Silica-filled elastomer/methacrylate systems as soft liners

Long-Term Soft Denture Lining Materials

Long-term soft denture lining (LTSDL) materials are used to alleviate the trauma associated with wearing complete dentures. Despite their established clinical efficacy, the use of LTSDLs has been limited due to the unfavorable effects of the oral environment on some of their mechanical and performance characteristics. The unresolved issue of LTSDL colonization by Candida albicans is particularly problematic. Silicone-based LTSDL (SLTSDL) materials, which are characterized by more stable hardness, sorption and solubility than acrylic-based LTSDLs (ALTSDLs), are currently the most commonly used LTSDLs. However, SLTSDLs are more prone to debonding from the denture base. Moreover, due to their limitations, the available methods for determining bond strength do not fully reflect the actual stability of these materials under clinical conditions. SLTSDL materials exhibit favorable viscoelastic properties compared with ALTSDLs. Furthermore, all of the lining materials exhibit an aging solution-specific tendency toward discoloration, and the available cleansers are not fully effective and can alter the mechanical properties of LTSDLs. Future studies are needed to improve the microbiological resistance of LTSDLs, as well as some of their performance characteristics.

The interaction of various liquids with long-term denture soft lining materials

OBJECTIVES

To study the uptake of liquids, representative of those encountered orally, by long-term denture soft lining materials, and analyze the data in terms of appropriate theories.

METHODS

Four proprietary and one experimental soft lining material were investigated, and the weight change presented as a function of time in both aqueous and organic fluids over the course of a year. A separate experiment determined the equilibrium swelling in ethanol of poly(ethyl methacrylate) and poly(methyl methacrylate).

RESULTS

Uptake date for the five soft lining materials in various aqueous solution, coconut oil and HB307 are reported. The experimental value for the equilibrium swelling of poly(ethyl methacrylate) and poly(methyl methacrylate) in ethanol was reported to indicate the solubility parameter of the system.

SIGNIFICANCE

The results have been analyzed by relevant theoretical models, which have been shown to explain the experimental data.