Antibacterial effect and impact on caries activity of nanosilver fluoride and silver diamine fluoride in dentin caries of primary teeth: a randomized controlled clinical trial.

BACKGROUND: The use of silver diamine fluoride (SDF) in caries treatment in children has increased despite the disadvantage of causing tooth discoloration. Nanosilver fluoride (NSF) is a possible alternative. This study aimed to assess the antibacterial effect of NSF and SDF and their impact on the activity of dentin caries in primary teeth. METHODS: Synthesis and characterization of the physical and biological properties of NSF were conducted. Fifty children aged 4-6 years with dentin caries (active caries corresponding to ICDAS code 5) in deciduous teeth were randomly assigned to treatment by NSF or SDF. Baseline assessment of Streptococcus mutans (S. mutans) and lactobacilli counts as CFU/mL in caries lesions was done, followed by the application of the agents. After one month, microbiological samples were recollected, and lesion activity was reassessed. Groups were compared using Mann-Whitney and Chi-Square tests, while intragroup comparisons were done using Wilcoxon and McNemar tests. Multilevel logistic regression analysis was used to assess the effect of different variables on the outcomes. RESULTS: There were 130 teeth in 50 children; mean ± SD age = 4.75 ± 0.76 years, 63% were posterior teeth. At the one-month follow-up appointment, both groups showed a significant decrease from baseline bacterial counts. There was a significant difference in the reduction of S. mutans between NSF and SDF (21.3% and 10.5%, respectively, p = 0.002), while not in lactobacilli (13.9% and 6.0%, respectively, p = 0.094). In both groups, there was a significant reduction in the number of active caries from baseline (p < 0.0001) with no significant difference between groups (percentage inactive = 64.4% and 63.4%, p = 0.903). Multilevel regression revealed non-significant differences in S. mutans and lactobacilli counts (AOR 1.281, p = 0.737 and 1.888, p = 0.341, respectively), and in the number of inactive lesions (AOR 1.355, p = 0.731) between groups. CONCLUSION: The short-term antibacterial efficacy of NSF was similar to that of SDF. In both groups there was a significant reduction of S. mutans and lactobacilli counts in active dentin caries, and two-thirds of the lesions became inactive with no differences between the two interventions. Further research is needed to investigate the long-term efficacy of NSF and its suitability for clinical use in caries management. TRIAL REGISTRATION: This trial was prospectively registered on the clinicaltrials.gov registry with ID: NCT05221749 on 03/02/2022.

The antibacterial effect of nanosilver fluoride in relation to caries activity in primary teeth: a protocol for a randomized controlled clinical trial.

BACKGROUND: Minimally invasive dentistry is a highly convenient and efficient method of managing caries in pediatric patients. Silver diamine fluoride (SDF) is commonly used to arrest active caries lesions. However, the associated black stain, possibility of soft tissue injury, and unpleasant taste often limit its use. Recently, nanosilver fluoride (NSF) emerged as a promising topical fluoride agent with potent cariostatic and antibacterial potentials. This novel anticaries agent has gained attention as an alternative to overcome the drawbacks of SDF in caries arrest. OBJECTIVES: To assess the antibacterial effect of NSF in relation to caries activity in dentin caries lesions, as well as to investigate the change in saliva bacterial levels in primary teeth in comparison to SDF after 1 and 3 months. MATERIALS AND METHODS: Fifty children aged 4 to 6 years old with active dentin caries lesions (score 5 according to International Detection and Assessment System (ICDAS II) criteria) will be enrolled in the study. They will be equally and randomly allocated into 2 groups: a group receiving NSF and a control group receiving SDF treatment. Microbiological samples will be collected from the carious lesions and from unstimulated saliva at the baseline and at the 1 and 3 months' follow-up appointments. Bacterial counts will be assessed using Mitis Salivarius agar (selective culture media for S. mutans) and Rogosa agar (selective culture media for lactobacilli), and the results will be expressed in colony-forming units. Data regarding the children's oral health will be collected and their dmf index will be scored. The arrest of active carious lesions will be measured at the follow-up appointments according to ICDAS II criteria. RESULTS: The relation between bacterial colony counts and lesion activity for both groups will be assessed, as well as the change in salivary bacterial counts. The collected data will be statistically evaluated and tabulated. This clinical trial has been registered on ClinicalTrials.gov in January 2022 (original version) with ID: NCT05221749.

