Solubility, porosity and fluid uptake of calcium silicate-based cements

Objective: To evaluate the absorption/fluid uptake, solubility and porosity of White mineral trioxide aggregate (MTA) Angelus, Biodentine (BIO), and zinc oxide-eugenol (ZOE). Material and Methods: Solubility was evaluated after immersion in distilled water for 7 and 30 days. Porosity was evaluated using digital inverted microscope, scanning electron microscope (SEM) and micro-computed tomography (micro-CT). For the fluid uptake test, specimens were immersed in Hank's balanced salt solution (HBSS) for 1, 7, 14 and 28 days. Fluid absorption, solubility and porosity of the materials were measured after each period. Statistical evaluation was performed using one-way analysis of variance (ANOVA) and Tukey tests, with a significance level at 5%. Results:After 7 and 30 days, BIO showed the highest solubility (p<0.05). All methods demonstrated that MTA had total porosity higher than BIO and ZOE (p<0.05). Micro-CT analysis showed that MTA had the highest porosity at the initial period, after its setting time (p<0.05). After 7 and 30 days, ZOE had porosity lower than MTA and BIO (p<0.05). Absorption was similar among the materials (p>0.05), and higher fluid uptake and solubility were observed for MTA in the fluid uptake test (p<0.05). Conclusions: BIO had the highest solubility in the conventional test and MTA had higher porosity and fluid uptake. ZOE had lower values of solubility, porosity and fluid uptake. Solubility, porosity and fluid uptake are related, and the tests used provided complementary data

Evaluation of physicochemical properties of root-end filling materials using conventional and Micro-CT tests

Objective To evaluate solubility, dimensional stability, filling ability and volumetric change of root-end filling materials using conventional tests and new Micro-CT-based methods. Material and Methods 7 Results The results suggested correlated or complementary data between the proposed tests. At 7 days, BIO showed higher solubility and at 30 days, showed higher volumetric change in comparison with MTA (p;0.05) at 7 days. At 30 days, they presented similar solubility. BIO and MTA showed higher dimensional stability than ZOE (

Solubility, porosity, dimensional and volumetric change of endodontic sealers

Made available in DSpace on 2019-10-06T15:51:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-07-01. Added 1 bitstream(s) on 2019-10-09T18:34:58Z : No. of bitstreams: 1 S0103-64402019000400368.pdf: 231317 bytes, checksum: 55f93b71e9cc966f98ddf8025bcd31c8 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The aim Of this study was to evaluate physical properties Of endodontic sealers (AH Plus, MTA Fillapex and Endofill), by conventional and micro-CT tests. Dimensional stability was evaluated after immersion Of materials in distilled water for 30 days. Solubility and volumetric change were evaluated after 7 and 30 days Of immersion in distilled water. Solubility was evaluated by means Of mass loss and volumetric change was assessed by micro-CT. Porosity was evaluated under a microscope after 7 days Of immersion in distilled water, and by using micro-CT after setting and immersion in distilled water for 7 and 30 days. Statistical analysis was performed by ANOVA and Tukey’s test with 5% significance level. MTA Fillapex presented the highest solubility (p0,05). In conclusion, MTA Fillapex presented higher solubility, dimensional and volumetric change besides porosity compared to the Other evaluated sealers. The assessed physical properties of sealers are related, and the different tests provided complementary data. Micro-CT is a valuable method for assessment Of physical properties Of endodontic materials.Department of Restorative Dentistry School of Dentistry UNESP – Universidade Estadual PaulistaDepartment of Dentistry School of Dentistry UFBA – Universidade Federal da BahiaSchool of Dentistry Institute of Clinical Sciences College of Clinical and Medical Sciences University of Birmingham, EdgbastonDepartment of Restorative Dentistry School of Dentistry UNESP – Universidade Estadual PaulistaCAPES: 2014/16510-0FAPESP: 2014/16510-0CAPES: 2015/03437-6FAPESP: 2015/03437-6CAPES: 2016/00321-0FAPESP: 2016/00321-0CAPES: 2017/19049-0FAPESP: 2017/19049-

Effect of Silver Nanoparticles on Physicochemical and Antibacterial Properties of Calcium Silicate Cements

