Evaluation of the effects of different surface modification methods on the bond strength of high-performance polymers...

The purpose of this in vitro study was to investigate the effects of various surface treatment methods on the shear bond strength of self-adhesive resin cement to polymer-infiltrated materials.

One hundred twenty-eight polymer-infiltrated specimens (n = 32) for four different computer aided design-computer-aided manufacturing (CAD-CAM) materials, polyether ether ketone (PEEK) (PE), polyether ketone ketone (PEKK) (PK), composite resin nanoceramic (Cerasmart) (CS), and polymer-infiltrated ceramic network (PICN) (VITA ENAMIC) (VE) were milled from CAD-CAM blocks. They were divided into two groups (n = 16) in terms of surface treatments: airborne-particle abraded (AA) or silica-coated (SC) and two subgroups (n = 8) according to adhesive application or no adhesive. The surface roughness, contact angle, and shear bond strength (SBS) values of specimens were measured. Data were analyzed with Shapiro-Wilk test, the generalized linear models' method, and Bonferroni corrected t test (α ˂ 0.05).

No statistically significant differences were found between the groups in terms of surface roughness and SBS values (P > 0.05). A statistically significant effect of the main adhesive interaction on the bond strength was found independent of the material and surface treatments (P < 0.001). While the average bond strength of the non-adhesive was 4.9 MPa, the average of the adhesive applied was 9.1 MPa. On the other hand, there is a statistically significant difference between the means of the contact angle values (P ˂ 0.001). While the highest mean contact angle value was 117.1 ± 14.8° obtained from the non-adhesive PK in the AA group, the lowest mean contact angle value 22.6 ± 4.3° was obtained from the VE without adhesive in the SC group.

Roughness and SBS values were similar between groups after surface treatments. Adhesive application increased the SBS values. Surface treatments were found to have an effect on the contact angle.

Since the AA and SC surface treatments used in the study show similar bond strength values, the Cojet system, which is more practical and easier to use, can be preferred as an alternative to AA after restoration production with CAD-CAM as a chairside.