In order to evaluate the safety of newly developed ingredients of a light-cured resin for a denture rebase, di (trifluoroethoxy) hexamethacryloxyethoxy cyclophosphazene (4PN) and p-N, N-dimethylaminobenzoic acid ethylmethacrylate (DMAB), two studies were undertaken. First, quantitative analysis of 4PN and DMAB extracted into the solutions from a light-cured resin, Light-liner^[○!R] composed of 20% 4PN, 2% DMAB and the other agents, was made by means of a high performance liquid chromatography. Sample strips of Light-liner^[○!R] were dipped into saline or 20v/v% ethanol solution for 3 days and 1 week. The maximum amount of the extracted per 1cm^2 of the surface of the resin strip was 2.8μg in saline and 3.9μg in 20% ethanol. No extraction of 4PN was detected in either solution. Then acute toxicity in male mice of 4PN and DMAB was examined by oral and intraperitoneal administration. In a dose of 13.1g/kg for 4PN and 1.2g/kg for DMAB, both 4PN and DMAB brought no death but a slight change in appearance and behavior, which became unrecognizable in a few days. Body weight gain in mice was hardly restrained by oral administration of either 4PN or DMAB. Body weight was decreased temporarily after intraperitoneal administration of them, and then increased to the control level. Therefore it is assumed that LD_50 value is much higher than the doses in this study concerning both 4PN and DMAB. It is considered that both 4PN and DMAB are practically non-toxic, and application of them scarcely increases the general toxicity of Light-liner^[○!R] which contains 20% of 4PN and 2% of DMAB as far as it is used properly for a denture rebase.
