An investigation was conducted to determine a simple, effective method for reconditioning stainless steel orthodontic attachments in the orthodontic office. In total, 100 new brackets were bonded to premolar teeth, then debonded and the bond strength recorded as a control for the reconditioning process. The debonded brackets were divided into six groups and each group reconditioned using different techniques as follows: attachments in four groups were flamed and then either (1) sandblasted, (2) ultrasonically cleaned, (3) ultrasonically cleaned followed by silane treatment, (4) rebonded without further treatment. Of the two remaining groups, one was sandblasted, while the brackets in the other were roughened with a greenstone. The brackets were rebonded to the premolar teeth after the enamel surfaces had been re-prepared, and their bond strengths measured. The results indicated that sandblasting was the most effective in removing composite without a significant change in bond strength compared with new attachments. Silane application did not improve the bond strength values of flamed and ultrasonically cleaned brackets. Attachments that had only been flamed had the lowest bond strength, followed by those that had been roughened with a greenstone.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/ejo/cjh100 | DOI Listing |
Inorg Chem
January 2025
Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China.
Dative bonds are typically polar, weaker, and longer than electron-sharing covalent bonds. The intriguing diatomic BeF anion uniquely exhibits triple Be-F dative bonding with a considerable bond dissociation energy (BDE) of 88 kcal/mol. Here, we report exceptionally strong dative-bonded systems, [CO]BeF and [CO]BeF, with BDE values exceeding 155 kcal/mol by integrating [CO] and [CO] groups into the BeF framework.
View Article and Find Full Text PDFScience
January 2025
Department of Chemistry, Northwestern University, Evanston, IL, USA.
Mechanical bonds arise between molecules that contain interlocked subunits, such as one macrocycle threaded through another. Within polymers, these linkages will confer distinctive mechanical properties and other emergent behaviors, but polymerizations that form mechanical bonds efficiently and use simple monomeric building blocks are rare. In this work, we introduce a solid-state polymerization in which one monomer infiltrates crystals of another to form a macrocycle and mechanical bond at each repeat unit of a two-dimensional (2D) polymer.
View Article and Find Full Text PDFNano Lett
January 2025
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China.
Watson-Crick and Hoogsteen hydrogen bonds aid the formation of highly ordered structures in genomic DNA that dynamically govern genetic modes such as gene regulation and replication. Hence, measuring and distinguishing these two types of hydrogen bonds in different DNA contexts are essential for understanding DNA architectures. However, due to their transient nature and minimal structure differences at the sub-nanometer scale, differentiating Watson-Crick hydrogen bonds from Hoogsteen hydrogen bonds is difficult.
View Article and Find Full Text PDFInt Dent J
January 2025
Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, Bunkyo-ku, Tokyo, Japan.
Introduction And Aims: Marginal sealing by enamel bonding is important to enhance the durability of the restoration and prevent secondary caries after operative procedure. This study aimed to evaluate the enamel acid resistance and bond strength of an experimental calcium-containing adhesive system.
Methods: All materials were provided by Kuraray Noritake Dental, Inc.
J Prosthet Dent
January 2025
Associate Professor, Department of Prosthodontics, Dental Branch, Islamic Azad University of Medical Sciences, Tehran, Iran.
Statement Of Problem: The optimal zirconia pretreatment, contingent upon the type of cement used, warrants further research.
Purpose: The purpose of this investigation was to evaluate the influence of various surface pretreatments on the bonding efficacy of cement to zirconia.
Material And Methods: A comprehensive search was conducted across the PubMed, Embase, Scopus, and Web of Science databases for in vitro studies related to bonding with zirconia up to April 2024, supplemented by a manual search.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!