Antibacterial effects and cellular mechanisms of iron oxide magnetic nanoparticles coated by piroctone olamine against some cariogenic bacteria.

Background: The present study aims to study antibacterial effects and cellular mechanisms of iron oxide magnetic nanoparticles loaded with piroctone olamine (Fe3O4@PO NPs) against some cariogenic bacteria (Streptococcus mutans and Actinomyces viscosus). Methods: Nanoparticles was synthesized by the coprecipitation method. Antibacterial effects of Fe3O4@PO NPs were performed by calculating the minimum inhibitory concentration (MIC). We also evaluated the level of reactive oxygen species (ROS) and protein leakage to assess whether antibacterial effects may be dependent on these mechanisms. Results: The results demonstrated that PO showed the lowest antibacterial effect compared to other drugs tested with MICs values of 53.33 and 64 µg/ml for S. mutans and A. viscosus, respectively. In contrast, the highest antibacterial effect was related to Fe3O4@PONPs with MICs values of 2.66 and 3.33 µg/ml for S. mutans and A. viscosus, respectively. Fe3O4@PONPs, Fe3O4MNP, and PO markedly increased (p < 0.001) ROS production and protein leakage of tested bacteria at ≥» MIC, ≥1/3 MIC, and ½ MIC, respectively. Conclusion: The findings of the present survey revealed the promising antibacterial effects of Fe3O4@PONP against some cariogenic bacteria; whereas it triggered the ROS production and protein leakage as the possible antibacterial mode of action of anti-infective agents. However, additional surveys are necessary to elucidate the accurate mechanisms of these nanoparticles.

The Short-Term Effects of Intravitreal Injection of Bevacizumab on the Plasma Levels of Vascular Endothelial Growth Factor, Insulin-Like Growth Factor-1, and Growth Parameters in Infants with Retinopathy of Prematurity.

PURPOSE: To determine the changes in serum levels of free vascular endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF-1), and growth parameters in infants with retinopathy of prematurity (ROP) who received intravitreal injection of the bevacizumab (IVB). METHODS: A prospective interventional case series study, including 10 infants with Type 1 ROP was conducted. Using the enzyme-linked immunosorbent assay, serum levels of VEGF and IGF-1 were measured before, 1 month and 2 months after treatment with IVB in both eyes. Growth parameters, including weight, length, and head circumference and their Fenton's z-score, were also measured. RESULTS: Serum VEGF levels were suppressed 1 month after IVB (P = 0.007) and then increased between 1 and 2 months (P = 0.064). Z-scores of all growth parameters except weight z-score decreased in the 1st and 2nd months. CONCLUSION: Serum VEGF levels showed a transient reduction after IVB which lasted at least 2 months. Growth velocity of premature infants may be affected by anti-VEGF therapy and should be followed with particular attention.

Accuracy of linear measurements of galileos cone beam computed tomography in normal and different head positions.

Introduction. The aim of this study was to determine the accuracy of linear measurements in dry human skulls in ideal position and different deviated positions of the skull. Methods. 6 dry human skulls were included in the study. Opaque markers were attached to alveolar bone. Buccolingual and mesiodistal distances and heights were measured in 5 different regions of either jaws using a digital caliper. Radiographic distances were measured in ideal, rotation, tilt, flexion, and extension positions of the skulls. The physical and radiographic measurements were compared to estimate linear measurement accuracy. Results. The mean difference between physical measurements and radiographic measurements was 0.05 ± 0.45. There was a significant difference between physical measurements and radiographic measurements in ideal, rotation, tilt, and extension positions (P value < 0.05). Conclusions. The accuracy of measurements in GALILEOUS CBCT machine varies when the position of the skull deviates from ideal; however, the differences are not clinically significant.

Prevalence of congenitally missing permanent teeth in Iran.

BACKGROUND: Hypodontia or congenitally missing teeth is among dental anomalies with different prevalence in each region. The aim of this study was to evaluate the prevalence of congenitally missing permanent teeth in Iranian population. MATERIALS AND METHODS: A descriptive, retrospective and cross-sectional study was done. Panoramic radiographs of 2422 Iranian patients (1539 girls and 883 boys), 7-25 years old, were collected. The radiographs were studied for evidence of congenitally missing teeth. Data were analyzed using Paired t-test, Mann-Whitney test, Fisher exact test and Chi-square test (α = 0.05). RESULTS: Prevalence of congenitally missing teeth was totally 45.7% and 34.8% for third molars. The most frequent congenitally missing teeth was mandibular second premolars (23.34%) followed by maxillary second premolars (22.02%). Upper jaw showed significantly higher number of congenitally missing teeth (P value < 0.001). According to Chi-square test, congenital missing teeth was found approximately 10.9% in both females and males and there were no statistically significant difference between sexes (P = 0.19). CONCLUSION: The prevalence of congenitally missing teeth (CMT) in Iranian permanent dentition was 10.9%. The most common congenitally missing teeth were mandibular second premolar fallowed by maxillary second premolars.

Bilateral bifid mandibular canal.

One of the normal interesting variations that we may encounter in the mandible is bifid mandibular canal. This condition can lead to difficulties when performing mandibular anesthesia or during extraction of lower third molar, placement of implants, and surgery in the mandible. Therefore diagnosis of this variation is sometimes very important and necessary.