Salivary melatonin level as an antioxidant was lower in HIV-positive patients. Further studies are necessary to understand the exact role of melatonin in HIV-positive patients and its therapeutic effects.

Introduction Bacteria associated with dental caries have a high ability to produce organic acids from dietary carbohydrates during growth and metabolism under acidic conditions. In contrast, many symbiotic bacteria produce ammonia through the arginine deiminase (ADS) system, which modulates the pH of the oral cavity. l-Arginine metabolism by ADS is a significant inhibitor in the progression of tooth decay. This study aimed to investigate the effect of l-arginine on growth, biofilm formation, and antibiotic susceptibility in Streptococcus mutans. Methods In this study, the effect of l-arginine in different concentrations on the growth rate, antibiotic susceptibility, and inhibition of biofilm formation in S. mutans was investigated. Results The bacterial exponential growth rate was enhanced by 100 μM l-arginine (P > 0.05). The growth inhibition zone diameter of CAZ, CTR, AMP, and AMC-Clav antibiotics was reduced after 24 h of exposure in the presence of various concentrations of l-arginine specifically at 100 μM. l-Arginine also enhanced biofilm development at 5 and 10 μM concentrations, but reduced it at 50 and 100 μM concentrations. Conclusion According to the results of the present study, optimization of l-arginine concentration and its use as an adjunctive therapy or in combination with mouthwash or varnish is recommended to prevent oral caries.

HIV can alter salivary antioxidant capacity as well as vitamin C and catalase levels. Saliva may reflect serum antioxidative changes in these patients. Therefore, further research is necessary on salivary and serum oxidants and the antioxidant changes.

Introduction: Physiological changes during pregnancy affect the teeth and tissues of the mouth and gums, which increases the severity of problems such as caries, inflammation, bleeding and swelling of the gum. Therefore, pregnant people need regular check-ups and provide adequate education. The aim of this study was evaluation of oral and dental health status in pregnant women referring to Fatemieh Hospital in Hamadan City during 2018. Methods: This study was performed on 96 pregnant women. The adjusted questionnaire was completed for each individual by interview method in order to complete the section on personal and pregnancy data and examination in order to complete the section on oral and dental health status. Statistical analysis was performed using SPSS version 16 software. Results: The mean age of the participants was 29.64. The Decay Missing Filling Teeth (DMFT) index in pregnant women was 10.48 ± 3.81. 75.74% of the participants were positive in terms of BOP. 12.50% had dry mouth. Using gingival index, 68.75% of the subjects had gingivitis and the mean gingival index was 0.98 ± 0.79%. In terms of oral hygiene, using the index plaque assessment, the majority of the participants was moderate (45.83%) and the mean plaque index was 1.27 ± 0.62%. Conclusion: Pregnant mothers have a moderate oral health. For this reason, it is necessary to inform physicians in order to refer them to dentists and educate pregnant women to observe oral hygiene and prevent the occurrence of oral diseases and gingivitis in pregnancy.

The giant cell fibroma is a fibrous tumor with characteristic clinicopathologic features. It accounts for approximately 2% to 5% of all oral fibrous proliferations submitted for biopsy. It does not appear to have a clear etiology. In this article, we present seven cases of giant cell fibroma retrieved from the Archive of the Department of Oral and Maxillofacial Pathology, Dental Faculty, Hamadan University of Medical Sciences.