Green synthesis of SnO2-ZnO-eggshell nanocomposites and study of their application in removal of mercury (II) ions from aqueous solution.

BACKGROUND: Mercury (Hg) in dental amalgam is the world's hidden source of mercury contamination. The development of more eco-friendly and cost-effective adsorbents to reduce mercury pollutants in wastewater is highly desirable and is still a major challenge. In this study, a novel nanocomposite was synthesized and used as an efficient adsorbent for the removal of Hg(II) ions from aqueous solution. METHODS: A green and cost-effective method was described to the synthesis of SnO2-ZnO-eggshell nanocomposites using teucrium polium extract as a renewable reductant and mild stabilizer. The biosynthesized nanocomposites were characterized by various techniques. The novel SnO2-ZnO-eggshell nanocomposites were used as an effective adsorbent in the removal of mercury (II) ions. To achieve the maximum absorption efficiency of Hg(II) ions, the effect of operating factors such as pH value, the dose of catalyst, the initial metal concentration of Hg(II) ions, and catalyst type were evaluated. RESULTS: The removal percentage and adsorption capacity of Hg(II) were obtained 99.15% and 396.6 mg.g-1, respectively, under optimal conditions after 5 minutes. The selectivity of SnO2-ZnO-eggshell nanocomposites for the adsorption of metal ions was studied, and the highest selectivity was obtained for adsorption of Hg (II) ions. Furthermore, the SnO2- ZnO-eggshell nanocomposites could be recovered and reused at least three times without considerable loss of their efficiency. CONCLUSIONS: The present approach has advantages such as rapidity, simplicity, selectivity, low cost and, most importantly, the use of nanocomposites containing a bio-waste material of eggshell for removal of Hg(II) ions from aqueous solution.

Salivary levels of IgE and ECP in patients with recurrent aphthous stomatitis.

BACKGROUND: Recurrent aphthous stomatitis is a common oral mucosa disease, with no specific etiology. Atopy has been implicated in the development of this disease. In this study, the salivary levels of immunoglobulin E (IgE) and eosinophil cationic protein (ECP) were measured as allergy-related biomarkers in patients with aphthous stomatitis. MATERIAL AND METHODS: In this case-control study, non-stimulated saliva was collected from 85 participants and IgE and ECP were measured. Data were analyzed in SPSS 20 through the Mann-Whitney test, and p<0.05 was considered significant. RESULTS: The salivary levels of IgE and ECP were 1.11±0.65 Iu/ml and 26.93±6.95 ng/ml in the case group and 0.73±0/39 Iu/ml and 21.97±6.72 ng/ml in the control group. There was a significant difference between the two groups in terms of salivary levels of IgE and ECP (p=0.001). CONCLUSIONS: The results showed that patients with oral aphthous had higher levels of salivary IgE and ECP than controls. Therefore, measurement of these biomarkers may be useful in the initial evaluation of patients with aphthous stomatitis. Key words:Recurrent aphthous stomatitis, saliva, immunoglobulin E, eosinophil cationic protein.

Comparison of Salivary Cotinine Concentrations in Male Smokers and Smokeless Tobacco Users

Objective: Smoking cigarettes and smokeless tobacco are one of the causes of oral cancer. This study compared the salivary level of cotinine in male smokeless tobacco users and smokers. Methods: In this cross-sectional (descriptive-analytical) study, stimulated saliva samples from 30 male smokers and 30 male smokeless tobacco consumers were collected and their cotinine contents were measured using the competitive ELISA method according the standard curve. The data was analyzed with independent t-test and linear regression using SPSS-19, and P<0.05 was considered significant. Result: Among the 60 subjects with the mean age of 21.27±2.6 years, the average level of cotinine in smokers (12.32±7.5 ng/ml) had no significant difference with that of smokeless tobacco consumers (11.23±4.4 ng/ml) (p=0.49). Conclusion: Salivary levels of cotinine were not significantly different in smokeless tobacco users and cigarette smokers. In addition, increases in the number of cigarettes smoked and in pack of smokeless tobacco used, were associated with increased salivary levels of cotinine. The increase was higher in smokeless tobacco consumers.

Comparing the effect of diode laser against acyclovir cream for the treatment of herpes labialis.

BACKGROUND: Recently alternative therapies such as the use of diode laser therapy have been introduced for recurrent herpes labial infection. The aim of this study was to evaluate the effectiveness of diode laser for treatment of recurrent herpes labialis. MATERIAL AND METHODS: This was single-blind randomized clinical trial to evaluate the efficacy of diode laser for the treatment of recurrent herpes labial. In total, 60 patients whit recurrent herpes simplex labialis were selected and randomly divided in to three groups. 20 patients received treatment whit diode laser (at a wavelength of 870 nm, energy density 4.5 j/cm2), 20 patients were treated with acyclovir cream 5%, 20 patients received treatment with laser-off (placebo). The end point was lesions crusting. Data analyzed by Tukey HSD Test and One-way ANOVA (at a significance level of 0.05) in SPSS-20 software. RESULTS: The mean length of recovery time (day) in the laser, off laser, and acyclovir groups was 2.20±0.41, 4.30±1.03, and 3.4±1.142, respectively. There is a significant difference between three groups in this regard (P<0.0001). The mean duration of pain (day) was 1.35±0.74, 2.65±1.27, and 2.30±0.92 for laser, off laser, and acyclovir groups, respectively (P<0.0001). CONCLUSIONS: Treatment with diode laser reduced the length of recovery time and pain severity faster than treatment with acyclovir cream. Key words:Recurrent herpes labial, Acyclovir, Low level laser therapy.

