Effects of Soft Denture Liners on L929 Fibroblasts, HaCaT Keratinocytes, and RAW 264.7 Macrophages

The effects of six soft liners (Ufi Gel P (UG), Sofreliner S (SR), Durabase Soft (D), Trusoft (T), Coe Comfort (CC), and Softone (ST)) on L929, HaCat, and RAW 264.7 cells were investigated. Eluates (24 and 48 h) from the materials were applied on the cells and the viability, type of cell death, and morphology were evaluated. Cells were also seeded on the specimens' surfaces (direct contact) and incubated (24 or 48 h), and viability was analyzed. Controls were cells in culture medium without eluates or specimens. For cell viability, no significant differences were found among materials or between extraction periods, and the liners were noncytotoxic or slightly cytotoxic. Morphology of RAW 264.7 cells was altered by the 24 h eluates from CC and D and the 48 h eluates from SR, CC, and D. The 24 and 48 h eluates from all materials (except T) increased the percentages of L929 necrotic cells. For direct contact tests, the lowest cytotoxicity was observed for UG and SR. Although eluates did not reduce viability, morphology alterations and increase in necrosis were seen. Moreover, in the direct contact, effects on viability were more pronounced, particularly for D, T, CC and ST. Thus, the use of UG and SR might reduce the risk of adverse effects.