In vitro analysis of the cytotoxicity of indirect restorative materials

Abstract This study aimed to compare the cytotoxicity of the Vita AC12, Lava Ultimate, Vita Enamic and InSync indirect restorative materials. Extracts of each material were prepared by incubation for 1, 7 and 40 days, with daily washing. Human gingival fibroblasts were exposed to the extracts, and cell viability was evaluated by sequential assessment of mitochondrial activity (XTT), membrane integrity (NRU) and cell density (CVDE). Extracts of polystyrene beads and latex fragments were used as negative and positive controls, respectively. Differences between groups and experimental times were evaluated by analysis of variance. At the 24 h extraction, significant differences between the control and both Vita AC-12 and InSync were observed in the XTT assay (p<0.05), and between the control and both Enamic and Lava Ultimate, in the CVDE assay (p<0.05). AC12, Lava Ultimate, and InSync presented significantly lower cell viability than Enamic and the control group, in the NRU assay (p<0.05). The Vita Enamic and Lava Ultimate hybrid ceramic-like materials presented better biocompatibility at the 24 h extraction time point than the AC12 and InSync ceramic materials. However, a simulation of the removal of toxic components by biological fluids, conducted by using longer extraction times and daily washing, led to the absence of cytotoxicity in all the tested restorative materials. These findings can be viewed as positive for the clinical indication of these restorative materials, considering their contact with adjacent soft tissues for extended periods of time.

Resumo Este estudo teve como objetivo comparar a citotoxicidade dos materiais restauradores indiretos Vita AC12, Lava Ultimate, Vita Enamic e InSync. Extratos de cada material foram preparados por incubação por 1, 7 e 40 dias, com lavagem diária. Fibroblastos gengivais humanos foram expostos aos extratos e a viabilidade celular foi medida por avaliação sequencial da atividade mitocondrial (XTT), integridade da membrana (NRU) e densidade celular (CVDE). Extratos de esferas de poliestireno e fragmentos de látex foram utilizados como controles negativos e positivos, respectivamente. As diferenças entre os grupos e os tempos experimentais foram avaliadas por análise de variância. Na extração de 24 h, observaram-se diferenças significativas entre o controle e Vita AC-12 e InSync no teste do XTT (p<0,05) e entre o controle e os materiais Enamic e Lava Ultimate, no teste CVDE (p<0,05 ). AC12, Lava Ultimate e InSync apresentaram viabilidade celular significativamente menor do que o Enamic e o grupo controle, no ensaio NRU (p<0,05). Os materiais cerâmicos híbridos Vita Enamic e Lava Ultimate apresentaram melhor biocompatibilidade no ponto de tempo de extração de 24 h do que os materiais cerâmicos AC12 e InSync. No entanto, uma simulação de remoção de componentes tóxicos por fluidos biológicos, realizada com o uso de tempos de extração mais prolongados e lavagem diária, levou à ausência de citotoxicidade em todos os materiais restauradores testados. Esses achados podem ser vistos como positivos para a indicação clínica desses materiais restauradores, considerando seu contato com tecidos macios adjacentes por longos períodos de tempo.

Analysis of radiopacity, pH and cytotoxicity of a new bioceramic material

AbstractObjective RetroMTA® is a new hydraulic bioceramic indicated for pulp capping, perforations or root resorption repair, apexification and apical surgery. The aim of this study was to compare the radiopacity, pH variation and cytotoxicity of this material to ProRoot® MTA.Material and Methods Mixed cements were exposed to a digital x-ray along with an aluminum stepwedge for the radiopacity assay. pH values were verified after incubation period of 3, 24, 48, 72 and 168 hours. The cytotoxicity of each cement was tested on human periodontal ligament fibroblasts using a multiparametric assay. Data analysis was performed using ANOVA and Tukey’spost hoc in GraphPad Prism.Results ProRoot® MTA had higher radiopacity than RetroMTA®(p<0.001). No significant differences were observed for the pH of the materials throughout experimental periods (p>0.05) although pH levels of both materials reduced over time. Both ProRoot® MTA and RetroMTA® allowed for significantly higher cell viability when compared with the positive control (p<0.001). No statistical difference was observed between ProRoot® MTA and RetroMTA® cytotoxicity level in all test parameters, except for the ProRoot® MTA 48-hour extract media in the NR assay (p<0.05).Conclusion The current study provides new data about the physicochemical and biological properties of Retro® MTA concerning radiopacity, pH and cytotoxic effects on human periodontal ligaments cells. Based on our findings, RetroMTA® meets the radiopacity requirements standardized by ANSI/ADA number 572, and similar pH values and biocompatibility to ProRoot® MTA. Further studies should be performed to evaluate additional properties of this new material.

