Evaluation of setting kinetics, mechanical strength, ion release, and cytotoxicity of high-strength glass ionomer cement contained elastomeric micelles.

BACKGROUND: Low mechanical properties are the main limitation of glass ionomer cements (GICs). The incorporation of elastomeric micelles is expected to enhance the strength of GICs without detrimentally affecting their physical properties and biocompatibility. This study compared the chemical and mechanical properties, as well as the cytotoxicity, of elastomeric micelles-containing glass ionomer cement (DeltaFil, DT) with commonly used materials, including EQUIA Forte Fil (EF), Fuji IX GP Extra (F9), and Ketac Molar (KT). METHOD: Powder particles of GICs were examined with SEM-EDX. Setting kinetics were assessed using ATR-FTIR. Biaxial flexural strength/modulus and Vickers surface microhardness were measured after immersion in water for 24 h and 4 weeks. The release of F, Al, Sr, and P in water over 8 weeks was analyzed using a fluoride-specific electrode and ICP-OES. The toxicity of the material extract on mouse fibroblasts was also evaluated. RESULTS: High fluoride levels in the powder were detected with EF and F9. DT demonstrated an initial delay followed by a faster acid reaction compared to other cements, suggesting an improved snap set. DT also exhibited superior flexural strength than other materials at both 24 h and 4 weeks but lower surface microhardness (p < 0.05). EF and F9 showed higher release of F, Al, and P than DT and KT. There was no statistically significant difference in fibroblast viability among the tested materials (p > 0.05). CONCLUSIONS: Elastomeric micelles-containing glass ionomer cement (DT) exhibited satisfactory mechanical properties and cytocompatibility compared with other materials. DT could, therefore, potentially be considered an alternative high-strength GIC for load-bearing restorations.

Toxicological risk assessment of bisphenol a released from dialyzers under simulated-use and exaggerated extraction conditions.

Bisphenol A (BPA) belongs to a group of chemicals used in the production of polycarbonate, polysulfone, and polyethersulfone which are used, among other applications, in the manufacture of dialyzers. While exposure to BPA is widespread in the general population, dialysis patients represent a population with potentially chronic parenteral BPA exposures. To assess the potential risk of BPA exposure to dialysis patients through dialyzer use, exposure estimates were calculated based on BPA levels measured by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry following extractions from dialyzers manufactured by Fresenius Medical Care. Extraction conditions included both simulated-use leaching and exaggerated extractions to evaluate possible leachable and extractable BPA, respectively, from the devices. The mean BPA concentrations were 3.6 and 108.9 ppb from simulated-use and exaggerated extractions, respectively, from polycarbonate-containing dialyzers. No BPA was detected from polypropylene-containing dialyzers. Margins of Safety (MOS) were calculated to evaluate the level of risk to patients from estimated BPA exposure from the dialyzers, and the resulting MOS were 229 and 45 for simulated-use and exaggerated extractions, respectively. The findings suggest that there is an acceptable level of toxicological risk to dialysis patients exposed to BPA from use of the dialyzers tested in the current study.

Acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) filaments three-dimensional (3-D) printer emissions-induced cell toxicity.

During extrusion of some polymers, fused filament fabrication (FFF) 3-D printers emit billions of particles per minute and numerous organic compounds. The scope of this study was to evaluate FFF 3-D printer emission-induced toxicity in human small airway epithelial cells (SAEC). Emissions were generated from a commercially available 3-D printer inside a chamber, while operating for 1.5 h with acrylonitrile butadiene styrene (ABS) or polycarbonate (PC) filaments, and collected in cell culture medium. Characterization of the culture medium revealed that repeat print runs with an identical filament yield various amounts of particles and organic compounds. Mean particle sizes in cell culture medium were 201 ±â€¯18 nm and 202 ±â€¯8 nm for PC and ABS, respectively. At 24 h post-exposure, both PC and ABS emissions induced a dose dependent significant cytotoxicity, oxidative stress, apoptosis, necrosis, and production of pro-inflammatory cytokines and chemokines in SAEC. Though the emissions may not completely represent all possible exposure scenarios, this study indicate that the FFF could induce toxicological effects. Further studies are needed to quantify the detected chemicals in the emissions and their corresponding toxicological effects.

Modulating bioactivities of primary ammonium-tagged antimicrobial aliphatic polycarbonates by varying length, sequence and hydrophobic side chain structure.

