Oxidative stress responses after exposure to triclosan sublethal concentrations: an integrated biomarker approach with a native (Corydoras paleatus) and a model fish species (Danio rerio).

Triclosan (TCS) is a synthetic broad-spectrum antimicrobial agent commonly used world-wide in a range of personal care and sanitizing products detected frequently in aquatic ecosystems. The aim of this study was to examine biochemical markers responses triggered by TCS in Danio rerio and in a native South American fish species (Corydoras paleatus). Further, an integrated approach comparing both test fish species was undertaken. These fish organisms were exposed to 100 or 189 µg TCS/L for 48 h. The activities of catalase (CAT), glutathione-s-transferase (GST), superoxide dismutase (SOD), and lipid peroxidation levels (LPO) and total antioxidant capacity against peroxyl radicals (ACAP) were determined in liver, gills, and brain. Acetylcholinesterase activity (AChE) was measured in the brain. Multivariate analysis showed that the most sensitive hepatic parameters were activities of GST and SOD for C. paleatus while LPO levels were for D. rerio. In gills the same parameters were responsive for C. paleatus but CAT in D. rerio. ACAP and GST activity were responsive parameters in brain of both species. Integrated biomarker responses (IBR) index demonstrated similar trends in both species suggesting this parameter might serve as a useful tool for quantification of integrated responses induced by TCS.

Inducible nitric oxide synthase (iNOS) mediates ethanol-induced redox imbalance and upregulation of inflammatory cytokines in the kidney.

Overexpression of the inducible isoform of the enzyme nitric oxide synthase (iNOS) has been associated to pathological processes in the kidney. Ethanol consumption induces the renal expression of iNOS; however, the contribution of this enzyme to the deleterious effects of ethanol in the kidney remains elusive. We examined whether iNOS plays a role in the renal dysfunction and oxidative stress induced by ethanol consumption. With this purpose, male C57BL/6 wild-type (WT) or iNOS-deficient (iNOS-/-) mice were treated with ethanol (20% v/v) for 10 weeks. Treatment with ethanol increased the expression of Nox4 as well as the concentration of thiobarbituric acid reactive substances and the levels of tumor necrosis factor α in the renal cortex of WT but not iNOS-/- mice. Augmented serum levels of creatinine and increased systolic blood pressure were found in WT and iNOS-/- mice treated with ethanol. WT mice treated with ethanol showed increased production of reactive oxygen species and myeloperoxidase activity, but these responses were attenuated in iNOS-/- mice. We concluded that iNOS played a role in ethanol-induced oxidative stress and pro-inflammatory cytokine production in the kidney. These are mechanisms that may contribute to the renal toxicity induced by ethanol.

Electrocorticographic patterns dominated by low-frequency waves in camphor-induced seizures.

Camphor is an aromatic terpene compound found in the essential oils of many plants, which has been used for centuries as a herbal medicine, especially in children. However, many studies have shown that camphor may have major side effects, including neurological manifestation, such as seizures. In the present study, we investigated the electrocorticographic patterns of seizures induced by camphor in male adult Wistar rats. Each rat received 400 mg/kg (i.p.) of camphor prior to monitoring by electrocorticography. The application of camphor resulted a rapid evolution to seizure and marked changes in the electrocorticographic readings, which presented characteristics of epileptiform activity, with an increase in the total power wave. The decomposition of the cerebral waves revealed an increase in the delta and theta waves. The analysis of the camphor traces revealed severe ictal activity marked by an increase in the polyspike wave. Our data thus indicate that camphor may cause seizures, leading to tonic-clonic seizures. Clearly, further studies are necessary to better elucidate the mechanisms through which camphor acts on the brain, and to propose potential treatments with anticonvulsant drugs that are effective for the control of the seizures.

In utero and lactational exposure to triclocarban: Age-associated changes in reproductive parameters of male rat offspring.

