Method: Forty rats (Rattus norvergicus albinus wistar) were divided into 8 groups (n=5). Two plasticized acrylic resin: Dentuflex (DF) and Trusoft (TS), a tissue conditioner: Dentusoft (DS) and a silicon-based: Ufigel (UG) resilient denture liners were tested. Acrylic custom-made palatal devices (Lucitone 550) were relined from dynamic impressions with the resilient liners tested (n=10). One half of the acrylic devices (n=5) was installed without post-polymerization treatment (NT), and the other half (n=5) was immersed in water-bath at 55°C for 10 minutes (HT) before the fixing stage. Rats wore acrylic devices for fourteen days (FR). Surface roughness was recorded immediately after rebasing (IR) and after 14 days (FR) using a Surftest SJ-401 (four readings were made by specimen and mean values were obtained - Ra). The Ra (µm) parameter was chosen to provide conditions for comparison with results of other studies, reflecting the value of the arithmetic mean of all absolute distances of the roughness profile. Data were analyzed by three-way ANOVA and Tukey test (α= 0.05).
Result: NT and HT were not statistically different (P≥ 0.05). IR was not different between all materials tested (P≥ 0.05). TS showed the highest FR compared to DS=DF>UG (P≤ 0.05). FR for UG was significantly lower than DF=DS