Oral manifestation and salivary changes in renal patients undergoing hemodialysis.

BACKGROUND: Salivary changes in hemodialysis patients may result in various oral manifestations. This research intended to determine oral manifestations and some salivary markers in hemodialysis patients. MATERIAL AND METHODS: This cross-sectional study was conducted on 30 hemodialysis patients (the patient group) and 30 healthy individuals (the control group). Saliva urea and calcium levels and pH values of the participants were measured, and oral manifestations such as pale mucosa, xerostomia, halitosis, changes in the sense of taste, increased calculus formation, gingival bleeding, etc. were recorded in the information collection form. The data was analyzed using T-test and chi-square, and p<0.05 was considered to be significant. RESULTS: The mean salivary urea level and pH value in the patient group were significantly higher compared to those of the control group (P<0.05), but there were no significant differences between the two groups with respect to salivary calcium. Halitosis, xerostomia, and increased calculus were the most prevalent manifestations, and gum bleeding was the least prevalent among the patients. CONCLUSIONS: Advanced chronic renal insufficiency can increase salivary urea level, pH value, halitosis, xerostomia, and calculus formation, and may cause pale mucosa. Key words:Renal dialysis, biomarkers, oral manifestation, saliva.

Salivary Sialic Acid Levels in Smokeless Tobacco Users.

BACKGROUND: Smokeless tobacco chewing is one of the known risk factors for oral cancer. It is consumed widely by residents of southeastern Iran. OBJECTIVES: In this study, salivary free and total sialic acid, and total protein were compared in paan consumers and non-consumers. PATIENTS AND METHODS: In this cross-sectional study, unstimulated saliva of 94 subjects (44 paan consumers and 50 non-consumers) who were referred to the oral medicine department of the dentistry school of Zahedan were collected. Salivary free and total sialic acid, and total protein concentration were measured by standard biochemical methods, and the obtained data were analyzed using SPSS 20 through the non-parametric Mann-Whitney test. RESULTS: The concentration of salivary free sialic acid (23.21 ± 18.98 mg/L) was significantly increased in paan consumers. The concentration of salivary Total sialic acid (TSA) (39.57 ± 26.58 mg/L) and total protein (0.77 ± 0.81 mg/mL) showed increases in paan consumers, however, the results were not statistically significant. CONCLUSIONS: Salivary free and total sialic acid, and total protein were higher in the paan consumers compared to non-consumers. Due to the carcinogenic effect of smokeless tobacco, measurement of these parameters in saliva may be useful in early detection of oral cancer.

Salivary Levels of ErbB2 and CEA in Oral Squamous Cell Carcinoma Patients.

Oral squamous cell carcinoma (OSCC) is one of the ten most common causes of cancer death worldwide. Assessment of molecular changes can help detect and control lesions. The aim of this study was evaluation of salivary levels of ErbB2 and CEA in OSCC patients. In this case-control study, 27 OSCC patients and 26 healthy controls participated. After obtaining consent and filling out a questionnaire, unstimulated saliva samples were collected from people in the morning for measurement of the two markers using ELISA. Data were analyzed using Mann Whitney U test in SPSS 19 software with P<0.05 considered significant. Subjects were in the age range of 40 to 65 years. \Salivary level CEA was elevated in OSCC samples (42.6 ± 21.1 ng/ml) as compared to those of controls (22.6 ± 22.1ng/ml) (p< 0.01), but no significant variation was noted for ErbB2 (5.2 ± 1.8ng/ml and 4.93 ± 2.14ng/ml, p=0.28). The role of ErbB2 as a tumor marker in patients with OSCC must still be regarded as controversial and needs further studies to clarify any significance for early detection or screening. In contrast the salivary level of CEA may find application for early detection of patients.

Immunohistochemical Assessment of HER3 Expression in Odontogenic Cysts.

BACKGROUND: It has been demonstrated that HER3 plays an important role in some human cancers and the HER3 expression is associated with worse survival in solid tumors. OBJECTIVES: This study was conducted to compare HER3 expression in epithelial lining of radicular cysts (RCs), dentigerous cysts (DCs) and odontogenic keratocysts (OKCs). MATERIALS AND METHODS: This was a descriptive-analytical study, which assessed all 57 paraffin blocks of RCs, DCs and OKCs (21 RCs, 16 DCs, 20 OKC) from pathological archive of Dentistry College of Zahedan, Iran. The HER3 expression in cytoplasm and membrane was examined by immunohistochemical method. The data collected was analyzed using SPSS16 by ANOVA and Chi-square. P < 0.05 was considered as statistically significant. RESULTS: The HER3 expression had positive results in 52.4% of OKC, 50% of DC and only 20% of RC samples. There was a significant difference between HER3 expression in OKCs and RCs. CONCLUSIONS: The HER3 expression in developmental odontogenic cysts was higher than that in inflammatory odontogenic cysts. The higher rate of HER3 expression in OKC may justify inherent growth potential, stimulation-independent proliferation capability, invasive growth and high recurrence rate of the cyst accepted today as a tumor.