Triclocarban (TCC) is an antimicrobial compound, widely used in personal care products, such as soaps, toothpaste, and shampoo. This agent is incompletely removed by wastewater treatment and represents an environmental contaminant. Studies show that TCC has been associated with some endocrine disruptions. In vitro, TCC demonstrated potent androgen-augmenting activity and aromatase inhibition. In this sense, exposure during critical periods of development (gestation and lactation) could lead to some adverse health outcomes in offspring. Therefore, the present study evaluated if maternal exposure to three different doses of TCC could interfere in the reproductive parameters of male offspring. Pregnant female Wistar rats were separated into four groups: vehicle Control (CTR); TCC 0.3 mg/kg (TCC 0.3); TCC 1.5 mg/kg (TCC 1.5); TCC 3.0 mg/kg (TCC 3.0). Dams were treated daily by oral gavage from gestational day 0 to lactational day 21. The males were evaluated in different timepoint: infancy (PND 21), puberty (PND 50) and adult life (PND 90-120). The histomorphometric analysis of testis and testosterone level were assessed on PND 21, 50, 120; sexual behavior and sperm parameters at adulthood. In the TCC 3.0 group, a decrease in the testis interstitial volume and an increase in testosterone levels were observed on PND 21. Moreover, there was a decrease in the diameter of the seminiferous tubules on PND 50, and a decrease in sexual competency in adulthood. These results suggest that exposure to a human relevant dose of TCC may interfere with reproduction and could have implications for human health.

Silver serum levels in burned patients treated with silver sulfadiazine and its toxicity on inflammatory cells.

BACKGROUND: Silver sulfadiazine (SSD) has been widely used in burned patients for the prevention of local infections. To be biologically active and exert antimicrobial properties, silver needs to be present in the form of silver ions (Ag1+) that bind to negatively charged proteins, namely, the RNA and DNA in microorganisms. However, previous published studies conducted with SSD in the 1990s reported a high level of silver absorption through damaged skin and noted the potential cytotoxicity of Ag1+ to human cells. SSD toxicity, however, had been described in cell cultures using arbitrary silver concentrations. In the present study, we determined the serum silver levels in burned patients treated with SSD and, taking into account the molar Ag1+ concentrations found in these patients, we evaluated the Ag1+ toxicity effects on inflammatory cells (ROS and cytokine production) in vitro. METHODS: Twenty patients with an average burned body surface area of 27.68% were included in this study. RESULTS: Patients' Ag1+ serum levels reached up to 558 times those of the unexposed controls. Ag1+ was then added to inflammatory cells in vitro at levels up to 2000 times the level of the control, and there was no effect on the viability of the cells nor on the rate of apoptosis. We observed a decrease in reactive oxygen species production by mononuclear (MN) and polymorphonuclear (PMN) cells, as well as a substantial decrease in cytokines IL-1ß, IL-6, IL-8, IL-10, and TNF-α production by leukocytes (MN and PNM). CONCLUSION: These findings suggest that Ag1+ may contribute to negative outcomes after burns, decreasing the primary defense mechanism (respiratory burst) and altering cytokine production.

Investigation of the potential effects of triclosan as an endocrine disruptor in female rats: Uterotrophic assay and two-generation study.

Triclosan (TCS) is a phenolic compound with antimicrobial action widely used in cosmetics and other personal care products and other industry segments. Its widespread use over the decades has made TCS one of the most commonly detected compounds in wastewater and effluent worldwide already being found in human urine, plasma and milk. In this study, the (anti)estrogenicity of TCS was evaluated in the uterotrophic assay in 18-day old female Wistar rats. In a second protocol, female rats were evaluated for the reproductive effects of TCS in a two-generation reproduction toxicity study. Female rats were daily treated by gavage with TCS at the doses of 0.8, 2.4 and 8.0 mg/kg/day or corn oil (control group) over 10 weeks (F0) and over 14 weeks (F1) prior to mating and then throughout mating, gestation and lactation until weaning of F1 and F2 generation respectively. TCS had no effect on the uterus weight in the uterotrophic assay. In the two-generation study, the TCS exposure compromised female sexual behavior, decreased maternal food consumption and increased pup grooming on TCS 2.4 group. The TCS chronic exposure also decreased the perimetrium thickness of F0 females from TCS 8.0 group and growing follicle number of TCS 2.4 females from F1 generation. Despite the some specific changes detected in the two-generation study, no impairment was observed in the uterotrophic assay and other important reproductive endpoints. In a weight of evidence evaluation, the results suggest that exposure to TCS at low doses did not act as an endocrine disruptor in the female rat reproductive system.

