Browsing by Author "Eskitascioglu, Gurcan"

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An Alternative Adhesive Strategy To Optimize Bonding To Root Dentin
(Elsevier Science inc, 2011) Belli, Sema; Cobankara, Funda Kont; Ozcopur, Betul; Eliguzeloglu, Evrim; Eskitascioglu, Gurcan
Introduction: This study examined the hypothesis that the shear-bond strengths of AH Plus (AH) and Hybrid Root Seal (HRS) to root dentin might be optimized by using a powdered dentin-reinforced bonding procedure. Methods: The surfaces of root halves obtained from extracted human premolars were ground (800-grit silicon carbide paper), treated (5.25% NaOCl 17% EDTA for 5 minutes followed by distilled water) and randomly allocated into two groups according to the sealer and then into three subgroups according to bonding procedure. Dentin particles with a maximum size of 25 mu m were incorporated into the adhesive of Clearfil Liner Bond 2V, and groups were created as follows: no adhesive, adhesive alone, and with powdered dentin reinforced adhesive; 3 x 3 mm high buildups were created using sealer and allowed to set (37 degrees C, 100% humidity, 72 hours). Shear tests were performed (1 mm/min). Data were calculated as MPa and analyzed (two-way analysis of variance, Tukey test). Results: A significant difference was found between the groups (P = .000). Adhesive or reinforced adhesive had a negative effect on the shear-bond strength of AH, but they significantly increased the shear-bond strength of HRS (P = .000). HRS showed a similar bond strength with either adhesive alone or adhesive reinforced with powdered dentin. AH group was characterized by mixed failure, whereas the predominant failure type of the HRS group was cohesive failure within the sealer. Conclusions: Reinforcing adhesive resin with powdered dentin may be considered an alternative for optimizing the bonding of methacrylate-based sealers to root dentin and might affect the shear bond strength. (J Endod 2011;37:1427-1432)
Conservative Restoration of Severely Damaged Endodontically Treated Premolar Teeth: a Fem Study
(Springer Heidelberg, 2011) Eraslan, Oznur; Eraslan, Oguz; Eskitascioglu, Gurcan; Belli, Sema
The aim of this finite element method (FEM) study was to test two different restorative techniques used for construction of severely damaged endodontically treated premolar teeth using Finite Element Stress Analysis Method. In this study, four types of three-dimensional (3-D) FEM mathematical models simulating (1) a sound lower single rooted premolar tooth with supporting structures; (2) a root-filled lower premolar tooth without lingual cusp, restored with resin composite; (3) a root-filled lower premolar tooth without lingual cusp restored with resin composite in combination with a polyethylene fiber which is placed circumferentially to help to create a composite lingual wall; (4) a root-filled lower premolar tooth without lingual cusp restored with resin composite in combination with a glass fiber post, were modeled. A 300-N static vertical occlusal load was applied on the node at the center of occlusal surface of the tooth to calculate stress distributions. Solidworks/Cosmosworks structural analysis programs were used for FEM analysis. The analysis of the von Mises stress values revealed that maximum stress concentrations were located at loading areas for all models. Root dentine tissue, lingual cortical bone, and apical bone structures were other stress concentration regions. There were stress concentration differences among the models at root dentine tissue. Although the distribution pattern was similar with composite resin restored tooth model, highest stress values were observed at root dentine in the model restored with post-and-core. Post structure accumulated more stress on its own body. Stress distribution patterns of sound tooth and fiber-reinforced restoration models were found as similar. The present study showed that the use of post material increased the stress values at root dentine structure while reinforcing the restoration with a fiber decreases stress transmission. Fiber-reinforced restoration provided stress distributions similar to sound tooth.