Cationic aliphatic polycarbonates bearing primary ammonium side chains have been developed with relatively high molecular weights and controlled macromolecular architectures. These polycarbonates exhibit reasonable antimicrobial activity against Gram-negative and Gram-positive bacteria. The prepared homopolymers could be effective against Gram-negative bacteria whose growth is usually inhibited by copolymers with hydrophobic comonomer units when quaternary ammonium salts (QAS) are used at the cationic side chains. A methoxyethyl (ME) side chain was explored as a comonomer unit for modulating biological activities, besides conventional hydrophobic side chains including ethyl and benzyl groups. In contrast to the ethyl side chain that increases both antimicrobial and hemolytic activities, the ME side chain serves to enhance the antimicrobial activity, but suppresses the hemolytic activity. This could be attributed to the unique characteristics of an aliphatic polycarbonate bearing a ME side chain: hemocompatibility, cell adhesion property, and selective interactions with proteins. The benefits of blood compatibility of the cationic aliphatic polycarbonates with the use of the primary ammonium side chains have been reported for the first time. The polycarbonate main chain is subjected to hydrolysis, which reduces the inherent cytotoxicity of polycations. This hydrolytic property is specific to these primary ammonium-tagged polycarbonates and could be an advantage over previously reported QAS-tagged antimicrobial polycarbonates.

Bisphenol A and immunotoxic potential: A commentary.

Bisphenol A (BPA) is used in the manufacture of polycarbonate and epoxy resin plastics. There has been interest in the possibility that BPA has immunotoxic properties, and a variety of investigations have explored this. Among the approaches taken have been human observational and cross-sectional studies, investigations using experimental animals, and in vitro studies, some of which have been reviewed previously by the European Food Safety Authority (EFSA). This commentary aims to provide a focused review of data regarding the ability of BPA to perturb the immune system, including the developing immune system, and to cause related adverse health effects. The objective is to complement the evaluations conducted by EFSA, with a focus on the ability of BPA to impair immune function, to promote respiratory allergy and airway inflammation, and to compromise immunological tolerance to dietary proteins. The conclusion drawn is that there is currently no persuasive evidence that BPA has significant immunotoxic potential. This is, in part, due to some of the data reviewed being apparently contradictory or inconsistent, and the investigations from which those data were derived having limitations with regard to experimental design. The conclusion drawn here is that presently there is no clear evidence that BPA has the potential to cause immunotoxicity resulting in adverse health effects.

Recyclable plastics as substrata for settlement and growth of bryozoans Bugula neritina and barnacles Amphibalanus amphitrite.

Plastics are common and pervasive anthropogenic debris in marine environments. Floating plastics provide opportunities to alter the abundance, distribution and invasion potential of sessile organisms that colonize them. We selected plastics from seven recycle categories and quantified settlement of (i) bryozoans Bugula neritina (Linnaeus, 1758) in the lab and in the field, and of (ii) barnacles Amphibalanus (= Balanus) amphitrite (Darwin, 1854) in the field. In the laboratory we cultured barnacles on the plastics for 8 weeks and quantified growth, mortality, and breaking strength of the side plates. In the field all recyclable plastics were settlement substrata for bryozoans and barnacles. Settlement depended on the type of plastic. Fewer barnacles settled on plastic surfaces compared to glass. In the lab and in the field, bryozoan settlement was higher on plastics than on glass. In static laboratory rearing, barnacles growing on plastics were initially significantly smaller than on glass. This suggested juvenile barnacles were adversely impacted by materials leaching from the plastics. Barnacle mortality was not significantly different between plastic and glass surfaces, but breaking strength of side plates of barnacles on polyvinyl chloride (PVC) and polycarbonate (PC) were significantly lower than breakage strength on glass. Plastics impact marine ecosystems directly by providing new surfaces for colonization with fouling organisms and by contaminants shown previously to leach out of plastics and impact biological processes.

Effect of Different Concentrations of Chlorhexidine in Glass-ionomer Cements on In Vivo Biocompatibility.