[Microbicides for preventing sexually transmitted infections: Current status and strategies for preclinical evaluation of new candidates]. / Microbicidas para la prevención de infecciones de transmisión sexual: estado actual y estrategias para la evaluación preclínica de nuevos candidatos.

Microbicides are a new tool, still under investigation, which could help prevent infection by the human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Increasing evidence shows that the complexity of sexual transmission of viral pathogens requires the identification of compounds able to block the early events during the cycle of viral infection. In this manuscript we provide a comprehensive review of the different microbicide strategies that have been studied or are currently being considered for STI prevention, particularly emphasizing those having the potential to block HIV infection. The manuscript also reviews the complex process that is required to conduct future clinical studies in humans and concludes with a brief discussion of the strategies that could be part of the immediate future in microbicide research.

Microbicidas para la prevención de infecciones de transmisión sexual: estado actual y estrategias para la evaluación preclínica de nuevos candidatos. / [Microbicides for preventing sexually transmitted infections: Current status and strategies for preclinical evaluation of new candidates].

Microbicides are a new tool, still under investigation, which could help prevent infection by the human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Increasing evidence shows that the complexity of sexual transmission of viral pathogens requires the identification of compounds able to block the early events during the cycle of viral infection. In this manuscript we provide a comprehensive review of the different microbicide strategies that have been studied or are currently being considered for STI prevention, particularly emphasizing those having the potential to block HIV infection. The manuscript also reviews the complex process that is required to conduct future clinical studies in humans and concludes with a brief discussion of the strategies that could be part of the immediate future in microbicide research.

In vitro and in vivo investigation of the biological and mechanical behaviour of resin-modified glass-ionomer cement containing chlorhexidine.

OBJECTIVES: To evaluate: (1) the in vitro antibacterial, cytotoxic and mechanical properties of a resin-modified glass ionomer cement (RMGIC) containing different concentrations of chlorhexidine (CHX) and (2) the in vivo microbiologic action of the best concentration of CHX associated with the RMGIC applied on remaining dentine after indirect pulp treatment (IPT). METHODS: For the in vitro studies, RMGIC was associated with 0.2, 0.5, 1.25 and 2.5% CHX. Microbiologic evaluation consisted of an agar diffusion test on cariogenic bacteria for 24h. Odontoblast-like cell metabolism and morphology analyses measured the cytotoxic effects of the RMGIC groups after 24h. The same groups were submitted to compressive and diametral tensile strength. The in vivo treatment consisted of IPT using an RMGIC associated with the best CHX concentration. Clinical and microbiologic evaluations were performed before and after 3 months. RESULTS: The use of 1.25% CHX significantly improved the antibacterial effects of the evaluated RMGIC, without causing any detrimental effects to the odontoblast-like cells and on the mechanical properties. This RMGIC and CHX combination completely eliminated mutans streptococci after 3 months of IPT. CONCLUSION: The RMGIC and 1.25% CHX mixture showed great biological and mechanical behaviour and could be a good treatment against caries progression. CLINICAL SIGNIFICANCE: The association of CHX with a liner RMGIC opens a new perspective for arresting residual caries after IPT.

Wound healing under the effect of iodine cadexomer in rats.

PURPOSE: To assess the action of iodine cadexomer in the healing process of surgical wounds in rats and if cytotoxicity occurs with the systemic absorption of iodine. METHODS: Thirty six Wistar rats were used and performed 53 wounds with surgical punch of 6 mm diameter on them. Two lesions were made diametrically opposed on groups with distilled water (GAD) and sodium chloride (GCS); on the right lesions were used bandage with distilled water and on the left ones dressing with sodium chloride. In cadexomer iodine (GCI) group, a punch injury was made only on the left side and the dressing was carried out with cadexomer iodine. The groups were divided in two sub-groups according to the day of death (7 and 14). Microscopically was used H&E staining, through which the inflammation could be observed and also the neovascularization. Staining with Masson trichrome studied fibrosis. TSH and free T4 were used for absorption recognition of iodine, and its toxic potential was performed before death with the animal anesthetized. RESULTS: Microscopic analysis showed more marked intensity of inflammation in group GAD, subgroup 14 days. Neovascularization showed be discrete in GCS sub-group 14 days. Fibrosis was more pronounced in the group GCI. Comparing the types of treatment, there was statistical significance between groups GCI and GCS (p<0.013). The TSH and T4, showed no difference between the control group and GCI in relation to the absorption of iodine. In evaluating the GCI and control groups, within each treatment, statistical significance was found between them (p<0.001) when compared the days of observation. CONCLUSION: Cadexomer iodine had beneficial effects in all phases of the healing process without cytotoxicity due iodine absorption.

