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Öğe Adhesion between glass fiber posts and resin cement: evaluation of bond strength after various pre-treatments(INFORMA HEALTHCARE, 2014) Sipahi, Cumhur; Piskin, Bulent; Akin, Gulsah E.; Bektas, Ozden Ozel; Akin, HakanPurpose. To evaluate surface roughness and bond strength of glass fiber posts to a resin cement after various surface treatments. Materials and methods. Sixty individually formed glass fiber posts with a diameter of 1.5 mm and a length of 20 mm were used for this study. They were randomly assigned to six groups of pre-treatment (n = 10/group): Group C, untreated (control); Group SB, sandblasted; Group SC, silica coated; Group HF, hydrofluoric acid-etched; Group N, Nd: YAG laser irradiated; Group E, Er: YAG laser irradiated. Surface roughness of the posts was measured before and after pre-treatment. The posts were then bonded to resin cement and tensile bond strengths were determined in a universal testing machine. For statistical analysis, two-way ANOVA and post-hoc comparison tests (alpha = 0.05) were performed. Results. The highest bond strength value was observed in group HF, followed by group SC. There was a statistically significant difference in bond strength between group C and groups HF, SC and E (p < 0.001, p = 0.002 and p = 0.041, respectively). Posts of group SB and group N showed the highest surface roughness. Conclusions. The findings of the present study reveal that hydrofluoric acid-etching, silica coating and Er: YAG laser irradiation provided a significant increase in bond strength between glass fiber posts and resin cement.Öğe Effect of Different Surface Treatments and Roughness on the Repair Bond Strength of Aged Nanohybrid Composite(Mary Ann Liebert, Inc, 2019) Eren, Digdem; Dogan, Canan Arslan; Bektas, Ozden OzelObjective and background: Different surface treatments have been tested in composite repair studies. However, there is still no consensus on the most effective repair protocol. The aim of this study is to measure the roughness values of eight different surface treatments for the repair procedure, to examine the effect of each surface treatment and three different composites on the repair bond strength with and without silane, and to evaluate whether there is a correlation between bond strength and roughness. Methods: The blocks were prepared with Filtek Z550 (3M ESPE) for the roughness measurements and divided into eight groups according to surface treatments. The roughness values of the surface treatments were measured by a 3D scanning contact profilometer (Nanomap LS). For the shear test, further samples were prepared, aged, and divided into three subgroups for the repair procedure with Filtek Z550 (3M ESPE), Vertise Flow (Kerr, USA), and G-aenial Flo (GC, Japan) after the surface treatments. Then, the shear test was performed. The Kruskal-Wallis and Spearman's Correlation tests were used for statistical evaluation of the data. Results: Significant differences were found between surface treatments and composite resins in terms of bond strength (p<0.05). There is no correlation between the roughness and bond strength values. Conclusions: In bond strength, surface topography is more important than the numerical value of roughness. In the repair of composite restorations, methods that are already in clinical practice and more practical can be used instead of methods that require additional costs and devices.Öğe Effect of external tooth bleaching on dental plaque accumulation and tooth discoloration(MEDICINA ORAL S L, 2008) Gursoy, Ulvi Kahraman; Eren, Digdem Isin; Bektas, Ozden Ozel; Hurmuzlu, Feridun; Bostanci, Vildan; Ozdemir, HakanObjectives: Treatment of dental discolorations with external bleaching is becoming very common in dentistry, however, possible irreversible alterations on enamel surface due to bleaching procedures is a topic of discussion. The aim of this study was to evaluate the clinical effects of bleaching by measuring the dental plaque accumulation on human enamel and tooth discoloration in vivo. Study Design: Forty-four teeth in eleven patients not revealing any restorations or periodontal problems were enrolled in this study. Bleaching agent applied only to labial surfaces of incisors using commercial 35 % hydrogen peroxide gel. Dental plaque and tooth color measured in the same group of participants, at the end of non-brushing periods lasting 3 and 5 days, respectively, before and after bleaching. Results: The results of the comparison of pre- and post-bleaching measurements showed that, after a non-brushing period lasting 3 day, discoloration scores and plaque accumulation scores for bleached surfaces were lower than the non-bleached surface scores. However, at the end of a non-brushing period lasting 5 day, even the color measurement score in post-bleaching period was lower than the pre- bleaching counterpart, plaque index measurements showed higher plaque accumulation scores in the bleached group. Conclusions: According to these results, bleaching with 35 % hydrogen peroxide seem to favor plaque accumulation after non-brushing period lasting 5 day and tooth discoloration after bleaching is not in correlation with the amount of plaque accumulation.