PURPOSE: To examine whether a difference exists between the in vivo biocompatibility of glass-ionomer cements (GICs) containing chlorhexidine (CHX) in different concentrations. MATERIALS AND METHODS: Eighty-four male Wistar rats were distributed into 7 groups (n = 12) and received subcutaneous implants of small tubes containing different materials, as follows: Ketac control (K), Ketac-CHX 10% (K10), Ketac-CHX 18% (K18), Resilience control (R), Resilience-CHX 10% (R10), Resilience-CHX 18% (R18), Control (polyethylene). The animals were then sacrificed on post-insertion days 7, 15 and 30, and tissues were examined under an optical microscope for inflammatory infiltrate, edema, necrosis, granulation tissue, multinucleated giant cells, and collagen fibers. The results were statistically analyzed using Kruskal-Wallis and Dunn's tests (p < 0.05). RESULTS: Groups K18 and R18 showed larger areas of intense inflammatory infiltrate, with significant differences between group C and groups K18 and R18 (p = 0.007) at 7 days, and between groups C and K18 (p = 0.017) at 15 days. In terms of tissue repair, groups K18 and R18 demonstrated a lower quantity of collagen fibers with significant differences from group C (p = 0.019) at 7 days, and between group K18 and group C (p = 0.021) at 15 days. CONCLUSION: The 18% concentration of CHX was shown to have a toxic effect. The 10% concentration of CHX was shown to be suitable for tissue contact. The addition of CHX to the glass-ionomer cements is a highly promising method for obtaining of an antibacterial GIC for use in clinical practice.

Formulation and photoirradiation parameters that influenced photoresponsive drug delivery using alkoxylphenacyl-based polycarbonates.

Recently, we reported the synthesis and biocompatibility of alkoxylphenacyl-based polycarbonates (APP); a promising new class of polymers that undergo photo-induced chain scission. In the current study, nanoparticles (NPs) were prepared from the APP polymer (APP-NPs) and loaded with doxorubicin (DOX) (DOX-APP-NPs) in order to identify and evaluate formulation and photoirradiation parameters that influence photoresponsive efficacy. Stable and spherical APP-NPs were prepared with diameters between 70-80nm depending on APP concentration (10-40mg/mL). There was a direct relationship between APP concentration and resultant particle size. Drug release studies indicated that exposure to the photo-trigger was capable of altering the rate and extent of DOX released. Photoresponsive DOX release was markedly influenced by the frequency of photoirradiation while the effect of APP concentration was most likely propagated through NP size. DOX released by photoactivation retained its efficacy as assessed by cytotoxicity studies in human lung adenocarcinoma (A549) cells. Studies in BALB/c mice indicated that DOX-APP-NPs induce less cardiotoxicity than DOX alone and that DOX-APP-NPs are not susceptible to dose dumping after photoirradiation.

Biodegradable amphiphilic block-graft copolymers based on methoxy poly(ethylene glycol)-b-(polycarbonates-g-polycarbonates) for controlled release of doxorubicin.

In this paper, novel biodegradable amphiphilic block-graft copolymers based on methoxy poly(ethylene glycol)-b-(polycarbonates-g-polycarbonates) (mPEG-b-(PATMC-g-PATMC)) were synthesized successfully for controlled release of doxorubicin (DOX). Backbone block copolymer, methoxy poly(ethylene glycol)-b-poly(5-allyloxy-1,3-dioxan-2-one) (mPEG-b-PATMC) was synthesized in bulk catalyzed by immobilized porcine pancreas lipase (IPPL). Then, mPEG-b-PATMC-O, the allyl epoxidation product of mPEG-b-PATMC, was further grafted by PATMC itself also using IPPL as the catalyst. The copolymers were characterized by (1)N HMR and gel permeation chromatography results showed narrow molecular weight distributions. Stable micelle solutions could be prepared by dialysis method, while a monomodal and narrow size distribution could be obtained. Transmission electron microscopy (TEM) observation showed the micelles dispersed in spherical shape with nano-size before and after DOX loading. Compared with the block copolymers, the grafted structure could enhance the interaction of polymer chains with drug molecules and improve the drug-loading capacity and entrapment efficiency. Furthermore, the amphiphilic block-graft copolymers mPEG-b-(PATMC-g-PATMC) had low cytotoxicity and more sustained drug release behavior.

Migration of plasticisers from Tritan™ and polycarbonate bottles and toxicological evaluation.

