Browsing by Author "Diker, Nurettin"

Now showing 1 - 8 of 8

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.
Comparison of Success Rate of Dental Implants Placed in Autogenous Bone Graft Regenerated Areas and Pristine Bone
(2020) Altiparmak, Nur; Akdeniz, Sidika Sinem; Diker, Nurettin; Bayram, Burak; Uckan, Sina; 32282668
Autogenous bone grafting still has been considered as the "gold standard" and wildly used in the case of alveolar bone reconstruction. The aim of the present study is to evaluate the success rate of implants placed in autogenous block augmented ridges and implants placed in pristine bone (PB). This study included 113 patients. Fifty-three patients were treated with autogenous block grafts and particulate bone, after 6 months of healing implant placements were performed in autogenous bone augmented (ABA) areas. In 60 patients implant placement was performed, with no need for grafting and implants were placed into the PB. Follow-up data (pain, mobility, exudation from peri-implant space, success rate, marginal bone resorption) were collected after 5 years of prosthetic loading. The cumulative implant success rate at the 5-year examination was 92.45% for the ABA group and 85% for PB group. There were 3 failed implants in the ABA group and 3 in PB group. Average marginal bone loss was 1.47 mm on ABA group and 1.58 mm on PB group. No statistically significant differences for pain, exudation from peri-implant space, implant mobility, implant success, peri-implant bone loss parameters, and patient satisfaction level were found between groups. The obtained data demonstrated that the success rate of implants placed in regenerated areas are very similar to the success rate of implants those placed in PB.
The effect of systemic rifampicin treatment on inferior alveolar nerve regeneration in rats following crush injury
(2020) Diker, Nurettin; Caglayan, Berrak; Helvacioglu, Fatma; Kilic, Ertugrul; 0000-0002-6026-0045; 32236990; AAH-8887-2021
Axonal regeneration of the inferior alveolar nerve (IAN) is a therapeutic target for functional recovery after peripheral nerve injury. Rifampicin exerts anti-apoptotic, anti-inflammatory, and anti-oxidant effects on nerve tissues that may enhance functional recovery after peripheral nerve injury. The aim of the present study was to evaluate the therapeutic effects of systemic rifampicin following IAN crush injury. Following the nerve crush injuries of the IAN, 24 Sprague-Dawley rats were randomly divided into three groups to receive daily intraperitoneal injections of either vehicle, 5 mg kg(-1) rifampicin, or 20 mg kg(-1) rifampicin. Twenty-four days after induction of nerve injuries, Fluorogold (FG) was injected over the mental foramen for the evaluation of neuronal survival. At the end of the four-week period, histologic and histomorphometric examination of IAN samples were performed and FG positive cells were counted in the trigeminal ganglion sections. FG positive cells were significantly more frequent in the 20 and 5 mg kg(-1) rifampicin groups than in the vehicle-treated group. Electron microscopic analyses revealed that the percentage of axons with optimum g-ratio was significantly lower in the vehicle group than in both treatment groups. In conclusion, systemic rifampicin treatment can enhance peripheral nerve regeneration.
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.
Effects of Platelet-Rich Fibrin Membrane on Sciatic Nerve Regeneration
(2018) Bayram, Burak; Akdeniz, Sidika Sinem; Diker, Nurettin; Helvacioglu, Fatma; Erdem, Saban Remzi; 0000-0002-7825-1083; 0000-0002-6026-0045; 0000-0002-7537-2170; 29381631; AAS-4519-2020; AAH-8887-2021; AAJ-2370-2021
Alternative treatment approaches to improve the regeneration capacity of damaged peripheral nerves are currently under investigation. The objective of the present study was to evaluate the effects of platelet-rich fibrin (PRF) membrane after sciatic nerve crush injury in rabbits by histomorphometric and electromyographic analysis. The left sciatic nerves of 20 male Vienna rabbits were clamped for 30seconds to induce crush injuries. Animals were randomly divided into 2 groups: PRF and control. For each animal in the PRF group, a PRF membrane was wrapped around the injured part of the sciatic nerve to form a tube. No additional treatment was performed in the control group. After a 12-week healing period, tissue samples from the injured nerve region were harvested and the g-ratio of axons, axon density, and impulse transmission changes were evaluated. Analysis revealed that axon density differences were not statistically significant between groups (P=0.139). The rate of nerve fibers with optimum g-ratio was significantly lower in the PRF group than in the control group (P=0.02). Conduction velocity differences between groups were not statistically significant. Although PRF application has previously shown positive regeneration effects on maxillofacial tissues, local PRF membrane application in tube form did not show any histomorphometric or functional improvement in peripheral nerve crush injury recovery.
Evaluation of light-emitting diode photobiomodulation on bone healing of rat calvarial defects
(2015) Deniz, Ediz; Arslan, Ahmet; Diker, Nurettin; Olgac, Vakur; Kilic, Ertugrul
One of the major problems in modern dentistry is the recovery of bone defects. The aim of this prospective experimental study was to evaluate the effect of light-emitting diode (LED) photobiomodulation therapy on bone healing of rat calvarial defects. Twenty-eight male Sprague Dawley rats were used for the study. Critical size defects with 5 mm diameter were made with a trephine bur used in a low-speed handpiece under continuous sterile saline irrigation on each side of the sagittal suture. All critical size defects on the right side were filled with corticocancellous bone graft material and all the defects on the left side were left empty. The animals were randomly divided into two groups of 14 rats each. Group I received LED therapy and Group II did not receive any therapy. OsseoPulse (R) LED device (Biolux Research Ltd.) 618 nm wavelength and 20 mW/cm(2) output power irradiation was started immediately after the surgery and was applied for 20 minutes at 24-h intervals for 7 and 14 days. In each group, seven rats were sacrificed on the 8th day and the remaining rats were sacrificed on the 15th day. Bone healing of the non-grafted side was statistically significant in Group I on both 8th day and 15th day; on the other hand, in the grafted side, enhanced bone healing was dominantly observed on the 15th day in Group I, compared to Group II, although the difference was not significant. Within the limits of this study, the findings suggested that LED therapy might have a favourable effect in the early phase of bone healing.
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.
Feasibility of Carbon-Fiber-Reinforced Polymer Fixation Plates for Treatment of Atrophic Mandibular Fracture: A Finite Element Method
(2018) Diker, Nurettin; Burak, Bayram; 0000-0002-7825-1083; 30340836; AAS-4519-2020
The objective of this study was to conduct a computer assessment of the biomechanical stability of locking fixation plates of different thicknesses, made of titanium alloy and carbon-fiber- reinforced polyetheretherkotone (CFR-PEEK) in Class III atrophic mandibular fractures. Class III atrophic mandibular models were constructed using three-dimensional finite element models. After simulation of fracture on the left side, plates with different thicknesses (1.0, 1.5, 2.0, and 2.5 mm) were adapted to the models and three locking screws on each side of the fracture were used for fixation. Titanium alloy and CFR-PEEK material properties were assessed for all plate models. Von Mises stress values decreased gradually with an increase in plate profile thickness. Von Mises stress values for screws and plates were lower in models using CFR-PEEK plates. An increase in plate profile enhanced the load-sharing performance of the fixation systems, with rigid titanium alloy plates sharing the load among the screws more evenly. 1.0 mm, 1.5 mm, and 2.0 mm CFR-PEEK plates produced strain values of 2-10%, which promote proper healing via formation of callus in the fracture line. In terms of investigated biomechanical parameters, and with a Young's modulus similar to that of cortical bone, CFR-PEEK materials appear to be suitable for the treatment of atrophic mandibular fractures. (C) 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.