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Öğe Comparison of the Effects of Low-Level Laser Therapy and Ozone Therapy on Bone Healing(JOURNAL OF CRANIOFACIAL SURGERY, 2015) Alan, Hilal; Vardi, Nigar; Ozgur, Cem; Huseyin, Ahmet; Yolcu, Umit; Dogan, Derya OzdemirThis study aims to compare the effect of low-level laser therapy (LLLT) and ozone therapy on the bone healing. Thirty-six adult male Wistar albino rats were used for this study. Monocortical defects were shaped in right femur of all rats. Defects were filled with nano-hydroxyapatite graft. The animals were divided into 3 groups and each group was than divided into 2 subgroups. Then, LLLT with a diode laser was applied to the first group (G1), ozone therapy was applied to the second group (G2), and no treatment was applied to the third group as a control group (G3). Animals were sacrificed after 4th and 8th weeks and the sections were examined to evaluate the density of the inflammation, the formation of connective tissue, the osteogenic potential, and osteocalcin activity. As a result, there were no significant differences among the groups of 4 weeks in terms of new bone formation. In the immunohistochemical assessment, the number of osteocalcin-positive cells was higher in the laser group compared to the other group of 4 weeks; this difference was statistically significant in the LLLT and ozone groups (P < 0.05). Histomorphometric assessment showed that the new bone areas were higher in the LLLT and ozone groups; furthermore, there was a statistically significant difference in the LLLT in comparison with the control group at 8th week (P < 0.05). At the same time immunohistochemical assessment showed that osteocalcin-positive cells were considerably higher in G2 than G1 at 8th week (P < 0.05). The findings of this study may be the result of differences in the number of treatment sessions. Further studies are therefore needed to determine the optimal treatment modality.Öğe Comparison of the Effects of Low-Level Laser Therapy and Ozone Therapy on Bone Healing(Lippincott Williams & Wilkins, 2015) Alan, Hilal; Vardi, Nigar; Ozgur, Cem; Huseyin, Ahmet; Yolcu, Umit; Dogan, Derya OzdemirThis study aims to compare the effect of low-level laser therapy (LLLT) and ozone therapy on the bone healing. Thirty-six adult male Wistar albino rats were used for this study. Monocortical defects were shaped in right femur of all rats. Defects were filled with nano-hydroxyapatite graft. The animals were divided into 3 groups and each group was than divided into 2 subgroups. Then, LLLT with a diode laser was applied to the first group (G1), ozone therapy was applied to the second group (G2), and no treatment was applied to the third group as a control group (G3). Animals were sacrificed after 4th and 8th weeks and the sections were examined to evaluate the density of the inflammation, the formation of connective tissue, the osteogenic potential, and osteocalcin activity. As a result, there were no significant differences among the groups of 4 weeks in terms of new bone formation. In the immunohistochemical assessment, the number of osteocalcin-positive cells was higher in the laser group compared to the other group of 4 weeks; this difference was statistically significant in the LLLT and ozone groups (P < 0.05). Histomorphometric assessment showed that the new bone areas were higher in the LLLT and ozone groups; furthermore, there was a statistically significant difference in the LLLT in comparison with the control group at 8th week (P < 0.05). At the same time immunohistochemical assessment showed that osteocalcin-positive cells were considerably higher in G2 than G1 at 8th week (P < 0.05). The findings of this study may be the result of differences in the number of treatment sessions. Further studies are therefore needed to determine the optimal treatment modality.