This study is aimed to compare Tritan™ and polycarbonate (PC) from a point of view of migration of monomers and additives and toxicological evaluation. Migration assays were performed according with Commission Regulation (UE) No. 10/2011. Samples were incubated at 40°C for three consecutive periods of 10 days. Identification and quantification of the compounds intended to migrate was done using solid phase extraction (SPE) followed by gas chromatography coupled to mass spectrometry (GC-MS) in scan mode. Compounds identified in Tritan™ were 2-phenoxyethanol (2-PE), 4-nonylphenol (4-NP), bisphenol A (BPA), benzylbuthyl phthalate (BBP) and dimethyl isophthalate (DMIP) at levels from 0.027 ± 0.002 to 0.961 ± 0.092 µg/kg, although in the 3rd migration period, BBP and DMIP were the only compounds detected well below the specific migration limit. On the other hand, BPA was the only compound detected in PC polymers at a mean concentration of 0.748 µg/kg. In vitro bioassays for (anti)estrogenic, (anti)androgenic as well as retinoic acid- and vitamin D-like activity were negative for Tritan™ and PC migrates. BPA and DMIP were estrogenic in high concentrations. Exposure of the estrogen-sensitive molluskan sentinel Potamopyrgus antipodarum confirmed the estrogenic activity of BPA in vivo at 30 µg/L.

Biocompatibility and in vivo tolerability of a new class of photoresponsive alkoxylphenacyl-based polycarbonates.

Potential toxicities of chromophoric or polymeric units of most photoresponsive delivery systems have impacted clinical relevance. Herein, we evaluated the biocompatibility and tolerability of alkoxylphenacyl-based polycarbonates (APPs) as a new class of photoresponsive polymers. The polymers were applied as homopolymer or copolymers of polyethylene glycol (10%, w/w) or polycaprolactone (10%, w/w). APP polymers were comparable to poly(lactic-co-glycolic acid) (PLGA) based on cytotoxicity, macrophage activation, and blood compatibility. Data from biodistribution studies in BALB/c mice showed preferential accumulation in kidney and liver. Meanwhile, potential application of APP polymers as immediate or sustained (implants) drug delivery systems indicated that liver and kidney functions were not distorted. Also, plasma levels of tumor necrosis factor-alpha and interleukin-6 were comparable to PLGA-treated mice (p > 0.05). A histological analysis of liver and kidney sections showed no detectable damage for APP polymers. The overall data strongly supported potential consideration of APP polymers as photoresponsive delivery systems especially as implantable or tissue-mimicking photopatterned biomaterials.

Cytotoxic effects of polycarbonate-based orthodontic brackets by activation of mitochondrial apoptotic mechanisms.

OBJECTIVES: The aim of the study was to evaluate the biological effects of water eluents from polycarbonate based esthetic orthodontic brackets. METHODS: The composite polycarbonate brackets tested were Silkon Plus (SL, fiber-glass-reinforced), Elan ME (EL, ceramic particle-reinforced) and Elegance (EG, fiber-glass-reinforced). An unfilled polyoxymethylene bracket (Brilliant, BR) was used as control. The brackets' composition was analyzed by ATR-FTIR spectrometry. The cytotoxicity and estrogenicity of the eluents obtained after 3 months storage of the brackets in water (37 °C) were investigated in murine fibroblasts (NIH 3T3), breast (MCF-7) and cervical cancer (CCl-2/Hela) cell lines. RESULTS: SL and EG were based on aromatic-polycarbonate matrix, whereas EL consisted of an aromatic polycarbonate-polyethylene terepthalate copolymer. A significant induction of cell death and a concurrent decrease in cell proliferation was noted in the EG eluent-treated cells. Moreover, EG eluent significantly reduced the levels of the estrogen signaling associated gene pS2, specifically in MCF7 cells, suggesting that cell death induced by this material is associated with downregulation of estrogen signaling pathways. Even though oxidative stress mechanisms were equally activated by all eluents, the EG eluents induced expression of apoptosis inducing factor (AIF) and reduced Bcl-xL protein levels. SIGNIFICANCE: Some polycarbonate-based composite brackets when exposed to water release substances than activate mitochondrial apoptosis.

Cytotoxicity of esthetic, metallic, and nickel-free orthodontic brackets: cellular behavior and viability.

