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Öğe Amalgam repair: Evaluation of bond strength and microleakage(OPERATIVE DENTISTRY INC, 2002) Ozer, F; Unlu, N; Ozturk, B; Sengun, AThis study evaluated the tensile bond strength of "repaired" amalgams and compared the degree of microleakage. Amalgam (Cavex avalloy) was condensed into plastic tubes (3 mm in diameter, 10 mm. in height) to the half-length. After storage in water at 37degreesC for two days, the remaining parts of tubes were filled with amalgam (A), cavity varnish (CV)+A, Liner Bond 2V (LB2V)+A, 3M Opal Luting Cement (3MOLC)+A, Panavia F(PF)+A, Metabond(MB)+A, Fuji BondLC(FB)+A, HytacOSB(HOSB)+Hytac Aplitip (H), Liner Bond2V+Clearfil AP-X(CAP). The bond strengths for 15 samples of each restoration group were determined. For the microleakage study, MOD cavities of 90 extracted human premolars were used. The distal half of cavities were filled with amalgam. After storage in water at 37degreesC for two days, the mesial half of the cavities were filled to simulate a clinical repair. The "repair" was placed using the procedures applied in the bond strength study. The teeth were stained with basic fuchsine (0.5%), sectioned and evaluated for dye penetration. In both parts of study, the data were analyzed by ANOVA and Duncan's multiple range tests. Bond strength values (MPa) were: A+PF+A 3.84+/-1.08, A+LB2V+A 3.15+/-0.97, A+LB2V+CAP 3.05+/-0.53, A+MB+A 2.86+/-0.88, A+HOSB+H 2.58+/-0.51, A+3MOLC+A 2.11+/-0.75, A+FB+A 0.68+/-0.59. The repaired A+A and A+CV+A groups were separated before testing. The A+PF+A group showed the highest bond strength (p<0.05). Microleakage in the cervical margins of repaired restorations was lower in the amalgam groups than microleakage in the resin composite and compomer groups. PF, MB, 3MOLC and FB performed better at the amalgam "repair" interface. The A+LB2V+A group showed no microleakage at both the occlusal and gingival test regions.Öğe Apical leakage of resin based root canal sealers with a new computerized fluid filtration meter(ELSEVIER SCIENCE INC, 2005) Orucoglu, H; Sengun, A; Yilmaz, NIn this in vitro study, the apical leakage of three root-canal sealers: AH Plus, Diaket, and EndoREZ was evaluated using a new computerized fluid filtration meter. Forty-five extracted human premolar teeth with single root and canal were used. The coronal part of each tooth was removed and the root canals were prepared using GT Rotary files and crown-down technique. The roots were randomly divided into three groups of 15 samples, filled with one of the test materials and gutta-percha cones by the cold lateral condensation technique and were stored at 37 degrees C and 100% humidity for 7 days. One-week later, apical parts of roots of 10 +/- 0.05 mm were attached to computerized fluid filtration meter. Apical leakage quantity was determined as mu l/cmH(2)O/min(-1). Statistical analysis indicated that root fillings with Diaket in combination with cold lateral condensation technique showed lower apical leakage than the others (p < 0.05). In addition, this new computerized fluid filtration meter allowed quantitative measurement of leakage easily. As it is a newly developed device to measure apical leakage of endodontic sealers, the reliability of it needed to be tested.Öğe Effect of desensitizers on the bond strength of a self-etching adhesive system to caries-affected dentin on the gingival wall(OPERATIVE DENTISTRY INC, 2005) Sengun, A; Koyuturk, AE; Sener, Y; Ozer, FA self-etching dentin adhesive was evaluated for its ability to bond to caries-affected and sound dentin after applying three desensitizers to the gingival walls. Sixty extracted human molars, with approximal dentin caries, were cut horizontally on the long axis of the tooth through caries-affected gingival walls. Carious dentin was removed with SiC paper by means of a caries detector to expose caries-affected dentin. The molars were randomly assigned to four groups: control and three experimental groups-Micro Prime, Glauma Desentizer and Cervitec. Desensitizers were applied to the dentinal surfaces according to manufacturers' instructions. A resin composite was bonded to both the caries-affected and sound dentin of each tooth using a bonding system and plastic rings. The restoration was debonded by shear bond strength. The application of Micro Prime and Gluma Desensitizer to caries-affected dentin did not show any effect on bond strength testing. However, Cervitec caused a decrease in bond strength to caries-affected dentin. The effect of desensitizers on the bond strength of the self-etch bonding agent to caries-affected dentin changed according to the chemical composition of the materials. Desensitizer application on sound dentin is recommended with self-etch bonding systems.