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  • Küçük Resim
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    Effect of Various Treatment Modalities on Surface Characteristics and Shear Bond Strengths of Polyetheretherketone-Based Core Materials
    (WILEY, 2020) Culhaoglu, Ahmet Kursat; Ozkir, Serhat Emre; Sahin, Volkan; Yilmaz, Burak; Kilicarslan, Mehmet Ali
    Purpose To investigate the effect of different surface treatments on the surface roughness (Ra), wettability, and shear bond strength of polyetheretherketone (PEEK) to composite resin. Materials and Methods One hundred ninety eight PEEK specimens were divided into six groups (n = 33). Specimen surfaces were treated with the following surface treatment modalities: silicoating (CoJet), acetone treatment, acid etching (H2SO4), airborne particle abrasion (Al2O3), laser irradiation (Yb:PL laser), and the nontreated surface serving as the control. Surface roughness was measured with an profilometer (n = 11) and a goniometer was used to measure the surface wettability through contact angle (theta)(n = 11). PEEK surfaces were veneered with a composite resin (n = 11). The specimens were then thermocycled for 10,000 cycles at 5 to 55 degrees C. Shear bond strengths between the PEEK and composite resin were measured with an universal test machine. One-way ANOVA was used to analyze the data. Tukey's post-hoc test was used to determine significant differences between groups (alpha = 0.05). Results Surface roughness and wettability of PEEK surfaces along with shear bond strength of PEEK to composite resin were influenced by the surface treatments. (p < 0.01) Highest mean Ra values were obtained for PEEK surfaces treated by laser irradiation (2.85 +/- 0.2 mu m) followed by airborne particle abrasion (2.26 +/- 0.33 mu m), whereas other surface treatment modalities provided similar Ra values, with the acid-etched PEEK surfaces having the lowest mean Ra values (0.35 +/- 0.14 mu m). Silicoating provided the most wettable PEEK surfaces (48.04 +/- 6.28o), followed by either acetone treatment (70.19 +/- 4.49o) or acid treatment (76.07 +/- 6.61o). Decreased wettability was observed for airborne particle abraded (84.83 +/- 4.56o) and laser-treated PEEK surfaces (103.06 +/- 4.88o). The highest mean shear bond strength values were observed for acid-etched PEEK surfaces (15.82 +/- 4.23 MPa) followed by laser irradiated (11.46 +/- 1.97 MPa), airborne particle abraded (10.81 +/- 3.06 MPa), and silicoated PEEK surfaces (8.07 +/- 2.54 MPa). Acetone-treated (5.98 +/- 1.54 MPa) and untreated PEEK surfaces (5.09 +/- 2.14 MPa) provided the lowest mean shear bond strengths. Conclusions The highest mean shear bond strengths were observed for acid-etched PEEK surfaces, followed by laser-irradiated, airborne particle abraded, and silicoated PEEK surfaces providing similar mean shear bond strengths. Since shear bond strengths higher than 10 MPa are considered acceptable, acid etching, laser irradiation, and airborne particle abrasion of PEEK surfaces may be considered viable surface treatment modalities for the PEEK material tested.
  • Küçük Resim
    Öğe
    Surface roughness and adaptation of different materials to secure implant attachment housings
    (Mosby-Elsevier, 2017) Ozkir, Serhat Emre; Yilmaz, Burak; Kurkcuoglu, Isin; Culhaoglu, Ahmet; Unal, Server Mutluay
    Statement of problem. Various materials are available to secure implant attachment housings in overdentures. Surface roughness and the adaptation of these materials to the denture base and the housings may increase the microcracks and bacterial adhesion at the interfaces in the long term. The surface characteristics of the interface between the denture base orientation material and the attachment housing have not been extensively studied. Purpose. The purpose of this in vitro study was to evaluate the surface roughness and the adaptation of 5 different housing orientation materials to the housings and the denture base. Material and methods. Fifty-five poly(methyl methacrylate) (PMMA) specimens (15 mm in diameter and 4 mm in height) were prepared with a clearance inside to allow the insertion of over denture housings. Five different materials were used for housing orientation (Quick Up, Ufi Gel Hard, Tokuyama Rebase II Fast, Meliodent, and Paladent). The specimens were thermocycled 5000 times between 5 degrees C and 55 degrees C. The surface roughness (Ra values) of the specimens was measured with a noncontact profilometer. Scanning electron images were made in order to inspect the PMMA-orientation material-housing interfaces. The Kruskal-Wallis test was used to investigate the differences between the surface roughness values of the orientation materials, and the Iman-Conover test was used for pairwise comparisons (alpha=.05). Results. The surface roughness values significantly differed between Quick up and Ufi Gel orientation materials only, and Quick up had smaller surface roughness values than Ufi Gel (P=.009). Microcracks were observed among the groups only at the junction of the orientation material and the housing after thermocycling. Conclusions. Ufi Gel Hard showed the roughest surfaces around the overdenture attachment housings. The adaptation between the orientation material and the housing may deteriorate, and increased surface roughness and microcrack formation may be seen around the housings.