Browsing by Author "Oguz, Yener"

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Comparative effects of photobiomodulation therapy at wavelengths of 660 and 808 nm on regeneration of inferior alveolar nerve in rats following crush injury
(2020) Diker, Nurettin; Aytac, Duygu; Helvacioglu, Fatma; Oguz, Yener; 0000-0002-6026-0045; 31273571; AAH-8887-2021
The aim of the present study was to investigate the therapeutic effects of 660-nm and 880-nm photobiomodulation therapy (PBMT) following inferior alveolar nerve (IAN) crush injury. Following the nerve crush injuries of IAN, 36 Wistar rats were randomly divided into three groups as follows: (1) control, (2) 660-nm PBMT, and (3) 808-nm PBMT (GaAlAs laser, 100 J/cm(2), 70 mW, 0.028-cm(2) beam). PBMT was started immediately after surgery and performed once every 3 days during the postoperative period. At the end of the 30-day treatment period, histopathological and histomorphometric evaluations of tissue sections were made under a light and electron microscope. The ratio of the inner axonal diameter to the total outer axonal diameter (g-ratio) and the number of axons per square micrometer were evaluated. In the 808-nm PBMT group, the number of nerve fibers with suboptimal g-ratio ranges of 0-0.49 (p < 0.001) is significantly lower than expected, which indicates better rate of myelinization in the 808-nm PBMT group. The number of axons per square micrometer was significantly higher in the 808-nm PBMT group when compared with the control (p < 0.001) and 660-nm PBMT group (p = 0.010). The data and the histopathological investigations suggest that the PBMT with the 808-nm wavelength along with its settings was able to enhance IAN regeneration after nerve crush injury.
Effects of Hyaluronic Acid and Hydroxyapatite/Beta-tricalcium Phosphate in Combination on Bone Regeneration of a Critical-size Defect in an Experimental Model
(2018) Diker, Nurettin; Gulsever, Serap; Koroglu, Taner; Akcay, Eda Yilmaz; Oguz, Yener; https://orcid.org/0000-0002-7825-1083; 29438204; AAS-4519-2020
Hyaluronic acid (HyA) is an outstanding new product in the field of oral and maxillofacial surgery. The aim of this study was to evaluate the effects of HyA on bone regeneration in critical-size calvarial defects. Twenty-four female Sprague-Dawley rats were used in the present study. In each rat, 4 critical-size defects received different treatments: no treatment (control); HyA; Graft; and HyA+Graft combination. New bone formation, defect closure, inflammation, vascular proliferation, immature bone formation, mature bone formation, and bone marrow existence were investigated based on histological findings. The healing parameters related to bone formation (new bone formation, defect closure, immature bone formation) were significantly higher in the HyA group compared with the control group. However, HyA alone was unable to induce sufficient bone regeneration compared with treatments involving graft materials (Graft and HyA+Graft). In the Graft and HyA+Graft groups, prominent enhancement of all healing parameters was noted. The present results demonstrate that HyA alone did not adequately enhance bone regeneration in critical-size defects. Moreover, addition of HyA to a biphasic alloplastic graft material did not result in improved regeneration compared with the graft material alone.
