Methods: The experimental material containing Tridecafluorooctyl-methacrylate was prepared (FSL). The two commercial products examined were an acrylic-based soft lining material (VertexSoft, VVS) and a silicone rubber-based soft lining material (Molloplast-B, DMB). Cylindrical specimens (10mm in diameter, 10mm high, n=5) were fabricated for each material. The viscoelastic properties of the specimens were measured using a creepmeter. Changes in the displacement of the probe with loading were recorded as immediate elastic displacement after immersion in deionized water at 37°C for 1, 28, 84 or 168 days. The displacement data were statistically analyzed by ANOVA /Tukey's HSD test at a significance level of 0.05.
Results: The immediate elastic displacement values (mm, mean ± sd) were as follows (after 1-, 28-, 84- and 168-day displacement, respectively): 0.40±0.13, 0.40±0.05, 0.39±0.02 and 0.36±0.05 for FSL; 0.41±0.01, 0.20±0.01, 0.18±0.01 and 0.17±0.05 for VVS; and 0.74±0.05, 0.75±0.04, 0.72±0.04 and 0.69±0.04 for DMB. Significant effects (p<0.0001) were found in two main factors (lining materials and immersion period), and their interaction ANOVA. The immersion period significantly decreased the immediate elastic displacements of VVS; however, it did not change the immediate elastic displacements of FSL and DMB (p>0.05).
Conclusions: In the present study, the experimental material FSL appeared to have long-term, stable viscoelastic properties, as did DMB, suggesting that the fluorinated monomer can be applied to soft denture lining materials. This study was supported in part by a Grant-in-Aid for Young Scientists (B) (No. 23792274) from JSPS and in part by a Research Grant for Longevity Sciences (No. 23-20) from the MHLW, Japan.
Keywords: Dental materials, Prosthodontics and Viscoelastic properties
See more of: Dental Materials 7: Polymer-based Materials-Physical Properties and Performance