Surface treatment with methyl formate–methyl acetate increased the shear bond strength between reline resins and denture base resin

Background Chemical surface treatment increases the shear bond strength ( SBS ) between hard reline resins ( HRR s) and denture base resin. Objective To evaluate the effect of methyl formate–methyl acetate ( MF ‐ MA ), when used as a surface treatment agent, on the SBS between denture base resin and different HRR s. Materials and Methods One hundred and twenty specimens of heat‐polymerised acrylic resin denture base ( M eliodent ® ) were divided into 12 groups. These groups comprised denture base relined with three self‐polymerised HRR s [ U nifast trad ® ( UT ), T okuyama ® R ebase II F ast ( TR ), U fi gel hard ® ( UG )], and treated with their respective B onding A gent ( BA ) or by MF : MA solutions at ratios of 35:65, 25:75, and 15:85 for 15 s. The SBS was measured using a U niversal T esting M achine. The data were analysed using two‐way anova and post hoc T ukey's analysis at p  <   0.05. Results The highest SBS was in the UT treated with MF : MA at a ratio of 25:75 group, followed by UT treated with MF : MA at ratios of 15:85, 35:65, UT treated with BA , and all UG treated with MF : MA groups. The SBS of the UT treated with MF : MA at a ratio of 25:75 group was significantly higher than those of the groups treated with BA . The SBS of the UG treated with MF : MA groups was significantly higher than control. The TR groups treated with BA or MF : MA groups showed no significant difference in SBS . Conclusion Surface treatment with MF ‐ MA significantly enhanced the SBS of denture base resin and UT and UG compared to that of the groups treated with BA .