Öğe Effect of tooth age on microtensile bond strength of two fluoride-releasing bonding agents(QUINTESSENCE PUBLISHING CO INC, 2005) Ozer, F; Sengun, A; Ozturk, B; Say, EC; Tagami, JPurpose: The purpose of this study was to evaluate the effect of age of dentin and enamel on the microtensile bond strengths of a glass-ionomer based, all-in-one, single-step, self-etching adhesive system (Reactmer Bond, RB) and an antibacterial, two-step self-etching primer system (ABF Bond, ABF). \ Materials and Methods: Extracted molars from 3 age groups (20 to 25, 35 to 40, and 50 to 55 years) were used. Enamel was removed from the occlusal surfaces of the teeth, and the entire flat surfaces were covered with composite resin (4 mm in height) following application of bonding agents. The bonded specimens were thinly sectioned parallel to the long axis of the tooth into 0.87 0.03 mm(2) rectangular sections, resulting in 6 to 7 enamel specimens and 10 to 15 dentin specimens per tooth. The specimens were subjected to the microtensile test at a crosshead speed of 1 mm/min. The data were analyzed by Univariate ANOVA, Tukey HSD, and regression analysis. Results: The bond strength of ABF to both enamel and dentin was higher than the bond strength of RB. Bond strengths of ABF to dentin were significantly higher than the bond strengths to enamel (p < 0.05). The 35- to 40-year age group of ABF showed the highest bond strength of all. In RB dentin groups, 34% of specimens showed cohesive failure in composite resin material. Conclusion: Bond strength values to enamel were not affected by age of teeth in either bonding system. Dentinal bond strength using ABF changed according to age of the teeth. Age did not affect bond strength values of RB to dental hard tissues. However, the high number of cohesive failures in Reactmer paste indicated low tensile strength of the material.Öğe The effect on shear bond strength of different antimicrobial agents after acid etching(OXFORD UNIV PRESS, 2005) Malkoc, S; Demir, A; Sengun, A; Ozer, FThe aim of the present study was to determine whether the application of different primers containing antibacterial agents (Micro Prime (TM), Seal&Protect (TM), and Gluma Desensitizer (TM)) can affect the shear bond strength (SBS) of an orthodontic resin composite. Seventy-two crowns of extracted lower human incisors were mounted in acrylic resin leaving the buccal surface of the crowns parallel to the base of the moulds. The teeth were randomly distributed into three experimental and one control group, each containing 18 teeth. In each experimental group, the primers were applied to the etched enamel surfaces. In the control group, no antibacterial primer was used. An orthodontic composite resin was applied to the surface into cylindrical-shaped plastic matrices after application of an orthodontic adhesive primer (Transbond XT). For shear bond testing, a stubby-shaped force transducer apparatus (Ultradent) was applied at a crosshead speed of 1 mm/minute to each specimen at the interface between the tooth and the composite until failure occurred. A Kruskal-Wallis one-way ANOVA and a Mann-Whitney U-test with a Bonferroni adjustment were used for statistical analysis. There was no significant difference between Seal&Protect (TM) (27.98 +/- 8.73 MPa) and the control (35.15 +/- 7.85 MPa) (P > 0.05). However, Gluma (TM) (21.61 +/- 7.96 MPa) and Micro Prime (TM) (14.89 +/- 5.55 MPa) caused a decrease in bond strength (P < 0.05). No statistically significant difference was observed between Seal&Protect (TM) and Gluma (TM) (P > 0.05). As triclosan containing Seal&Protect (TM) did not cause a significant decrease in bond strength, it can potentially be used under an orthodontic resin composite to obtain an antibacterial effect. However, further in vivo studies are required.