Microleakage of five separated nickel-titanium rotary file systems in the apical portion of the root canal.

Background: The aim of this study was to evaluate the rate of apical microleakage following the fracture of five types of nickel-titanium rotary file systems (ProTaper Universal, Mtwo, RaCe, Revo-s, HeroShaper) in the apical one-third of the canal. Materials and Methods: In this laboratory experiment, 49 mandibular premolars were collected and randomly divided into seven groups. Root canal treatment was performed by five different rotary file systems with different cross-sections. All files, except in the control groups, were scratched at the 3-mm end by a handpiece. After separation of the apical end of the file in the root canal, the apical seal was measured, using the fluid infiltration technique. Data were analyzed in SPSS, using one-way ANOVA and Tamhane's T2 tests at P < 0.05. Results: The Hero Shaper and RaCe files showed the highest (3.14 µL/min) and the lowest (2.51 µL/min) rates of microleakage over time, respectively. There were significant differences between the Hero Shaper and RaCe files and between Hero Shaper and ProTaper files in terms of microleakage (Tamhane's T2 tests, P < 0.05). Conclusion: The presence of a separated file and its cross-section type affects the apical microleakage.

Comparison of antibacterial activity and fluoride release in tooth-colored restorative materials: Resin-modified glass ionomer, zirconomer, giomer, and cention N.

Background: Considering the important role of fluoride in preventing caries by reducing the number and activity of cariogenic bacteria and introducing new fluoride-releasing tooth-colored restorative materials, this study was performed to compare and evaluate fluoride ion release and antibacterial activity of resin-modified GI, zirconomer, giomer (Beautifil), and Cention N. Materials and Methods: In this experimental in vitro study, eighty samples (20 samples in each group) were prepared, 10 samples for fluoride testing and 10 samples for antibacterial activity. To evaluate the release of fluoride (PPM), fluoride ion-selective electrode was used on days 1st, 3rd, 7th, 14th, and 21st; and antibacterial activities against Streptococcus mutans were examined using direct contact test by absorption of light hourly once every 5 h and days 1st, 2nd, and 7th using an ELISA reader with a microplate reader of 800 TS at a wavelength of 630 nm. The results were analyzed using one-way ANOVA, Tamhane post hoc test, and paired t-test in SPSS software (IBM, Somers, NJ, USA) at a significant level of (P < 0.05). Results: The release of fluoride from materials showed a statistically significant difference (P < 0.001). The maximum mean of fluoride released during the 1st, 3rd and 7th days belonged to the zirconomer group and the minimum for the giomer group. During the measurement period of light absorption from 0 to 24 h after planting, light absorption of foursubstances together was found to be statistically significant (P <.001). Zirconomer light absorption increased on the 7th day, unlike other substances, but still, the minimum light absorption was related to zirconomer. Conclusion: The highest fluoride release was in zirconomer, Cention N, fuji II LC, and giomer, sequentially. Zirconomer showed maximum and giomer showed minimum antibacterial activities.

A novel drug delivery system using acyclovir nanofiber patch for topical treatment of recurrent herpes labialis: A randomized clinical trial.

OBJECTIVES: Topical treatment with acyclovir cream has shown low efficacy in recent studies. Nano drug delivery systems, have received much attention in recent decades. The aim of this study was to compare the efficacy of acyclovir nanofiber patch with acyclovir cream. MATERIAL AND METHODS: In this double-blind three-armed randomized clinical trial, a total of 60 patients with recurrent labial herpes, were randomly divided into three groups, each consisting of 20. The patients in the first, second, and third groups were treated with acyclovir nanofiber patch, placebo nanofiber patch, and acyclovir cream, respectively. A numerical scale was used by the patients to record the self-reported symptoms. Symptoms score, crusting time and healing time were assessed by the clinician. Kruskal-Wallis test was used to compare the symptoms between the three groups, a survival test was also performed to evaluate the crusting and healing time. Data were analyzed in SPSS V22 at P-value < 0.05. RESULTS: The mean scores of symptoms at baseline were 1.6, 1.5, and 1.4 in the first, second, and third groups, respectively. The symptoms were not significantly different between the three groups on different treatment days. The mean crusting time was 2.3, 2.4, and 2.6 days in the three groups, and the mean healing time was 7.4, 7.2, and 7.7 days, respectively. Crusting time and healing time were not significantly different between the three groups. CONCLUSIONS: Acyclovir nanofiber patches are recommended for accelerating symptom relief in recurrent labial herpes, however, they are not effective in shortening the crusting or healing time. CLINICAL TRIAL REGISTRATION NUMBER: IRCT20141124020073N2. Registered in: Iranian Registry of Clinical Trials (www.irct.ir).

The -592C>A variation of IL-10 gene and susceptibility to chronic periodontitis: A genetic association study and in-silico analysis.

OBJECTIVES: Chronic periodontitis (CP) is a common inflammatory disorder with a considerable impact of genetic variations in the interleukin family on predisposition to this disease. This study aimed to investigate the association between the -592C>A polymorphism of the interleukin 10 (IL-10) gene with CP risk in an Iranian population. This experimental study was followed by a meta-analysis and in silico examination. METHODS: In a case-control study, 270 subjects, including 135 patients with CP and 135 healthy controls, were enrolled. The -592C>A genotyping was performed using the PCR-RFLP method. In the meta-analysis, valid databases were systematically searched to identify relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were computed to examine the association between -592C>A and CP. In silico analysis was conducted using bioinformatics tools to evaluate the impact of the -592C>A polymorphism on IL-10 gene function. RESULTS: Our case-control study revealed a significant association between polymorphism and CP risk. Overall, we found significant associations between -592C>A genetic variation and CP and stratified meta-analysis. In silico analysis revealed that this polymorphism could change the pattern of the transcription binding site upstream of the IL-10 gene. It may also alter the hsa-miR-101-3p miRNA-targeted sequence upstream of IL-10. CONCLUSIONS: Based on our results, the -592C>A variation in IL-10 may be a genetic risk factor for susceptibility to chronic periodontitis. However, further studies in different ethnicities and results adjusted for clinical and demographic characteristics are needed to obtain more accurate deductions.