Raman Spectroscopy as Spectral Tool for Assessing the Degree of Conversion after Curing of Two Resin-Based Materials Used in Restorative Dentistry

(1) Background: The treatment of dental cavities and restoration of tooth shape requires specialized materials with specific clinical properties, including being easy to model, light-cured, having a natural color, reduced shrinkage, a hardness similar to hydroxyapatite, and no leakage. The dimensional stability of resin composite materials is affected by polymerization shrinkage, degree of conversion (number of π carbon bonds converted into σ ones), thermal contraction and expansion, and interactions with an aqueous environment. (2) Methods: The materials used in our investigation were two composite resins with similar polymer matrices, but different filler (micro/nano filler). To evaluate the properties of samples, we employed the pycnometer technique (pycnometer from Paul Marienfeld Gmbh, Lauda-Königshofen, Germany), RAMAN spectroscopy technique (MiniRam Equipment from B&W Tek Inc., Plainsboro Township, NJ, USA; 785 nm laser source), SEM and EDX (FEI Inspect S.). (3) Results: The size of the filler plays an important role in the polymerization: for the pycnometric results, the larger particle filler (Sample 1) seems to undergo a rapid polymerization during the 45 s curing, while the nanoparticle filer (Sample 2) needs additional curing time to fully polymerize. This is related to a much larger porosity, as proved by SEM images. The lower degree of conversion, as obtained by Raman spectroscopy, in the same geometry means that the same volume is probed for both samples, but Sample 1 is more porous, which means less amount of polymer is probed for Sample 1. (4) Conclusions: For the two composites, we obtained a degree of conversion of 59% for Sample 1 and 93% for Sample 2, after 45 s of curing

Performance Assessment of Three Similar Dental Restorative Composite Materials via Raman Spectroscopy Supported by Complementary Methods Such as Hardness and Density Measurements

(1) Background: A widespread problem in oral health is cavities produced by cariogenic bacteria that consume fermentable carbohydrates and lower pH to 5.5–6.5, thus extracting Ca2+ and phosphate ions (PO43−) from teeth. Dental restorative materials based on polymers are used to fill the gaps in damaged teeth, but their properties are different from those of dental enamel. Therefore, a question is raised about the similarity between dental composites and natural teeth in terms of density and hardness. (2) Methods: We have used Raman spectroscopy and density and microhardness measurements to compare physical characteristics of several restorative dental composites at different polymerization intervals. (3) Results: XRVHerculite®, Optishade®, and VertiseFlow® showed the very different characteristics of the physical properties following four polymerization intervals. Of the three composites, OptiShade showed the highest polymerization rate. (4) Conclusions: Only fully polymerized composites can be used in teeth restoring, because incomplete polymerization would result in cracks, pitting, and lead finally to failure

Human Rights in Patient Care: A Practitioner Guide - Romania

Health systems can too often be places of punishment, coercion, and violations of basic rights—rather than places of treatment and care. In many cases, existing laws and tools that provide remedies are not adequately used to protect rights.This Practitioner Guide series presents practical how-to manuals for lawyers interested in taking cases around human rights in patient care. The manuals examine patient and provider rights and responsibilities, as well as procedures for protection through both the formal court system and alternative mechanisms in 10 countries.Each Practitioner Guide is country-specific, supplementing coverage of the international and regional framework with national standards and procedures in the following:ArmeniaGeorgiaKazakhstanKyrgyzstanMacedoniaMoldova (forthcoming)RomaniaRussia (forthcoming)SerbiaUkraineThis series is the first to systematically examine the application of constitutional, civil, and criminal laws; categorize them by right; and provide examples and practical tips. As such, the guides are useful for medical professionals, public health mangers, Ministries of Health and Justice personnel, patient advocacy groups, and patients themselves.Advancing Human Rights in Patient Care: The Law in Seven Transitional Countries is a compendium that supplements the practitioner guides. It provides the first comparative overview of legal norms, practice cannons, and procedures for addressing rights in health care in Armenia, Georgia, Kazakhstan, Kyrgyzstan, Macedonia, Russia, and Ukraine.A Legal Fellow in Human Rights in each country is undertaking the updating of each guide and building the field of human rights in patient care through trainings and the development of materials, networks, and jurisprudence. Fellows are recent law graduates based at a local organization with expertise and an interest in expanding work in law, human rights, and patient care. To learn more about the fellowships, please visit health-rights.org