Öğe Effects of chlorhexidine and povidone-iodine mouth rinses on the bond strength of an orthodontic composite(E H ANGLE EDUCATION RESEARCH FOUNDATION, INC, 2005) Demir, A; Malkoc, S; Sengun, A; Koyuturk, AE; Sener, YThe purpose of this study was to determine whether the application of two antibacterial mouth rinses to etched and unetched enamel affects the shear bond strength (SBS) of an orthodontic composite resin. Eighty-five lower human incisors were divided into five groups, ie, group 1: control group, no mouth rinse was used; groups 2 and 3: mouth rinses were applied to the intact enamel surface before etching; groups 4 and 5: mouth rinses were applied to the etched enamel. A bonding agent and a composite resin were applied to the teeth surface. For shear bond testing, the specimens were mounted in a universal testing machine, and an apparatus attached to a compression load cell was applied to each specimen until failure occurred. The data were analyzed using analysis of variance and Tukey honestly significance tests. Fracture modes were analyzed by Mann-Whitney U-test. There was no statistically significant difference between the SBS values of group 1 (31.64 +/-- 3.62 MPa) and group 4-five experimental applications (P >= .05). However, the SBS value of group 3 (36.56 +/- 5.95 MPa) was significantly larger than those of group 4 (30.00 +/- 4.97 MPa) and group 5 (30.26 +/- 7.30 MPa). In addition, no significant differences were observed between group 1 and groups 2 (34.33 +/- 7.26 MPa) and 3 (36.56 +/- 5.95 MPa) (P >= .05). Because the application of chlorhexidine and povidone-iodine before acid etching did not cause any decrease in bond strength, it is advisable for use under the orthodontic resin composite to obtain an antibacterial effect or to prevent the risk of bacteremia.Öğe Evaluation of internal adaptation in ceramic and composite resin inlays by silicon replica technique(BLACKWELL PUBLISHING LTD, 2005) Karakaya, S; Sengun, A; Ozer, FThis study was aimed at investigating the internal adaptation of a ceramic (Ceramco II) and two composite resin inlay materials (SureFil and 3M Filtek Z 250(TM)) using silicon replica technique as an indicator. Forty-five standard mesial-occlusal-distal (MOD) cavities were prepared into brass moulds by using computer numerically controlled system. Inlays were prepared according to manufacturers' instructions with indirect methods. Replicas of the prepared cavities and inlays were produced with a polyvinyl siloxane material (Elite H-D). The spaces between inlays and cavities were filled by different coloured light-body polyvinyl siloxane material. Two parallel slices (mesio-distally) were obtained from the replicas with a sharp blade. Different coloured polyvinyl siloxane material thickness between cavity and inlay was measured at seven points (mesial, occlusal and distal). The data were evaluated with ANOVA and Tukey's honestly significantly different (HSD) statistical tests. In the SureFil and Ceramco II groups, the sizes of the contraction gaps at mesial and distal gingival floors were greater than that of the occlusal marginal walls. In comparison of gap formation at occlusal regions, while the 3M composite group showed highest gap values (204.33 +/- 75.45 mu m), the Ceramco II group revealed the lowest (141.17 +/- 23.66 mu m) (P < 0.05). At the gingival floors, gap formation of Ceramco II group was the highest (227.08 +/- 51.95 mu m). Neither the 3M Filtek Z250 nor SureFil group showed any statistical difference between gap values of their self-occlusal and gingival floors (P > 0.05). In conclusion, our results showed that ceramic inlays did not confer any big advantage for internal adaptation over the composite inlays.