INTRODUCTION: In this study, we evaluated the cellular viability of various esthetic, metallic, and nickel-free orthodontic brackets. METHODS: The sample was divided into 11 groups (n = 8): cellular control, negative control, positive control, metallic, polycarbonate, 2 types of monocrystalline ceramic, 3 types of nickel free, and polycrystalline ceramic brackets. Cell culture (NIH/3T3-mice fibroblasts) was added to the plates of 96 wells containing the specimens and incubated in 5% carbon dioxide at 37°C for 24 hours. Cytotoxicity was analyzed qualitatively and quantitatively. Cell growth was analyzed with an inverted light microscope, photomicrographs were obtained, and the results were recorded as response rates based on modifications of the parameters of Stanford according to the size of diffusion halo of toxic substances. Cell viability was analyzed (MTT assay); a microplate reader recorded the cell viability through the mitochondrial activity in a length of 570 nm. The values were statistically analyzed. RESULTS: All tested brackets had higher cytotoxicity values than did the negative control (P <0.05), with the exception Rematitan and Equilibrium (both, Dentaurum, Ispringen, Germany) (P >0.05), suggesting low toxicity effects. The values showed that only polycarbonate brackets were similar (P >0.05) to the positive control, suggesting high toxicity. CONCLUSIONS: The brackets demonstrated different ranges of cytotoxicity; nickel-free brackets had better biocompatibility than the others. On the other hand, polycarbonate brackets were made of a highly cytotoxic material for the cells analyzed.

Cytotoxic effects of polybasic acids, poly(alkenoic acid)s, and the monomers with various functional groups on human pulp fibroblasts.

This study evaluated the cytotoxicity of various polybasic acids, poly(alkenoic acid)s, and the monomers with various acidic functional groups such as carboxyl, phosphoryl, and sulfo group. The cell growth of fibroblasts cultivated in medium containing polybasic acids and polymers up to the concentration to 5 mmol/L was not significantly different compared with that of control without their acids. On the other hand, the cell growth fibroblasts cultivated in medium containing 1 mmol/L of the monomers with acryloyloxy and phosphoryl or carboxyl group decreased remarkably compared with that of the control and the cells were probably lifeless. Those exposed to the monomers with a ether bond and a carboxyl group or a amide bond and a sulfo group was not significantly different compared with that of control.

In-vitro study of cellular viability and nitric oxide production by J774 macrophages stimulated by interferon gamma with ceramic, polycarbonate, and polyoxymethylene brackets.

INTRODUCTION: Ceramic brackets are chemically inert in the oral cavity, whereas polycarbonate and polyoxymethylene brackets can degrade and release bisphenol-A and formaldehyde, respectively. More reliable tests are needed to assess the potential toxicity of these materials. In addition to traditional cytotoxicity tests, the study of nitric oxide (NO) cellular production stimulated by a specific material has been shown to be a reliable tool for evaluating cytotoxic potential. The purpose of this study was to assess, with esthetic brackets, cellular viability by 3,(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide assay (Sigma, St. Louis, Mo) in the macrophage cell line J774 stimulated with interferon gamma. Interferon gamma is a key cytokine in the activation of macrophages, plays an important role in immunologic processes, and also quantifies NO production by these macrophages. METHODS: Well plates were seeded with 2 x 104 J774 cells per well, in a volume of 100 microL, resuspended in Roswell Park Memorial Institute Supplemented Medium 1640. The macrophage cell line J774 was stimulated with interferon gamma. Ceramic, polycarbonate, and polyoxymethylene brackets were added and kept in the culture for 24, 48, or 72 hours in 5% carbon dioxide at 37 degrees C; the control samples did not include brackets. At the end of each incubation period, the supernatant was collected for posterior NO quantification, and the cells were evaluated for cytotoxicity. RESULTS: Cellular viability in all groups was higher at 72 hours than at 24 hours. The final means in the bracket groups did not show significant differences compared with the control group. NO production was significantly greater in all groups at the final time than at the initial time. However, the brackets with the interferon gamma stimulation did not result in greater NO production than did the cells in the control group.

In-vitro study of the cellular viability and nitric oxide production by J774 macrophages with ceramic, polycarbonate, and polyoxymethylene brackets.

INTRODUCTION: Studies show that ceramic brackets are chemically inert in the oral cavity, whereas polycarbonate and polyoxymethylene brackets can degrade, releasing bisphenol-A and formaldehyde, respectively. In addition to the traditional cytotoxicity tests, the study of nitric oxide cellular production stimulated by a specific material has been shown to be a reliable tool for evaluating its cytotoxic potential. METHODS: We aimed to assess cellular viability by MTT (Sigma, St. Louis, Mo): 3,(4,5-dimethylthiazol-2-yl)-2,5diphenyl tetrazolium bromide assay in a murine macrophage cell line J774 with esthetic brackets and quantify nitric oxide production by these macrophages. Cell cultures were evaluated at 3 times: 24, 48, and 72 hours. RESULTS: Cellular viability in all groups was higher at 72 hours compared with 24 hours. This increase was significant in the control and ceramic brackets groups. Final means in the bracket groups showed no significant differences compared with the control group. Nitric oxide production was significantly greater in all groups at final time. There was no significant difference between the final means of the bracket groups and the control group, although polyoxymethylene brackets showed significantly greater means at 24 and 48 hours. CONCLUSIONS: Final means in the bracket groups showed no significant differences compared with the control group.

