IADR Abstract Archives
Investigation of Hydration, Leaching and Cushioning Effects of Denture Adhesives
Objectives: Previously, formulation understanding of denture adhesives was mainly focused on “hold”. There is therefore a lack of knowledge about other properties such as speed of hydration, leachability and stress absorption capability, which could contribute significantly to in-mouth usage experience. This study aimed to investigate the hydration rate and leachability of two denture fixatives composed of different polymer systems, and assessed their cushioning effects in an artificial jaw.
Methods: Denture adhesives based on either poly(methyl vinyl ether-maleic anhydride) copolymer (PVM/MA) or poly(acrylic acid) (PAA) were tested. For the hydration and leachability assessment, a strip of adhesive with fixed bandwidth was placed between two glass slides. The sample was then immersed in deionized water with images taken for up to 8 hours. Hydration bandwidths were measured hourly. Organic materials leached into water were analyzed over the 8-hour period using gas chromatography with flame ionisation detection (GC-FID). To determine the cushioning capability of the adhesives, formulations were applied between a denture and the artificial jaw. Force was applied to the denture while transferred strains on the gum mimicking layer was captured using a Digital Image Correlation (DIC) system.
Results: At 4 hours, PAA based denture adhesive hydrated with bandwidth increased by a mean of 740µm, whereas PVM/MA based adhesive hydrated by 2250µm. Over 8 hours, a mean of 15.20mg/g of organics were leached from the PVM/MA based adhesive; in contrast, only 4.35mg/g was leached from the PAA based formulation. When applied onto a denture, both adhesives demonstrated a cushioning effect with less strain transferred to artificial gum compared the “no adhesive” control.
Conclusions: This study enabled a comprehensive analysis of denture adhesive properties. The results allowed differentiation between distinct formulations and can potentially better predict in-mouth usage profile of adhesives.
Methods: Denture adhesives based on either poly(methyl vinyl ether-maleic anhydride) copolymer (PVM/MA) or poly(acrylic acid) (PAA) were tested. For the hydration and leachability assessment, a strip of adhesive with fixed bandwidth was placed between two glass slides. The sample was then immersed in deionized water with images taken for up to 8 hours. Hydration bandwidths were measured hourly. Organic materials leached into water were analyzed over the 8-hour period using gas chromatography with flame ionisation detection (GC-FID). To determine the cushioning capability of the adhesives, formulations were applied between a denture and the artificial jaw. Force was applied to the denture while transferred strains on the gum mimicking layer was captured using a Digital Image Correlation (DIC) system.
Results: At 4 hours, PAA based denture adhesive hydrated with bandwidth increased by a mean of 740µm, whereas PVM/MA based adhesive hydrated by 2250µm. Over 8 hours, a mean of 15.20mg/g of organics were leached from the PVM/MA based adhesive; in contrast, only 4.35mg/g was leached from the PAA based formulation. When applied onto a denture, both adhesives demonstrated a cushioning effect with less strain transferred to artificial gum compared the “no adhesive” control.
Conclusions: This study enabled a comprehensive analysis of denture adhesive properties. The results allowed differentiation between distinct formulations and can potentially better predict in-mouth usage profile of adhesives.