Abstract
Background: denture liners are frequently used for various applications in prosthetic dentistry. Purpose: Evaluate the effect of two types of plasticizers on the hardness, elastic modulus and water solubility and to study the changes induced after the incorporation of the additives used in this study. Methods: Soft liner specimens made of acrylic were created by mixing two distinct concentrations of (2% and 5%) % wt of plasticizers glycerol and Di-2-ethylhexyl phthalate (DEHP) plasticizers. The surface hardness of the modified soft liner, the disk-shaped specimens of 30 mm in diameter and 3 mm in thickness were constructed for the shore (A) hardness test, with Dumbbell-shaped specimens and a central cross- sectional area of (25 × 4 × 2 mm) for elastic modulus and specimens were prepared for water solubility, with the dimension of (10 diameter x 5mm thickness). Fourier transformation infrared (FTIR) study was performed to assess potential chemical reactions between plasticizers and acrylic-based soft liners. Data were analyzed with one-way ANOVA and Duncan's multiple range test. Results: The surface hardness (shore A) of both experimental groups was lower than that of the control group in the modified resin, with the 2% DEHP group exhibiting the lowest elastic modulus values and no statistically significant difference in the amount of water solubility of the control group when compared to that of experimental groups at p ≤ 0.05. No chemical reaction between the soft liner and plasticizers at varied concentrations was observed. Conclusion: The hardness and elastic modulus were decreased with plasticizers, no chemical interaction between soft lining material and plasticizers.