Effect of EVA-TiO2 composite interfacial buffer layer in improving the bond strength between PMMA denture base and PDMS liner

Abstract

Polydimethylsiloxane (PDMS) is the most common dental liner that is used with acrylic dentures. A strong bond between the liner and the denture is a must, for the proper functioning and the longevity of the prosthesis. Debonding of the liner may occur due to an inefficient bond with the denture, or low cohesive strength due to wettablility/hydration and water/liquid storage-retention. The increased wettability/hydration pass on the moisture to the acrylic boundary surface causing initiation of debonding process. Hence, in order to prevent the debonding due to wettablility/hydration a novel method of introducing a hydrophobic polymer interfacial buffer layer between the acrylic denture surface and the PDMS liner surface is suggested. In, the present research work, ethylene vinylacetate (EVA) reinforced with titania (TiO2) polymer microfilm composite layer is prepared by solution casting method. The thin polymer film is placed between the acrylic denture surface and the PDMS liner surface and heat cured together to obtain a hydrophobic interfacial buffer layer. Wettability, fluid absorption and retention tests were performed to investigate the hydrophobic properties of the composite interfacial buffer layer. Mechanical strength properties on the prepared specimen (as per ISO 178) revealed that the EVA-TiO2 layer offered superior bonding and also improved the overall mechanical properties of the acrylic dentures without disturbing the mass and density of the denture.