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Introduction: The purpose of this study was to comparatively examine physicochemical and biocompatible properties of 20 wt% bismuth oxide (Bi(2)O(3))-containing dicalcium silicate cement and white-colored mineral trioxide aggregate (WMTA)., Methods: The radiopacity, setting time, diametral tensile strength, pH value, morphology, and phase composition of the cements with and without Bi(2)O(3) were measured after mixing powders with water. Cement biocompatibility was evaluated by incubating the cement specimens with MG63 human osteoblast-like cells., Results: The addition of Bi(2)O(3) to the cement led to a significant increase (p < .05) in the setting time of 24 minutes. It was accompanied by a small decrease in the pH value but without adversely affecting diametral tensile strength. The radiopacity value of the Bi(2)O(3)-containing cement was equivalent to 7.3 mm of aluminum, which was significantly higher (p < 0.05) than pure cement without Bi(2)O(3) (1.1 mm of aluminum) but lower (p < .05) than WMTA (9.3 mm of aluminum). However, it was greater than 3 mm of aluminum, which is the value recommended by ISO 6876/2001 standards. MG63 cell viability cultured on Bi(2)O(3)-containing cement was higher than that cultured on WMTA at all culture times., Conclusions: The dicalcium silicate cement with 20 wt% Bi(2)O(3) showed shortened setting time and good biocompatibility and thus may have the potential to be a root-end filling material alternative to MTA., (Crown Copyright © 2010. Published by Elsevier Inc. All rights reserved.)

Introduction: Mineral trioxide aggregate (MTA) and calcium silicate (CS) cements exhibit acceptable levels of cytocompatibility. The aim of the present study was to evaluate MTA and CS cement genotoxicity in a human osteosarcoma cell line (MG63)., Methods: A mitochondrial colorimetric assay was used to evaluate the MG63 survival rate. A DNA precipitation assay was used to detect the MG63 DNA damage after contact with MTA or CS cement extracts., Results: The results showed that MTA and CS are cytocompatible with MG63 cells. There was no significant difference in the survival rate with MTA and CS materials (P > .05). Neither MTA nor CS cements causing MG63 cell DNA damage showed significant genotoxicity (P > .05)., Conclusions: Both MTA and CS cements are compatible with MG63 cells, and they are not cancer-causing agents., (Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Mineral trioxide aggregate (MTA) and calcium silicate (CS) cements exhibit acceptable physical and chemical properties. The aim of the present study was to evaluate the effects of MTA and CS cements on inflammatory reactions in primary cultured human dental pulp cells., Methods: The mitochondrial colorimetric assay was used to evaluate pulp cell survival rates. Fluorescent immunohistochemistry was used to observe focal adhesion kinase (FAK) and cyclooxygenase-2 (COX-2) distributions in the cells. Reverse transcription-polymerase chain reaction was used to assess COX-2 expression., Results: The results showed that MTA and CS are biocompatible with pulp cells (P>.05). FAK was well-distributed in pulp cells in contact with both cements. Both MTA and CS cements induced pulp cell inflammation as evidenced by increased COX-2 expression., Conclusions: The present study demonstrated that MTA and CS cements are biocompatible with primary cultured pulp cells. Both cements can induce inflammatory COX-2 expression in the pulp cells., (Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to examine the in vitro bioactivity and biocompatibility of sol-gel-derived dicalcium silicate cements., Methods: The morphology, phase composition, and compressive strength of the novel cement were investigated after immersion in a simulated body fluid for different periods of time. Cement biocompatibility was evaluated by incubating the cement specimens with MG63 human osteoblast-like cells., Results: After immersion in a simulated body fluid as little as 1 hour, the cements were covered with clusters of bone-like apatite spherulites. The characteristic peaks of apatite at 2theta = 25.9 degrees and 31.8 - 32.9 degrees appeared. The compressive strength of the cement was increased from the initial strength value of 12.3 MPa to 1-day strength value of 20.2 MPa; these values were significantly different (P < .05). The MG63 cell viability increased 15% and 23% on the cement surfaces when compared with the control on hour 6 and day 7 of incubation, respectively. The cells appeared flat and exhibited intact, well-defined morphology on the cement surface., Conclusions: Both bioactivity and biocompatibility of the dicalcium silicate cement consistently make it a potential candidate for endodontic use.

Introduction: The purpose of this study was to examine the physicochemical properties of novel calcium silicate cements (CSCs) prepared by using a sol-gel method., Methods: The compressive strength, morphology, and phase composition of various cements were evaluated after mixing with water, in addition to setting time and pH value., Results: As solid phases, the sol-gel-derived powders mainly consisted of beta-dicalcium silicate. Setting times for cements mixed with water ranged from 12-42 minutes and were lower for cements with higher starting CaO content. The compressive strength of the CSCs ranged from 0.3-15.2 MPa; these values were significantly different (P < .05). Calcium silicate hydrate (C-S-H) was the principal phase that formed in the hydration process. The CSCs' pH values changed from an initial 11 to a high of 13., Conclusions: CSCs display advantageously shortened setting times and might have potential for endodontic use, although further tests are necessary to confirm this.

