Evaluation of the cytotoxicity of polyurethane and non-latex orthodontic chain elastics

allergy caused by latex proteins has been well documented. thus, the study of non-latex materials, is necessary. the aim of this study is to evaluate the cytotoxicity of silver-coloured orthodontic chain elastics, of polyurethane and latex-free. nine chain elastics from different manufactures (3 latex-free and 6 polyurethane) were divided into 9 groups of 10 elastics each: group uk (latex-free, 3m unitek), group tp (látex-free, tp orthodontics), group ao (látex-free, american orthodontics), group o (polyurethane, orthosource), group m (polyurethane, morelli), group td (polyurethane, tecnident), group ud (polyurethane, uniden), group az (polyurethane, abzil) and group ak (polyurethane, aditek). the cytotoxicity essay was performed using cell cultures (l-929 line cells, mouse fibroblast) that were submitted to the cell viability test with neutral red ("dye-uptake") at 1, 2, 3, 7 and 28 days. analysis of variance (anova) with multiple comparisons and tukey's test were employed (p<.05). the results showed no statistically significant differences between groups uk, tp and ao in all experimental times (p>.05), except between the groups uk and tp at 28 days (p<.05). there was significant statistically difference (p<.05) between the viability of the cells in the groups o and td with the groups m, az, ak at 1 and 2 days. the polyurethane elastics showed lower cell viability in the first 48 hours, with increase on 3rd and 7th day, and viability similar to latex-free elastics at 28 days. it can be concluded that the latex-free chain elastic showed higher cell viability. the orthosource and tecnident trademark showed lower cell viability the initial 48 hours.