Compliance of resilient denture liners immersed in effervescent denture cleansers

Six resilient denture liners (RDL) were exposed to two immersion effervescent denture cleansers to evaluate change in compliance over a simulated 1 year time interval.

Ten samples of each material, Molloplast B, Mollosil, MPDS-SL, Permasoft, Softline, and Sofreliner were exposed to either Fixodent or Efferdent denture cleanser. A cyclic load was applied in a squarewave fashion to derive a load displacement curve to measure compliance at 0, 7, 30, 180, and 360 simulated days.

All 12 of the material/cleanser combinations demonstrated a significant change in compliance at each time interval relative to baseline. Mollosil had the greatest increase in flexibility from baseline, and MPDS-SL had the smallest increase in flexibility. In general, chairside materials demonstrated greater change in compliance from baseline compared to laboratory materials. Materials subjected to Fixodent cleanser, when averaged over time, were significantly more flexible than materials exposed to Efferdent cleanser.

Exposure of resilient soft liners to two common cleansers resulted in a significant increase in flexibility. This change in flexibility depended slightly, though significantly, on the type of cleanser, and appeared to be more significant with time. In general, chairside materials seemed to change more than laboratory-processed liners. The exception was Permasoft that was fabricated as a laboratory material but behaved like a chairside material.

The initiator of the polymerization reaction rather than the mode of polymerization may be more important in predicting a change in the flexibility of RDLs. Constituents within the oral environment may be more responsible for changes in RDL flexibility than denture cleansers.