AbstractsChemistry

Light-curable epoxy resins, methacrylate-based resins in particular, were a major improvement to the dental field, especially to orthodontic treatments. Indeed they provide a strong bonding of the bracket to the enamel while requiring the minimal amount of work as they do not require mixing time and only take a few second to polymerise when submitted to the proper wavelength. However, if optimal polymerisation is not met, or if the resin is submitted to wet conditions while still uncured, methacrylate monomers are known to leach out in the mouth environment. Besides being potentially harmful, cytotoxic, and the cause of bad, or incomplete treatments, these leakages create an extremely bitter aftertaste forcing the practitioner to rush their work, leading to improper polymerisation. In this work, a natural sweetener protein was used to modify the taste of the monomers leakage without altering the resins’ properties. The protein chosen, thaumatin, is an intensely sweet protein with a sweetness threshold in the nanomolar range. This flavour adjuvant was successfully added to a methacrylate- based orthodontic epoxy resin before being submitted to water or simulated saliva in order to analyse the leakage. Significant differences were found between the release in water and the release in simulated saliva. Mechanical tests were performed to see the effects, if any, the protein had on the dental resin properties, such as microhardness and rate of conversion during the polymerisation process. The studies performed for this Thesis, suggest that using a protein, such as thaumatin, is a viable method to modify the taste of the dental composite leakage without weakening the composite’s structural integrity.