RESUMO
The aim of the present study was to evaluate the antibiofilm activity against Enterococcus faecalis, compressive strength. and radiopacity of Portland cement (PC) added to zirconium oxide (ZrO2), as radiopacifier, with or without nanoparticulated zinc oxide (ZnO). The following experimental materials were evaluated: PC, PC + ZrO2, PC + ZrO2 + ZnO (5%), and PC + ZrO2 + ZnO (10%). Antibiofilm activity was analyzed by using direct contact test (DCT) on Enterococcus faecalis biofilm, for 5 h or 15 h. The analysis was conducted by using the number of colony-forming units (CFU/mL). The compressive strength was performed in a mechanical testing machine. For the radiopacity tests, the specimens were radiographed together with an aluminium stepwedge. The results were submitted to ANOVA and Tukey tests, with level of significance at 5%. The results showed that all materials presented similar antibiofilm activity (P > 0.05). The addition of nanoparticulated ZnO decreased the compressive strength of PC. All materials presented higher radiopacity than pure PC. It can be concluded that the addition of ZrO2 and ZnO does not interfere with the antibiofilm activity and provides radiopacity to Portland cement. However, the presence of ZnO (5% or 10%) significantly decreased the compressive strength of the materials.
Assuntos
Biofilmes/efeitos dos fármacos , Compostos de Cálcio/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Materiais Restauradores do Canal Radicular/farmacologia , Silicatos/farmacologia , Óxido de Zinco/farmacologia , Zircônio/farmacologia , Animais , Biofilmes/crescimento & desenvolvimento , Compostos de Cálcio/química , Bovinos , Força Compressiva/efeitos dos fármacos , Meios de Contraste/química , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Enterococcus faecalis/fisiologia , Técnicas In Vitro , Incisivo/cirurgia , Teste de Materiais , Nanopartículas/química , Materiais Restauradores do Canal Radicular/química , Silicatos/química , Óxido de Zinco/química , Zircônio/químicaRESUMO
ß-dicalcium silicate (ß-Ca2 SiO4, ß-C2 S) is one of the main constituents in Portland cement clinker and many refractory materials, itself is a hydraulic cement that reacts with water or aqueous solution at room/body temperature to form a hydrated phase (C-S-H), which provides mechanical strength to the end product. In the present investigation, ß-C2 S was synthesized by sol-gel process and it was used as powder to cement preparation, named CSiC. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid solutions and human osteoblast cell cultures for various time periods, respectively. The results showed that the sol-gel process is an available synthesis method in order to obtain a pure powder of ß-C2 S at relatively low temperatures without chemical stabilizers. A bone-like apatite layer covered the material surface after soaking in SBF and its compressive strength (CSiC cement) was comparable with that of the human trabecular bone. The extracts of this cement were not cytotoxic and the cell growth and relative cell viability were comparable to negative control.
Assuntos
Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/farmacologia , Cimentos Ósseos/síntese química , Cimentos Ósseos/farmacologia , Compostos de Cálcio/química , Teste de Materiais/métodos , Silicatos/química , Sobrevivência Celular/efeitos dos fármacos , Força Compressiva/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Tamanho da Partícula , Pós , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de Tempo , Difração de Raios XRESUMO
Carrageenans have unique properties in the pharmaceutical and food industries that involve interactions with lipid interfaces, which may be accessed if surface chemistry techniques are employed. The interaction between three different types of carrageenans with dipalmitoylphosphatidylcholine (DPPC) was investigated using Langmuir monolayers as biointerface models. With a combination of data on Surface Pressure-Area Isotherms and Polarization Modulation Infrared Reflection-Absorption Spectroscopy (PM-IRRAS), the effect of different fractions on DPPC monolayers was compared by considering the chemical and structural differences as well as the anticoagulant activity of each fraction. Thus, a model is proposed in which carrageenans can encompass interactions that are maximized due to geometrical adaptations on behalf of the interactions between polysaccharide sulfate groups and lipid polar heads.