WATER SORPTION AND WATER SOLUBILITY OF 3D PRINTED AND CONVENTIONAL PMMA DEN- TURE BASE POLYMERS

Background: Patients who cannot afford more ex-pensive prosthetic restorations, such as implant-supported fixed prostheses, prefer removable dentures. Removable dentures have been manufactured with different types of acrylics, including conventional polymer polymethyl methacrylate (PMMA) and the popular nowadays three- dimensional (3D) printed resins. Water sorption and water solubility often occur because these prosthetic restorations are constantly immersed in saliva and always have inter-actions with oral fluids.Review results: Alternating processes of imbibition and drying of acrylics lead to internal stresses and fatigue. As a result, dental resins undergo significant dimensional changes. The water diffuses into the dental resin and in-flicts a gradual expansion and volume increase, which may cause aging of the material and discomfort during masti-catory function.Denture base resins have low water solubility, which results from the leaching out of unreacted monomer and soluble additives into the oral cavity. This is an undesired property and may cause soft tissue reactions.Conclusion: The affinity of dental resins for water degrades their mechanical and physical properties and causes dimensional changes in the denture base, which results in internal stresses that have a negative impact on the denture's long-term success.