Evaluation of the effect of different surface treatments on bond strength of dental ceramic and PEKK

Polyetherketonketone (PEKK) is a polymeric material belonging to the polyaryletherketone (PAEK) family. The aim of this study is to evaluate the effects of different surface treatments applied on the PEKK surface on the bond strength between PEKK and ceramic material. PEKK test specimens are divided into four groups according to the surface treatment to be applied (Group A: Sandblasting surface treatment, Group B: Acid etching surface treatment, Group C: Sandblasting + acid etching surface treatment, Group D: Control group with no surface treatment). The surface roughness values of the PEKK test specimen groups with surface treatments were measured with a profilometer device before and after the surface treatment. In addition, the surface topographies of the PEKK test specimens were evaluated by SEM. After the prepared PEKK test specimens were bonded to the lithium disilicate glass ceramic test specimens with resin cement, the test specimens were kept in distilled water at 37°C for 24 hours. Half of the test specimens in each surface treatment group were thermally cycled in the thermal cycler. The other half was kept in distilled water at 370C. Then, all test specimens were subjected to the shear bond strength test. Fracture types were evaluated using light microscopy and SEM. Statistical analysis; showed that the surface treatments created significant roughness on the PEKK surface (p=0,005). Test specimens treated with sandblasting surface treatment showed the highest roughness values, while test specimens treated with acid etching surface treatment showed the lowest roughness values. When the shear bond strength data of the thermocycling test groups were examined, it was observed that the sandblasting + acid etching surface treatment group showed the highest bond strength values, followed by the sandblasting > acid etching > control group, respectively. Among the shear bond strength data of the non-thermocycling test groups, it was observed that the sandblasting surface treatment group showed the highest bond strength values, followed by the acid etching > control > sandblasting + acid etching group, respectively. In line with the research results, it is recommended to use appropriate surface treatments to increase the bond strength of PEKK material with ceramic.