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ABSTRACT Aim: This study evaluated cytotoxicity and antioxidant gene expression of resin cements on human gingival fibroblasts (hGF). Materials and Method: RelyX Ultimate™(RXU), Variolink™II(VLII), and RelyXU200™(RXU200) resin cements were incubated with culture medium for 24 h to obtain eluates. Then, the eluates were applied over hGF to assess cell viability at 24 h, 48 h, and 72 h and antioxidant gene expression at 24 h. hGF cultures non-exposed to the eluates were used as Control. Data were submitted to ANOVA and Bonferroni tests (α≤0.05). Results: RXU and RXU200 reduced the number of viable cells in 24 h. Longer exposure to cement extracts caused cell death. Gene expression showed peroxiredoxin 1 (PRDX1) induction by all resin cement types, and superoxide dismutase 1 (SOD1) induction by RXU200 and VLII. Moreover, RXU200 induced not only PRDX1 and SOD1, but also glutathione peroxidase 1 (GPX1), catalase (CAT), and glutathione synthetase (GSS). Conclusions: All resin cements showed toxicity, and induced antioxidant genes in hGF. Antioxidant gene induction is at least partly associated with cytotoxicity of tested cements to oxidative stress experience.
RESUMO Objetivo: O objetivo deste estudo foi avaliar a toxicidade dos cimentos resinosos Rely X Ultimate 2, Rely X U200 e Variolink II, bem como sua influência na expressão de genes antioxidantes em fibroblastos gengivais humanos. Materiais e Método: Corpos de prova de cada cimento foram colocados em meio de cultura por 24 h e os extratos correspondentes foram aplicados aos fibroblastos. A viabilidade celular foi avaliada após 24, 48 e 72 h de exposição pelo ensaio de exclusão do azul de tripano e MTT. A expressão gênica foi avaliada por PCR quantitativo após 24 h de exposição aos extratos. Estes parâmetros foram comparados aos das células não expostas aos cimentos. Os dados foram submetidos ao teste ANOVA, seguido pelo pós-teste de Bonferroni (a≤0.05). Resultados: Os resultados demonstraram que todos os cimentos promoveram redução do número de células viáveis e da atividade mitocondrial nos períodos de 48 e de 72 h (p < 0,01), sendo que o Variolink II apresentou o menor efeito e os cimentos Rely X Ultimate e Rely X U200 promoveram similarmente os maiores efeitos. A análise de expressão gênica evidenciou influência significativa em todos os cimentos avaliados sobre os níveis de transcritos de PRDX1, SOD1, GPX1 e GSS (p> 0,05), com um aumento considerável no Rely X U200. Conclusão: A indução de genes antioxidantes está, pelo menos em parte, associada à citotoxicidade dos cimentos testados para a experiência de estresse oxidativo.
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ABSTRACT Melatonin (MLT) is a hormone responsible for regulating several physiological processes. It has been shown that MLT can be an important mediator in bone formation and stimulation, promoting osteoblast differentiation. In clinical practice, in tissue regeneration procedures, it is necessary to use membranes or barriers, associated with biomaterials, or not. The aim of this in vitro study was to assess the effect of melatonin on the activity of osteoblastic cells, associated, or not, with a resorbable collagen membrane (Bio-Gideä). For this, mice-derived pre-osteoblastic cells MC3T3 obtained from the ATCC (American Type Culture Collection) were used. Cultured cells were subject to the following treatments: MLT with a concentration of 1mM, a Bio-Gideä membrane and a membrane associated with MLT (Bio-Gideä + MLT). Proliferation and cell viability assays and protein lysate (ELISA test) quantification for the BMP-2 protein were carried out, in periods of 72 hours, 7 days and 10 days. After analyzing the data (one-way ANOVA, alpha=5%) it was observed that when MLT was used in isolation, there was an increase in cell proliferation and viability in osteoblastic cells (p<0.05). But, when MLT was associated with resorbable membranes, there was an inverse behavior, both in terms of proliferation and viability (p<0.05). In the case of the ELISA test, no secretion of BMP-2 was detected in any of the analyzed groups. It is concluded that MLT has a stimulatory effect on osteoblasts, but, when associated with Bio-Gideä resorbable membranes, it does not show any viable action in osteoblastic cell stimulation.
RESUMO A melatonina (MLT) é um hormônio responsável pela regulação de diversos processos fisiológicos no nosso organismo. Tem sido demonstrado que a melatonina possa ser um importante mediador na formação e estimulação óssea, promovendo a diferenciação dos osteoblastos. Clinicamente, para o procedimento de regeneração tecidual, faz-se necessário a utilização de membranas ou barreiras, associadas ou não a biomateriais. Assim, o objetivo deste estudo in vitro foi avaliar o efeito da melatonina na atividade de células osteoblásticas, associada ou não a uma membrana de colágeno reabsorvível (Bio-Gide®). Para isto foram utilizadas células pré-osteoblásticas MC3T3 do ATCC (American Type Culture Collection), de camundongos. As células em cultura foram submetidas aos seguintes tratamentos: MLT na concentração de 1mM, membrana Bio Gide® e membrana associada à MLT (Bio-Gide® + MLT). Foram realizados os ensaios de proliferação e viabilidade celular e quantificação do lisado proteico (teste ELISA), para a proteína BMP-2, nos períodos de 72 horas, 7 e 10 dias. Após a análise dos dados (ANOVA um critério, alfa=5%) pode-se observar que a MLT quando utilizada sozinha, resultou em um aumento na proliferação e viabilidade celular nas células osteoblásticas (p<0,05). Entretanto, quando a MLT foi associada à membrana reabsorvível foi observado um comportamento inverso, tanto na proliferação quanto na viabilidade (p<0,05). Para o teste ELISA realizado, não houve secreção detectável de BMP-2 para nenhum grupo analisado. Conclui-se que a melatonina possui uma ação estimuladora nos osteoblastos, mas quando associada à membrana reabsorvível Bio-Gide®, não demonstra uma ação viável na estimulação de células osteoblásticas.
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PURPOSE: The purpose was to evaluate two sedation protocols during dental sessions in anxious children. MATERIALS AND METHODS: It was a randomized and double-blind study, with each individual being his/her own control within each protocol. Furthermore, the two protocols were compared. Twenty children (36 to 84 months old) who exhibited "definitely negative" behavior according to the Frankl scale were assigned to receive oral chloral hydrate (40 mg/kg) (Group I) or Diazepam (5 mg) (Group II). Behavior during local anesthesia, application of rubber dam, cavity preparation, restorative procedures was evaluated, considering the degree of sleep, body movement, crying and overall behavior. Vital signs were assessed at three different times. The Wilcoxon, Mann-Whitney, Exact Fisher's and Spearman correlation tests were used to analyze the data. RESULTS: Group I presented higher scores for sleep during the CH session than placebo session during rubber dam application (P = 0.0431) and restoration (P = 0.0431). In Group II there was no statistically significant difference (p > 0.05). There were no statistically significant differences between sessions and groups in the evaluation of body movement, crying and vital signs. Overall behavior in the placebo session was better than in the CH session during local anesthesia, but there was no difference between the two drug regimens. There was influence of age during anesthesia and cavity preparation in Group I and during rubber dam application in Group II. It was concluded that oral diazepam and chloral hydrate had no influence on the behavior management for dental treatment with the studied sample.