Biocompatibility of 3D-Printed Methacrylate for Hearing Devices

The capacity of 3D printing (3DP) technologies to initiate speedy polymerization of solvent-free resins accounts for their utility in the manufacturing of medical devices. Nonetheless, independent biological evaluation of 3D-printed materials is recommended due to the unique parameters of the manufacturing process, which can influence their physical, chemical and biological properties. In this study, E-Shell 450 clear methacrylate indicated for 3DP of hearing devices was examined for biological safety using zebrafish bioassays adapted to Organization for Economic Cooperation and Development (OECD) fish embryo test. In addition, the proprietary material was characterized for composition using headspace gas chromatography–mass spectrometry (GC–MS). To initiate the biological test, newly fertilized zebrafish eggs were cultured on non-treated and ethanol-treated methacrylates in glass petri dishes with ultrapure water, incubated at 28.5 °C and assessed for developmental endpoints of toxicity at 24 h intervals until 96 h. Toxicological data indicate that non-treated methacrylate is extremely toxic in zebrafish bioassays, whereas ethanol-treated counterpart showed a relative lower toxicity possibly due to ethanoic–aqueous interactions as observed by GC–MS. With the current influx of 3D printing materials, users are urged to exercise caution. Operators must also take cognizance of the potential toxicity of the chemicals used in 3DP and implement safety measures to limit their exposure