Öğe Effect of immediate dentin sealing, bonding technique, and restorative material on the bond strength of indirect restorations(Universidade Estadual Paulista, Institute of Science and Technology of Sao Jose dos Campos, 2020) Sag, Bilal Utku; Bektas, Ozden OzelObjective: The objective of this study was to evaluate the effect of immediate dentin sealing, bonding technique, and restorative material on the dentin bond strength of an indirect composite (Solidex) and a resin nanoceramic CAD/CAM block (LAVA Ultimate). Material and Methods: A total of 120 periodontally extracted human molar teeth were abraded horizontally and divided into two groups according to dentin sealing procedures (delayed dentin sealing [DDS] and immediate dentin sealing [IDS]). Next, all teeth were attached to a simulated pulpal pressure mechanism. The specimens were removed from the mechanism after a week. Teeth were subdivided into three groups based on the bonding technique and the type of cement used (Acid-etching + Single Bond Universal + RelyX Ultimate, Single Bond Universal + RelyX Ultimate, RelyX Unicem). Each subgroup was further divided into 2 subgroups according to the type of restorative material used (Solidex [n = 10], Lava Ultimate CAD/ CAM restorative material [n = 10]). Sixty cylindrical samples prepared using both the restorative materials were bonded to the tooth surface according to their group’s bonding procedures. All specimens were embedded in chemically cured acrylic resin for shear bond strength test. The shear bond strength (SBS) of the specimens was determined by a universal testing machine with a headspeed of 0.5 mm/min. Results: Three-way ANOVA, independent-sample t test and post hoc Tukey comparison tests (?=0.05) were performed on all data. There were significant differences between the groups. It was found that IDS process significantly increased bond strength in all groups. When dentin bond strengths of tested luting cements were compared, the highest bond strength values were recorded in groups in which the specimens were luted with RelyX Ultimate cement using etch-and-rinse technique. The lowest bond strength values were obtained from groups that used RelyX Unicem as the luting cement. Conclusion: IDS improves bond strength of indirect restorations. Moreover, bonding techniques may have critical effects on the dentin bond strength of indirect restorative materials. The cements’ specific affinity levels to both restorative materials and dentin could be considered as the reason of the situation. © 2020, Universidade Estadual Paulista, Institute of Science and Technology of Sao Jose dos Campos. All rights reserved.Öğe Effect of thermocycling on the bond strength of composite resin to bur and laser treated composite resin(SPRINGER LONDON LTD, 2012) Bektas, Ozden Ozel; Eren, Digdem; Siso, Seyda Herguner; Akin, Gulsah E.The objective of this study was to investigate the effect of two different surface treatments (Er:YAG laser and bur) and three different numbers of thermal cycling (no aging, 1,000, 5,000, and 10,000 cycles) on the micro-shear bond strength of repaired composite resin. Ninety-six composite blocks (4 mm x 4 mm x 1 mm) obtained with a micromatrix hybrid composite were prepared. The composite blocks were then randomly divided into four groups (n = 24), according to the thermal cycling procedure: (1) stored in distilled water at 37A degrees C for 24 h (control group), (2) 1,000 cycles, (3) 5,000 cycles, and (4) 10,000 cycles. After aging, the blocks were further subdivided into two subgroups (n = 12), according to surface treatment. Bur and laser-treated composite surfaces were treated with an etch&rinse adhesive system. In addition, a microhybrid composite resin was bonded to the surfaces via polyethylene tubing. Specimens were subjected to micro-shear bond strength test by a universal testing machine with a crosshead speed of 0 and 5 mm/min. The data were analyzed using one-way analysis of variance and Tukey tests (alpha = 0.05) for micro-shear bond strengths. After conducting a bond strength test, it was found that the laser and bur-treated specimens had similar results. Aging with 10,000 thermocycles significantly affected the repair bond strength of composite resins.Öğe Evaluation of a self-adhering flowable composite in terms of micro-shear bond strength and microleakage(TAYLOR & FRANCIS LTD, 2013) Bektas, Ozden Ozel; Eren, Digdem; Akin, Emine Gulsah; Akin, HakanPurpose. The objective of this study was to evaluate dentin bond strength and microleakage of a self-adhering flowable resin with or without adhesive resin. Materials and methods. Dentin pieces were randomly assigned to three groups (n = 10): Group OR (Optibond+Revolution Formula 2 Flow); Group VF (Vertise Flow); and Group OVF (Optibond+Vertise Flow). Then specimens were stressed in shear at a cross-head speed of 1 mm/min until the bond failed. Moreover, microleakage was determined by restoring Class V cavities. A statistical analyses was carried out using Mann-Whitney U and Kruskal-Wallis tests (p < 0.05). Results. Group OVF specimens produced the highest mean shear bond strength. In addition, the results showed that the marginal seal in group VF was similar to that in group OR. Conclusion. Self-adhering flowable composite resin combined with adhesive resin provided stronger dentin bond strength and a better marginal seal than when it was used individually. VF is a useful material with an acceptable bond strength and marginal seal.