Effect of Restoration Technique on Stress Distribution in Roots With Flared Canals: an Fea Study
(Quintessence Publishing Co inc, 2014) Belli, Sema; Eraslan, Oznur; Eraslan, Oguz; Eskitascioglu, Gurcan
Purpose: The aim of this finite element analysis (FEA) study was to test the effect of different restorative techniques on stress distribution in roots with flared canals. Materials and Methods: Five three-dimensional (3D) FEA models that simulated a maxillary incisor with excessive structure loss and flared root canals were created and restored with the following techniques/materials: 1) a prefabricated post: 2) one main and two accessory posts; 3) i-TFC post-core (Sun Medical); 4) the thickness of the root was increased by using composite resin and the root was then restored using a prefabricated post; 5) an anatomic post was created by using composite resin and a prefabricated glass-fiber post. Composite cores and ceramic crowns were created. A 300-N static load was applied at the center of the palatal surface of the tooth to calculate stress distributions. SolidWorks/Cosmosworks structural analysis programs were used for FEA analysis. Results: The analysis of the von Mises and tensile stress values revealed that prefabricated post, accessory post, and i-TFC post systems showed similar stress distributions. They all showed high stress areas at the buccal side of the root (3.67 MPa) and in the cervical region of the root (> 3.67 MPa) as well as low stress accumulation within the post space (0 to 1 MPa). The anatomic post kept the stress within its body and directed less stress towards the remaining tooth structure. Conclusion: The creation of an anatomic post may save the remaining tooth structure in roots with flared canals by reducing the stress levels.
Effect of Root Filling on Stress Distribution in Premolars With Endodontic-Periodontal Lesion: a Finite Elemental Analysis Study
(Elsevier Science inc, 2016) Belli, Sema; Eraslan, Oguz; Eskitascioglu, Gurcan
Introduction: Endodontic-periodontal (EP) lesions require both endodontic and periodontal therapies. Impermeable sealing of the root canal system after cleaning and shaping is essential fora successful endodontic treatment. However, complete healing of the hard and soft tissue lesions takes time, and diseased bone, periodontal ligament, and tooth fibrous joints are reported to have an increased failure risk for a given load. Considering that EP lesions may affect the biomechanics of teeth, this finite elemental analysis study aimed to test the effect of root fillings on stress distribution in premolars with EP lesions. Methods: Three finite elemental analysis models representing 3 different types of EP lesions (primary endodontic disease [PED], PED with secondary periodontic involvement, and true combined) were created. The root canals were assumed as nonfilled or filled with gutta-percha, gutta-percha/apical mineral trioxide aggregate (MTA) plug, and MTA-based sealer. Materials used were assumed to be homogenous and isotropic. A 300-N load was applied from the buccal cusp of the crown with a 135 angle. The Cosmoworks structural-analysis program (SolidWorks Corp, Waltham, MA) was used for analysis. Results were presented considering von Mises criteria. Results: Stresses at the root apex increased with an increase in lesion dimensions. Root filling did not affect stress distribution in the PED model. An MTA plug or MTA-based sealer created more stress areas within the root compared with the others in the models representing PED with periodontic involvement and true combined lesions. Conclusions: Stresses at the apical end of the root increase with increases in lesion dimensions. MTA-based sealers or an MTA plug creates more stresses when there is periodontic involvement or a true combined lesion.
Effects of Ozone and Prophylactic Antimicrobial Applications on Shear Bond Strength of Orthodontic Brackets
(Aves Press Ltd, 2017) Alkan, Ozer; Coven, Betul Oktay; Ozcopur, Betul; Kazanci, Fatih; Kaya, Yesim; Aydogan, Cihan; Eskitascioglu, Gurcan
Objective: The present study aimed to evaluate the effects of ozone and prophylactic antimicrobial applications on the shear bond strengths and bond failure interfaces of orthodontic brackets. Methods: Sixty human canine teeth were randomly divided into three groups (n=20), receiving the following treatments: Group I-pumice prophylaxis (Isler Dental, Ankara, Turkey)+37% orthophosphoric acid (Dentsply, Rio de Janeiro, Brazil)+Transbond XT primer and adhesive (3M Unitek, Monrovia, USA); Group II-prophylaxis paste (Topex, NJ, USA)+37% orthophosphoric acid (Dentsply, Rio de Janeiro, Brazil)+Transbond XT primer and adhesive paste (3M Unitek, Monrovia, USA); and Group III-ozone application (Biozonix GmbH, Munich, Germany)+37% orthophosphoric acid (Dentsply, Rio de Janeiro, Brazil)+Transbond XT primer and adhesive (3M Unitek, Monrovia, USA). All specimens were stored at 37 degrees C water for 24 h. Shear bond strength was assessed using a universal testing device (Autograph AGS-X; Shimadzu, Japan). Adhesive remnant index (ARI) scores were obtained through examination of teeth under stereomicroscope at 10x magnification after debonding. Results: Shear bond strengths of orthodontic brackets were 16.10, 18.01, and 19.23 MPa for Groups I, II, and III, respectively. No statistically significant difference in shear bond strength of orthodontic brackets was found among the groups (p=0.273), based on Kruskal-Wallis analysis. Additionally, no significant difference was found in the ARI scores of each group using chi-square analysis (p=0.992). Conclusion: Shear bond strength of orthodontic brackets and ARI scores was not found to be negatively impacted by ozone application.
