Enamel Thickness before and after Orthodontic Treatment Analysed in Optical Coherence Tomography

Despite the continuous development of materials and techniques of adhesive bonding, the basic procedure remains relatively constant. The technique is based on three components: etching substance, adhesive system, and composite material. The use of etchants during bonding orthodontic brackets carries the risk of damage to the enamel. Therefore, the article examines the effect of the manner of enamel etching on its thickness before and after orthodontic treatment. The study was carried out in vitro on a group of 80 teeth. It was divided into two subgroups of 40 teeth each. The procedure of enamel etching was performed under laboratory conditions. In the first subgroup, the classic method of enamel etching and the fifth-generation bonding system were used. In the second subgroup, the seventh-generation (self-etching) bonding system was used. In both groups, metal orthodontic brackets were fixed and the enamel was cleaned with a cutter fixed on the micromotor after their removal. Before and after the treatment, two-dimensional optical coherence tomography scans were performed. The enamel thickness was assessed on the two-dimensional scans. The average enamel thickness in both subgroups was not statistically significant

The Use of Optical Coherence Tomography in Dental Diagnostics: a State-of-the-Art Review

Optical coherence tomography provides sections of tissues in a noncontact and noninvasive manner. The device measures the time delay and intensity of the light scattered or reflected from biological tissues, which results in tomographic imaging of their internal structure. This is achieved by scanning tissues at a resolution ranging from 1 to 15 μm. OCT enables real-time in situ imaging of tissues without the need for biopsy, histological procedures, or the use of X-rays, so it can be used in many fields of medicine. Its properties are not only particularly used in ophthalmology, in the diagnosis of all layers of the retina, but also increasingly in cardiology, gastroenterology, pulmonology, oncology, and dermatology. The basic properties of OCT, that is, noninvasiveness and low wattage of the used light, have also been appreciated in analytical technology by conservators, who use it to identify the quality and age of paintings, ceramics, or glass. Recently, the OCT technique of visualization is being tested in different fields of dentistry, which is depicted in the article

Evaluation of changes in enamel thickness after orthodontic treatment depending on the force applied to remove orthodontic brackets: OCT analysis and universal testing machine

Background. Adhesive materials used in orthodontics have contributed to the broadening of treatment options with fixed braces. The adhesive materials physically and chemically bond to the enamel surface and orthodontic bracket base, which, apart from offering advantages, also entails the risk of enamel damage when removing these materials from the tissue surface after the treatment is complete. Objectives. The objective of this study was to assess how the bond strength of adhesive materials affects enamel thickness after removing brackets and whether the type of bonding system affects the amount of adhesive strength of the discussed materials. Material and methods. The tests were carried out on 2 groups of 40 bovine teeth in each group. In the 1st group, the classical orthophosphoric acid and the Transbond Plus self-etching primer (SEP) were used. In the 2nd group, the Transbond XT SEP was applied. In both groups, Transbond XT Light Cure Adhesive was used. The same metal orthodontic brackets were attached to the enamel surface. Optical Coherence Tomography (OCT) scans were made before and after removing brackets, which enabled tissue thickness measurements. The bond strength was evaluated using a universal testing machine. Parametric tests were performed on all obtained variables. Student’s t-tests for independent samples and analysis of correlation with Pearson’s r were carried out. Results. The bond strength between the orthodontic bracket and enamel is statistically significantly different in the 1st group and the 2nd group, and is higher in the 2nd group. Conclusions. There are no significant differences in enamel thickness depending on the bonding system type and there is no correlation between the enamel thickness and the bond strength of orthodontic brackets to the enamel

Calcium Alginate Gels as Stem Cell Matrix - Making Paracrine Stem Cell Activity Available for Enhanced Healing after Surgery