Sintomas respiratórios como indicadores de estado de saúde em trabalhadores de indústrias de cerâmicas / Respiratory symptoms as health status indicators in workers at ceramics manufacturing facilities

OBJETIVO: Analisar a prevalência de sintomas respiratórios e sua associação com as características sociodemográficas e do ambiente de trabalho. MÉTODOS: Estudo transversal realizado com 464 trabalhadores das indústrias de cerâmicas localizadas no município de Várzea Grande (MT). Para a coleta de dados, foi aplicado um questionário constituído de questões referentes às características sociodemográficas, ambiente de trabalho e sintomas respiratórios. Para a análise dos dados, foi utilizada a razão de prevalência e seu respectivo IC95 por cento entre a variável dependente (sintomas respiratórios) e as demais variáveis explicativas. Na análise multivariada, foram construídos dois modelos hierárquicos, tendo como resposta as variáveis "sintomas respiratórios gerais" e "sintomas respiratórios graves". RESULTADOS: Na população estudada, a prevalência de "sintomas respiratórios gerais" foi de 78 por cento, e aquela de "sintomas respiratórios graves" foi de 35 por cento. Os fatores associados a "sintomas respiratórios gerais" foram sexo, faixa etária, escolaridade, ocupação, exposição à poeira e exposição a produto químico. Os fatores associados a "sintomas respiratórios graves" foram escolaridade, exposição à poeira e exposição a produto químico. CONCLUSÕES: Os resultados apontam para a presença de doenças da via aérea superior e inferior na população estudada.

OBJECTIVE: To assess the prevalence of respiratory symptoms and their association with sociodemographic variables and with the characteristics of the work environment. METHODS: A cross-sectional study comprising 464 workers employed at ceramics manufacturing facilities located in the city of Várzea Grande, Brazil. Data were collected by means of a questionnaire comprising questions regarding sociodemographic variables, work environment characteristics, and respiratory symptoms. Data were analyzed by means of prevalence ratios and their respective 95 percent CIs between the dependent variable (respiratory symptoms) and the other explanatory variables. In the multivariate analysis, two hierarchical models were built, the response variables being "all respiratory symptoms" and "severe respiratory symptoms". RESULTS: In the sample studied, the prevalence of "all respiratory symptoms" was 78 percent, whereas that of "severe respiratory symptoms" was 35 percent. The factors associated with "all respiratory symptoms" were gender, age bracket, level of education, type of occupation, exposure to dust, and exposure to chemical products. The factors associated with "severe respiratory symptoms" were level of education, exposure to dust, and exposure to chemical products. CONCLUSIONS: Our results indicate the presence of upper and lower airway disease in the population studied.

