Tensile bond strength between polyether ether ketone and resilient denture liners

To investigate the initial 24-h tensile bond strength (TBS) between polyether ether ketone (PEEK) and three resilient denture liners (RDLs) after different surface treatments.

The TBSs of two silicone RDLs (Reline II Soft [RL] and Sofreliner Tough Supersoft [ST]) and one methyl methacrylate RDL, Denture Liner [DL], on PEEK were evaluated. Square PEEK plates (n=240) were prepared and polished with #2000 SiC paper. Surface treatments included control (C; no treatment), sandblasting (SB) with 50-µm alumina powder, manufacturer-provided primer application (P), and SB + P. Ten specimens for each condition were prepared by sandwiching the RDL between two PEEK plates. TBS after 24-h water storage at 37°C was measured, and failure modes were recorded. Median TBS values were statistically analyzed.

Significant differences in TBS were found among RDLs within each surface treatment (P < 0.01) and among surface treatments within each RDL (P < 0.001). Median TBSs of C were 0.30, 0.17, and 0.73 MPa for RL, ST, and DL, respectively. SB and P increased median TBS, especially SB for DL (2.12 MPa) and P for RL (1.84 MPa) and ST (1.37 MPa). SB + P had the highest median TBSs regardless of material (1.64-2.55 MPa). All fracture surfaces showed adhesive failure except RL and ST treated with P and SB + P, which showed mixed and cohesive failures, respectively.

Initial TBSs varied with RDLs and surface treatments. P was more effective for silicone materials, whereas SB was more effective for the methyl methacrylate material.