Polymerization kinetics of 3D-printed orthodontic aligners under different UV post-curing conditions.

Background: The purpose of the study was to measure the degree of conversion (DC) of direct-printed aligners (DPA) that were post-cured under ambient and nitrogen atmosphere at specific time intervals and investigate the kinetics of polymerization reaction of this material.

Methods: A total of 48 aligners were produced in 4 printing series by a 3D printer with TC-85DAC resin (Graphy Inc). From each series of printing, 12 aligners were included.

An Evaluation of Experimental Calcium Ion-Leachable Nanocomposite Glass Ionomer Cements.

Glass ionomer cements (GICs) are among the main restorative dental materials used broadly in daily clinical practice. The incorporation of clay nanoparticles as reinforcing agents is one potential approach to improving GIC properties. This study aims to investigate whether the incorporation of calcium-modified clay (Ca-clay) nanoparticles in conventional GICs alters their structural characteristics, along with their physicochemical and mechanical properties.

Synthesis and Characterization of Dental Nanocomposite Resins Reinforced with Dual Organomodified Silica/Clay Nanofiller Systems.

Quaternary ammonium (QA) compounds have been widely studied as potential disinfectants in dental restorative materials. The present work investigates whether the gradual displacement of nanosilica by QA-clay nanoparticles may have an impact on the physicochemical and mechanical properties of dental nanocomposite resins. For this purpose, Bis-GMA/TEGDMA-based composite resins were initially synthesized by incorporating 3-(trimethoxysilyl)propyl methacrylate (γ-MPS)-modified nanosilica/QA-clay nanoparticles at 60/0, 55/5, 50/10, 40/20, and 30/30 wt% filler loadings.

Cardiotoxicity of Chemical Substances: An Emerging Hazard Class.

(1) Background: Human health risks and hazards from chemical substances are well regulated internationally. However, cardiotoxicity, is not defined as a stand-alone hazard and therefore there are no defined criteria for the classification of substances as cardiotoxic. Identifying and regulating substances that cause cardiovascular adverse effects would undoubtedly strengthen the national health systems.

Children and Parents' Awareness Regarding Potential Hazards Derived from the Use of Chemical Products in Greece.

Over the last decades, human activities prompted the high production and widespread use of household chemical products, leading to daily exposure of humans to several chemicals. The objective of this study was to investigate the frequency of chemicals' use by children and parents in Greece and estimate the level of risk awareness and understanding among them. A total of 575 parents and children were asked to answer an anonymous, closed-ended, validated, and self-administered questionnaire.