Molecular Study of Adenovirus Genotypes 40 and 41 in Children with Acute Gastroenteritis.

BACKGROUND: Adenovirus is a common virus associated with acute gastroenteritis in children. There are certain genotypes that are prevalent in these infections, such as genotypes 40 and 41. OBJECTIVE: The aim of the present study was to investigate the incidence of adenovirus genotypes 40 and 41 in children with acute gastroenteritis by polymerase chain reaction (PCR) and also to determine the possibility of Adenovirus co-infections with Rotavirus. METHODS: The study was a cross-sectional study that included 100 children with acute gastroenteritis. The children were subjected to full history taking and clinical examination. Stool samples from the patients were subjected to detection of adenovirus and rotavirus antigens by enzyme-linked immunosorbent assay (ELISA) and detection of adenovirus genotypes 40 and 41 by polymerase chain reaction (PCR). RESULTS: The most prevalent virus by the used methods was rotavirus antigen in the stool (35%). Adenovirus antigen detection was positive in 23% of the stool samples, with positive PCR for these samples in 22%. The ADv40 was detected in 13 samples, and ADv41 was detected in 9 samples. One positive sample by adenovirus antigen ELISA was negative by PCR for these genotypes. Mixed rotavirus and adenovirus by ELISA were detected in 7% of the children. In patients with positive adenovirus antigen by ELISA, the most common symptoms were vomiting (54.5%) and abdominal pain (45.5%). An insignificant difference between fever (P=0.94) and abdominal pain (P=0.63) was detected in children infected with adenovirus compared to patients infected with other organisms. The adenovirus was detected in 68.2% of children with acute gastroenteritis ≤ 24 months. Vomiting was significantly increased in children with adenovirus (54.5%) compared to children negative for adenovirus (23.1%-P=0.004, OR 4.0, 95%CI: 1.5-10.8). CONCLUSION: The study highlights the presence of adenovirus genotypes 40 and 41 in the stool of children with acute gastroenteritis. Combined rotavirus and adenovirus infections were detected in our study.

Evaluation of Combined Ciprofloxacin and azithromycin free and nano formulations to control biofilm producing Pseudomonas aeruginosa isolated from burn wounds.

BACKGROUND: Nanoparticles are becoming increasingly important against resistant superbugs including Pseudomonas aeruginosa infections. AIMS: Exploration of Azithromycin as an adjunctive therapy to Ciprofloxacin for treatment of P. aeruginosa infections. Also, preparation of Ciprofloxacin-Azithromycin nanoparticles on chitosan nanocarrier (Cipro-AZM-CS) and assessment of its antimicrobial effect in vitro and in vivo. METHODS: Detection of biofilm production and biofilm-specific antibiotic resistance ndvB and tssC1 genes was attempted. Minimal inhibitory concentration (MIC) and Minimum biofilm eradication concentration (MBEC) were done in vitro for assessment of P. aeruginosa planktonic and biofilm forms eradication, respectively. In In vivo study, Cipro-AZM-CS and free form were used to evaluate survival rate, wound contraction and bacterial load in mice after third degree burn. RESULTS: All isolates were positive for biofilm production and ndvB and tssC1 genes. Majority of isolates (37, 74%) were extensively drug resistant. In the planktonic state, MIC values of Cipro-AZM free and CS forms were significantly lower than free Cipro MIC (P = 0.015 and P < 0.001 respectively). Also, Cipro-AZM free and CS MBEC values were significantly lower than that of free Cipro (P < 0.010 and P < 0.001 respectively). Furthermore, The MIC and MBEC values of free Cipro-AZM decreased significantly when challenged with Cipro-AZM-CS (P = 0.009 and P < 0.001 respectively). In vivo study combined free and Cipro-AZM-CS treated subgroups showed 100% mice survival with early resolution of infection and wound contraction (75%, 77.5% respectively) VS 45% for Cipro CS (P < 0.001). CONCLUSION: Combined free and Cipro-AZM-CS showed promising results in vitro and in vivo overcoming high resistance of biofilm producing P. aeruginosa.