Wound healing under the effect of iodine cadexomer in rats / Cicatrização de feridas sob efeito do cadexômero iodo em ratos

PURPOSE: To assess vthe action of iodine cadexomer in the healing process of surgical wounds in rats and if cytotoxicity occurs with the systemic absorption of iodine. METHODS: Thirty six Wistar rats were used and performed 53 wounds with surgical punch of 6 mm diameter on them. Two lesions were made diametrically opposed on groups with distilled water (GAD) and sodium chloride (GCS); on the right lesions were used bandage with distilled water and on the left ones dressing with sodium chloride. In cadexomer iodine (GCI) group, a punch injury was made only on the left side and the dressing was carried out with cadexomer iodine. The groups were divided in two sub-groups according to the day of death (7 and 14). Microscopically was used H&E staining, through which the inflammation could be observed and also the neovascularization. Staining with Masson trichrome studied fibrosis. TSH and free T4 were used for absorption recognition of iodine, and its toxic potential was performed before death with the animal anesthetized. RESULTS: Microscopic analysis showed more marked intensity of inflammation in group GAD, subgroup 14 days. Neovascularization showed be discrete in GCS sub-group 14 days. Fibrosis was more pronounced in the group GCI. Comparing the types of treatment, there was statistical significance between groups GCI and GCS (p<0.013). The TSH and T4, showed no difference between the control group and GCI in relation to the absorption of iodine. In evaluating the GCI and control groups, within each treatment, statistical significance was found between them (p<0.001) when compared the days of observation. CONCLUSION: Cadexomer iodine had beneficial effects in all phases of the healing process without cytotoxicity due iodine absorption.

OBJETIVO: Avaliar a ação do cadexômero iodo na cicatrização de feridas cirúrgicas em ratos e se ocorre citotoxicidade com a absorção sistêmica do iodo. MÉTODOS: Utilizou-se 36 ratos Wistar nos quais realizaram-se 53 feridas cirúrgicas com punch de 6 mm de diâmetro. Foram confeccionados duas lesões diametralmente opostas nos animais dos grupos água destilada (GAD) e cloreto de sódio (GCS). Na lesão do lado direito foi utilizado curativo com água destilada e, na do esquerdo, curativo com cloreto de sódio. No grupo cadexômero iodo (GCI), foi feita apenas uma lesão com o punch no lado esquerdo e o curativo foi realizado com cadexômero iodo. Os grupos foram divididos em dois subgrupos conforme o dia da morte (7 e 14). Microscopicamente foi utilizada a coloração H&E, através da qual foi observado o processo inflamatório e a neovascularização. Com a coloração tricômio de Masson foi estudada a fibrose. Para o reconhecimento da absorção do iodo e o seu potencial tóxico foi realizado, antes da morte com o animal anestesiado, dosagem do TSH e do T4 livre. RESULTADOS: Na análise microscópica a intensidade da inflamação apresentou-se mais acentuada no grupo GAD, subgrupo 14 dias. Na análise da neovascularização ela apresentou-se discreta no GCS subgrupo 14 dias. Na avaliação da fibrose foi mais acentuada no grupo GCI. Na comparação nos tipos de tratamento houve significância estatística entre os grupos GCI e GCS (p<0,013). A dosagem do TSH e T4, não apresentou diferença entre o grupo controle e GCI em relação à absorção do iodo. Na avaliação dos grupos GCI e controle, dentro de cada tratamento, houve significância estatística entre eles (p<0,001), quando comparados os dias. CONCLUSÃO: O cadexômero iodo apresentou efeito benéfico em todas as fases do processo cicatricial sem citotoxicidade pela absorção do iodo.

