The Probable Effect of Irrigation Solution and Time on Bond Strength to Coronal Dentin: An In Vitro Evaluation

Introduction: The aim of this study was to evaluate the effect of root canal irrigants on the microtensile bond strength of 2-step self-etch adhesive to dentin. Methods and Materials: In this study 36 sound extracted human third molars were used. After grinding 3 mm of occlusal surface, teeth were randomly divided into 6 groups based on irrigation material naming normal saline, 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) and also irrigation time (5 or 30 min). Next, teeth were restored with Clearfil SE bond adhesive resin system and Z250 composite. The teeth were then thermo cycled by thermo cycling machine, for 500 cycles between 5º and 55ºC with 60 sec dwell time and 12 sec transfer time. All samples were sectioned into bucco-lingual slabs. The sections were submitted to the micro tensile testing machine at a crosshead speed of 0.5 mm/min until fracture. Data was analyzed using the one-way ANOVA test with the level of significance set at 0.05. Results: Irrigation with normal saline, 5.25% NaOCl and 2% CHX for 5 or 30 min did not significantly change the microtensile bond strength of adhesive to dentin (P=0.729 for time and P=0.153 for material). However the maximum and minimum microtensile bond strength was attributed to normal saline (44.13 N) and NaOCl (31.29 N) groups, respectively. Conclusion: Iirrigation solution and time have no influence on microtensile bond strength of two-step self-etch adhesive to coronal dentin.Keywords: Bond Strength, Dentin, Irrigation Solution

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

The concentration of potentially toxic elements (PTEs) in honey : a global systematic review and meta-analysis and risk assessment

However, the consumption of honey offers several beneficial advantages; it can be sources of some contaminants, such as potentially toxic elements (PTEs). In the current study, the related investigations regarding the concentration of PTEs in honey a global scale among the international databases including Scopus, PubMed, ISI Web of Science and Embase were collected and analyzed. Also, the health risk assessment in the children and adults due to ingestion of PTEs via consumption honey was estimated by calculating hazard quotient (HQ) and total hazard quotient (THQ) and cancer risk (CR). Meta-analysis of 33 articles with 45 studies indicates that the overall rank order of PTEs according to their pooled concentration PTEs can be summarized as Fe (5.657 mg-kg-DW) > Mn (3.430 mg-kg-DW) > Pb (0.555 mg-kg-DW) > Cr (0.496 mg-kg-DW) > Cu (0.330 mg-kg-DW) > Ni (0.312 mg-kg-DW) > Cd (0.049 mg-kg-DW) > As (0.026 mg-kg-DW) > Hg (0.002 mg-kg-DW). The rank order of PTEs according to HQ was defined as Pb > Cd > Mn > Fe > Ni > As > Cu > Hg > Cr. Moreover, the lowest and highest values of HQ were observed in Macedonia and Turkey, respectively. The corresponded values of HQ and THQ in all countries investigated was lower than 1 value. Therefore, consumers are not at non-carcinogenic risk. Also, CR inorganic of As in the consumers in all countries investigated was lower than < 1.00E-06 value. Hence, consumers are not at significant carcinogenic risk91498506The authors would like to thank the student research committee at Shahid Beheshti University of Medical Sciences for the financial grants of this study (1397/68953). We thank Katia Jonas for helping us during the preparation of this manuscrip