Effect of laser surface treatment on shear bond strength between polyetheretherketone and heat-activated...

To compare the shear bond strength between polyetheretherketone (PEEK) and heat activated polymethylmethacrylate (PMMA) resin after laser treatment.

A total of 128 PEEK discs were fabricated (10 mm diameter and 2 mm thickness) and allocated into two groups. Group 1 was subjected to surface treatment followed by thermal cycling for 5000 cycles and group 2 was subjected to surface treatment followed by thermal cycling for 10,000 cycles. Each group was further subdivided into four subgroups (n = 16) which were: no surface treatment; primer treatment; acid etching; and laser surface treatment. PEEK was then bonded with PMMA resin using the conventional flasking technique. The shear bond strength was evaluated using a universal testing machine with a crosshead speed of 1 mm/min. Statistical analysis was done using one-way ANOVA for comparing within groups, followed by Tukey HSD test. Student's T-test was done to evaluate between the two groups.

In group 1, the highest shear bond strength was exhibited by the laser group (19.08 ± 0.16 MPa) followed by the acid etch group (14.84 ± 0.23 MPa), and the primer group (6.43 ± 0.20 MPa), while the least shear bond strength was observed in the no surface treatment group (4.98 ± 0.34 MPa) which was found to be significant (p < 0.05). In group 2, the highest shear bond strength was observed in the laser group (18.21 ± 0.23 MPa) followed by the acid etch group (13.77 ± 0.48 MPa), and the primer group (6.04 ± 0.11 MPa), while the least shear bond strength was observed in no surface treatment group (4.35 ± 0.21 MPa) which was found to be significant (p < 0.05).

The shear bond strength between PEEK and PMMA resin was highest for specimens that were surface treated with laser and followed by specimens treated with acid etching, primer application, and without surface treatment, respectively. Increasing thermal cycling from 5000 cycles to 10,000 cycles also reduced the bond strength.