Antimicrobial properties and cytotoxicity of an antimicrobial monomer for application in prosthodontics.

PURPOSE: This study aimed to investigate the antimicrobial properties and cytotoxicity of the monomer methacryloyloxyundecylpyridinium bromide (MUPB), an antiseptic agent capable of copolymerizing with denture base acrylic resins. MATERIALS AND METHODS: The antimicrobial activity of MUPB was tested against the species Candida albicans, Candida dubliniensis, Candida glabrata, Lactobacillus casei, Staphylococcus aureus, and Streptococcus mutans. The minimum inhibitory and fungicidal/bactericidal concentrations (MIC, MFC/MBC) of MUPB were determined by serial dilutions in comparison with cetylpyridinium chloride (CPC). The cytotoxic effects of MUPB at concentrations ranging from 0.01 to 1 g/L were assessed by MTT test on L929 cells and compared with methyl methacrylate (MMA). The antimicrobial activity of copolymerized MUPB was tested by means of acrylic resin specimens containing three concentrations of the monomer (0, 0.3, 0.6% w/w). Activity was quantified by means of a disc diffusion test and a quantification of adhered planktonic cells. Statistical analysis employed the Mann-Whitney test for MIC and MFC/MBC, and ANOVA for the microbial adherence test (α = 0.05). RESULTS: MUBP presented lower MIC values when compared with CPC, although differences were significant for C. dubliniensis and S. mutans only (p= 0.046 and 0.043, respectively). MFC/MBC values were similar for all species except C. albicans; in that case, MUPB presented significantly higher values (p = 0.046). MUPB presented higher cytotoxicity than MMA for all tested concentrations (p < 0.001) except at 0.01 g/L. Irrespective of the concentration incorporated and species, there was no inhibition halo around the specimens. The incorporation of MUPB influenced the adhesion of C. albicans only (p = 0.003), with lower CFU counts for the 0.6% group. CONCLUSIONS: It was concluded that non-polymerized MUPB has an antimicrobial capacity close to that of CPC and high cytotoxicity when compared with MMA. The antimicrobial activity of MUPB after incorporation within a denture base acrylic resin did not depend on its elution, but was shown to be restricted to C. albicans.

Chlorhexidine delivery system from titanium/polybenzyl acrylate coating: evaluation of cytotoxicity and early bacterial adhesion.

OBJECTIVES: The formation of biofilms on titanium dental implants is one of the main causes of failure of these devices. Streptococci are considered early colonizers that alter local environment favouring growing conditions for other colonizers. Chlorhexidine (CHX) is so far the most effective antimicrobial treatment against a wide variety of Gram-positive and Gram-negative organisms as well as fungi. This study was designed to develop a CHX delivery system appropriate for healing caps and abutments, with suitable drug release rate, effective as antimicrobial agent, and free of cytotoxic effects. METHODS: Polybenzyl acrylate (PBA) coatings with and without CHX (Ti/PBA and Ti/PBA-CHX, respectively) and different drug loads (0.35, 0.70, and 1.40%, w/w) were assayed. The cytotoxic effect of CHX released from the different substrates on UMR106 cells was tested by alkaline phosphatase specific activity (ALP), and microscopic evaluation of the cells. Non-cytotoxic drug load (0.35%, w/w) was selected to evaluate the antimicrobial effectiveness of the system using a microbial consortium of Streptococcus species. RESULTS: The kinetic profile of CHX delivered by Ti/PBA-CHX showed an initial fast release rate followed by a monotonic increase of delivered mass over 48 h. The number of attached bacteria decreased in the following order: Ti>Ti/PBA>Ti/PBA-0.35. CONCLUSIONS: PBA-0.35 coating is effective to inhibit the adhesion of early colonizers on Ti without any cytotoxic effect on UMR-106 cells.

Maternal exposure to triclosan impairs thyroid homeostasis and female pubertal development in Wistar rat offspring.

