaluminosilicate glass with polyacrylic acid. Seven dental composites were produced from the same organic matrix (70/30wt% Bis-GMA/TEGDMA), with partial replacement of barium borosilicate (BaBSi) fillers (60wt%) by PRG-Ca fillers (wt%): E0 (0) - control, E1 (10), E2 (20), E3 (30), E4 (40), E5 (50) and E6 (60). Enamel remineralization was evaluated in caries-like enamel lesions induced by S. mutans biofilm using micro-CT. The following properties were characterized: degree of conversion (DC%), roughness (Ra), Knoop hardness (KHN), flexural strength (FS), flexural modulus (FM), water sorption (Wsp), water solubility (Wsl), and translucency (TP). Data were analyzed to one-way ANOVA and Tukey's HSD test (α=0.05). RESULTS: All composites with PRG-Ca induced enamel remineralization. E0 and E1 presented similar and highest DC% than E2=E3=E4=E5=E6. Ra and KHN were not influenced by PRG-Ca fillers (p<0.05). The higher the content of PRG-Ca, the lower FS, FM and TP (p<0.05). Wsp increased linearly with the content of PRG-Ca fillers (p<0.05). E6 presented the highest Wsl (p<0.05), while the Wsl of the other composites were not different from each other (p>0.05). SIGNIFICANCE: Incorporation of 10-40wt.% of PRG-Ca fillers endowed remineralizing potential to dental composites without jeopardizing the overall behavior of their physicochemical properties. Dental composites with PRG-Ca fillers seems to be a good alternative for reinforcing the enamel against caries development.
Assuntos
Cálcio , Resinas Compostas , Bis-Fenol A-Glicidil Metacrilato , Esmalte Dentário , Dureza , Teste de MateriaisRESUMO
The aim of this study was to fabricate and characterize dental composites containing hydroxyapatite nanoparticles (HApNPs). Four dental composites were produced from the same organic matrix (70 wt% Bis-GMA and 30 wt% TEGDMA), with partial replacement of BaBSi particles (65 wt%) by HApNPs in the following concentrations (wt%): E0 (0) - control, E10 (10), E20 (20) and E30 (30). Ca2+ and PO43- release was evaluated in solutions with different pHs (4, 5.5, and 7) using atomic emission spectroscopy with microwave-induced nitrogen plasma while the enamel remineralization potential was evaluated in caries-like enamel lesions induced by S. mutans biofilm using micro-CT. The following properties were characterized: degree of conversion (DC%), microhardness (KHN), flexural strength (FS), elastic modulus (EM) and translucency (TP). The higher the HApNPs content, the higher the Ca2+ and PO43- release. The ions release was influenced by pH (4 > 5.5 > 7) (p < 0.05). All composites loaded with HApNPs were able to remineralize the enamel (E30 = E20 > E10) (p < 0.05). Contrarily, E0 was not able of recovering the enamel mineral loss. E0 and E10 presented highest DC%, while E20 and E30 showed similar and lowest DC%. KHN and FS were decreased with the addition of HApNPs, while EM was not influenced by the incorporation of HApNPs. E10 presented statistically similar TP to E0, while this property decreased for E20 and E30 (p < 0.05). Incorporation of HApNPs into dental composites promoted enamel remineralization, mainly at potentially cariogenic pH (= 4), while maintained their overall performance in terms of physicomechanical properties.
Assuntos
Durapatita , Nanopartículas , Bis-Fenol A-Glicidil Metacrilato , Resinas Compostas , Teste de Materiais , Ácidos PolimetacrílicosRESUMO
The aim of this study was to characterize low-shrinkage dental composites containing methacrylethyl-polyhedral oligomeric silsesquioxane (ME-POSS). Four experimental composites were manufactured, two of which contained organic matrixes of BisGMA-TEGDMA (70/30â¯wt% - BGC) and BisEMA-TEGDMA (80/20â¯wt% - BEC). The two other experimental composites replaced BisGMA and BisEMA with 25â¯wt% of ME-POSS (BGP and BEP). The composites also contained 70â¯wt% of 0.7⯵m silanized BaBSi particles. The following properties were evaluated: Degree of conversion (DC%), volumetric polymerization shrinkage (VS%), polymerization shrinkage stress (Pss), flexural strength (FS), Flexural modulus (FM), hardness (KHN), water sorption (Wsp), water solubility (Wsl), diffusion coefficient (D), and wear. The DC% was not influenced by the presence of ME-POSS, with BEC (75.6%) and BEP (74.8%) presenting higher DC% than BGC (60.6%) and BGP (55.6%). The ME-POSS-containing composites (BGP and BEP) presented significantly lower VS% and Pss. The FS ranged from 92.7 to 142.0â¯MPa and the FM from 3.6 to 10.3â¯GPa. ME-POSS did not influence the KHN. BEC and BEP presented lower Wsp and Wsl when compared to BGC and BGP. D ranged from 1.0â¯×â¯10-6 to 7.4â¯×â¯10-6 cm2 m-1. Incorporation of ME-POSS significantly decreased the wear for both binary matrices (pâ¯<â¯0.05). With the exception of FS and FM for BGP, the incorporation of ME-POSS decreased the VS% and Pss without jeopardizing the other properties of the experimental dental composites.