Aim: The present study compared in vitro four types of latex
intraoral elastics (5/16 = 7.9 mm, mean load) regarding their possible
cytotoxic effects. Material and Methods: The sample was allocated to
four groups of 24 elastics: Group A (American Orthodontics), Group M
(Morelli), Group T (TP Orthodontics), and Group U (Uniden).
Cytotoxicity assays were performed using cell culture medium containing
epithelioid-type cells (Hep-2 line) derived from human laryngeal
carcinoma. Two methods for evaluating the cytotoxicity, the agar
overlay test and "dye-uptake" test, were employed at two different
moments (0 and 24 h). Data were compared by analysis of variance
(ANOVA) and Tukey's test (p<0.05). Results: The results showed
statistically significant difference (p<0.05) between Groups T and
M, T and U, A and M, and A and U, for dye-uptake test at 0 and 24 h. No
cell lysis was found in Groups T and A for the agar overlay test,
whereas 80% cell lysis was found in Groups M and U after 24 h according
to the Stanford's response index (RI). Conclusion: Both TP
Orthodontics and American Orthodontics elastics evoked less cell lysis
than Morelli and Uniden elastics