Regeneration after surgery can be improved by the administration of anabolic growth factors. However, to locally maintain these factors at the site of regeneration is problematic. The aim of this study was to develop a matrix system containing human mesenchymal stem cells (MSCs) which can be applied to the surgical site and allows the secretion of endogenous healing factors from the cells. Calcium alginate gels were prepared by a combination of internal and external gelation. The gelling behaviour, mechanical stability, surface adhesive properties and injectability of the gels were investigated. The permeability of the gels for growth factors was analysed using bovine serum albumin and lysozyme as model proteins. Human MSCs were isolated, cultivated and seeded into the alginate gels. Cell viability was determined by AlamarBlue assay and fluorescence microscopy. The release of human VEGF and bFGF from the cells was determined using an enzyme-linked immunoassay. Gels with sufficient mechanical properties were prepared which remained injectable through a syringe and solidified in a sufficient time frame after application. Surface adhesion was improved by the addition of polyethylene glycol 300, 000 and hyaluronic acid. Humans MSCs remained viable for the duration of 6 weeks within the gels. Human VEGF and bFGF was found in quantifiable concentrations in cell culture supernatants of gels loaded with MSCs and incubated for a period of 6 weeks. This work shows that calcium alginate gels can function as immobilization matrices for human MSCs

Calcium Alginate Gels as Stem Cell Matrix - Making Paracrine Stem Cell Activity Available for Enhanced Healing after Surgery

Regeneration after surgery can be improved by the administration of anabolic growth factors. However, to locally maintain these factors at the site of regeneration is problematic. The aim of this study was to develop a matrix system containing human mesenchymal stem cells (MSCs) which can be applied to the surgical site and allows the secretion of endogenous healing factors from the cells. Calcium alginate gels were prepared by a combination of internal and external gelation. The gelling behaviour, mechanical stability, surface adhesive properties and injectability of the gels were investigated. The permeability of the gels for growth factors was analysed using bovine serum albumin and lysozyme as model proteins. Human MSCs were isolated, cultivated and seeded into the alginate gels. Cell viability was determined by AlamarBlue assay and fluorescence microscopy. The release of human VEGF and bFGF from the cells was determined using an enzyme-linked immunoassay. Gels with sufficient mechanical properties were prepared which remained injectable through a syringe and solidified in a sufficient time frame after application. Surface adhesion was improved by the addition of polyethylene glycol 300, 000 and hyaluronic acid. Humans MSCs remained viable for the duration of 6 weeks within the gels. Human VEGF and bFGF was found in quantifiable concentrations in cell culture supernatants of gels loaded with MSCs and incubated for a period of 6 weeks. This work shows that calcium alginate gels can function as immobilization matrices for human MSCs

Für | For Manfred from his Students

Dieses Buch enthält Beiträge von Personen, die ihre Magister- oder Doktorarbeit unter der Betreuung von Manfred Krifka geschrieben haben. Es ist als kleines Abschiedsgeschenk für Manfred Krifka zum Ende seiner Amtszeit als Direktor des Leibniz-Zentrums für Allgemeine Sprachwissenschaft gedacht. Die Herausgeberin und der Herausgeber haben Beiträge zu sprachwissenschaftlichen und nicht-sprachwissenschaftlichen Themen in einer Vielzahl von Genres gesammelt. Diese Vielfalt spiegelt die Interessen und Forschungsthemen von Manfred Krifka wider. Sie spiegelt auch die Vielfalt der Menschen wider, denen Manfred Krifka geholfen hat

Abstracts from the 8th International Conference on cGMP Generators, Effectors and Therapeutic Implications

This work was supported by a restricted research grant of Bayer AG

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Loyalität, Overperforming und aufgezwungene Expertise: LSBTQ* – Identitäten und Arbeitsalltag in der Polizei

Molitor V, Zimenkova T. Loyalität, Overperforming und aufgezwungene Expertise: LSBTQ* – Identitäten und Arbeitsalltag in der Polizei. In: Seeliger M, Gruhlich J, eds. Intersektionalität, Arbeit und Organisation. Arbeitsgesellschaft im Wandel . Weinheim: Beltz Juventa; 2019: 210