Öğe An evaluation of surface hardness, roughness and wear of restorative composites, porcelain, and enamel following abrasion by enamel(TRANS TECH PUBLICATIONS LTD, 2004) Unlu, N; Donmez, N; Sengun, A; Ozer, FThis study was performed to evaluate wear, surface hardness and roughness characteristics of light cured restorative composites, porcelain and enamel when opposed by human enamel. Five composite resins (3MSilux, ClearfilAP-X, 3MFiltek Z250, Pekalite, SureFil), one ceramic (VitadurAlpha) and enamel were selected as experimental materials. The antagonist abrasives were made by using buccal enamel of anterior teeth. Ten rectangular specimens were prepared for each material. The at the beginning of the study, the mean weight, roughness and hardness values of specimens were obtained. Then the specimens were opposed by human enamel and subjected to 20.000 sliding cycles in a prototype wear machine. Surface characteristics and final weights of each materials were recorded and compared to the values obtained at the beginning. Statistically significant differences were found among the hardness and roughness of materials (p<0.05). After wear procedure, surface hardness of all materials increased. There was not any significant difference among the wear values of materials and enamel.Öğe Evaluation of the dental plaque pH recovery effect of a xylitol lozenge on patients with fixed orthodontic appliances(E H ANGLE EDUCATION RESEARCH FOUNDATION, INC, 2004) Sengun, A; Sari, Z; Ramoglu, SI; Malkoc, S; Duran, IThe purpose of this study was to evaluate the influence of a xylitol lozenge on the dental plaque pH profile of fixed orthodontic patients. Twelve volunteers participated in this study. Before the measurement of plaque pH, subjects were asked to refrain from brushing their teeth for 48 hours and from eating and drinking for two hours. The subjects' baseline dental plaque pH was recorded using the touch technique. It was followed by a one-minute rinse with 15 ml of a 10% solution of sucrose, and subsequent plaque pH measurements were carried out during the next one hour. Xylitol lozenges were taken five times a day during a 14-day period. The variables of resting-plaque pH, minimum-plaque pH (MP pH), time required to reach MP pH (TMP), last-plaque (LP) pH at the end of one hour, cH area (CH), and pH at each test time were calculated for each pH test of the subjects. The paired sample t-test was used for statistical comparison. The mean MP pH values increased from 4.81 to 5.09 in the experimental measurement (P < .05). The mean TMP was not affected by the use of xylitol (P > .05). Although the LP pH showed an increase during the experimental period, the difference between control and experimental periods was not statistically significant (P > .05). The CH of the experimental period was significantly less than that of the control period (P < .05). As a result, the use of a xylitol lozenge after a sucrose challenge can be an advisable practice for fixed orthodontic patients to prevent future dental caries.Öğe In vitro dentine permeability evaluation of HEMA-based (desensitizing) products using split-chamber model following in vivo application in the dog(WILEY, 2005) Duran, I; Sengun, A; Yildirim, T; Ozturk, BThe aim of this study was to evaluate in vitro dentine permeability evaluation of 2-Hydroxyethyl methacrylate (HEMA)-based desensitizing products using split-chamber model following in vivo application in the dogs for three experimental time periods of 1 week, 1 month and 3 months. Buccal enamel of upper and lower canines of nine young dogs was removed and flat dentinal surface was obtained using a water-cooled diamond bur. The dentinal surface divided into four quarters, three experimental and a control. Health-Dent and Gluma Desensitizing agent and Single bond were applied to respective quarters of one tooth, according to manufacturers' instructions. The last quarters were left as control without any applications. For the each experimental period, 10 dentine samples from each group including control were used to measure the hydraulic conductance values. The dentine discs were placed pulp-side down in a split-chamber device in which the plastic spacers containing the rubber 0 rings have a surface area of 1 mm(2) and permeability was measured by fluid filtration. The data were expressed as hydraulic