Aims The aim of the present study was (i) to analyze the molecular interactions after mixing ethylenediamine tetra-acetic acid (EDTA) and sodium hypochlorite solutions using spectroscopic methods, (ii) to analyze the interaction after experimental cold plasma energy transferring mimicking physicochemical activation of solutions. Methods Freshly opened pharmaceutical lavage solutions of 5.25% hypochlorite (pH= 9.35) and 17% EDTA (w/v; pH=7.32) were used in experiments. Mixture of 40 ml was prepared using 5.25% hypochlorite / 17% EDTA at a 1:1 ratio. The experimental cold atmospheric-pressure argon plasma jet treatment was performed using a dielectric barrier discharge device for mimicking the activation of lavage solutions. Spectral changes were analyzed with Fourier-transform infrared spectroscopy and ultraviolet-visible spectrophotometry. Results The main findings were that carbon and nitrogen bonds formed on the EDTA molecule at 2356.99 cm-1 and 2309.00 cm-1 after oxidation with hypochlorite. The newly formed peaks corresponding to carbon-nitrogen on the oxidized EDTA molecule were disappeared after the experimental atmospheric-pressure argon plasma jet treatment. Due to stimulation at a higher energy level, π-π* electronic transition was towards the bathochromic shift whereas, n-π* electronic transition was towards the hypsochromic shift. Conclusions The molecular structure of EDTA was observed to change after the oxidization by hypochlorite. The subsequent molecule occurred by the oxidization by hypochlorite or activated hypochlorite is different from each other and also is different from the characteristic structure of EDTA. Experimentally activated hypochlorite was observed to cause the molecular electronic transitions of EDTA. Thus, the interaction of EDTA and hypochlorite is more complex than the previously described theory.

Aims (I) To assess apical morphological data of mandibular first and second premolars in a Turkish population at a young-adult age range (II) to analyze potential correlations between the size and position of the foramina. Materials and Methods Extracted sound teeth with varied reasons were collected from an adult volunteer population as willing to donate. The mean age of volunteers was 25.4±4.6. Morphological data were obtained from specimens using a stereomicroscope integrated with the software. The number, size, shape, and position of apical foramina and frequency of accessory foramina were quantified. Mann-Whitney U and Spearman’s rank correlation tests were performed (α=0.05). Results A total of 237 teeth were investigated. The majority of the specimens had one major apical foramen. The frequency of major apical foramina was between 1–3 for both groups. The median (Q1-Q3) apical foramina size in mandibular first and second premolars were 55,180µm2 (39,119-85,639µm2) and 67,483µm2 (43,757-98,410µm2), respectively. The majority of foramina shape was irregular (38.2%) for the mandibular first premolars whereas, was oval (35.3%) for the second premolars. The median (Q1-Q3) location of apical foramina with respect to the anatomic apex was 664 µm (512-907µm) in mandibular first premolars and 677µm (515-1053µm) in mandibular second premolars. Conclusions The size and location of apical foramina mostly overlap between the mandibular first and second premolars of a young adult Turkish population. The shape of the apical foramina might be the only relevant variation concerning the apical morphology between the mandibular first and second premolars in young adults. The interaction between the size and location of apical foramina in mandibular premolars of young adults seems not significant.