Oral cancer knowledge of senior dental students in Zahedan, South-East of Iran.

BACKGROUND: Oral carcinoma is one of the common types of cancer and one of the 10 leading causes of death around the world. This study was conducted to evaluate senior dental student knowledge about oral cancerous lesions in Zahedan Dental School. MATERIALS AND METHODS: In this cross-sectional research, all the students in the last academic year at the School of Dentistry were studied during year of 2013. The study questionnaire covered demographic data as well as 12 questions concerning the knowledge of oral cancer. Data were collected and analyzed with SPSS18 using independent t-test, one way ANOVA. Significance level was considered as p≤0.05. RESULTS: Of the 104 senior dental students, with an average age of 27.34± 7.79 years, who participated in this study, 32 (30.8%) were female and 72 (69.2%) were male. The mean score of the students regarding the knowledge of oral cancer was 7.24±2.61. 20 students (19.2%) had a weak knowledge, 45 students (43.3%) had a moderate knowledge, and 39 students (37.5%) had a good knowledge. CONCLUSIONS: The student knowledge of oral cancer is not satisfactory and they need to receive additional information and education.

An analytical study on the common type of smokeless tobacco available in the Iranian market.

BACKGROUND: The use of smokeless tobacco is considered as a risk factor for oral cancer. OBJECTIVES: The current study aimed to chemically analyze, separate and measure the existing substances in a type of chewing tobacco. MATERIALS AND METHODS: In the current descriptive study, the investigated sample was a type of smokeless tobacco, known as BT, manufactured in India. First steam distillation method and Clevenger machine were used to separate and extract the essential oil of the sample. The presence of the desired compounds was evaluated in the essential oil, using gas chromatography (GC) and then gas chromatography coupled to mass spectrometry (GC/MS) analysis. RESULTS: Based on the results obtained by the applied technique, the presence of carcinogenic compounds, N-nitrosomethyl-vinylamine (162 µg/g), N-nitrosonornicotine (6.3 µg/g), and Acetaldehyde (117 µg/g) was confirmed in the sample. CONCLUSIONS: Chemical analysis of the sample confirmed the existence of carcinogenic compounds.

Geographic Tongue and Associated Risk Factors among Iranian Dental Patients.

BACKGROUND: Geographic Tongue is a benign disorder involving the dorsal surface of the tongue characterized by depapillated areas with leading and folded edges in yellowish or grayish white color and sometimes with unclear borders. Many studies have reported a relationship between such condition and different risk factors. This study aimed to investigate the prevalence rate and the risk factors of geographic tongue in the patients referring to the Department of Oral Medicine of Zahedan Dental School, in 2012. METHODS: Using Poisson regression model, 2000 patients referred to the Department were selected for this cross-sectional study. Data collection method included an investigation into the medical history as well as doing intraoral examinations. Using SPSS 17 software and Chi-square statistical test, the collected data were analyzed. RESULT: Among the 2000 patients selected, 7.8% (156 persons) suffered from geographic tongue. The results of our study show that there is a significant relationship between the occurrence of geographic tongue and a history of allergy and fissured tongue (P<0.001). There was no significant statistical relationship between the occurrence of geographic tongue and gender, smoking and medication. CONCLUSION: The geographic tongue is more frequently in the patients suffering from atopy or allergy as well as the patients with fissured tongue.

Use of smokeless tobacco among male students of Zahedan universities in Iran: a cross sectional study.

BACKGROUND: Smokeless tobacco consumption is one of the causes of oral cancer. The aim of this study was to determine the prevalence of smokeless tobacco consumption among male students of Zahedan universities and associated factors in 2012. MATERIALS AND METHODS: In this cross-sectional study, 431 students were selected from the universities of Zahedan using multi-stage random cluster sampling. The data collection tool was a questionnaire including questions about demographic information, history of smokeless tobacco consumption, and awareness of smokeless tobacco hazards. Data were analyzed by SPSS19 using Chi-square test and multinomial logistic regression, with p<0.05 considered significant. RESULTS: At the time of conducting this study, 102 students (23.7%) had already consumed smokeless tobacco and 49 students (11.4%) were current users (consuming at least once in 30 days before the study). There was a significant relationship between history of smokeless tobacco consumption, university/college, place of living, mean GPA, and mother's education level (p<0.05). Also there was a significant association between knowledge and prevalence of smokeless tobacco use (p<0.001). CONCLUSIONS: There is a relatively high prevalence of smokeless tobacco consumption among the male students of universities of Zahedan, which shows the need to emphasize the provision and implementation of prevention programs in universities.