Effect of Denture Cleansers on Properties of Various Denture Materials

Objectives: Assess the effect of denture cleansers on color stability, surface hardness, surface roughness, and flexural strength of 3D-printed and heat polymerized denture acrylics.
Methods: A total of 216 disc specimens (12 mm × 2mm) were made from each material: Lucitone Digital Print, DENTCA Denture Base II, Formlabs denture resin, and Lucitone 199 and divided into four treatments: Efferdent, Polident, dish soap, and water. Specimens were exposed to a total of 28 cycles of immersion in denture cleanser, while being stored in water at 37C. Baseline values were obtained for color (i7 Spectrophotometer, delta E using CIE L*a*b*), Vickers microhardness, Ra surface roughness (Mitutoyo Surftester), and biaxial flexural strength (Instron). Color, surface roughness, and surface hardness values were obtained at the 8^th, 16^th, and 28^thcycles. Biaxial strength was tested at the 28^th cycle. Data was analyzed using the Tukey HSD test (=0.05) and MANOVA test (=0.05)
Results: Lucitone 199 had the largest color change when exposed to dish soap. Lucitone 199 and Lucitone Digital Print had the lowest microhardness values after exposure to treatments. Initially, surface roughness was higher for all 3D specimens. Lucitone 199 had the largest increase in surface roughness with exposure to Efferdent and Polident, Surface roughness of 3D printed specimens did not significantly increase with exposure to treatments. Lucitone 199 had the lowest flexural strength in both treatment and control groups compared to 3D-printed materials. Formlabs had the greatest decrease in biaxial flexural strength.
Conclusions: 3D-printed materials were more color stable than heat-polymerized Lucitone 199. Lucitone 199 had a smoother initial surface but had a significant increase. 3D-printed materials had no significant change in roughness. Biaxial flexural strength of all materials decreased significantly with the exposure to all treatments.