The aim of this study was to investigate the effect of surface treatments on the microtensile bond strength
of bis-acryl resin provisional restoration (ProtempTM4) and self-curing acrylic resin (UnifastTMTRAD). Specimens of
cylindrical bis-acryl resin blocks 10 millimeters in diameter and 5 millimeters in height were prepared and stored
in artificial saliva at 37-degree celsius for 14 days. The specimens were randomly divided into 3 groups (n=20) according
to the types of surface treatments: (I) Sandblast with Al2O3 50 micron (2) Single bond universal adhesive (3) Untreated
group. After bis-acryl resin blocks were prepared according to their group of surface treatment, blocks were adhered to self-curing acrylic resin and cut into dump-bell shape 1 mm2.Each group was divided into 20 pieces. Microtensile
bond strength test was performed by using a universal testing machine. The data were statistically analysed by
using one-way ANOVA and Tukey HSD at significance level of 0.05. The fractured surfaces were examined under
stereomicroscope to classify the mode of failure and examined surface by scanning electron microscope (SEM). The
study showed that the highest microtensile bond strength was observed in sandblast group with statistically significant
differences of highest average bond strength compared to other groups. The study revealed no statistically significant
differences between untreated group and single universal adhesive group. The modes of failure were primarily of
cohesive type for both bis-acryl resin and self-curing acrylic resin. The study concluded that surface treatment with
sandblast technique on bis-acryl resin prior adhering to self-curing acrylic resin provided the highest microtensile
bond strength, which was significantly higher than other groups.