Although the effects of triclosan have been examined in male reproductive functions, it is unknown whether this potent antibacterial agent affects pregnancy and female pubertal development. Effects of maternal exposure to triclosan on thyroid homeostasis (TH) and reproductive-tract development in female Wistar rats were thus studied. Dams were exposed daily to triclosan (0, 1, 10, or 50 mg/kg/d) from 8 d before mating to lactation day 21. Offspring were also exposed after weaning. In vivo triclosan estrogenic activity was screened by uterotrophic assay and vaginal opening (VO), with first estrus and uterus and ovarian weight determined in offspring. Dam blood samples were taken during pregnancy and lactation to examine the effect of triclosan on TH. No apparent external signs of toxicity or differences in mean numbers of implantation sites were observed in treated rats. Triclosan treatment decreased total serum T(4) and T(3) in pregnant rats and also lowered sex ratio, lowered pup body weights on postnatal day (PND) 20, and delayed VO in offspring. In addition, the highest dose of triclosan significantly reduced the live birth index (percentage) and 6-d survival index. Data indicate that triclosan impairs thyroid homeostasis and reproductive toxicity in adult rats and produces fetal toxicity in offspring exposed in utero, during lactation, and after weaning.

Toxicity of chlorhexidine on odontoblast-like cells.

UNLABELLED: Chlorhexidine gluconate (CHX) is recommended for a number of clinical procedures and it has been pointed out as a potential cavity cleanser to be applied before adhesive restoration of dental cavities. OBJECTIVE: As CHX may diffuse through the dentinal tubules to reach a monolayer of odontoblasts that underlies the dentin substrate, this study evaluated the cytotoxic effects of different concentrations of CHX on cultured odontoblast-like cells (MDPC-23). MATERIAL AND METHODS: Cells were cultured and exposed to CHX solutions at concentrations of 0.06%, 0.12%, 0.2%, 1% and 2%. Pure culture medium (alpha-MEM) and 3% hydrogen peroxide were used as negative and positive control, respectively. After exposing the cultured cells to the controls and CHX solutions for 60 s, 2 h or 60 s with a 24-h recovery period, cell metabolism (MTT assay) and total protein concentration were evaluated. Cell morphology was assessed under scanning electron microscopy. CHX had a dose-dependent toxic effect on the MDPC-23 cells. RESULTS: Statistically significant difference was observed when the cells were exposed to CHX in all periods (p<0.05). Significant difference was also determined for all CHX concentrations (p<0.05). The 60-s exposure time was the least cytotoxic (p<0.05), while exposure to CHX for 60 s with a 24-h recovery period was the most toxic to the cells (p<0.05). CONCLUSION: Regardless of the exposure time, all CHX concentrations had a high direct cytotoxic effect to cultured MDPC-23 cells.

Toxicity of chlorhexidine on odontoblast-like cells

Chlorhexidine gluconate (CHX) is recommended for a number of clinical procedures and it has been pointed out as a potential cavity cleanser to be applied before adhesive restoration of dental cavities. OBJECTIVE: As CHX may diffuse through the dentinal tubules to reach a monolayer of odontoblasts that underlies the dentin substrate, this study evaluated the cytotoxic effects of different concentrations of CHX on cultured odontoblast-like cells (MDPC-23). MATERIAL AND METHODS: Cells were cultured and exposed to CHX solutions at concentrations of 0.06 percent, 0.12 percent, 0.2 percent, 1 percent and 2 percent. Pure culture medium (á-MEM) and 3 percent hydrogen peroxide were used as negative and positive control, respectively. After exposing the cultured cells to the controls and CHX solutions for 60 s, 2 h or 60 s with a 24-h recovery period, cell metabolism (MTT assay) and total protein concentration were evaluated. Cell morphology was assessed under scanning electron microscopy. CHX had a dose-dependent toxic effect on the MDPC-23 cells. RESULTS: Statistically significant difference was observed when the cells were exposed to CHX in all periods (p<0.05). Significant difference was also determined for all CHX concentrations (p<0.05). The 60-s exposure time was the least cytotoxic (p<0.05), while exposure to CHX for 60 s with a 24-h recovery period was the most toxic to the cells (p<0.05). CONCLUSION: Regardless of the exposure time, all CHX concentrations had a high direct cytotoxic effect to cultured MDPC-23 cells.