Öğe The effects of therapeutic x-ray doses on mechanical, chemical and physical properties of poly methyl methacrylate(Taylor & Francis Ltd, 2013) Dogan, Derya Ozdemir; Ozguven, Yildiray; Karakus, Gulderen; Sahin, Onur; Polat, Nilufer Tulin; Yucel, Birsen; Dogan, MansurAim. The aim of this study was to investigate the effect of radiation doses very close to the human dose for oral cancers on mechanical, chemical and physical properties for poly methyl-methacrylate (PMMA). Methods. PMMA samples were divided into four different groups: no irradiated group, 25-Gy irradiated group, 50-Gy irradiated group and 75-Gy irradiated group. Each group contained nine samples. After 24 h, a three-point loading test was applied to each PMMA groups. The transverse strength and the elastic modulus were calculated using the test results. The results were analyzed statistically by using one-way analysis of variance. The structural characterizations of the PMMA samples were carried out by a Fourier Transform Infrared (FTIR) spectrophotometer to evaluate the chemical structure differences. Results. The transverse strength values of 25-Gy, 50-Gy and 75-Gy radiation groups were significantly higher than that of the no radiation group (p < 0.05). There was no significant difference among the elastic modulus values of the study groups (p > 0.05). The FTIR findings demonstrated that the irradiation process did not change the chemical structure of the PMMA polymeric materials. Conclusion. The therapeutic radiation doses increase the mechanical properties of the PMMA; however, the chemical and structural properties have no effect. When the findings of this study are taken into account, it can be said that patients can wear dentures during the radiotherapy.Öğe Evaluation of All-on-Four Concept and Alternative Designs with 3D Finite Element Analysis Method(Wiley, 2014) Dogan, Derya Ozdemir; Polat, Nilufer Tulin; Polat, Serkan; Seker, Emre; Gul, Esma BasakPurpose: The aim of the present study was to evaluate the effect of the forces on the implant and supporting alveolar ridge in all on four concept and alternative designs using finite element analysis. Materials and Methods: Different treatment alternatives with various implant designs were performed in an edentulous mandible. In Design 1, implants were placed according to All-on-Four concept; Design 2, two long (13 mm long, 4 mm diameter) and two short (7 mm long, 4 mm diameter) implants; Design 3, four long and two short implants; and Design 4, two long and four short implants were placed vertically. A force of 100 N for each tooth, a total of 300 N load was applied. Finite element analysis was used to evaluate and compare the different designs. Results: The stress concentration within the cortical bone was significantly higher than the trabecular bone around the neck of the implants. The maximum stress values were located around the cortical bone of the distal implant for all designs. The reduction in the number of implants did not diminish the success of the design. Conclusions: In the presence of vertically resorbed posterior mandibula, although the all on four concept is a feasible approach clinically, short implants had decreased the amount of force transmitted to the supporting bone.Öğe Histopathological evaluation of the effects of fiber reinforced acrylic resins on living tissues(Informa Healthcare, 2013) Ozdemir, Ali Kemal; Polat, Nilufer Tulin; Turgut, Mehmet; Dogan, Derya Ozdemir; Goze, FahrettinObjective. The aim of this study was the histopathological evaluation of the effects of the fiber reinforced acrylic resins on living tissues. Materials and methods. The study was performed on 21 rabbits. Three groups, each including seven subjects, were formed. There was no applied plate in the control group. For the second group, heat-polymerized acrylic resin plates were inserted. For the third group, heat-polymerized acrylic resin plates containing proportionally 5% chopped silanated E type glass fiber were inserted. Plates were fixed to the palatine bone of the rabbits with titanium screws. Before the implementation of the plates and 1 month after the plates were applied, soft tissue samples were taken from the buccal mucosa of the rabbits. Also, tissue samples were taken from the control group. All samples were evaluated histopathologically. Results. In the control group, only a focal atrophy was observed. In the acrylic group, large decomposition containing erythrocytes under the parahyperkeratotic region and micro-vesicle like spongiotic tissue reactions were observed. In the fiber reinforced acrylic group, widespread focal atrophy, bulgy look of the epithelium cells similar to apoptosis, over-distension and sub-corneal decomposition had been observed. In terms of atrophy and hyperkeratosis there were no statistically significant differences among groups. However, in respect to sub-corneal decomposition, there was a statistically significant difference in the fiber reinforced group (p < 0.01). Conclusions. The statistically significant difference in the sub-corneal decomposition of the fiber reinforced group had made us think that fiber edges had a traumatic effect on the reaction.