Surface Roughness of Acrylic and Silicone‐Based Soft Liners: In Vivo Study in a Rat Model

PURPOSE: The aim of this in vivo animal study was to investigate changes in the surface roughness of soft liners over time. MATERIALS AND METHODS: Forty adult Wistar rats (Rattus norvergicus albinus) were fitted with acrylic custom-made palatal plates relined by dynamic impressions and tested with the following soft liners: Dentuflex (DF), Trusoft (TS), Dentusoft (DS), and Ufi Gel P (UG). Half of the animals for each tested material had the plates fitted during the material reline procedure. Their surface roughness was read immediately (IRa group, n = 5). The other half used the palatal plates for 14 days before roughness readings were performed (FRa group, n = 5). The surface roughness (Ra) of the inner surface from the relined dentures was recorded using a Surftest SJ-401 with eight readings per specimen, and mean values were obtained. Data (μm) were analyzed by two-way ANOVA and Tukey's test (α = 0.05). RESULTS: IRa means (2.92 ± 0.87 μm) and FRa means (3.35 ± 0.65 μm) were significantly different (p = 0.016). UG showed a lower (p = 0.01) Ra mean (2.1 ± 0.52 μm) than DF (3.94 ± 0.81 μm), TS (4.12 ± 0.64 μm), and DS (3.27 ± 0.64 μm). CONCLUSIONS: Ufi Gel P showed the smoothest surface among the materials evaluated. The period of use resulted in changes in the surface roughness of the materials tested.