Effect of Acetylcholinesterase on the Cytotoxicity of Acrylic Reline Resins

Method: Disc shaped specimens (n=6) of each of three acrylic reline resins, Kooliner (K), Ufi Gel Hard (U) and Probase Cold (P), were divided into control and experimental groups and immersed in 5mL of Dulbecco’s Modified Eagle’s Medium (DMEM). 5 U/mL of AChE was added to specimens of experimental group every 24h, for 3 days. The in vitro cytotoxicity of their eluates was measured by the MTT reduction assay and the release of LDH in cultured adult human dermal fibroblasts. Enzyme, negative and positive controls were included in each assay. Mann-Whitney tests were used to compare cell viability between control and experimental groups, at a significance level of 5%.

Result: Control K specimens exhibited a severely cytotoxic potential, whereas control U diminished cell’s viability in 49%, revealing a moderately cytotoxic potential. Specimens submitted to AChE presented an increase in cell viability in both materials (p<0.05), without changing the severity of their cytotoxic potential. Material P showed to be a non-cytotoxic material, in both groups. LDH assay didn´t revealed differences between control and experimental groups, considering all three materials.

Conclusion: This study shows that AChE diminishes the cytotoxic effect of two acrylic reline resins, without changing their cytotoxic potential. Also, MTT test was found to be more sensitive than the LDH assay when assessing the cytotoxic effect of the evaluated biomaterials.