Abstract
High-performance liquid chromatography coupled to an ultra-violet detector method was used to monitor the elution profile of methyl methacrylate monomer from poly (methyl methacrylate) resin produced by various polymerization modes. Three types of polymer were investigated, one auto-polymerised, one heat-polymerised, and a microwave-polymerised resin type. The study was conducted on five discs from each type in both distilled water and artificial saliva.
The results showed that the three resins demonstrated a rapid dumping of their residual methacrylic acid whereas their un-polymerised methyl methacrylate monomer continued to leach out to both artificial saliva and distilled water throughout the five-week test period. It was shown that the three resins differed significantly (p< 0.05) in the elution profile of their methyl methacrylate, with the microwave-polymerised type showing the highest amount of leached out monomer whereas the heat-polymerised type showed the lowest amount of monomer diffusion. The results also showed that the amount of eluates leached out from the investigated polymers into the artificial saliva was larger than into water.
The findings of this study warned that the risk of a chemical trauma to the oral soft tissues is significant and imminent immediately after delivery of a newly constructed prosthesis. Such a trauma, however, could be substantially minimised by immersing the oral appliances in water for one week before insertion.