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Raman spectra of aluminum oxide, Al2O3, have been a subject of interest over the last two decades. The origin of the fluorescence background in the Raman spectra of Al2O3 is still a subject of discussion. It has been believed to be due to hydrocarbon, iron ion impurities, or hydroxy groups on the surface of Al2O3. In this paper, Raman spectra of Al2O3 are reported that were acquired with different excitation frequencies as well as different spectrometers and different temperatures. It is shown that, whereas at an excitation frequency of 1064 nm a strong fluorescence background is observed, a sample of Al2O3 heated at 1250 °C when excited with a 632.8-nm frequency exhibits strong and remarkable fluorescence ne structure. It is concluded that the origin of the fluorescence background in the Raman spectra of Al2O3 is iron, and Fe impurity, and the intensity of this fluorescence depends upon the structure of Al2O3 and the excitation frequency used.

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Introduction:Oral Lichen Planus (OLP) and Oral Lichenoid Lesions (OLLs) are clinically and histopathologically similar lesions but with different etiologies and treatment plan, thus differentiating these two has been the center of many researches. Studies in different populations have been performed on clinical and histopathologic features of OLP and OLLs. Thus aim of the present study was to evaluate and also compare the clinical and histopathologic features of these two diseases in a 10-year period in Esfahan.Materials and Methods:This descriptive–analytic study was based on retrospective survey of 232 records with clinical and histopathologic diagnosis of OLP and OLLs available from archive of oral pathology, Esfahan dental school 2000-2010. Data was statistically analyzed by use of independent t-test, Fisher exact, and Chi-square.Results:Involvement of lip was the only clinically significant difference between OLP and OLLs, most seen in OLLs. Band-like inflammatory infiltrate mainly composed of lymphocyte, saw toothed rete ridges, Max Joseph space, and atrophic epithelium was significantly seen in OLP. While hyperkeratosis, deep connective tissue infiltrate composed of eosinophil, neutrophil, and plasma cell were seen in OLLs.Conclusion:Involvement of lip was the only clinically significant difference between OLP and OLLs. Histopathologically strict band like infiltration, atrophic epithelium, saw toothed rete ridges, and Max Joseph space are reliable criteria for differentiation of OLP as deep connective tissue infiltration and hyperparakeratosis are for diagnosis of OLLs.

Objectives: Melatonin induces human stem cells, converts pre-osteoblasts to mature osteoblasts, and reduces the duration of this transition. However, melatonin itself prevents activation of osteoclasts. Here, we evaluate the role of melatonin in prevention of bisphosphonate-related osteonecrosis of the jaw. Materials and Methods: In this experimental-interventional study, 30 rats were evaluated in 3 groups. The first and second groups received saline and zoledronic acid, respectively, for 4 weeks and the third group received 4 weeks of zoledronic acid and 3 weeks of melatonin simultaneously. Firstright-maxillary-molar extraction was performed for all animals, which were sacrificed after 4 weeks of recovery. The extraction sockets were examined histologically for the presence of osteonecrosis, number of osteoclasts and fibroblasts, severity of inflammation, and vascularization. Data were analyzed by chi-square, one-way ANOVA, Tukey, Kruskal-Wallis and Fisher's exact statistical tests (α=0.05). Results: Osteonecrosis was observed in 20%, 90%, and 70% of the first, second and third groups, respectively (P=0.008). The lowest number of osteoclasts and fibroblasts was seen in the third group. Conclusion: Melatonin may effectively prevent some undesirable side effects of bisphosphonates. However, further studies are required to confirm the results of this study.

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BackgroundCandidiasis, the infection caused by Candida albicans, is one of the most common infections of the oral cavity in humans. Candidiasis causes irritation and is known for its carcinogenic effects. Thus, it is important to recognize the predisposing factors for this opportunistic infection. Several previous studies have demonstrated an increased frequency of vaginal candidiasis in relation to oral contraceptive consumption.ObjectivesOnly a few studies on the relation between oral contraceptives and oral candidiasis have been previously conducted. This study aims to evaluate the possible relation between oral contraceptive pills and oral candidiasis.MethodsThis analytic, case-control study included 40 non-pregnant women divided into two groups: 20 who used oral contraceptive pills and 20 who did not. The groups were matched according to age, oral health, and past and present medical history. Samples were collected from the tongue’s dorsum using a cotton swab and inoculated on CHROMagar culture plates. The frequency of positive cultures and the number of Candida colonies were compared between the two groups using independent t-tests and Mann-Whitney statistical tests with SPSS18 software.ResultsThe frequency of positive cultures of Candida albicans was higher (P value = 0.03) for the case group. Also, the number of C. albicans and C. krusei was significantly higher for the case group compared to the control group (P value = 0.04, P value = 0.03).ConclusionsThe results of the present study demonstrate that oral contraceptives containing estradiol can lead to Candida colonization in the oral cavity. It is recommended that further studies comparing the influence of oral contraceptives on Candida’s adherence to the epithelium is highly recommended.