Öğe Influence of Different Surface Treatments on Bond Strength of a Self-Adhesive Resin Cement to CAD-CAM Materials(Univ Costa Rica, Fac Odontologia, 2023) Kaptan, Alper; Bektas, Ozden Ozel; Eren, Digdem; Dogan, Derya Ozdemir; Mehrican, SukruTo evaluate the shear bond strength (SBS) of self-adhesive resin cement when used with two different computer-aided design (CAD)-computer-aided manufacturing (CAM) materials after various surface treatments. Nanoceramic resin Lava Ultimate (LU) and feldspathic ceramic Vita Mark II (VM) CAD-CAM block samples were prepared with 1.5-mm thickness, and a total of 90 samples were obtained (N=90), with five samples of each block. The samples were divided into the following five groups according to the surface treatments (n=9): group 1, untreated (control); group 2,5% hydrofluoric acid etching; group 3, Er: YAG laser irradiation; group 4, tribochemical silica coating (Cojet); and group 5, air-abrasion with Al2O3. After silane application, resin cement was applied on a transparent matrix (diameter, 3mm; height, 2mm) on the blocks. SBS was determined using a universal testing device at a crosshead speed of 1 mm/min. Two-way analysis of variance (ANOVA) and Tukey's post hoc tests were used to analyze the SBS values. LU showed the highest SBS value in group 4. The average SBS values in groups 3 and were found to be lower than that in the control group (p<0.05). When VM was examined, while all surface treatments increased the SBS values significantly, the highest SBS value was observed in group 4 (p<0.05). This study revealed that all surface treatments used negatively affected the bond strength values of self-adhesive resin cement to LU, except for Cojet application. The SBS values of resin cement with VM increased in all surface treatment application groups.Öğe Microleakage effect on class V composite restorations with two adhesive systems using different bleaching methods(TAYLOR & FRANCIS LTD, 2013) Bektas, Ozden Ozel; Eren, Digdem; Akin, Gulsah Goktolga; Sag, Bilal Utku; Ozcan, MutluObjective. The main objective of this study was to evaluate the effects of an at-home and two in-office (chemically activated and KTP laser-activated) bleaching methods on the microleakage of composite resin restorations bonded with etch-and-rinse and self-etch adhesive systems. Materials and methods. Class V cavity preparations were performed on 96 premolars and teeth were divided into two groups according to the two adhesive systems (etch-and-rinse and self-etch). After cavities were restored with an adhesive systems and composite resin, they were submitted to thermocycling procedures. Teeth were divided into four sub-groups according to the bleaching systems (control, at-home bleaching, chemically activated office bleaching and KTP laser-activated office bleaching). After the bleaching procedure, teeth were evaluated for marginal leakage. All data were analyzed using the Mann-Whitney U and Kruskal-Wallis tests (p < 0.05). Results. The results of the present study showed that the control group presented lower microleakage values compared with the groups treated with bleaching agents, except for the chemically activated in-office bleaching. When the scores of microleakage at the enamel and gingival margins of the four groups were compared, the differences among the groups were found to be statistically significant (p < 0.05). Comparing the gingival and enamel margins in each group, statistically significant differences were found in the at-home group (p < 0.05) and no significant differences were seen in the other groups (p > 0.05). No significant difference was found between the adhesive systems after treatment with the same bleaching techniques. Conclusion. Under the conditions of this study, microleakage of composite resin restorations differs according to the bleaching methods used and no difference was found between the adhesive systems.Öğe Three different adhesive systems; three different bond strength test methods(TAYLOR & FRANCIS LTD, 2013) Eren, Digdem; Bektas, Ozden Ozel; Siso, Seyda HergunerObjective. The aim of this study was to evaluate the efficacy of the microtensile, microshear and shear bond strength test methods to assess the bond strength of two self-etch adhesives and one etch&rinse adhesive on dentin. Materials and methods: Seventy-five extracted human molars were ground to expose their flat dentin surfaces and randomly assigned to one of three groups according to the type of test method (15 for microtensile, 15 for microshear, 45 for shear). Each of these groups was then assigned to three sub-groups according to the bonding systems (Clearfil SE Bond, Kuraray; G Bond, GC; Prime&Bond NT, Dentsply) used. Then, 15 specimens were prepared for each sub-group according to the test method employed (n = 15). After being stored in distilled water at 37 degrees C for 24 h, the specimens were placed in a universal testing machine for three test methods and stressed at a crosshead speed of 0.5 mm/min. Mean bond strengths were analyzed using Kruskall-Wallis and Mann-Whitney U-tests at a significance level of p < 0.05. Results. The microtensile test had the highest bond strength (p = 0.046). Clearfil SE Bond and Prime& Bond NT produced significantly higher values than the G Bond in the microtensile bond test (p < 0.05), whereas no significant differences were found among the adhesives in the microshear bond test (p > 0.05). For the shear test, Clearfil SE Bond showed higher bond strength than Prime&Bond NT and G Bond (p < 0.05). Conclusion: Bond strength to dentin depends on the material and the test method used.
