1.In vitro study of fracture strength of provisional crown materials.
Isil KARAOKUTAN ; Gulsum SAYIN ; Ozlem KARA
The Journal of Advanced Prosthodontics 2015;7(1):27-31
PURPOSE: The purpose of this report was to evaluate the effect of the fabrication method and material type on the fracture strength of provisional crowns. MATERIALS AND METHODS: A master model with one crown (maxillary left second premolar) was manufactured from Cr-Co alloy. The master model was scanned, and the data set was transferred to a CAD/CAM unit (Yenamak D50, Yenadent Ltd, Istanbul, Turkey) for the Cercon Base group. For the other groups, temporary crowns were produced by direct fabrication methods (Imident, Temdent, Structur Premium, Takilon, Systemp c&b II, and Acrytemp). The specimens were subjected to water storage at 37degrees C for 24 hours, and then they were thermocycled (TC, 5000x, 5-55degrees C) (n=10). The maximum force at fracture (Fmax) was measured in a universal test machine at 1 mm/min. Data was analyzed by non-parametric statistics (alpha=.05). RESULTS: Fmax values varied between 711.09-1392.1 N. In the PMMA groups, Takilon showed the lowest values (711.09 N), and Cercon Base showed the highest values (959.59 N). In the composite groups, Structur Premium showed the highest values (1392.1 N), and Acrytemp showed the lowest values (910.05 N). The composite groups showed significantly higher values than the PMMA groups (P=.01). CONCLUSION: Composite-based materials showed significantly higher fracture strengths than PMMA-based materials. The CAD-CAM technique offers more advantages than the direct technique.
Alloys
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Computer-Aided Design
;
Crowns*
;
Dataset
;
Polymethyl Methacrylate
;
Water
2.Amenorrhea as a Side Effect of Low Dose Aripiprazole: An Adolescent Case.
Gulen GULER ; Meryem Ozlem KUTUK ; Halil KARA
Clinical Psychopharmacology and Neuroscience 2018;16(3):343-345
Amenorrhea, oligomenorrhea, galactorrhoea, gynecomastia, infertility, and sexual dysfunction may arise as a consequence of hyperprolactinemia. Hyperprolactinemia is one of major side effects of treatment with antipsychotics, but aripiprazole is known as a dopamine stabilizer antipsychotic which can be used to improve hyperprolactinemia. In this report, it was described that an adolescent patient experienced amenorrhea after adding very low dose aripiprazole to ongoing fluoxetine treatment regime for major depressive disorder. Additionally, this case showed that the patient recovered from the amenorrhea with replacement of aripiprazole with quetiapine.
Adolescent*
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Amenorrhea*
;
Antipsychotic Agents
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Aripiprazole*
;
Depressive Disorder, Major
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Dopamine
;
Female
;
Fluoxetine
;
Gynecomastia
;
Humans
;
Hyperprolactinemia
;
Infertility
;
Male
;
Oligomenorrhea
;
Quetiapine Fumarate
3.Mechanical properties of zirconia after different surface treatments and repeated firings.
Meryem Gulce SUBASI ; Necla DEMIR ; Ozlem KARA ; A Nilgun OZTURK ; Faruk OZEL
The Journal of Advanced Prosthodontics 2014;6(6):462-467
PURPOSE: This study investigated the influence of surface conditioning procedures and repeated firings on monoclinic content and strength of zirconia before cementation. MATERIALS AND METHODS: Sintered bar-shaped zirconia specimens were subjected to no surface treatment (control), air abrasion, or grinding (n=21). Their roughness was evaluated using a profilometer, and microscope analysis was performed on one specimen of each group. Then, 2 or 10 repeated firings (n=10) were executed, the monoclinic content of specimens was analyzed by X-ray diffraction, and a three-point flexural strength test was performed. Surface roughness values were compared using one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests, the monoclinic content values were tested using Kruskal-Wallis and Mann-Whitney U tests, and the flexural strength values were tested using two-way ANOVA and Tukey HSD tests (P=.05). Spearman's correlation test was performed to define relationships among measured parameters. RESULTS: Surface-treated specimens were rougher than untreated specimens and had a higher monoclinic content (P<.005), and the relationship between roughness and monoclinic content was significant (P<.000). Neither surface treatment nor firing significantly affected the flexural strength, but Weibull analysis showed that for the air-abraded samples the characteristic strength was significantly lower after the 10th firing than after the 2nd firing. CONCLUSION: After firing, a negligible amount of monoclinic content remained on the zirconia surfaces, and rougher surfaces had higher monoclinic contents than untreated surfaces. Multiple firings could be performed if necessary, but the fracture probability could increase after multiple firings for rougher surfaces.
Cementation
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Ceramics
;
Fires*
;
X-Ray Diffraction
4.The Healing Effects of Autologous Mucosal Grafts in Experimentally Injured Rabbit Maxillary Sinuses.
Murat TOPDAG ; Ahmet KARA ; Esma KONUK ; Necdet DEMIR ; Murat OZTURK ; Sebla CALISKAN ; Deniz Ozlem TOPDAG ; Arif ULUBIL ; Ibrahim Gurkan KESKIN ; Mete ISERI
Clinical and Experimental Otorhinolaryngology 2016;9(1):44-50
OBJECTIVES: Healing processes of the nose and paranasal sinuses are quite complex, and poorly understood. In this study, we aimed to compare the effect of mucosal autologous grafts on the degenerated rabbit maxillary sinus mucosa with spontaneous wound healing. It is hypothesized that mucosal grafts will enhance ciliogenesis and improve the morphology of regenerated cilia. METHODS: Ten female New Zealand rabbits were included in the study. They underwent external maxillary sinus surgery through a transcutaneous approach. A total of 20 maxillary sinuses were randomly divided into 2 groups: 'spontaneous healing group' and 'autologous graft group.' The animals were sacrificed at the 14th day after the surgery. Scanning electron microscope (SEM), and light microscope were used for the evaluation. RESULTS: Cellular composition of the graft group is better than the spontaneous healing group. The graft group had larger areas covered with ciliary epithelium than the spontaneous healing group, and the mean length of the cilias were also longer. Additionally, there were wider cilia with abnormal morphology areas in the spontaneous healing group. CONCLUSION: In our opinion, covering of the denuded areas with a graft improves re-epithelization, and may prevent the early complications after sinus surgeries.
Animals
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Cilia
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Epithelium
;
Female
;
Humans
;
Maxillary Sinus*
;
Mucous Membrane
;
Nasal Mucosa
;
Nose
;
Paranasal Sinuses
;
Rabbits
;
Transplants*
;
Wound Healing