Surface Roughness and Bond Strength of PEEK Posts: Comparing Chemical, Mechanical, and Laser Methods

Assessing the effect of different surface pretreatments, that is, sulfuric acid (SA), air-particle abrasion (APA), Er, Cr: YSGG laser, and nonthermal plasma (NTP)on the push-out bond strength (PBS) and surface roughness (R_a) of Polyether ether ketone (PEEK) post bonded to canal dentin.

Fifty caries-free single-rooted premolars were selected and decoronated. Following access cavity preparation, the working length was standardized at 14 mm. Root canal treatment was completed, and post space preparation was carried out by removing 10 mm of gutta-percha using a Gates-Glidden drill. A total of one hundred prefabricated polyetheretherketone (PEEK) posts were randomly allocated into 5 groups according to the surface treatment protocol (n = 20): Group 1: No treatment (control), Group 2: SA, Group 3: APA, Group 4: Er, Cr: YSGG laser, and Group 5: NTP. R_a was measured using a contact profilometer (n = 5). Surface morphology of the pre-treated PEEK posts was evaluated using SEM (n = 5). Ten posts from each group were cemented into the prepared canals using a dual-cure self-adhesive universal resin cement, followed by thermocycling. The specimens were then sectioned and subjected to PBS testing using a universal testing machine. Failure modes were analysed under a stereomicroscope. ANOVA, followed by Tukey's post hoc test were used for data analysis, p < .05.

The maximum R_a was observed in Group 2 (SA) (1.5 ± 0.4 µm) specimens. Whereas the minimum R_a scores were recorded in Group 1 (control) (0.6 ± 0.2 µm) samples. The maximum PBS values were seen in Group 2 (SA) samples, particularly in the cervical region (10.2 ± 0.4 MPa). Whereas the minimum PBS values were recorded in the apical region of Group 1 (5.3 ± 0.3 MPa) samples.

APA and Er, Cr: YSGG laser treatment might be considered effective alternatives to SA for pretreating PEEK posts.

Sulfuric acid treatment, while producing the highest Ra and PBS values in PEEK surface treatment, carries inherent risks in a clinical setting - including tissue toxicity, handling hazards, and the need for strict neutralization protocols, making it less practical for routine chairside use. The finding that air-particle abrasion and Er, Cr: YSGG laser are effective alternatives. Both modalities are already present in well-equipped dental practices, require no hazardous chemical handling, and can be applied precisely and efficiently before post-cementation.