conductance (Lp). Differences in dentine permeability obtained for the desensitizing agents against the control were tested for statistical significance using Kruskal-Wallis one-way anova and Bonferroni-adjusted Mann-Whitney U-tests. Differences in permeability in three time periods for each desensitizing agent were analysed using Friedman's anova and Wilcoxon signed rank tests. All desensitizing applications caused decreased Lp values compared with the control Lp value at the end of 1 week. In the 1-month samples, between the Lp values of Single bond and control, no statistical difference was found (P > 0.05). At the end of the 3-month period, the Gluma Desensitizing agent had the lowest the Lp value (P < 0.05). The result of this study is that the topical application of desensitizing agents led to decrease in dentine permeability in the dog model. The Gluma Desensitizing agent provide the more lasting tubule-occluding effect than the other material tested in this model.Öğe The long-term effectiveness of five current desensitizing products on cervical dentine sensitivity(WILEY, 2004) Duran, I; Sengun, AThe aim of this study was to compare the long-term effectiveness of five desensitizing products on 25 male and 27 female patients (total 52) aged 21-67 years (mean 36 +/- 7 years) suffering from cervical dentine sensitivity. All subjects were seen by the same examiner (ID) who was blinded to the applied treatment for 3-month clinical study. Patients were asked to record their overall sensitivity by marking a point on a 10 cm Visual Analogue Scale (VAS). Two hundred and seventy-seven sensitive teeth were treated by one of the five desensitizing products, all of which were placed following manufacturers' instructions by the other investigator (AS). A paired (split mouth) study design was used and selection of quadrants was randomized. At the post-treatment and at 10 days and 3 months periods, sensitivity measurements were recorded by the same investigator (ID). Statistical analysis showed that all of the VAS scores at post-treatment evaluation points were significantly decreased compared with baseline data (P < 0.05). There was a significant reduction in mean sensitivity scores in the Protect Liner F and the Health-Dent Desensitizer groups when compared with Fluoline varnish at the 10-day time point (P < 0.05). At 3 months, the Protect Liner F group continued to show a significantly reduced sensitivity level when compared with Health-Dent Desensitizer, Single Bond, Fluoline and Gluma Desensitizer (P < 0.05). The present study demonstrated that although at the end of 3-month evaluation period all desensitizers showed lower VAS sensitivity values compared with baseline, there were differences in the level of reduction of cervical dentine sensitivity.Öğe Microtensile bond strength of two resin composite materials placed with direct and indirect techniques under simulated pulpal pressure(QUINTESSENCE PUBLISHING CO INC, 2005) Sengun, A; Unlu, N; Ozturk, B; Ozer, FPurpose: The aim of this in vitro study was to compare the dentin bond strength of directly and indirectly inserted composite restorations. Materials and Methods: Twenty extracted human mandibular molars were prepared to form a flat occlusal dentin surface using an Isomet saw under water. Five-mm-thick composite restorations (Filtek Z 250 and Clearfil AP-X) were placed on the dentin surfaces by direct or indirect techniques. The direct restorations were bonded with Single Bond and Clearfil SE Bond bonding agents. Indirect restorations were cemented with two composite luting cements (3M Opal Luting Cement and Panavia F). All restorative procedures were applied under simulated pulpal pressure (15 cm H2O). Each tooth was then vertically sectioned with an Isomet saw through the composite buildups and the dentin. Thus, for microtensile testing, 0.65 x 0.65 mm specimens were obtained from pulpal and remote dentin regions. The results were analyzed according to the regional dentinal surfaces (pulpal and remote dentin). For statistical analyses, two-way ANOVA and Duncan post-hoc tests were used (p < 0.05). Results: Direct application of Clearfil AP-X showed that tensile bond strengths were higher than those obtained for directly and indirectly applied Filtek Z 250 and indirectly applied Clearfil AP-X. No significant difference in tensile bond strengths was demonstrated between pulpal and remote dentin (p > 0.05). Conclusion: It is concluded that the bond strengths of resin luting cements to dentin need further improvement.