Bone cell (MG63) biocompatibility and bone marker expression were compared after calcium and silicate base cement (CS) and mineral trioxide aggregate (MTA) treatment. X-ray diffraction was used to identify material surface structure, and tetrazolium bromide colorimetric assay was used to evaluate the cell viability. The relative mitogen activation protein kinase expression was compared with Western blot, and bone marker expression was evaluated with reverse transcriptase polymerization chain reaction. The results showed that CS and MTA are similar chemical structures and biocompatible with MG63 cells. CS and MTA cements showed good MG63 cell proliferation by high phosphor extracellular signal-regulated kinase expression levels. CS and MTA cements showed the evident type I collagen, osteocalcin, alkaline phosphatase, bone sialoprotein, and osteopontin expression. Both MTA and CS cements are biocompatible and appear to have osetoconduction effects on bone cells.

The purpose of the study was to examine the physicochemical properties of mineral trioxide aggregate (MTA)-like cements prepared from SiO(2), CaO, and Al(2)O(3) as matrices, and ZnO, MgO, and Fe(2)O(3) as additives. The MTA-like cements showed a significantly (p < 0.05) faster setting time (<14 minutes) than MTA when mixed with water, although there was a significant decrease (p < 0.05) in diametral tensile strength, ranging from 0.9 to 3.1 MPa in comparison to MTA (4.4 MPa). The addition of ZnO, MgO, and Fe(2)O(3) to the MTA-like cement led to a significantly (p < 0.05) higher strength than MTA-like cement without additives. The pH values of the MTA-like cements were changed from an initial 11 to a high of 13, similar to the results of MTA. Future characterization of the examined MTA-like cement with shortened setting time is needed before it is considered a viable candidate for dental root-end-filling applications.

The purpose of this study was to investigate the effect of two solutions differing by pH (6.4 and 4.0) and the use of a setting accelerator (15% Na(2)HPO(4) solution) on the properties of white-colored mineral trioxide aggregate (WMTA). These studies indicated that pH 4.0 had a deleterious effect on the morphology of WMTA mixed with water, however, not for WMTA mixed with Na(2)HPO(4). When immersed in a pH 4.0 solution for 7 days, WMTA mixed with water or Na(2)HPO(4) achieved a diametral tensile strength of 7.9 and 9.0 MPa, respectively, which was significantly lower (p < 0.05) than those obtained at pH 6.4 (11.2 and 12.0 MPa) but significantly higher (p < 0.05) than day 0 samples (4.4 and 4.8 MPa). Mixing WMTA with the accelerator did not significantly affect the microstructure, solubility, or strength in an acidic environment.

The purpose of this study was to investigate the effect of a sodium phosphate dibasic (Na2HPO4) setting accelerator on the properties of white-colored mineral trioxide aggregate (WMTA). Setting times were measured by using a Gilmore needle. Changes in the pH value, diametral tensile strength, and phase composition of WMTA were evaluated. By using a 15% Na2HPO4 solution as a liquid phase mixed with WMTA, the setting time was significantly reduced to 26 minutes rather than the usual 3 hours. The 15% Na2HPO4 promoted WMTA to achieve a maximum diametral tensile strength of 4.9 MPa at an initial 6-hour aging time and 1 MPa for the cement mixed with water. The pH value of the 15% Na2HPO4-mixed cement was changed from an initial 11.0 to a high of 13.2, which was similar to the results using water. The results suggest that the Na2HPO4 solution may be an effective setting accelerator for WMTA.

The aim of this study was to compare the effects of different materials used in primary root canal fillings on the cell viability of human osteosarcoma cell lines. The experimental group contained six different types of root canal filling materials, including zinc oxide (ZnO) + eugenol + formocresol (FC), Ca(OH)(2) + FC, Ca(OH)(2) + Iodoform, Ca(OH)(2) + Iodoform + camphorated parachlorophenol (CPC), Ca(OH)(2) + CPC, and Vitapex. Cell viability tests were performed using tetrazolium bromide colorimetric (MTT) assay on human osteosacorma cell lines (U2OS). The results were analyzed using one-way analysis of variance (ANOVA) and Student-Newman-Keul's test with p < 0.05 showed statistical differences. The ZnO + eugenol + FC group and Ca(OH)(2) + FC group showed the lowest survival rates (p < 0.05). The Ca(OH)(2) + Iodoform + CPC group and Ca(OH)(2) + CPC group showed significantly lower survival rates at concentrations above 6 microL/mL (p < 0.05). The Ca(OH)(2) + Iodoform group and Vitapex group showed the highest survival rates (p < 0.05). We concluded that the use of calcium hydroxide with iodoform as a root filling base material is a better option than other medications., ((c) 2006 Wiley Periodicals, Inc.)

There are three types of the root canal sealers commonly used in clinical applications. They are calcium hydroxide base (Sealapex), zinc oxide-eugenol base (Canals), and epoxy-resin base (AH Plus). Elutable substances and degradation products from root canal sealers may gain access to periodontal tissue in a number of ways. The purpose of the present study was to evaluate the biologic effects of the root canal sealers on human oral cancer cell line (OC2). The tetrazolium bromide (MTT) assay was to evaluate the cell's survival rate. The DNA electrophoresis was used to evaluate the OC2 cell's DNA damage. The results demonstrated that the above root canal sealers' survival rates are in dose-dependent increase (p < 0.05). The toxicity of fresh mix group is higher than that of the mixed after 24h group. DNA fragmentation assay of sealer treated OC2 cells shows a smear layer pattern on the electrophoresis gel. There is no DNA damage found. The toxicity that regulated the cell death is not by the apoptic change of cells.