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    Effect of different surface treatments on the shear bond strength of resin cement to zirconia ceramic and metal alloy
    (TAYLOR & FRANCIS LTD, 2018) Yucel, Munir Tolga; Kilic, Ismail; Okutan, Yener; Tobi, Elif Sumeyye; Kilic, Hamdi Sukur; Kepceoglu, Abdullah; Donmez, Mustafa Borga
    The bonding of resin cement to ceramic materials plays an important role in dentistry. The purpose of this study is to evaluate the effects of various surface treatments on the shear bond strength (SBS) of zirconia ceramic and metal alloy. A total of 60 specimens were prepared from Y-TZP ceramic and metal alloy. The specimens were divided into three subgroups (n=10) that received different surface treatments for each material. An Er:YAG laser (ER), a femtosecond laser (FS), and air-borne particle abrasion (A) were employed as surface treatments. One specimen from each group was analyzed using a scanning electron microscope (SEM) at 500 x magnification after surface treatments. The self-adhesive resin cement was then bonded to the treated surfaces using a Teflon mold. The specimens were thermocycled for 5,000 cycles at 5-55 degrees C, and then the SBS test was performed. Kruskal-Wallis and Mann-Whitney U tests were used to determine the differences between the groups (p=0.05), and failure modes were evaluated for each specimen. Statistical analyses revealed significant differences between the surface treatment methods. The mean SBS values of the air-borne particle-abraded groups were higher than those of the other groups. The femtosecond-irradiated groups of each material showed significantly higher SBS values than the Er:YAG-irradiated groups (p<0.05). Within the limitations of this study, air-borne particle abrasion and the femtosecond laser were more effective than Er:YAG laser treatment.
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    Effect of femtosecond laser beam angle and formed shape on surface roughness and shear bond strength between zirconia and resin cement
    (TAYLOR & FRANCIS LTD, 2018) Yucel, Munir Tolga; Kilic, Ismail; Kilic, Hamdi Sukur; Gundogdu, Yasemin; Okutan, Yener
    Achieving adhesion between resin cement and zirconia requires pretreatment of the surface. This in vitro study aimed to evaluate the effect of femtosecond laser beam angle and the shape of the formed surfaces, on the roughness and shear bond strength (SBS) of resin cement to zirconia ceramic. Seventy Y-TZP ceramic specimens were divided into seven groups (n=10). A femtosecond laser irradiation was performed on the ceramic surface of three shapes (spiral (SP), square (SQ) and circular (CI) and at two angles (30 and 90 degrees) to give SP-30, SQ-30 and CI-30 and SP-90, SQ-90 and CI-90, respectively. After treatment, the surface roughness of all specimens was evaluated using a profilometer. One specimen from each group was analysed using a scanning electron microscope. The bonded specimens were thermocycled 5000 times and then an SBS test was performed. Kruskal-Wallis and Mann-Whitney U tests were used to analyse surface roughness and SBS values. The control group had statistically lower surface roughness (R-a) values than the treated groups (p<0.05). SP-30 and SQ-30 laser treated specimens showed higher R-a values than the other specimens. Statistically significant SBS values (p=0.000) were observed between the groups. All laser treated samples showed greater SBS compared to the control group. SP-30, SQ-30 and SQ-90 groups showed the highest SBS values. Within the limitations of this experimental study, the highest mean values for R-a and SBS were achieved with SP and SQ surfaces using a 30 degrees angle laser beam.
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    Effect of surface treatment methods on the shear bond strength between resin cement and all-ceramic core materials
    (ELSEVIER, 2012) Yucel, Munir Tolga; Aykent, Filiz; Akman, Serhan; Yondem, Isa
    This study compared the influence of various surface treatments on the shear bond strength between resin cement and lithium disilicate glass-ceramics. A series of 120 lithium disilicate ceramic samples were prepared to compare the effect of different surface treatments on the shear strength of a luting cement bonded to two all-ceramic systems. IPS Empress 2 and IPS e.max Press ceramic samples were fabricated according to the manufacturer's instructions. The ceramic samples were divided into the following 6 surface treatment groups for each ceramic system: 1-no treatment (C), 2-airborne-particle abrasion (A), 3-acid etching (E), 4-airborne-particle abrasion + acid etching (AE), 5-Nd:YAG laser (L), 6-Nd:YAG laser + acid etching (LE). Resin cement was then bonded to the treated ceramic surfaces and light polymerized. The shear bond strengths of the specimens were measured using a universal testing machine. Two-way ANOVA and Tukey HSD (alpha=0.05) test were used to determine differences in shear bond strength between the groups. The ANOVA revealed significant differences between the treatment groups and ceramic types (p < 0.05). The shear bond strengths of IPS Empress 2 were significantly higher than those of IPS e.max Press. (C) 2012 Elsevier B.V. All rights reserved.
