Snus is a type of smokeless tobacco widely used in the Nordic countries. A range of adverse health effects is associated with use of snus, and it is suggested that nicotine may mediate many of these effects.
A major component in most resin based dental restoratives is methacrylate monomers. Commonly, these materials polymerize in situ, but due to incomplete conversion, methacrylates leak after curing. Methacrylate monomers are able to induce biological effects including cell death in vitro. Snus users that receive dental treatment with resin based dental materials are exposed to a mixture of methacrylates and nicotine. Although many studies have described the effects of methacrylates and HEMA individually, the knowledge of combined exposure effects is scarce. The aim of this study was to compare individual and combined exposure to nicotine and HEMA on cell viability.
The human oral squamous carcinoma cell line PE/CA-PJ49 was exposed to HEMA (2-4 mM) and nicotine (10 mM). The number of viable cells was measured using MTT assay. To analyze differences between treatment groups one-way ANOVA and Tukeys multiple comparisons test was used in GraphPad Prism software.
Exposure to HEMA caused a dose dependent decrease in PJ49 cell viability whereas nicotine exposure had no measurable effect. Compared to HEMA exposure alone, exposure to HEMA and nicotine in combination further reduced the cell viability for the concentrations investigated.
The reduction in cell viability after the combined exposure to HEMA and nicotine are significantly higher than the individual effects. This could imply that nicotine exposure amplify potential adverse effects of HEMA exposure. Further studies to elucidate the mechanisms causing this amplification are needed.
Tarja Tanner (Presenter), University of Oulu, Institute of Dentistry
Håkon Rukke, Nordic Institute of Dental Materials (NIOM)
Rune Becher, Nordic Institute of Dental Materials (NIOM)
Jan Tore Samuelsen, Nordic Institute of Dental Materials (NIOM)
This poster was presented at the 2018 IADR conference in London, UK.