Evaluation of the Effects of Low-Level Laser Therapy on Diabetic Bone Healing
(2019) Diker, Nurettin; Aytac, Duygu; Helvacioglu, Fatma; Dagdelen, Cansu; Oguz, Yener; 31232987
The aim of the present study was to evaluate the effects of low-level laser therapy (LLLT) and biphasic alloplastic bone graft material on diabetic bone healing. Induction of diabetes was performed in 14 male Sprague-Dawley rats by intraperitoneal injection of a 50 mg/kg dose of streptozotocin. Two bilaterally symmetrical non-critical-sized bone defects were created in the parietal bones in each rat. Right defects were filled with biphasic alloplastic bone graft. Rats were randomly divided into 2 groups, with 1 group receiving 10 sessions of LLLT (GaAlAs, 78.5 J/cm(2), 100mW, 0.028 cm(2) beam). The LLLT was started immediately after surgery and once every 3 days during postoperative period. At the end of treatment period, new bone formation and osteoblast density were determined using histomorphometry. Empty (control), graftfilled, LLLT-treated and both graft-filled and LLLT-treated bone defects were compared. New bone formation was higher in the graft treatment samples compared with the control (P = 0.009) and laser samples (P = 0.029). In addition, graft-laser combination treatment samples revealed higher bone formation than control (P = 0.008) and laser (P = 0.026) samples. Osteoblast density was significantly higher in the laser treatment (P < 0.001), graft treatment (P = 0.001) and graft-laser combination treatment (P < 0.001) samples than control samples. In addition, significantly higher osteoblast density was observed in the graft-laser combination treatment samples compared to the graft treatment samples (P = 0.005). The LLLT was effective to stimulate osteoblastogenesis but failed to increase bone formation. Graft augmentation for treatment of bone defects seems essential for proper bone healing in diabetes, regeneration may be supported by the LLLT to enhance osteoblastogenesis.
Incidence of root canal treatment of second molars following adjacent impacted third molar extraction
(2016) Oguz, Yener; Soydan, Sidika Sinem; Onay, Emel Olga; Cubuk, Secil; 30894952
Background/purpose: The aim of this study was to evaluate the incidence of requirement for root canal treatment of adjacent second molars following the surgical extraction of an impacted third molar. Materials and methods: The dental records of 6323 consecutive patients who had impacted third molars removed surgically were evaluated and the incidence of postoperative root canal treatment requirement of adjacent second molars was determined. Patients who required root canal treatment of neighboring second molars were accepted as the study group, while the remaining patients were accepted as a control group. Sex, age at the time of the operation, localization of third molar, the depth of impaction, angulation of the tooth, and the professional experience of the surgeon performing the operation were evaluated from patient records. Results: The incidence of requirement of root canal treatment for second molars following a neighboring impacted third molar extraction was 0.17% (11/6323) and invariably occurred in the mandible. The mean age of the study group was found to be significantly higher than the control group (31 years vs. 23 years). The years of professional experience of the surgeons was significantly lower in the study group than in the control group. Conclusion: Although the incidence is minimal, iatrogenic subluxation injuries occurring during the surgical removal of impacted third molars can lead to pulpal complications and a requirement for root canal treatment of adjacent second molars. Copyright (C) 2015, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC.
Odontogenic effects of two calcium silicate-based biomaterials in human dental pulp cells
(2018) Onay, Emel Olga; Yurtcu, Erkan; Terzi, Yunus Kasim; Ungor, Mete; Oguz, Yener; Sahin, Feride İffet; 30070078
Background. The goal of treating exposed pulp with an appropriate pulp capping material is to promote the dentinogenic potential of the pulpal cells. There have been recent attempts to develop more effective pulp-capping materials. Objectives. The aim of this study was to evaluate the effect of newly developed calcium silicate-based material on odontogenic differentiation of primary human dental pulp cells (HDPCs), in comparison with a contemporary calcium silicate-based material. Material and methods. Human dental pulp cells isolated from dental pulps were cultured in standard culture conditions in Dulbecco's Modified Eagle's Medium (DMEM) and then the effects of Micro-Mega mineral trioxide aggregate (MM-MTA) (Micro-Mega, Besancon, France) and ProRoot MTA (MTA) (Dentsply Sirona, Tulsa, USA) (positive control) were evaluated on HDPCs at 1, 7 and 14 days. Untreated cells were used as a negative control. Odontoblastic differentiation was assessed by alkaline phosphatase (ALP) activity. Runtrelated transcription factor 2 (RUNX2), alkaline phosphatase liver/bone/kidney (ALPL), bone morphogenetic protein 2 (BMP2), dentin sialophosphoprotein (DSPP), and Distal-less homeobox 3 (DLX3), as odontoblastic/ osteoblastic expression markers, were evaluated by semi-quantitative real-time polymerase chain reaction (RT-PCR) analysis. Calcium levels of culture media were also determined. Results. The MM-MTA group significantly increased the expression of BMP2 compared with that of the MTA group at 3 different time periods (p < 0.05). The up-regulation of ALPL between day 1 and 14 and the up-regulation of DSPP between day 7 and 14 were significant in both groups (p < 0.05). Micro-Mega MTA and MTA exhibited similar messenger RNA (mRNA) expression levels of ALPL, DSPP, RUNX2, DLX3, and ALP activities, as well as calcium levels. Conclusions. Based on the cell responses observed in this study, MM-MTA might be used efficiently in dental pulp therapy as a potential alternative to MTA.