Subcutaneous tissue response of isogenic mice to calcium hydroxide-based pastes with chlorhexidine.

This study was evaluated the response of subcutaneous connective tissue of isogenic mice to calcium hydroxide-based pastes with chlorhexidine digluconate (CHX). Seventy isogenic male BALB/c mice aged 6-8 weeks and weighing 15-20 g were randomly assigned to 8 groups. The animals received polyethylene tube implants as follows: Groups I, II, and III (n=10) - Calen paste mixed with 0.4% CHX (experimental paste; Calen/CHX) for 7, 21, and 63 days, respectively; Groups IV, V, and VI (n=10) - UltraCal paste mixed with 2% CHX (experimental paste supplied by Ultradent Products Inc.; Ultracal/CHX) for 7, 21, and 63 days, respectively; and Groups VII and VIII (n=5): empty tube for 7 and 21 days, respectively. At the end of the experimental periods, the implants were removed together with the surrounding tissues (skin and subcutaneous connective tissue). The biopsied tissues were subjected to routine processing for histological analysis. Using a descriptive analysis and a four-point (0-3) scoring system, the following criteria were considered for qualitative and quantitative analysis of the tissue around the implanted materials: collagen fiber formation, tissue thickness and inflammatory infiltrate. A quantitative analysis was performed by measuring the thickness (microm), area (microm(2)) and perimeter (microm) of the reactionary granulomatous tissue formed at the tube ends. Data were analyzed statistically by the Kruskal-Wallis test and Dunn's post-test (alpha=0.05). Calen/CHX showed biocompatibility with the subcutaneous and reactionary tissues, with areas of discrete fibrosis and normal conjunctive fibrous tissue, though without statistically significant difference (p>0.05) from the control groups. In Groups I to III, there was a predominance of score 1, while in Groups IV to VI scores 2 and 3 predominated for all analyzed parameters. UltraCal/CHX, on the other hand, induced the formation of an inflammatory infiltrate and abundant exudate, suggesting a persistent residual aggression from the material, even 63 days after implant placement. In conclusion, the Calen paste mixed with 0.4% CHX allowed an adequate tissue response, whereas the UltraCal paste mixed with 2% CHX showed unsatisfactory results.

Subcutaneous tissue response of isogenic mice to calcium hydroxide-based pastes with chlorhexidine

This study was evaluated the response of subcutaneous connective tissue of isogenic mice to calcium hydroxide-based pastes with chlorhexidine digluconate (CHX). Seventy isogenic male BALB/c mice aged 6-8 weeks and weighing 15-20 g were randomly assigned to 8 groups. The animals received polyethylene tube implants as follows: Groups I, II, and III (n=10) - Calen® paste mixed with 0.4 percent CHX (experimental paste; Calen/CHX) for 7, 21, and 63 days, respectively; Groups IV, V, and VI (n=10) - UltraCal™ paste mixed with 2 percent CHX (experimental paste supplied by Ultradent Products Inc.; Ultracal/CHX) for 7, 21, and 63 days, respectively; and Groups VII and VIII (n=5): empty tube for 7 and 21 days, respectively. At the end of the experimental periods, the implants were removed together with the surrounding tissues (skin and subcutaneous connective tissue). The biopsied tissues were subjected to routine processing for histological analysis. Using a descriptive analysis and a four-point (0-3) scoring system, the following criteria were considered for qualitative and quantitative analysis of the tissue around the implanted materials: collagen fiber formation, tissue thickness and inflammatory infiltrate. A quantitative analysis was performed by measuring the thickness (µm), area (µm²) and perimeter (µm) of the reactionary granulomatous tissue formed at the tube ends. Data were analyzed statistically by the Kruskal-Wallis test and Dunn's post-test (á=0.05). Calen/CHX showed biocompatibility with the subcutaneous and reactionary tissues, with areas of discrete fibrosis and normal conjunctive fibrous tissue, though without statistically significant difference (p>0.05) from the control groups. In Groups I to III, there was a predominance of score 1, while in Groups IV to VI scores 2 and 3 predominated for all analyzed parameters. UltraCal/CHX, on the other hand, induced the formation of an inflammatory infiltrate and abundant exudate, ...