Evaluation of the Effect of Rotary Systems on Stresses in a New Testing Model Using a 3-Dimensional Printed Simulated Resin Root With an Oval-Shaped Canal: a Finite Element Analysis Study
(Elsevier Science inc, 2016) Eken, Rahmi; Sen, Ozgur Genc; Eskitascioglu, Gurcan; Belli, Sema
Introduction: This finite element analysis study was aimed at evaluating the effects of rotary systems on stresses in photopolymerized resin root models with oval-shaped canals. Methods: Among the data collected by computed tomographic imaging, a mandibular second premolar tooth with an oval-shaped canal was selected, recorded as Digital Imaging and Communications in Medicine, and transferred to Materialise's Interactive Medical Image Control System software. Three-dimensional modeling was performed to produce photopolymerized resin root models. Root canals were prepared by OneShape (OS; MicroMega, Besancon, France); ProTaper Universal (PTU; Dentsply Tulsa Dental, Tulsa, OK); WaveOne (WO, Dentsply Maillefer, Ballaigues, Switzerland); Mtwo (MT; VDW, Munich, Germany); Twisted File (TF; Kerr Dental, Orange, CA); ProTaper Next (PTN, Dentsply Tulsa Dental), and hand files (HFs) (control). The models were scanned (micro computed tomographic imaging; SkyScan 1174; Kontich, Belgium), finite element analysis models were created, and stresses were calculated under 300-N loading (at a 45 degrees angle and vertically). Results: The maximum stress values were found to be higher when the roots were loaded at an angle. The range of the stress values was PTU > MT > WO > HF > PTN > OS > TF. The stresses were forwarded toward the apical area in the PTN, OS, and TF models. When loaded vertically, the highest maximum stress values were recorded in the WO model. High stress concentrations were observed at coronal, thus less stress was forwarded toward the apical, giving an advantage to the root. The range of the others was as follows: PTN >= PTU > MT > TF > OS >= HF. The TF model showed lower maximum stress values, whereas the HF model showed more homogenous stress distribution. Conclusions: Considering the stress distributions, and stress values within the models, it can be concluded that oval-shaped canals prepared by HFs and WO were less likely to result in root fracture.
Influence of Powdered Dentin on the Shear Bond Strength of Dentin Bonding Systems
(Japanese Soc dental Materials devices, 2012) Eliguzeloglu Dalkilic, Evrim; Genc, Ozgur; Ozcopur, Betul; Belli, Sema; Eskitascioglu, Gurcan; Ozcan, Mutlu
This study evaluated the effect of different amounts of dentin powder (DP) mixed in Clearfil SE Bond (CSB) or Single Bond (SB) on adhesion to dentin. Human third molars (n=96) were sectioned to expose the mid-coronal dentin and divided into eight experimental groups (n=12 per group), namely, Group 1: CSB, Group 2: CSB+1.5 mg DP, Group 3: CSB+3 mg DP, Group 4: CSB+4.5 mg DP, Group 5: SB, Group 6: SB+1.5 mg DP, Group 7: SB+3 mg DP, and Group 8: SB+4.5 mg DP. Filtek Z250 composite was bonded onto dentin, and all specimens were subjected to shear bond strength test at a crosshead speed of 1 mm/min. Highest bond strength was obtained in Groups 1, 2, and 3 (15.1, 13.5, and 16.4 MPa respectively; p>0.05) and the lowest in Groups 6, 7, and 8 (5.5, 5.6, 4 MPa; p>0.05). DP addition, regardless of amount, adversely affected the bond strength of SB. Bond strength of CSB was not affected when 1.5 or 3 rag of DP was added.
