Comparison of Bond Strength of Three Temporary Resins to Polyetherketoneketone

Objectives: Polyetherketoneketone(PEKK) is known for its excellent mechanical properties, therefore can be used for long-term provisional restorations or temporary implant abutments. Addition of temporary resin to PEKK is required in patients gradually raising vertical dimension on provisional restoration or modifying emergence profile in implant abutment. The purpose of this study was to compare the shear bond strength (SBS) of three different types of temporary resins(polymethylmethacrylate(PMMA), polyethylmethacrylate(PEMA), bis-acryl-composite-resin) to PEKK.
Methods: 60 PEKK disks were air-abraided with 110μm aluminum oxide and were divided into 6 groups according to 3 types of resin and 2 conditions of primer usage(Visio.link, Bredent, Senden, Germany). Primer application and bonding of temporary resins were done accordingly. The surface roughness of primed and unprimed specimens were assessed using non-contact 3D profiler. The SBS of 6 groups were measured using universal testing machine. After SBS test, the surface topography was assessed using scanning electron microscope(SEM) to classify failure mode. The surface roughness was analyzed statistically using a Mann-Whitney test(p=.05) and the SBS were compared using one-way ANOVA and Tukey HSD tests(p=.05).
Results: The results were as follows:
Before primer application, PMMA(19.60MPa) and PEMA(16.37MPa) groups showed significant difference in SBS with bis-acryl-composite-resin group(7.24MPa)(p<.05). But after primer application, there was no significant difference in SBS among the three groups(PMMA 15.17MPa, PEMA 14.79MPa, bis-acryl-composite-resin 12.30MPa)(p>.05).
The surface roughness of unprimed PEKK group(2.62±0.54μm) was greater than that of primed PEKK group(0.93±0.26μm), but there was no significant difference(p>.05).
On surface topography analysis using SEM, the fracture mode of all groups was 100% adhesive failure.
Conclusions: In conclusion, when bonding temporary resins to PEKK, PMMA and PEMA do not require primer application but for bis-acryl-composite-resin, primer application is recommended.