Person: KARA, ÖZLEM
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Publication Metadata only Custom Cast Post Treatment on an Implant Platform in 2 Patients(2015-08-01) DİLBER, Erhan; BAYTAROĞLU, Ebru Nur; Kara, Haluk Baris; Kara, Ozlem; KARA, ÖZLEMPublication Metadata only Effect of Various Lasers on the Bond Strength of Two Zirconia Ceramics(2015-02-01) Kara, Ozlem; Kara, Haluk Baris; Tobi, Elif Sumeyye; Ozturk, Atiye Nilgun; Kilic, Hamdi Sukur; KARA, ÖZLEMObjective: The purpose of this study was to compare and evaluate the effects of various laser systems on surface roughness and shear bond strengths of zirconia ceramics. Material and methods: Seventy-two ceramic discs (10 mmx2 mm) obtained from two sintered zirconia ceramics (Zirkonzahn, Zirkonzahn Prettau((R))) were divided into two groups (n=36) according to the computer-aided design (CAD)-computer-aided manufacturing (CAM) technique and then further divided into three groups (n=12). Each group was treated with one of the following: (1) femtosecond (FS), (2) Nd:YAG (NY), and (3) Er:YAG (EY) lasers. After laser irradiation, a scanning electron micrograph (SEM) was taken at 500x magnification for qualitative examination. Following surface roughness measurement by profilometry, resin cement (Rely X U200) was bonded to the ceramic specimens using Teflon tubes (3 mm height, 4 mm diameter). Specimens were stored in distilled water at 37 degrees C for 24 h and then thermal cycled for 5000 cycles. A shear bond strength (MPa) test was performed using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed by two way analysis of variance (ANOVA) and Tukey honest significant difference (HSD) tests for pairwise comparisons among groups (p=0.05). Results: MPa and roughness were significantly affected by laser type (p0.05). In the SEM, the surfaces of the FS group were rougher than those of the NY and EY groups. NY and EY surfaces were nearly smooth. Conclusions: FS laser is an effective surface treatment for roughening surfaces of zirconia ceramics. Furthermore, it reveals the highest MPa.Publication Metadata only Effect of different surface treatments on roughness of IPS Empress 2 ceramic(2012-03-01T00:00:00Z) Kara, Haluk Baris; Dilber, Erhan; Koc, Ozlem; Ozturk, A. Nilgun; Bulbul, Mehmet; KARA, ÖZLEMThe aim of this study was to evaluate the influence of different surface treatments (air abrasion, acid etching, laser irradiation) on the surface roughness of a lithium-disilicate-based core ceramic. A total of 40 discs of lithium disilicate-based core ceramic (IPS Empress 2; Ivoclar Vivadent, Schaan, Liechtenstein) were prepared (10 mm in diameter and 1 mm in thickness) according to the manufacturer-s instructions. Specimens were divided into four groups (n = 10), and the following treatments were applied: air abrasion with alumina particles (50 mu m), acid etching with 5% hydrofluoric acid, Nd:YAG laser irradiation (1 mm distance, 100 mJ, 20 Hz, 2 W) and Er:YAG laser irradiation (1 mm distance, 500 mJ, 20 Hz, 10 W). Following determination of surface roughness (R-a) by profilometry, specimens were examined with atomic force microscopy. The data were analysed by one-way analysis of variance (ANOVA) and Tukey HSD test (alpha = 0.05). One-way ANOVA indicated that surface roughness following air abrasion was significantly different from the surface roughness following laser irradiation and acid etching (P 0.05). Air abrasion increased surface roughness of lithium disilicate-based core ceramic surfaces more effectively than acid-etching and laser irradiation.Publication Metadata only The effect of different surface treatments on roughnessand bond strength in low fusing ceramics(2011-09-01T00:00:00Z) Kara, Haluk Baris; Ozturk, A. Nilgun; Aykent, Filiz; Koc, Ozlem; Ozturk, Bora; KARA, ÖZLEMThe aim of this study was to evaluate the influence of different surface treatments (air abrasion, acid etching, and laser irradiation) on the surface roughness and bond strength of a low fusing ceramic. Thirty-six discs of low fusing ceramic (Finesse, Ceramco) were prepared (10 mm in diameter and 2 mm in thickness) according to the manufacturer-s instructions. Specimens were divided into three groups (n = 12), and the following treatments were performed: Air abrasion with alumina particles (50 mu m), acid etching with 5% HF and Nd:YAG laser irradiation (distance: 1 mm, 100 mJ, 20 Hz, 2 W, and 141.54 J/cm(2)). Following determination of surface roughness (R-a) by profilometry, specimens were examined with scanning electron microscopy (SEM). The luting cement (Clearfil Esthetic Cement) was bonded to the ceramic specimens using Teflon tubes. After 24 h of water storage, shear bond strength test was performed using a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed with two-way analysis of variance (ANOVA) and Tukey HSD tests (alpha = .05). Two-way ANOVA indicated that surface roughness was significantly affected by surface treatments (p .05). The SEM image of the laser irradiation surface appeared to be relatively smooth as compared to the images of other the groups. Air abrasion of low-fusing porcelain surfaces was effective in improving the bond strength as compared to the acid-etching and laser-irradiation methods.