Insertion of Buccally Tilted and Placed Implants in Edentulous Atrophic Posterior Mandibular Sites
(Diagnosis Press Ltd, 2012) Ozkan, Birkan Taha; Eskitascioglu, Gurcan; Cigerim, Levent; Kaplan, Volkan
This paper presents our new methodology and evaluates the feasibility of buccally tilted and placed implant combined with standard abutment placement in patients with insufficient bone height through implant software programme. Forty patients with 62 mandibular sites were measured in computed tomography (CT) imaging. The Buccally tilted and placed implants combined with standard abutment simulation were administered in implant software programme. The different parameters were measured in CT The localization of inferior alveolar nerve and implant, inclination degree of implant, transversal and vertical thickness of local distances etc. were evaluated in order to eliminate the nerve injury with providing interocclusal relationship. The buccal distance at the mandibular canal level was higher than the lingual distance in posterior mandible at lower first molar region. The mean inclination degree of the implant fixtures were 17.85 +/- 8.01. The mean measurement of the acquired length of implant during implant placement simulation was 11.06 +/- 1.73. The mean distance of the vertical gain was 3.81 +/- 1.84. The hypothesis of buccally positioned and tilted implant placement instead of advanced surgical procedures would be preferable in atrophic posterior mandibula.
Micro-Shear Bond Strength of Adhesive Resins To Enamel at Different Relative Humidity Conditions
(Japanese Soc dental Materials devices, 2013) Bavbek, Andac Barkin; Demir, Erhan; Goktas, Baris; Ozcopur, Betul; Behram, Benin; Eskitascioglu, Gurcan; Ozcan, Mutlu
This study tested whether exhaled humid conditions would affect the adhesion of etch-and-rinse, two-step and one-step self-etch adhesive resins to enamel. Enamel surfaces of human maxillary anterior teeth (N=240, n=20) were exposed to four humid conditions (H1: 63-68%, H2: 73-78%, H3: 93-98%, H4: 36-45% RH) during bonding with Adper Single Bond 2 (SB2), Clearfil SE Bond (CSE) and Adper Easy Bond (AEB). Specimens were stored in distilled water at 37 degrees C for 24 h and tested to failure using micro-shear bond strength (mu SBS) test. Data were analyzed using two-way ANOVA and Tukey's test (p<0.05). The mu SBS to enamel with SB2, CSE and AEB was not significantly affected by humidity parameters. AEB resulted in significantly lower mu SBS in all conditions. The frequency of adhesive failures was the highest at H2, H3 for SB2, H3 for CSE and H1-4 for AEB indicating that humidity conditions may decrease adhesion quality to enamel.
Micro-Shear Bond Strength of Resin Cement To Dentin After Application of Desensitizing Toothpastes
(informa Healthcare, 2013) Bavbek, Andac Barkin; Goktas, Baris; Cekic Nagas, Isil; Egilmez, Ferhan; Ergun, Gulfem; Eskitascioglu, Gurcan
Objectives. The aim of the study was to evaluate the effect of three desensitizing toothpastes on bonding of resin cements to dentin. Materials and methods. The occlusal surfaces of 72 maxillary third molars were ground to obtain flat dentin surfaces and then divided into three groups according to three desensitizing toothpastes used: Sensodyne Rapid Relief (GlaxoSmithKline, SmithKline Beecham Ltd., Slough, UK), Signal Sensitive Expert (Unilever Sanayi ve Ticaret Turk A.S., Umraniye, Istanbul, Turkey) and Colgate Sensitive Pro-Relief (Colgate Palmolive, New York, NY). Following bonding of the resin cement (Clearfil (TM) SA Cement, Kuraray Co, Osaka, Japan) to dentin, the specimens were light cured for 40 s with a LED (Elipar S10, 3M Espe, St. Paul, MN). The strength measurements were accomplished with a micro-shear testing machine (Bisco, Schaumburg, IL) at a cross-head speed of 0.5 mm/min until the failure occurs. Failure modes were examined using a stereomicroscope and scanning electron microscope. The data were analyzed with one-way analysis of variance (ANOVA) and Tukey HSD test (alpha = 0.05). Results and conclusion. ANOVA revealed that the application of desensitizing toothpastes had significant effects on bond strength of the resin cement tested to dentin (p < 0.05). Mixed failures were observed in all of the groups. Clinical significance. The use of a desensitizing toothpaste before cementation might alter the bond strength of adhesively luted restorations.
