This study was conducted to investigate the bond strength of repair resin to heat-cured denture base resin or pour-type one. The repair surface of test specimens were treated with dichloromethane, methyl methacrylate and alumina air abrasive before self-curing resin was applied to the joint. A shear bond strength test and a three-point loading test were used to determine the shear bond strength and the transverse strength of the respective test specimens. Visual inspection was conducted to determine whether the failure mode was adhesive or cohesive.
The results were as follows:
1. Treating the surface of the denture base resin with dichloromethane and alumina air abrasive were effective to both heat-cured base resin and pour-type one.
2. Effects of both dichloromethane and alumina air abrasive treatments on pour-type base resin were superior than those on heat-cured one.
3. The variations of crosshead speed affected the values of shear bond strengths. This may be related to the failure modes of the specimens and physical properties of denture base resins.
4. A three-point loading test may be appropriate to determine the bond strength between base resin and repair resin.