Biosilicate® Ototoxicity and Vestibulotoxicity evaluation in guinea-pigs / Avaliação da ototoxicidade e vestibulotoxicidade do biosilicato® em orelhas de cobaias

Changes, destructions and interruptions in middle ear ossicular chain architecture may be caused by infection, trauma, tumors, congenital alterations or prior surgeries. Nonetheless, infectious and inflammatory processes, focal or generalized which affect the middle ear are the most prevalent, causing a great demand for ossiculoplasty. Biosilicato® is a new material which can be used in the middle ear with the goal of reconstructing the ossicular chain. It is a bioactive type A vitroceramic, in other words, it binds to bone or soft tissue in a matter of a few hours, thanks to the formation of hydroxy-carbonateapatatie in its contact surface when in contact with body fluids. AIMS: The goal of the present paper is to assess biosilicate ototoxicity and vestibular toxicity in experimental animals, for later use in humans. MATERIALS AND METHODS: This a clinical and experimental study in which otoacoustic emissions were performed before and after the placement of Biosilicate in the middle ear of experimental animals and a scanning electron microscopy was carried out in the cochlea, saccule, utriculus and macula of the semicircular canals after 30 and 90 days to assess oto and vestibular toxicity. RESULTS: There were no signs of oto or vestibular toxicity in any of the groups associated with biosilicate. CONCLUSION: Biosilicate is a safe material to be used in ossiculoplasties

As alterações, destruições e interrupções da arquitetura da cadeia ossicular da orelha média podem ser causadas por infecções, trauma, tumores, alterações congênitas ou cirurgias prévias. Entretanto os processos inflamatórios e infecciosos, focais ou generalizados que acometem a orelha média são os mais prevalentes, gerando uma enorme demanda de ossiculoplastias. O Biosilicato® é um novo material que pode ser usado em orelhas médias com o objetivo de reconstruir a cadeia ossicular. Constitui-se de uma vitrocerâmica bioativa do tipo A, ou seja, que se liga a tecido ósseo ou a tecido mole em algumas horas, devido à formação de hidroxicarbonatoapatita em sua superfície de contato quando em contato com fluidos corpóreos. OBJETIVO: O objetivo deste trabalho é avaliar a ototoxicidade e vestibulotoxicidade do Biosilicato em cobaias, para posterior utilização em humanos. MATERIAL E MÉTODO: Trata-se de um estudo clínico e experimental, onde foram realizadas emissões otoacústicas antes e após a colocação de Biosilicato na orelha média de cobaias e realizada microscopia eletrônica de varredura da cóclea, sáculo, utrículo e máculas dos canais semicirculares após 30 e 90 dias para avaliar a oto e vestibulotoxicidade. RESULTADOS: Não houve sinais de oto ou vestibulotoxicidade em nenhum dos grupos relacionados ao Biosilicato. CONCLUSÃO: O Biosilicato é um material seguro para ser usado em ossiculoplastias.

Cytotoxicity of cold ceramic compared with MTA and IRM

Biocompatibility is a desirable feature for root-end filling materials. In this study we aimed to compare a new material called cold ceramic [CC] with intermediate restorative material [IRM] and mineral trioxide aggregate [MTA] using Methyl-tetrazolium bromide [MTT] assay. The materials were tested in fresh and set states: [n=108]. The cytotoxicity was compared using L929 fibroblasts as an indicator; tested materials were eluted with culture medium according to ISO: 109935 standard. Distilled water and culture medium served as positive and negative controls, respectively [n=36]. The results were evaluated at 1, 24 hours and 7 days. Data were statistically analyzed by one-way ANOVA for each time interval and material status and t-tests. The cytotoxicity of the tested materials were statistically different at the various time intervals [P<0.001]. IRM was the most cytotoxic root-end filling material [P<0.001], MTA demonstrated the least cytotoxicity followed by CC. Despite displaying the greatest cytotoxicity, IRM is approved by the American Food and Drug Administration [PDA]. Cold ceramic had significantly lower cytotoxicity compared to IRM, in all but one subgroup. Further investigations are required to assess the clinical applicability of this novel material

Concentracion de plomo en sangre de ninos de familias alfareras / Lead concentration in the blood of children in families of potters

La ingestión directa o indirecta de sales de plomo al elaborar ceramica con barro vidriado es una de las fuentes de intoxicacion por plomo en México. En el presente estudio se indica el elevado riesgo de intoxicacion cronica en ninos de familias alfareras que utilizan compuestos de plomo para el acabado de las piezas