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    In vitro evaluation of the marginal fit of different all-ceramic crowns
    (ELSEVIER TAIWAN, 2013) Yucel, Munir Tolga; Aykent, Filiz; Avunduk, Mustafa Cihat
    Background/purpose: The marginal fit of all-ceramic restorations is a very important criterion for their long-term success. The aim of this in vitro study was to compare the marginal adaptation of crowns fabricated with four different all-ceramic systems using an image analysis method. Materials and methods: A standardized all-ceramic preparation was made on a stainless steel die. Eighty gypsum dies were duplicated from this die and randomly divided into four groups of 20 each. Cerec 3, In-Ceram, IPS Empress 2, and Celay crowns were fabricated on dies of each group following the manufacturers' instructions. Marginal gaps of the crowns were evaluated without cementation on their own gypsum dies and then on the master die with a stereomicro-scope and image analysis program. Two-way analysis of variance and Tukey's honest significant difference tests were used to evaluate the data (alpha = 0.01). Results: Mean gap dimensions and standard deviations at the marginal opening of the crowns evaluated on the gypsum dies were 21.5 +/- 4 mu m for Celay, 29.3 +/- 5 mu m for IPS Empress 2, 33 +/- 4 mu m for Cerec 3, and 74.6 +/- 10 mu m for In-Ceram crowns. Mean gap dimensions and standard deviations at the marginal opening of crowns evaluated on the master steel die were 27.8 +/- 4 mu m for Celay, 41.5 +/- 7 mu M for IPS Empress 2, 47.4 +/- 5 mu m for Cerec 3, and 94.9 +/- 10 mu m for In-Ceram crowns. Marginal opening values measured on the master die were higher than those of gypsum dies. Conclusion: In-Ceram all-ceramic crowns showed the largest marginal gap, and Celay crowns showed the smallest marginal gap in both die groups. The marginal discrepancies found in this study were all within the clinically acceptable standard of 120 mu m. Copyright (C) 2012, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved.
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    Influence of food simulating solutions on the hardness of composite resins
    (SAGE PUBLICATIONS LTD, 2008) Sevimay, Muejde; Yucel, Munir Tolga; Tak, Onjen
    The aim of this in vitro study was to evaluate the influence of food simulating solutions on surface hardness of three different composite resins. A total of 50 specimens were fabricated for each of Filtek Z 250, Clearfil ST, Aelite LS Packable according to the manufacturers' instructions. Ten specimens of each material were randomly selected and stored in 8% ethanol, 50% ethanol, heptane, distilled water, and air at 37 degrees C for 1 week. After one week conditioning period, hardness testing was carried out with a micro hardness tester. The hardness of composite resin materials are strongly influenced by food simulating solutions.
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    Novel ceramic primer vs. conventional treatment methods: Effects on roughness and bond strength of all-ceramic restorations
    (MOSHER & LINDER, INC, 2018) Donmez, Mustafa Borga; Yucel, Munir Tolga; Kilic, Ismail; Okutan, Yener
    Purpose: To compare the influence of various surface treatments on the shear bond strength and surface roughness of lithium disilicate glass-ceramics. Methods: 60 lithium disilicate ceramic samples were prepared according to the manufacturers' instructions and were divided into six groups according to the surface treatment: Control (C), 5% HF etching for 20 and 60 seconds (E20, E60), Monobond Etch & Prime etching (MEP), Nd:YAG (ND) and Er:YAG (ER) laser irradiation. All groups were treated with a universal primer except group MEP. A self-adhesive resin cement was bonded to all groups. The shear bond strengths of the specimens were measured using a universal testing machine while surface roughness was measured using a profilometer. Results: Kruskal-Wallis and Mann-Whitney U tests revealed significant differences (P<0.05). The shear bond strength of group E60 was higher than the other groups while surface roughness of groups MEP and ER were highest.