Performance of a Universal Adhesive on Etched and Non-Etched Surfaces: Changes in Dentin Permeability

Hybridization process for dentin is well known, but remains a difficult challenge as it is dependent on many factors related to dentin substrate, adhesive nature including its solvent. The development of universal adhesives followed the all-in-one concept of existing one-step self-etch adhesives, thus requiring water in their formulation to ionize hydrophilic acid monomers. Most often, carboxylate and/or phosphate groups are their primary functional monomers [1]. Jee, et al. published in 2016 that ethanol molecules penetrate via increasing solvent accessible surfaces induced by the rearrangement of collagen monomers in the gap region [2]. The aim of this study is to evaluate the discrepancy in dentin permeability after application of a universal adhesive used in self-etching (SE) mode or etch and rinse (E&R) mode, by means of hydraulic conductance measurement.

Installation of Test Setup and Measurement Procedures in Fir Wood Hydraulic Conductance Measurement

For a hydraulic conductor, through which liquid flows, hydraulic conductance (K, ml·s-1·MPa-1) is defined as the ratio of pressure difference at the inlet and outlet to the fluid amount passing through the hydraulic conductor in a unit time period. This property is one of the key functions of the wood, and is obtained by the flow rate (F – Flow, ml·s-1) along the wood sample divided by the pressure difference driving the flow (DP, MPa). This study aimed to establish a test setup to determine the hydraulic conductance values of Uludağ Fir (Abies bornmulleriana Mattf.). A test setup was established to measure the amount of water that flows in samples and pressure difference in characterized capillary tubes. In addition, calibration of the test apparatus is explained in detail. Fir wood samples taken from Yedigoller, which is affiliated to Kale Operation Chieftainship and Bolu Forest Regional Directorate, of 4 mm in diameter and 3 cm in length were prepared and hydraulic conductance measurements were performed, and the results are presented in this article. The installed test setup was used to obtain the following information about trees: operation of the hydraulic conduction system, the amount of needed water, seasonal effects and stress-related changes.

Studies on Some Hetero Binuclear Copper(II) Schiff base Complexes

A series of new hetero binuclear complexes of copper(II) and lead(II) using Schiff base have been synthesized. The Schiff base has been derived from the condensation reaction between Salicylaldehyde and 1,2-Ethylenediamine. The hetero binuclear complexes have been characterized by using elemental analysis, molar conductance measurement, magnetic susceptibility studies, UV-Vis and IR spectra. The studies revealed square planar geometry for the complexes with coordination number four.