Öğe The quantitative evaluation of apical sealing of four endodontic sealers(ELSEVIER SCIENCE INC, 2006) Cobankara, FK; Orucoglu, H; Sengun, A; Belli, SThe aim of this in vitro study was to evaluate the apical seal obtained with four root canal sealers: Rocanal 2, Sealapex, AH Plus, and RC Sealer. Forty root canals were prepared using the step-back technique. The specimens were divided into four groups of 10 samples and obturated by laterally condensed gutta-percha with one of the tested sealers. The computerized fluid filtration method was used for evaluation of apical sealing properties. The quantitative apical leakage of each specimen was measured after 7, 14, and 21 days. Statistical analysis indicated that the apical leakage of all sealers used in this study decreased gradually from 7 days to 21 days (p < 0.05). Sealapex showed better apical sealing than the other sealers at 7, 14, and 21 days (p < 0.05). RC Sealer, AH Plus, and Rocanal 2 showed similar apical leakage values at every period (p > 0.05).Öğe Shear bond strengths of self-etching adhesives to caries-affected dentin on the gingival wall(JAPANESE SOC DENTAL MATERIALS DEVICES, 2006) Koyuturk, AE; Sengun, A; Ozer, F; Sener, Y; Gokalp, AThe purpose of this study was to evaluate the bonding ability of five current self-etching adhesives to caries-affected dentin on the gingival wall. Seventy extracted human molars with approximal dentin caries were employed in this study. In order to obtain caries-affected dentin on the gingival wall, grinding was performed under running water. Following which, specimens mounted in acrylic blocks and composite resins of the bonding systems were bonded to dentin with plastic rings and then debonded by shear bond strength. With Clearfil SE Bond, bonding to caries-affected dentin showed the highest bond strength. With Optibond Solo Plus Self-Etch, bonding to caries-affected dentin showed higher shear bond strength than AQ Bond, Tyrian SPE & One-Step Plus, and Prompt-L-Pop (p<0.05). Further, the bond strengths of Clearfil SE Bond and Optibond Solo Plus Self-Etch to sound dentin were higher than those of Prompt-L-Pop, AQ Bond, and Tyrian SPE & One-Step Plus (p<0.05). In conclusion, besides micromechanical interlocking through hybrid layer formation, bond strength of self-etch adhesives to dentin may be increased from additional chemical interaction between the functional monomer and residual hydroxyapatite. The results of this study confirmed that differences in bond strength among self-etching adhesives to both caries-affected and sound dentin were due to chemical composition rather than acidity.Öğe Shear bond strengths of tooth fragments reattached or restored(BLACKWELL PUBLISHING LTD, 2003) Sengun, A; Ozer, F; Unlu, N; Ozturk, BThis study investigated the shear bond strengths of sectioned human mandibular incisor edge fragments reattached using luting cements, bonding agents or restored with composite resins. Seventy teeth were randomly distributed among six experimental groups and a control group. Leaving half of the anatomic crowns exposed, the teeth were embedded in self-cure acrylic resins with the exposed part then sectioned. The fragments in groups 1-4 were bonded to their respective teeth using Clearfil Liner Bond 2V, Scotch Bond Multi Purpose Plus, Panavia-F and 3M Opal Luting cement. The 5th and 6th groups were restored with composite resins (Silux 3M and Clearfil AP-X) using their bonding agents (Single Bond and Clearfil SE Bond). The results indicated that reattachment of fractured incisal fragments by using new generation bonding agents was effective against shear stresses, comparable with the intact teeth. Instead of restoration with composite resins therefore reattachment of a fractured fragment might be more preferable in cases of dental trauma.