Radioactive Potential of Zirconium-Dioxide Used for Dental Applications
(Sage Publications Ltd, 2014) Bavbek, Andac Barkin; Ozcan, Mutlu; Eskitascioglu, Gurcan
Purpose: The purpose of this study was to investigate the possible radioactive potential of zirconium dioxide (ZrO2) dental ceramics. Such information is necessary since they became an integral part of routine prosthetic rehabilitations and devoid of scientific information about their radioactivity creates some concern in the dental community. Methods: Four different types of commercial ZrO2 ceramics, namely Lava, Cercon, ICE Zirkon, and Everest Bio ZS were investigated before and after the sintering process. Sintering temperatures were applied according to each manufacturer's instructions. The compositions of the presintered and sintered specimens were analyzed using x-ray fluorescence spectrometer (XRF). Concentrations of the elements and compounds were also measured by this method. Determination of radioactivity continued with gamma-spectrometry measurements and gross alpha/beta analyses. Results: The activity of gamma and gross alpha/beta was below minimum detection limits (MDL) for presintered and sintered ZrO2. The MDLs of gross alpha/beta counting system were 0.02 Bq/g and 0.01 Bq/g for alpha and beta radioactivity, respectively. The sintering process played only a minor role in the composition of the compounds. Conclusions: Radioactivity of the ZrO2 ceramics studied showed negligible radionuclide activity that can be considered lower than many hazardous radioactive appliances in our environment.
The Use of Endodontically Treated And/Or Fiber Post-Retained Teeth as Abutments for Fixed Partial Dentures
(Springer Heidelberg, 2012) Akman, Serhan; Akman, Melek; Eskitascioglu, Gurcan; Belli, Sema
The purpose of this in vitro study was to evaluate the effect of endodontic treatment with or without fiber-post restorations on the fracture strength of abutment teeth under fixed partial dentures (FPDs). Seventy extracted premolar and canine teeth were used. Groups of fiber-post-retained and root-filled teeth were endodontically treated. The teeth were embedded in an acrylic resin perpendicular to the horizontal plane to create fixed partial dentures. The following groups were created using different abutments: (1) sound (S) canine/S premolar, (2) S canine/endodontically treated (ET) premolar, (3) ET canine/S premolar, (4) ET canine/ET premolar, (5) S canine/fiber-post-restored (FPR) premolar, (6) FPR canine/S premolar, and (7) FPR canine/FPR premolar. Each tooth was prepared for a complete-coverage full-metal crown. Impressions were taken; metal frameworks were fabricated and cemented. The samples were exposed to 5,000 cycles of thermomechanical fatigue and loaded compressively until fracture (2 mm/min). The data were statistically analyzed using (Kruskal-Wallis test, alpha = 0.05). No significant difference was found among the mean fracture strengths of the groups (p = 0.696). There were distinct differences in failure patterns. All of the fracture types were horizontal, and neither vertical nor non-restorable root fractures were recorded. Premolars seemed to be a critical abutment compared to canines when they were sound under FPDs. The percentage of cervical fractures was high in endodontically treated teeth when compared to post-retained groups. In case of post-debonding, the abutment fracture did not occur. When root-filled teeth are used as abutments for FPDs, fiber-post restorations or the creation of abutments from similar structures (ET/ET or FPR/FPR) results in improved conservation of root structure under loading when compared to the abutments from different structures (S/ET, ET/S, FPR/S, S/FPR).