Mineral trioxide aggregate (MTA) and Portland cement (PC) are calcium silicate cements. They have similar physicochemical, mechanical and biological properties. The addition of zirconium oxide (ZrO 2 ) to PC provides radiopacity. Silver nanoparticles (AgNPs) may improve some properties of cements. The aim of this study was to evaluate the effect of AgNPs on physicochemical/mechanical properties and antibacterial activity of white MTA (WMTA) and PC associated with ZrO 2 . The following materials were evaluated: WMTA; PC 70% + ZrO 2 30%; WMTA+ AgNPs; and PC 70% + ZrO 2 30% + AgNPs. The study evaluated radiopacity, setting time, pH, compressive strength and solubility. For radiopacity analysis, radiographs were made alongside an aluminum (Al) step wedge. To evaluate the antibacterial activity, direct contact test was performed on planktonic cells and Enterococcus faecalis biofilm induced on bovine root dentin for 14 days. The experimental periods were 5 and 15 h. Data were obtained as CFU mL -1 . The obtained data were submitted to ANOVA and Tukey tests (p<0.05). The addition of AgNPs to WMTA increased the pH, lowered the solubility and the initial and final setting times. The addition of AgNPs to PC/ZrO 2 maintained the pH, lowered the solubility, and increased the setting time and compressive strength. The radiopacity of all materials was higher than 4 mmAl. The addition of AgNPs promoted an increase in antibacterial activity for calcium silicate cements and favored the physicochemical and mechanical properties of the materials

Biocompatibility and bioactivity of calcium silicate-based endodontic sealers in human dental pulp cells

Mineral Trioxide Aggregate (MTA) is a calcium silicate-based material. New sealers have been developed based on calcium silicate as MTA Fillapex and MTA Plus. Objective The aim of this study was to evaluate biocompatibility and bioactivity of these two calcium silicate-based sealers in culture of human dental pulp cells (hDPCs). Material and Methods The cells were isolated from third molars extracted from a 16-year-old patient. Pulp tissue was sectioned into fragments with approximately 1 mm3 and kept in supplemented medium to obtain hDPCs adherent cultures. Cell characterization assays were performed to prove the osteogenic potential. The evaluated materials were: MTA Plus (MTAP); MTA Fillapex (MTAF) and FillCanal (FC). Biocompatibility was evaluated with MTT and Neutral Red (NR) assays, after hDPCs exposure for 24 h to different dilutions of each sealer extract (1:2, 1:3 and 1:4). Unexposed cells were the positive control (CT). Bioactivity was assessed by alkaline phosphatase (ALP) enzymatic assay in cells exposed for one and three days to sealer extracts (1:4 dilution). All data were analyzed by ANOVA and Tukey post-test (p≤0.05%). Results MTT and NR results showed suitable cell viability rates for MTAP at all dilutions (90-135%). Cells exposed to MTAF and FC (1:2 and 1:4 dilutions) showed significant low viability rate when compared to CT in MTT. The NR results demonstrated cell viability for all materials tested. In MTAP group, the cells ALP activity was similar to CT in one and three days of exposure to the material. MTAF and FC groups demonstrated a decrease in ALP activity when compared to CT at both periods of cell exposure. Conclusions The hDPCs were suitable for the evaluation of new endodontic materials in vitro. MTAP may be considered a promising material for endodontic treatments

Análise morfológica e morfométrica dos acupontos do meridiano do coração da preguiça-de-garganta-marrom Bradypus variegatus Schinz, 1825: Morphological and morphometric analysis of the heart meridian acupoints in the brown-throated sloth Bradypus variegatus Schinz, 1825

Os bichos-preguiça são animais que vivem nas florestas das Américas Central e do Sul,  alimentam-se basicamente de folhas e tem hábito predominantemente arborícola. Pertencentes à família Bradypodidae, a preguiça-de-garganta-marrom (Bradypus variegatus) tem grande ocorrência em território brasileiro, e devido a degradação de seu hábitat natural e relevante taxa de tráfico de animais selvagens, sua população encontra-se em declínio. Desta forma, estudos que viabilizem a ampliação de técnicas terapêuticas para estas populações tornam-se relevantes e contribuem para permanência da espécie. Neste contexto, o objetivo deste trabalho é realizar uma análise morfológica e morfométrica dos acupontos do Meridiano do Coração de B. variegatus, a fim de viabilizar-se o emprego da acupuntura veterinária como opção terapêutica para esta espécie. Para o presente estudo, utilizaram-se três cadáveres de preguiça-de garganta-marrom, de ambos os sexos, cedidos pelo Laboratório de Anatomia Animal da Universidade Federal do Norte do Tocantins, utilizando-se como critério de seleção das peças anatômicas a preservação da região dos membros torácicos  e do tórax, sendo que os cadáveres identificados aleatoriamente como P1, P2 e P3. Após preparo das peças anatômicas, os acupontos foram localizados e mensurados, comparando-os com a descrição destes em humanos. Foi possível a localização de todos os acupontos pertencentes ao Meridiano do Coração de B. variegatus, traçar o trajeto deste Meridiano pelo braço e tórax e verificou-se semelhança estatística entre a localização e distância dos acupontos do Meridicano do Coração de P1, P2 e P3, utilizando-se análise de correlação estatística, sendo que a correlação entre os exemplares foi fortemente positiva. Observaram-se também variações anatômicas de proporções corpóreas peculiares à espécie. Assim, conclui-se que é possível a localização macroscópica dos acupontos do Meridiano do Coração em B. variegatus, porém, recomendam-se mais estudos, incluindo in vivo, para se assegurar a máxima eficácia da técnica