Methodology: Forty removed human molar teeth (maxillary/mandibular) were used in this investigation. Extracted teeth were cleaned with an ultrasonic scaler (EMS, Switzerland) and kept in a 10% formalin solution to eliminate surface debris. An acrylic resin block of dimensions 10mm x10mm was fabricated using autopolymerising acrylic resin (DPI-RR Cold Cure, India) and the teeth were embedded in the center of block upto complete submergence of the root. Two groups were made (group A and group B), each comprising of 20 blocks and colour coding was done to distinguish the groups. Group A comprised of clear acrylic resin blocks in which the PEEK surfaces were modified by acid etching and group B comprised of pink acrylic resin blocks in which PEEK surface was modified by sandblasting.

Results: Mean ± SD of shear bond strength recorded for group A and B was 1.94 and 2.40 Mpa respectively with statistically significant difference as P<0.05.

Conclusion: It can therefore be concluded that surface modification with sandblasting is favored over acid etching to achieve good bonding between PEEK and dentin.