Browsing by Author "Eraslan, Oguz"

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Are Dentin Posts Biomechanically Intensive?: a Laboratory and Fea Study
(Taylor & Francis Ltd, 2014) Belli, Sema; Celik, Kezban; Akbulut, Makbule Bilge; Guneser, Mehmet Burak; Eraslan, Oguz; Eskitaccioglu, Gurcan
The goal of this laboratory and finite elemental stress analysis (FEA) study was to compare fracture strength of dentin post (DP) with stainless steel and glass fiber posts. Single-rooted teeth were decoronated and restored with ParaPost (PP), i-TFC (TFC), and DPs (n=10). Resin cores were created and loaded until failure (1.0mm/min). The data were analyzed (ANOVA, Tukey, Chi-Square tests). Three-dimensional FEA models of the posts were created and the stress distributions were calculated using Solid Works/Cosmos works structural analysis program. A significant difference was found among the groups (p<0.001). TFC group showed the highest and the DP group showed the lowest fracture resistance (p<0.001). PP created more stress at the root dentin and inside the post. Restoration of roots with glass fiber and DPs may reduce stresses within the core material and the remaining root. However, a fracture-resistant restoration cannot be achieved by using a DP.
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 Post-Restoration on Stresses in Premolars With Endodontic-Periodontal Lesion: an Fea Study
(Taylor & Francis Ltd, 2017) Belli, Sema; Eraslan, Oguz; Hakki, Sema Sezgin; Eskitascioglu, Murat; Eskitascioglu, Guercan
Aim: This finite elemental stress analysis (FEA) study was aimed to test the effect of fiber and metal posts on stress distribution in premolar teeth with endodontic-periodontal (EP) lesion. Methodology: Three FEA models representing different EP lesions (primary endodontic disease (PED), PED with periodontal involvement and true-combined) were created. Tooth-model without EP lesion was used as control. The root-canals were assumed as root-filled, restored using glass-fiber or metal posts, resin composite build-up, and ceramic crown. A 300 N load was applied from the palatal surface of the crown with a 135 degrees angle. The SolidWorks/Cosmosworks structural analysis program was used for FEA analysis. Results were presented by considering von Mises criteria. Results: Maximum stress values for PED, PED with periodontal-involvement and true-combined lesions were 2.26, 1.25, 0.74 MPa for glass-fiber post; 2.08, 1.51, 1.18 MPa for metal post, respectively. If there is PED, fiber-post gave an advantage to the tooth at core structure and coronal third of the root. Metal post kept the stress inside its body however caused small, high stress concentrated areas at cervical. When there is PED with periodontal-involvement, metal post forwarded less stress toward the apical while fiber-post saved the coronal structure. In true-combined lesion model, metal post kept the stresses within its body and forwarded less stress toward the remaining root structure and periodontium. Conclusion: EP lesions have an effect on stress distribution therefore the post material selection should be done based on the severity of the lesion. Metal posts might be preferrable since it forwards less stress toward the surrounding periodontal tissues during wound healing.
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.