Characterization of Extractables in Dental Bite Guards using Gas Chromatography and High Performance Time-of-Flight Mass Spectrometry

Dental bite guards are increasingly prescribed by dentists to prevent tooth grinding during sleep. These bite guards are categorized as medical devices and therefore must be characterized according to procedures described in ISO 10993 part 18: Chemical characterization of medical device materials within a risk management process. The purpose of these characterizations is to assess the potential for harmful substances that could transfer to the consumer during use. Over-the-counter dental bite guards were evaluated for this case study with Gas Chromatography and Time-of-Flight Mass Spectrometry (GC-TOFMS). The benefits of GC-TOFMS for highly sensitive non-targeted analyses will be demonstrated for detection and characterization of both volatile and semi-volatile chemical constituents in the dental bite guard products. The volatile chemical constituents were characterized using headspace GC-TOFMS and the semi-volatile chemical constituents were characterized via liquid injection of the extracts obtained from the bite guards. Extractables that were above a calculated analytical evaluation threshold (AET) were characterized and identified in this study. Identifications were determined based on mass spectral library database matches (NIST 23 and Wiley 12) and supporting retention index (RI) determinations. Chemical constituents that did not match to commercial mass spectral libraries were further analyzed using GC with high resolution TOFMS, utilizing a multi-mode ionization source to acquire both electron ionization and chemical ionization spectra on the same source, to aid in structural elucidation. The chemical constituents determined in this characterization included residual monomers, polymer additives, and process impurities. Details will be discussed during this presentation.