Biological tests on an experimental glass ionomer (silicopolyacrylate) cement

The biological compatibility of an experimental glass ionomer (silicopolyacrylate) cement has been assessed in in vitro (cell culture) and in vivo (monkey teeth) tests. For comparison a conventional silicate cement (Super Syntrex) was included in the in vivo experiments. In vitro, the glass ionomer cement was toxic when freshly prepared. The toxicity decreased, however, with increasing setting time. In experiments with prolonged cell-material contact time with specimens which had set for 24 h, the material appeared to be non-toxic. The in vivo experiments confirmed previous reports concerning unfavourable pulp reaction caused by silicate cement, while the glass ionomer cement caused mainly a mild pulp reaction after 8 days of observation. Unfortunately no longer-term observations were obtained since the material had been washed out of the cavities within 36 days.