Nanoparticles of zinc oxide defeat chlorpyrifos-induced immunotoxic effects and histopathological alterations.

BACKGROUND AND AIM: Chlorpyrifos (CPF) is a widely used organophosphate insecticide. Nanoparticles of zinc oxide (ZnO NPs) physically showed effective adsorbing property for some insecticides. The study was conducted to estimate the potential effect of ZnO NPs against CPF toxicity. MATERIALS AND METHODS: Four groups of male rats were used; control group and three groups received drinking water contained 75 mg/L CPF, combined 75 mg/L CPF and 200 mg/L ZnO NPs, and 200 mg/L ZnO NPs, respectively. RESULTS: CPF significantly decreased macrophage activity, serum lysozyme activity, and levels of interleukin-2 (IL-2) and IL-6; increased the percentage of DNA degeneration on comet assay of lymphocytes and significantly elevated hepatic and splenic malondialdehyde contents; and decreased their glutathione contents. The liver and spleen showed marked histological alterations after exposure to CPF with decreased expression of acetylcholinesterase. The coadministration of ZnO NPs ameliorated most of the undesirable effects of CPF, through elevation of macrophage and serum lysozyme activities, increased the levels of IL-2 and IL-6, corrected the oxidative stress markers, and alleviated most of the adverse effect exerted by CPF in liver and spleen tissues. CONCLUSION: The addition of ZnO NPs to CPF-contaminated drinking water may be useful as a powerful antioxidant agent against toxic damage induced by CPF particularly in individuals who are on daily occupational exposure to low doses of CPF.

Modulating effect of MgO-SiO2 nanoparticles on immunological and histopathological alterations induced by aflatoxicosis in rats.

INTRODUCTION: AflatoxinB1 (AFB1) is well-known as a feed borne-hepatotoxic and immunosuppressive mycotoxin. This study was conducted to evaluate the efficacy of nanocomposite magnesium oxide and silicon oxide (MgO-SiO2) in reducing the toxic effects of AFB1on the immunity and histological alterations in liver, spleen and intestine of adult male rats. EXPERIMENTAL DESIGN: Animals were divided into a control (Gp1) and three experimental groups (Gps); Gp2 received feed contained 200 ppb AFB1, Gp3 received feed contained 200 ppb AFB1 and 0.5 g/kg MgO-SiO2 nanocomposite. While, rats of Gp4 received feed contained 0.5 g/kg MgO-SiO2 nano-composite. METHODS: Cellular and humoral immune responses, as well as histopathological examination and caspase-3 expression in liver, spleen, and intestine, were all evaluated. Residual concentration of AFB1was determined in serum, liver and fecal samples. The obtained data were statistically analyzed. RESULTS: AFB1markedly reduced body weight gain and food and water consumption. Cellular immune response (total and differential leukocytes count, neutrophils' phagocytic activity, lymphocyte transformation, macrophage activity and serum lysozyme activity), serum total protein, and humoral immune response (fractions of protein as estimated by SDS- PAGE electrophoresis) were all severely reduced by AFB1. Moreover, AFB1induced marked histological alterations and apoptosis in liver, spleen, and intestine. CONCLUSION: These findings suggested that the nanocomposite MgO-SiO2 has high affinity to adsorb AFB1 and can effectively modulate its toxicity in rats. IMPACT STATEMENT: Nanocomposite MgO-SiO2 may offer a novel effective and cheap approach for the preventive management of aflatoxicosis in animals.