The induction of micronuclei in V79 cells by the root canal filling material AH Plus

The in vitro micronucleus test (MNT) is an alternative to the chromosomal a berration assay for the detection of chromosomal mutations. Here, the epoxy resin-based root canal filling material AH Plus, the compounds paste A and paste B were tested for cytotoxicity and the induction of micronuclei in V 79 cells. Paste A is the epoxy-resin-containing compound. AH Plus was teste d immediately after mixing and after a setting time of 24 h. The materials were eluted in dimethyl sulfoxide (DMSO) and physiologic saline for 24 h. D MSO eluates of the mixed material, paste A and paste B clearly reduced the viability of V79 cells, but eluates prepared with physiological saline were at least 10-100-fold less toxic. Likewise, freshly mixed AH Plus was mutag enic in a dose-dependent manner in V79 cells after elution in dimethyl sulf oxide only. The numbers of micronuclei were about 7-fold higher in treated cell cultures compared with untreated controls. No mutagenicity was observe d with DMSO and physiological saline eluates of mixed AH Plus set for 24 h. DMSO eluates of paste A induced effects similar to the freshly mixed AH Pl us, and paste B was not effective. Therefore, we provide evidence for the i nduction of chromosomal mutations by freshly mixed AH Plus under experiment al conditions. (C) 2000 Elsevier Science Ltd. All rights reserved.