The Effect of Denture Base Surface Treatments on Microlekage of Soft Lining Materials

Aims: To evaluate the effect of two acrylic resin denture base surface trearments on microleakage of 4 soft denture lining materials (Tru–soft, Bony plus, UfiGel–P and Molloplast–B after 2 periods of storage and thermalcycling. Materials and methods: One hundred eighty specimens for microleakage were prepared in a disc shape 30 mm diameter and 4 mm thickness (2 mm for acrylic resin part and 2 mm for soft lining material part). Soft lining materials were bonded to three different groups of acrylic resin surface pretreatments (untreated, sandblasted and monomer treated denture base). These specimens underwent two aging procedures: Storage with two periods (one week and one month), and 500 cycles of thermalcycling inside 2% methylene blue dye. Results: Statistical analysis showed that treating the acrylic resin denture base by sandblasting increased microleakage of silicone–based linings (UfiGel–P and Molloplast–B)and decreased microleakage of acrylic–based linings (Tru–soft and Bony plus) in comparison to untreated denture base, while treating the denture base with MMA monomer positively decreased microleakage for all tested soft lining materials in relation to untreated and sandblasted denture base at one week storage, one month storage and at thermalcycling. Conclusions: For all types of denture base surface treatments, microleakage was inevitable, however, wetting the acrylic resin denture base with MMA monomer was more effective in reducing microkeakage than sandblasted and untreated denture bases.