Modified polycarbonate urethane: synthesis, properties and biological investigation in vitro.

A new polycarbonate urethane (PCU-I) was synthesized from aliphatic monomers, i.e. polyhexamethylene carbonate diol and 4,4'-methylene-bis cyclohexane diisocyanate, a mixture of low molecular diols, and castor oil (containing mainly the triglyceride of 12-hydroxyoleic acid). The second synthesized polymer (PCU-II) did not contain castor oil. Both PCUs had good tensile strength, i.e. 32.5 and 27.8 MPa for PCU-I and PCU-II, respectively. Modification by castor oil led to a decrease in glass transition temperature (T(g) = -14 degrees C for PCU-I and -6 degrees C for PCU-II) and an increase in the softening temperature (135 and 125 degrees C for PCU-I and PCU-II, respectively). Partial crosslinking of PCU-I increased the storage modulus of elasticity and provided better resistance to sterilization by ETO and gamma radiation. Both PCUs displayed good stability when subjected to sterilization by hydrogen peroxide plasma. Neither PCU caused cytotoxic effect in mouse fibroblasts (3T3 Balb C). They also had no toxic effects on the morphotic components and did not influence changes in the hematologic parameters or plasmatic coagulation system of human blood.

Biocompatibility of glass-ionomer cements using mouse lymphoma cells in vitro.

Glass-ionomer cements are widely used in dentistry as restorative materials and adhesives for composite restorations. A number of genotoxicity studies have been conducted using these materials with results conflicting so far. Thus, the approach was aimed to look at the genotoxic and cytotoxic potential of three different glass-ionomer cements available commercially (Ketac Cem, Ketac Molar and Vitrebond) by the single cell gel (comet) assay and trypan blue exclusion test, respectively. For this, such materials were exposed to mouse lymphoma cells in vitro for 1 h at 37 degrees C. Data were assessed by Kruskall-Wallis non-parametric test. The results showed that all powders assayed did not show genotoxic effects. On the other hand, the liquid from Vitrebond at 0.1% dilution caused an increase of DNA injury. Significant statistically differences (P < 0.05) in cytotoxicity provoked by all powders tested were observed for exposure at 1,000 micro g mL(-1) concentration and 100 micro g mL(-1) for Ketac Molar. With respect to liquids of glass-ionomer cements evaluated, the major toxic effect on cell viability was produced at 1%, beginning at the dilution of 0.5% for Vitrebond. Taken together, these results support the notion that some components of glass-ionomer cements show both genotoxic and cytotoxic effects in higher concentrations.

Genotoxicity and cytotoxicity of glass ionomer cements on Chinese hamster ovary (CHO) cells.

Glass ionomer cements are widely used in dentistry as restorative materials and adhesives for composite restorations. However, the results of genotoxicity studies using these materials are inconclusive in literature. The goal of this study was to examine the genotoxic and cytotoxic potential of three different glass ionomer cements available commercially (Ketac Cem, Ketac Molar and Vitrebond) by the single cell gel (comet) assay and trypan blue exclusion test, respectively. For this, such materials were exposed to Chinese hamster ovary (CHO) cells in vitro for 1 h at 37( composite function)C. Data were assessed by Kruskall-Wallis nonparametric test. The results showed that the powder from Ketac Molar displayed genotoxicity only in the maximum concentration evaluated (100 microg/mL). In the same way, the liquid from Vitrebond at 0.1% dilution caused an increase of DNA injury. Significant differences (P<0.05) in cytotoxicity provoked by all powders tested of glass ionomer cements were observed for exposure at 1,000 microg/mL concentration. With respect to liquids of glass ionomer cements evaluated, the major toxic effect on cell viability was produced at 10%, beginning at the dilution of 0.5% for Vitrebond. Taken together, we conclude that some components of glass ionomer cements show both genotoxic and cytotoxic effects.