The effect of different surface treatments on the bond strength of PEEK composite materials.

ABSTRACT

OBJECTIVES: To evaluate the effect of different surface treatments on the bond strength between polyetheretherketone (PEEK) composite materials and each of two different luting cements. METHODS: One hundred specimens were randomly divided into five groups (n=20/group) as follows (A) no treatment, (B) 98% sulfuric acid, (C) 9.5% hydrofluoric acid, (D) argon plasma treatment, and (E) sandblast with 50µm Al2O3 particles. Each group was divided into two subgroups of different cements RelyX™ Unicem and SE Bond/Clearfil AP-X™. The cements were bonded onto the specimens. All specimens were stored in distilled water at 37° for 24h. Bond strength was measured in a shear test, and failure modes were assessed by stereomicroscopy. The surfaces were observed by SEM after the different pretreatments. RESULTS: Etching with 98% sulfuric acid and argon plasma treatment can significantly enforce the bond strength of RelyX™ Unicem or SE Bond/Clearfil AP-X™ to PEEK composite materials in comparison to the group of no treatment, hydrofluoric acid or sandblasting (p<0.05). No adhesion was established on the groups of no treatment and hydrofluoric acid when RelyX™ Unicem was used. Applying the SE Bond/Clearfil AP-X™ system, no statistical differences were found whether hydrofluoric acid was applied or not (p>0.05). The shear bond strength value of using SE Bond/Clearfil AP-X™ was higher than that of using RelyX™ Unicem with the same surface conditioning method (p<0.05). SIGNIFICANCE: The use of SE Bond/Clearfil AP-X™ after the surface of PEEK composite material treated with sulfuric acid or argon plasma can be recommended as an effective bonding method.