Cell migration, viability and tissue reaction of calcium hypochlorite based-solutions irrigants: An in vitro and in vivo study.

OBJECTIVE: This study aimed to analyze in vitro cytotoxicity to cultured 3T3 fibroblasts and in vivo inflammatory reaction in rats by calcium hypochlorite (Ca(OCl)2) solutions compared with sodium hypochlorite (NaOCl) solutions. DESIGN: Cultured 3T3 fibroblasts were exposed to different concentrations of (Ca(OCl)2) and NaOCl solutions, and a scratch assay was performed. The viability rate was analyzed with trypan blue assay. Both solutions of 1% and 2.5% concentrations were injected into the subcutaneous tissue of 18 male Wistar rats aged 18 weeks. The inflammatory tissue reaction was evaluated at 2h, 24h, and 14days after the injections. The samples were qualitatively analyzed using a light microscope. Statistical analysis was performed with ANOVA and Tukey post hoc tests for in vitro assays and Kruskal-Wallis and Dunn post hoc tests for in vivo assays (α=0.05). RESULTS: In the scratch assay, Ca(OCl)2 showed no significant difference compared with the control group (culture medium) at 24h (p<0.05). Solutions of 0.0075% and 0.005% NaOCl and Ca(OCl)2 concentrations presented similar results compared with those in the positive control group (hydrogen peroxide) (p>0.05) in the trypan blue assay. In the in vivo assay, 1% Ca(OCl)2 group showed a significant decrease in neutrophils at 2h and 24h (p=0.041) and 2h and 14days (p=0.017). There was no statistically significant difference for lymphocyte/plasmocyte and macrophage counts among the different concentration groups. CONCLUSIONS: Ca(OCl)2 showed favorable results of viability and induced a low-level inflammatory response. Ca(OCl)2 presented acceptable cytotoxicity and biocompatibility as an irrigant solution.

Mineral trioxide aggregate-based sealer: analysis of tissue reactions to a new endodontic material.

INTRODUCTION: The aim of this study was to evaluate the subcutaneous connective tissue reaction to mineral trioxide aggregate (MTA)-based sealer (Endo CPM Sealer; CPM Sealer; EGEO SRL, Buenos Aires, Argentina), MTA, and an epoxy resin-based sealer (AH Plus; Dentsply HERO Indústria e Comércio Ltda, Petrópolis, RJ, Brazil). METHODS: Polyethylene tubes containing the test materials and empty tubes (control group) were implanted in the subcutaneous tissue of 18 rats. After 7, 30, and 60 days, observations were made for cellular inflammatory components, fibrous condensation, and abscess formation. Comparisons between groups and periods of time were made using the Friedman test and the Kruskall-Wallis test. RESULTS: Lymphocytes and plasmacytes were more intensely observed in the reaction to AH Plus sealer after 30 days (p < 0.05). MTA and the Endo CPM Sealer presented a behavior similar to that of the control group throughout the whole experiment. CONCLUSION: The Endo CPM Sealer presented biological potential. Characteristics of the inflammatory reaction were equivalent to those produced by MTA.

Uso da esteriologia como método na pesquisa histológica / The use of stereology as method in histological research

Na pesquisa em Biologia Bucal freqüentemente são realizados estudos morfométricos de língua, mucosa, glândulas salivares e zonas de osseointegração. Para realização de medições de proporções envolvendo área, volume, número de estruturas, etc, o método estereológico é de grande utilidade. O objetivo deste artigo é descrever um método utilizado para a determinação de pontos amostrais em uma grade, e sua aplicação na análise de imagens em pequisa histológicos de 3 glândulas salivares submandibulares de camundongos como exemplo para explicar o método. A estereologia, quando bem indicada, é uma ferramenta que proporciona excelentes resultados; e sua utilização, quando respeitados os critérios para a determinação do número de pontos amostrais para avaliação de estruturas e tecidos, permite a obtenção de dados confiáveis quando da análise quantitativa de material de origem histológica