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

Abstract

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.

Fluorescent poly(hydroxyurethane): Biocompatibility evaluation and selective detection ofFe(III)

“…As for the long‐term cytotoxicity of FPHU, it might be due to some low molecular weight components in PU dissolved in the extract. This was consistent with other reports that PUs had a release of toxic ingredients at 48 h . If possible, GPC is a very suitable method to remove the low molecular weight components.…”

Citotoxicity of nonlatex elastomeric ligatures of orthodontic use

“…Spectrophotometric essay allows rapid and reliable evidence for cell viability to be obtained based on the use of vital stain incorporated by viable cells [23][24]. Dead or damaged cells cannot incorporate vital stain, thus not being recognized on optical reading.…”

Soy protein-modified waterborne polyurethane biocomposites with improved functionality

“…These results agreed with previous reports that polyurethanes may release toxic ingredients within 1-2 days in prepared extracts. 12 In this case, the slight cytotoxicity might come from complex factors. For example, when WPU dispersion was prepared, TEA was added to neutralize the carboxylic groups of DMPA.…”

“…9 WPU retains the excellent exibility of polyurethanes, but is also low toxic, non-polluting, low cost, and has good applicability and safety, 10 properties that are highly appreciated in the eld of tissue engineering; 2 however, it has been reported that WPU displayed slight cell toxicity and slow degradation rate. [11][12][13][14] In view of the extensive application as a tissue engineered scaffold, the cytocompatibility and biodegradability of WPU should be enhanced. The performance of cells attached to materials is mainly affected by the surface hydrophilicity/hydrophobicity, roughness, and microstructure of the materials.…”