Yazar "Özcan, Mutlu" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Adhesion of metal brackets to glassy matrix and hybrid CAD/CAM materials after different physico-chemical surface conditioning
    (TAYLOR & FRANCIS LTD, 2016) Dilber, Erhan; Ağlarcı, Cahide; Akın, Mehmet; Özcan, Mutlu
    This study compared the adhesion of metal brackets bonded to different CAD/CAM materials after various surface conditioning methods. CAD/CAM blocks (N=204, n=17 per group) of (a) VITA Mark II (VM), (b) IPS e.max CAD (IP), (c) Lava Ultimate (LU), and (d) VITA ENAMIC (VE) were conditioned with one of the following methods: C-Control: (fine diamond bur); CJ: (fine diamond bur+air-abrasion with 30 mu m SiO2+silane), and HF: (fine diamond bur +9.5% hydrofluoric acid+silane). Metal brackets were bonded to the conditioned surfaces of the specimens, stored in artificial saliva for 24h at 37 degrees C and thermocycled (x1000). Subsequently, the brackets were debonded under shear in a Universal Testing Machine (1mm/min). Failure types were analyzed under scanning electron microscope. Data were analyzed using two-way ANOVA and Tukey's tests (alpha=0.05). Two-parameter Weibull distribution values, including the Weibull modulus, scale, and shape, were calculated. Mean bond strength (MPa) values were significantly affected by the surface conditioning method (p<0.001) but not the CAD/CAM material type (p=0.052). Bond strengths for all CJ and HF-conditioned specimens were twofold higher (11.83 +/- 1.95 - 9.44 +/- 1.63) than those for control specimens with all materials (4.73 +/- 0.93 - 6.02 +/- 0.69). Lower mean values were obtained in LU-CJ (9.78 +/- 1.61) and LU-HF (9.44 +/- 1.63) than those for other groups (11.83 +/- 1.95 - 10.93 +/- 1.33) groups (p<0.05). Weibull distribution showed higher shape values for VM-CJ (11.26) and VM-HF (8.87) than those for other groups (0.82-1.83). In control groups, exclusively adhesive and after conditioning mainly mixed failures were observed. Chairside silica coating or HF conditioning significantly improved metal bracket adhesion to both glassy matrix and hybrid CAD/CAM materials tested, with the most reliable adhesion being observed for feldspathic ceramic.
  • Küçük Resim
    Öğe
    Effect of Artificial Aging Regimens on the Performance of Self-Etching Adhesives
    (WILEY-LISS, 2010) Ülker, Mustafa; Özcan, Mutlu; Şengün, Abdulkadir; Özer, Füsun; Belli, Sema
    This in vitro study was performed to compare the microtensile bond strengths (MTBS) of current self-etching adhesives to dentin and to evaluate the effects of artificial aging [(thermocycling (TC) and/or mechanic loading (ML)] on MTBS and on nanoleakage of self-etching adhesives. Two-step (AdheSE Bond, Clearfil Protect Bond, Clearfil SE Bond, Optibond Self-Etch) and one-step (Hybrid Bond, G-bond, Clearfil Tri-S Bond, and Adper Prompt L-Pop) self-etching adhesives were tested. Resin composite build-ups were created, and the specimens were subjected to 10(4) TC, 10(5) ML, and 10(4)/10(5) TC/ML. Non-aged specimens served as controls. In the control group, no significant differences were found among the MTBS of the one-step self-etching adhesives and among those of three two-step self-etching adhesives (AdheSE Bond, Clearfil Protect Bond, and Clearfil SE Bond) (p > 0.05). The MTBS of AdheSE Bond and Clearfil Protect Bond were higher than were those of all one-step self-etching adhesives and than those of Optibond Self-Etch. The MTBS of Clearfil SE Bond was higher than were those of two one-step self-etching adhesives (Adper Prompt L-Pop, G-bond) (p < 0.05). Compared with the non-aged controls, TC did not decrease (p > 0.05), but ML and TC/ML significantly decreased the MTBS of the adhesives tested (p < 0.05). Two-step self-etching adhesives tended to fail more cohesively in dentin. Transmission electron microscopy revealed different nanoleakage patterns in the adhesive and hybrid layers of all adhesives examined, and signs of additional silver-filled water channels were more readily detectable after TC/ML.