Microleakage study of various soft denture liners by autoradiography: effect of accelerated aging

The longevity of soft denture liners is a major clinical problem. Debonding of the soft liner from the denture base material is one of the factors that influence their longevity. Debonding of the soft liner can be attributed to microleakage at the interface.

This study investigated microleakage at the interface of various soft liners and base materials.

Six soft liners were investigated. Forty specimens of each material in disk form (10 mm in diameter, thickness of approximately 4 mm) were prepared. Twenty specimens of each material were stored in an accelerated weathering tester for 900 hours. For 2 days, all disks were immersed in (45)Ca radioisotope solution, then they were embedded in acrylic resin blocks and sectioned longitudinally. Autoradiographic imaging was used to determine microleakage at the interface of the soft liners and their bases.

Significant differences between nonaged materials were found (P<.05).The difference between Molloplast B and Mucopren (silanized) was not significant (P<.05). Differences among aged materials were significant (P>.05). Differences between Mucopren (nonsilanized), Mucopren (silanized), and Ufigel P-Tokuyama were not significant (P<.05). Significantly decreased microleakage characteristics were determined for Molloplast B, Mucopren (nonsilanized) and Ufigel P liners after aging.

Microleakage of Mucopren and Molloplast B lining materials was the lowest. However, the microleakage of Flexor and Simpa was the highest. The aging process did not significantly affect the microleakage characteristics of the Simpa, Flexor, Mucopren (silanized), or Tokuyama materials. Molloplast B, Mucopren (nonsilanized), and Ufigel P materials should significantly decrease microleakage properties after aging.