O objetivo do presente estudo foi avaliar a resposta do tecido conjuntivo subcutâneo de camundongos isogênicos frente a pastas à base de hidróxido de cálcio, associadas ao digluconato de clorexidina (CHX). Setenta camundongos isogênicos BALB/c machos, com 6-8 semanas e pesando 15-20 g foram aleatoriamente divididos em 8 grupos. Os animais receberam implantes de tubos de polietileno contendo: Grupos I, II e III (n=10) - pasta Calen® associada à CHX a 0,4 por cento (Calen/CHX), por 7, 21 e 63 dias, respectivamente; Grupos IV, V e VI (n=10) - pasta UltraCal™ associada à CHX a 2 por cento (pasta experimental fornecida pela Ultradent Products Inc.; Ultracal/CHX), por 7, 21 e 63 dias, respectivamente; e Grupos VII e VIII (n=5) - tubo de polietileno vazio, por 7 e 21 dias, respectivamente. Decorridos os períodos experimentais, os implantes foram removidos juntamente com os tecidos circundantes (pele e tecido conjuntivo). Os tecidos foram submetidos ao processamento histotécnico de rotina, para análise histopatológica. Empregando um sistema de escores, os seguintes critérios foram considerados para a análise qualitativa e quantitativa: fibrosamento, espessura tecidual e infiltrado inflamatório. Foi efetuada, também, a análise quantitativa da medida da espessura (µm), área (µm²) e perímetro (µm) do tecido granulomatoso reacional formado na abertura dos tubos. Os dados obtidos foram submetidos à análise estatística, empregando o teste de Kruskal-Wallis e o pós-teste de Dunn. O nível de significância adotado foi de 5 por cento. Os resultados demonstraram biocompatibilidade da pasta Calen associada à CHX a 0,4 por cento com o tecido adjacente, com fibrosamento discreto, assim como tecido conjuntivo normal, sem diferença estatística significante com os controles (p>0,05). Nos Grupos I, II e III houve predominância do escore 1, enquanto que nos Grupos IV, V e VI houve predominância dos escores 2 e 3, em todos os parâmetros analisados. Em relação ...

Effect of a calcium hydroxide-based paste associated to chlorhexidine on RAW 264.7 macrophage cell line culture.

OBJECTIVE: The objective of this study was to evaluate the effect of a calcium hydroxide Ca(OH)(2)-based paste (Calen) associated or not to 0.4% chlorhexidine digluconate (CHX) on RAW 264.7 macrophage cell line culture. STUDY DESIGN: The cell viability (MTT assay), immunostimulating properties (NO dosage), and anti-inflammatory properties (NO, TNF-alpha, and IL-1alpha dosage) were evaluated after cell exposure to the materials. Data were analyzed statistically by Kruskal-Wallis test at 5% significance level. RESULTS: There was low immunostimulating activity of the Calen paste associated or not to 0.4% CHX in the different materials' concentrations evaluated (P > .05). Anti-inflammatory activity with inhibition of NO and cytokine (TNF-alpha and IL1-alpha) release was observed only with Ca(OH)(2) + CHX at the highest concentration (25 microg/mL). CONCLUSION: As the Calen paste associated to 0.4% CHX did not alter cell viability or the immunostimulating and anti-inflammatory properties, the addition of CHX brought no benefits to the Ca(OH)(2)-based paste with regard to the tested parameters.

Do endodontic compounds induce genetic damage? A comprehensive review.

Taking into consideration genetic damage plays an important role in carcinogenesis, the purpose of this paper is to provide an overview on the genotoxic potential of some endodontic compounds currently used in dentistry, such as formocresol, paramonochlorophenol, calcium hydroxide, resin-based sealers, phenolic compounds, chlorhexidine, mineral trioxide aggregate, and others. Some of these compounds appear capable of exerting noxious activity on the genetic material. The action mechanisms are discussed. Therefore, this is an area that warrants investigation since the estimation of risk of these substances with respect to genotoxicity will be added to those used for regulatory purposes in improving oral health and preventing oral carcinogenesis.