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Öğe Bond strength of adhesively luted ceramic discs to different core materials(WILEY, 2009) Bozogullari, Nalan; Inan, Ozgur; Usumez, AslihanThe purpose of this in vitro study was to compare the shear bond strengths of resin, glass-ionomer, and ceramic-based core materials to all ceramic discs. Five core materials (Core max, Sankin; Clearfil AP-X, Kuraray; Empress Cosmo, Ivoclar-Vivadent; Photocore, Kuraray; Dyract Extra, Dentsply) were prepared as discs 10 mm in diameter and 2 mm in height according to the manufacturer's instructions. Ten disc specimens per group were prepared, and dentin served as the control. All resin specimens were embedded in autopolymerizing acrylic resin, with one surface facing up. All ceramic discs (IPS Empress I, Ivoclar-Vivadent) 3 mm in diameter and 2 mm in height were prepared and bonded to core specimens with a dual-curing luting resin cement (Variolink II, Vivadent). Specimens were stored in distilled water at 37 degrees C. Shear bond strength of each sample was measured after 24 h using a universal testing machine at a crosshead speed of 0.5 mm/min. The data were analyzed with one-way analysis of variance and Tukey HSD tests (alpha=0.05). Shear bond strength varied significantly depending on the core material used (p<0.05). Clearfil AP-X and Photocore showed the highest shear bond strength value while Empress Cosmo provided the lowest (p<0.05). There were no statistically significant differences among Clearfil AP-X, Photocore, and Core-Max (p>0.05). And also there were no statistically significant differences between Dyract Extra and the control group (p>0.05). In vitro shear bond strengths of ceramic discs bonded to resin-based core materials showed higher bond strength values than ceramic-based core material. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 89A: 466-471, 2009Öğe Determination of optimal EDM machining parameters for machined pure titanium-porcelain adhesion(SPRINGER LONDON LTD, 2009) Secilmis, Asli; Olmez, A. Murat; Dilmec, Murat; Halkaci, H. Selcuk; Inan, OzgurThe objective of this experimental study is to determine electrical discharge machining (EDM) parameters that offer the best adhesion at the interface of a machined titanium-porcelain composite. First of all, with Taguchi method, machining parameters that will be effective in the bonding strength as well as their interactions on each other were determined in the test. Then, multiple level experiments were conducted to determine how the effective parameters varied over a wide area. Slopes of the curves obtained in these tests were studied, and then, final tests were conducted to obtain the best bonding strength possible. In this way, machining parameters that would offer the highest bonding strength of the titanium-porcelain matrix in a stepwise adjustable EDM machine were obtained. By taking into consideration the steps on the EDM machine where the tests were conducted, it is seen that, when a full factorial experiment is undertaken, 5 power x 2 polarity x 2 type of dielectric x 2 sandblasting or non-sandblasting x 2 kind of electrode x 10 pulse-on time, it necessitates 800 different tests to be executed, but, with the applied method, 16 + 18 + 3 yields 37 different tests where the results that include all possible alternatives were obtained. As a result, EDM machining parameters that offer the highest adhesion and are relatively higher, 31.5 N/mm(2), than the acceptable minimum value of 25 N/mm(2) were specified.Öğe The Effect of Different Surface Finishing Procedures on Surface Roughness and Fracture Toughness in All-Ceramic Restorations(WILEY, 2011) Yondem, Isa; Inan, OzgurThe aim of this study was to determine the effect of different surface treatments on the flexural strength of four different ceramic specimens. The four ceramic systems investigated in this study were lithium disilicate reinforced, zirconium oxide reinforced, glass-infiltrated alumina reinforced, and feldspathic ceramic. For the first group, grinding burs, for the second group polishing kit and for the third group glazing procedures were applied for surface treatment. Surface roughness, mean fracture toughness, and a SEM were used to describe surface features. The surface treatments affected the flexural strength and surface roughness of the ceramic systems evaluated.Öğe Effect of finishing methods on surface roughness and color stability in all-ceramic systems(ELSEVIER SCIENCE BV, 2011) Yondem, Isa; Secilmis, Asli; Inan, OzgurThe objectives of the study were to evaluate the effect of the finishing methods on the surface roughness, and to investigate changes in CIE L*a*b* color coordinates of all-ceramic systems after different finishing methods and accelerated aging. Sixty specimens were prepared, 20 specimens each for Vitadur-N, IPS Empress II, and Cerec Vita Block Mark II. The surface roughness (Ra) following treatment with the different finishing methods was measured using a profilometer. Surface examinations in all groups were made by using a scanning electronic microscope. CIE L*a*b* values of the specimens were determined. After all specimens were subjected to accelerated aging, color measurements were repeated, and the total color differences (Delta E) were calculated. Data were analyzed statistically. Significant differences in surface roughness among all-ceramics were found (P < 0.05). No significant differences were found between the surface roughness of the glazed and polished all-ceramics (P > 0.05). After accelerated aging, all groups had acceptable color changes (Delta E < 2). (c) 2011 Elsevier B.V. All rights reserved.