Effect of surface pretreatments on the surface roughness and shear bond strength of a modified polyetheretherketone (PEEK) material

Aim of study:This study is aimed to evaluate the effect of different surface pretreatments on the surface roughness and shear bond strength of a modified polyetheretherketone (PEEK) material bonded to dentin.
Materials and methods: Eighty disk shaped PEEK specimens with dimensions (10 mm X 2 mm) were machined and allocated into 4 pretreatment groups, Group 1; no treatment, Group 2; etching with 98% sulfuric acid for 1 min, Group 3; air abrasion with 50 µm Al₂O₃, and Group 4; nitrogen plasma treatment. Surface roughness (Ra) was determined by a profilometer. Shear bond strength (SBS) to human dentin was tested using a universal testing machine at a crosshead speed of 1mm/min perpendicular to the bond interface. Data were statistically analyzed using ANOVA and Tukey's HSD, α = 0.05.
Results: Air abrasion with 50 μm alumina significantly increased the surface roughness (P<0.001). The highest shear bond strength values were observed for sulfuric acid etched group.
Conclusions:A modified PEEK material strengthened with 20% submicron ceramic fillers, could be treated by etching with 98% sulfuric acid for 1 min, to enhance bond strength to human dentin.