Evaluation of Microleakage of Soft Liners to Highly Impact Acrylic Resin

Aims: To evaluat the microleakage of four types of soft Liners materials(Vertex, Molloplast B, Bony plus and Silicon promedica) with different surface treatment: acetone, monomer, and laser at different period of storage to highly impact acrylic resin. Materials and Methods: Two hundred and forty specimens for microleakage have been prepared , each specimens consists of two parts: acrylic resin denture base part (30mm) diameter , ( 2mm) thickness of acrylic resin and (30mm) diameter, (2mm) thikness of soft liners. Soft denture liners bonded to three different groups of surface treatment: acetone, monomer, laser treated to denture base resin. Microleakage specimens underwent three aging procedures: storage at one week, one month without thermocyling and one month with thermocyling inside 2% methylen blue dye in 600 cycles. Results: The results showed that microleakage of Vertex and Molloplast_B in one week and in one month without thermocyling were the lowest value from the other types , in one month with thermocyling the vertex was the lowest of microleakage than others.Treating the surface of denture bases with acetone and monomer had the highest value of microleakage from other types of surface treatment in one week ,while in one month without thermocyling and one month with thermocycle, there were no significant difference in microleakage among the the different types of surface treatment of acrylic resin Conclusions: Permanent soft liner of acrylic type (vertex) had the lowest values of microleakage after different periods of storage and thermocyling .