Öğe EFFECT OF PONTIC FRAMEWORK DESIGN ON THE FRACTURE RESISTANCE OF IMPLANT-SUPPORTED ALL-CERAMIC FIXED PARTIAL DENTURES(UNIV SAO PAULO FAC ODONTOLOGIA BAURU, 2009) Inan, Ozgur; Secilmis, Asli; Eraslan, OguzObjective: The purpose of this study was to compare the fracture resistance of implant-supported all-ceramic fixed partial dentures, which have three different pontic designs. Material and Methods: Two implants were placed in a metal model simulating mandibular left second premolar and mandibular left second molar. Thirty standardized 3-unit all-ceramic fixed partial dentures with biconvex, convex or concave pontic designs were fabricated using IPS e.max system (n=10). Afterwards, specimens were centrally loaded on the pontics until failure with a universal testing machine. Results were analyzed by Kruskal-Wallis and Mann-Whitney U tests at 5% significance level. Results: The fracture resistance values of all-ceramic fixed partial dentures designed with biconvex, convex or concave pontics were 349.71, 438.20 and 300.78 N, respectively. There were no statistically significant differences between the fracture resistances of the groups (p>0.05), except for convex and concave groups (p<0.05 and p=0.009, respectively). Conclusions: Convex design showed the best mechanical properties as demonstrated by the high values of fracture resistance.Öğe Effects of different surface treatments on the bond strength of glass fiber-reinforced composite root canal posts to composite core material(ELSEVIER TAIWAN, 2012) Kurt, Murat; Guler, Ahmet Umut; Duran, Ibrahim; Uludamar, Altay; Inan, OzgurBackground/purpose: The purpose of this study was to investigate the effects of different surface treatments on the bond strength of glass fiber-reinforced composite (FRC) posts to composite core material. Materials and methods: A total of 18 FRC posts were randomly divided into six groups (n = 3), one of which was the untreated control group. Surface treatment of other groups were as follows: airborne particle abrasion with 50-mu m Al2O3 powder at 60 psi for 10 seconds through a nozzle distance of 10 mm; etching with 4% hydrofluoric (HF) acid; and surface preparation with an Er:YAG laser under three different power settings (of 300, 400, and 500 mJ, at 2 Hz and 100 mu(s)). A cylindrical Teflon mold was used to surround the treated posts, and the mold was filled with dual-cure composite core material. All samples were light-cured for 60 seconds through the top of the mold. After 24 hours of storage in water, specimens were sectioned perpendicular to the bonded interface under water cooling to obtain 2-mm thick post-and-core specimens. Each group consisted of 12 specimens. Push-out tests were performed at a cross-head speed of 0.5 mm/minute using a universal testing machine. Data were analyzed by one-way analysis of variance followed by Tukey's honestly significant difference test (alpha = 0.05). Results: The lowest bond strength was observed in the Er:YAG 500-mJ group (6.14 +/- 0.94 MPa). The acid-etched group revealed a higher bond strength (15.08 +/- 0.92 MPa) than the control group. The highest bond strength was observed in the airborne-particle abrasion group [18.89 +/- 0.83 MPa (P < 0.05)]. Conclusion: Er:YAG laser treatments on the FRC post surface decreased the bond strength. Airborne-particle abrasion and HF acid etching are alternative methods for increasing bond strength of FRC posts to composite core material. Copyright (c) 2012, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved.Öğe Evaluation of the topographical surface changes and roughness of zirconia after different surface treatments(SPRINGER LONDON LTD, 2012) Subasi, Meryem Gulce; Inan, OzgurThe purpose of this study was to investigate the surface morphology and roughness of zirconia after different surface treatments. Eighty sintered zirconia specimens were divided into four groups (n = 20) according to the surface treatments received: no treatment, erbium:yttrium-aluminum-garnet (Er:YAG) laser irradiation (400 mJ, 10 Hz, 4 W, 100 MPS, distance: 1 mm), tribochemical silica coating with 30 mu m aluminum oxide (Al2O3) modified by silica, and air abrasion with 110 mu m Al2O3 particles. After the surface treatments, the surface roughness (Ra in mu m) of the specimens was evaluated using a surface texture measuring instrument. Surface morphology of a specimen from each group was evaluated with atomic force microscope (AFM) and scanning electron microscope (SEM) analyses. The surface roughness values were statistically analyzed by the Kruskal-Wallis and Mann-Whitney U tests (p = 0.05). All of the surface treatments produced rougher surfaces than the control group (p < 0.005). While there were no significant differences between the surface roughness of laser and silica groups (p > 0.05). SEM and AFM analyses revealed changes in surface topography after surface treatments, especially in the laser group with the formation of rare pits and in the silica and air abrasion groups with the formation of microretentive grooves. According to the results of the statistical and microscopic analyses, all of the surface treatments can be used for roughening zirconia prior to cementation; however, air abrasion is the most effective surface treatment to obtain micromechanical retention.