Radiological and Histological Evaluation of the Effects of Cortical Perforations on Bone Healing in Mandibular Onlay Graft Procedures
(2016) Dayangac, Emre; Araz, Kenan; Oguz, Yener; Bacanli, Didem; Caylak, Berrin; Uckan, Sina; 24889104
BackgroundPerforations of the cortical bone may be an advantage for the success of the autogenous bone graft procedure, but whether this perforation has a positive effect on the bone remains controversial. PurposeThis study evaluates the effects of cortical perforation of the autogenous bone block graft radiologically and histologically. Materials and MethodsSeven adult pigs were used for this study. On the experimental side, cortical perforation at the host site was prepared, while no perforation was done on the control side. The specimens were evaluated, and the Wilcoxon signed-rank test was used for statistical analysis. ResultsIn the radiological evaluation, the Wilcoxon signed-rank test indicated no significant differences in densities among the grafts (p=.23) with a mean of 4.290.951 for the unperforated graft side and 3.57 +/- 0.976 for the decorticated graft side. In histological evaluation, there was a significant difference in the thickness of the grafts between the groups (experimental group 3.71 +/- 1.286, control group: 4.71 +/- 0.488; p=.033). However, when the remodeling and osteoblastic activity in the grafts were measured, no significant differences were observed between the groups (p=1 and p=.133, respectively). ConclusionIn augmentation with mandibular onlay bone grafts, cortical perforations in the recipient site make no distinct contribution to bone healing within 12 weeks.
Stress Distribution on Short Implants at Maxillary Posterior Alveolar Bone Model With Different Bone-to-Implant Contact Ratio: Finite Element Analysis
(2016) Yazicioglu, Duygu; Bayram, Burak; Oguz, Yener; Cinar, Duygu; Uckan, Sina; 26867093
The aim of this study was to evaluate the stress distribution of the short dental implants and bone-to-implant contact ratios in the posterior maxilla using 3-dimensional (3D) finite element models. Two different 3D maxillary posterior bone segments were modeled. Group 1 was composed of a bone segment consisting of cortical bone and type IV cancellous bone with 100% bone-to-implant contact. Group 2 was composed of a bone segment consisting of cortical bone and type IV cancellous bone including spherical bone design and homogenous tubular hollow spaced structures with 30% spherical porosities and 70% bone-to-implant contact ratio. Four-millimeter diameter and 5-mm-height dental implants were assumed to be osseointegrated and placed at the center of the segments. Lateral occlusal bite force (300 N) was applied at a 25 degrees inclination to the implants long axis. The maximum von Mises stresses in cortical and cancellous bones and implant-abutment complex were calculated. The von Mises stress values on the implants and the cancellous bone around the implants of the 70% bone-to-implant contact group were almost 3 times higher compared with the values of the 100% bone to -implant contact group. For clinical reality, use of the 70% model for finite element analysis simulation of the posterior maxilla region better represents real alveolar bone and the increased stress and strain distributions evaluated on the cortical and cancellous bone around the dental implants.