Effect of brushing on the surface properties of modified polyetheretherketone (PEEK).

Purpose: To evaluate the surface roughness (SR) and surface topography (ST) of mechanical brushing with pure-unfilled PEEK (U-PEEK) and PEEK materials with different contents [titanium-containing PEEK (T-PEEK), ceramic-modified PEEK (C-PEEK) and glass fiber-reinforced PEEK (G-PEEK)].

Methods: A total of 40 disc-shaped samples (10 mm x 2 mm) were obtained (n= 10) from each group (U-PEEK, T-PEEK, C-PEEK, G-PEEK). After sanding and polishing, a profilometer was used to analyze all discs' surface roughness (Ra). Qualitative analysis (QA) was performed on random samples with the help of a scanning electron microscope (SEM). Brushing was done with a custom-made brushing simulator, and the analyses were repeated. Statistical analysis was performed (P< 0.05).

Results: A statistically significant difference was found between the PEEK groups before and after brushing (P< 0.05). In the measurements before and after brushing, the lowest measurement value was seen in the C-PEEK and T-PEEK groups. While there was no significant difference between T-PEEK and C-PEEK measurements, both measurements found the highest measurement value in the G-PEEK group. In addition, in all groups, the average roughness values after brushing were statistically significantly higher than those before brushing. All groups except G-PEEK are below the clinically acceptable SR value (0.2 µm) before and after brushing. T-PEEK and C-PEEK show better SR values.

Clinical significance: With this study, knowing the effect of mechanical brushing on the SR of modified PEEK materials which may become widely used in dentistry, will be a guide for clinicians.