RESUMO
AIM: To evaluate the effects of the [NaF 12 g L-1 + NaCl 1 g L-1 ] solution used in the electrochemical dissolution process of fractured endodontic files, as well as its NiTi-containing product, on dentine hardness, topography and human fibroblast viability. METHODOLOGY: Sixty single-rooted human teeth were evaluated for dentine microhardness using the Vickers hardness test and the area and number of dentinal tubules by scanning electron microscopy. The samples were divided according to the dentine surface treatment: distilled water; 17% EDTA; [NaF 12 g L-1 + NaCl 1 g L-1 ]; and 17% EDTA + [NaF 12 g L-1 + NaCl 1 g L-1 ]. Thirty-six single-rooted human teeth were divided according to the irrigation protocol: Dulbecco's Modified Eagle's Medium + 10% foetal bovine serum; 5.25% NaOCl; [NaF 12 g L-1 + NaCl 1 g L-1 ]; and [NaF 12 g L-1 + NaCl 1 g L-1 + NiTi]. The extracts in contact with the apical foramen were used in the MTT assay to evaluate human fibroblast viability, with dilutions of 100%, 50%, 25% and 12.5%. Statistical tests used were paired t-tests, one-way anova, Tukey's test, Kruskal-Wallis test and Dunn's post-test. RESULTS: The [NaF 12 g L-1 + NaCl 1 g L-1 ] solution did not modify dentine microhardness or the average dentinal tubule area. However, EDTA induced changes in dentine structure and microhardness (P < 0.05). The [NaF 12 g L-1 + NaCl 1 g L-1 ] solution, and its NiTi-containing product had lower cytotoxicity than NaOCl at dilutions of 25% and 50% (P < 0.01). CONCLUSIONS: The [NaF 12 g L-1 + NaCl 1 g L-1 ] solution did not alter dentine microhardness or damage the dentine structure. It also demonstrated lower cytotoxicity than NaOCl.
Assuntos
Dentina/efeitos dos fármacos , Dentina/patologia , Técnicas Eletroquímicas , Níquel/toxicidade , Preparo de Canal Radicular/instrumentação , Titânio/toxicidade , Adolescente , Técnicas de Cultura de Células , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Criança , Pré-Escolar , Eletrólise , Falha de Equipamento , Fibroblastos/efeitos dos fármacos , Dureza , Humanos , Lactente , Microscopia Eletrônica de Varredura , Níquel/química , Pele , Cloreto de Sódio/farmacologia , Fluoreto de Sódio/farmacologia , Hipoclorito de Sódio/farmacologia , Solubilidade , Fatores de Tempo , Titânio/químicaRESUMO
A survey of 196 samples of corn-based infant foods from 13 cities of Sao Paulo State, Brazil, was carried out to investigate the fumonisin contamination in the products. Based on their ingredients, the products were divided into seven groups: infant cereal designated as types A-D, corn meal, corn starch and instant cereal baby food. Although certain infant food samples were free of fumonisin contamination (<20 microg kg(-1); corn starch and infant cereals of type A, B and D), contamination levels in the other products (corn meal, instant corn-based baby food and cereal type C) were of concern, particularly those in corn meal. All samples in these categories contained fumonisins. The mean level for total fumonisins (FB1 + FB2 + FB3) in corn meal was 2242 microg kg(-1) (maximum 8039 microg kg(-1)), in instant corn-based baby food was 437 (maximum 1096) microg kg(-1) and in infant cereal type C was 664 (maximum 1753) microg kg(-1).