Öğe Influence of surface treatments and resin cement selection on bonding to zirconia(SPRINGER LONDON LTD, 2014) Subasi, Meryem Gulce; Inan, OzgurThis study aimed to evaluate the surface changes caused in zirconia by different surface treatments and the influence of the surface treatment and cement selection on bonding to zirconia under aging. Sintered zirconia specimens were divided into five groups (n = 31) based on the surface treatment, namely, control, air abrasion, silica coating, laser and air abrasion + laser. After surface treatment, surface roughness and microscope analyses were performed on one specimen of each group. Composite cylinders were then bonded to conditioned ceramics using RelyX U100 (RXU), Clearfil Esthetic Cement (CEC) and Panavia F (PF) (n = 10). After 24 h, the bonded specimens were subjected to thermal cycling (6,000 times), and then, a shear bond strength test was conducted. The roughness values were analysed using Kruskal-Wallis and Mann-Whitney U tests, and the bond strengths were analysed by two-way analysis of variance and Duncan's test. The relationship between the roughness and the bond strength was determined by Spearman's correlation analysis. Specimens subjected to surface treatments were rougher than the control specimen (p < 0.000). However, there were no significant differences between the air abrasion and air abrasion + laser groups and the silica coating and laser groups. Specimens treated with laser showed lower bond strengths irrespective of the resin cement used. CEC and/or PF showed higher bond strengths than RXU for each surface treatment group. No significant relationship was observed between the roughness and the bond strength. The results of this study showed that all the surface treatments, except for laser irradiation, were suitable for treating zirconia ceramics. Cement selection was found to be more important than surface treatment, and phosphate monomer-containing cements were suitable for cementing zirconia.Öğe Occlusal Contact Changes with Removable and Bonded Retainers in a 1-Year Retention Period(E H ANGLE EDUCATION RESEARCH FOUNDATION, INC, 2009) Sari, Zafer; Uysal, Tancan; Basciftci, Faruk Ayhan; Inan, OzgurObjective: To test the hypothesis that there is no difference in the number of occlusal contacts in centric occlusion in patients treated with bonded and removable retention procedures and a control group during a 1-year retention period. Materials and Methods: Twenty-five patients received a removable Hawley retainer, and 25 patients received maxillary and mandibular bonded retainers. The retainer patients were compared with 20 control subjects with normal occlusions. Silicone-based impression bites were used to record occlusal contacts. Paired-sample t-test, analysis of variance (ANOVA), and Tukey tests were used to evaluate intragroup and intergroup differences. Results: An increased number of occlusal contacts were recorded in total-arch and posterior combined (actual/near) teeth during the retention period as compared with the control group. In the Hawley group, actual and total contacts on the first and second molar and actual contacts on the premolar and canine showed statistically significant increases. In the bonded retainer group, near and total contacts on the first and second molars and premolars showed statistically significant increases. Slight occlusal changes were seen in the control sample during the observation period, presumably from growth and development. ANOVA comparisons of total contacts of anterior and posterior teeth indicated statistically significant differences in the three groups on posterior segments. Conclusions: The hypothesis is rejected. Both retention procedures allowed relative vertical movement of the posterior teeth, but the number of contacts on the posterior segment was increased more in the bonded retainer group than in the Hawley and control groups at the end of retention. (Angle Orthod. 2009;79:867-872.)Öğe Occlusal contacts with different retention procedures in 1-year follow-up period(MOSBY-ELSEVIER, 2007) Basciftci, Faruk Ayhan; Uysal, Tancan; Sari, Zafer; Inan, OzgurIntroduction: The aim of this follow-up study was to evaluate the number of contacts in centric occlusion during a 1-year retention period in patients treated with 2 retention procedures and in a control sample. Methods: Twenty patients received modified wraparound Hawley retainers, and 20 received maxillary Jensen plates with mandibular fixed retainers. These retention patients were compared with a control group of 20 subjects with normal occlusions. Silicone-based impression bites were used to record occlusal contacts. Paired and independent-sample t tests were used to evaluate intragroup and intergroup differences. Results: Contacts increased in the total arch and the posterior combined (actual/near) during the retention period compared with the control group. In the Hawley retainer group, actual contacts on the second molars (P < .05), near contacts on the premolars (P < .05), and total contacts on the first molars (P < .05) and premolars (P < .01) had statistically significant increases. In the maxillary Jensen plate and mandibular fixed lingual retainer group, the number of actual contacts on the posterior segment increased. Actual contacts on the first molars (P < .01), second molars (P < .01), premolars (P < .05), and canines (P < .05), and total contacts on the first (P < .05) and second (P < .05) molars had statistically significant increases. During the observation period, some slight occlusal changes were seen in the control sample, presumably from growth and development. At the end of the study, during the 1-year follow-up period, no statistically significant occlusal contact differences were observed in the 3 groups. Conclusions: Retention procedures carried out in this study allowed relative vertical movement of the posterior teeth.
