Objective: The purpose of this in vitro study was to determine whether a hydrophilic primer (Transbond MIP, [MIP]) produces a significant difference in shear/peel bond strength compared with a traditional hydrophobic primer (Transbond XT, [XT]) in wet (W) or dry (D) conditions and if there is a difference in the site of bond failure.
Design: A randomized blinded in vitro design.
Setting And Sample Population: The University of Missouri-Kansas City School of Dentistry. Forty extracted human premolars were divided into four test groups (n = 10 each): MIP-dry conditions (MIPD), MIP-wet conditions (MIPW), XT-dry (XTD) and XT-wet (XTW).
Experimental Variable: Orthodontic brackets were bonded to the teeth according to the manufacturer's directions except XTW and MIPW were exposed to moisture.
Outcome Measure: Shear/peel test 24 h after bonding using an Instron at a crosshead speed of 0.5 mm/min and the adhesive remnant index to determine the site of bond failure.
Results: The bond strengths (X +/- SD) in MPa were XTD = 8.3 +/- 2.3; XTW = 0.8 +/- 0.7; MIPD = 7.5 +/- 1.8 and MIPW = 7.9 +/- 1.7. The shear/peel bond strengths were significantly different: XTD = MIPD = MIPW > XTW (p < or = 0.01; two-way ANOVA; Tukey HSD). The ARI scores were also significantly different: XTD = MIPD = MIPW > XTW (p < or = 0.01; Chi-square).
Conclusions: Orthodontists who suspect moisture contamination should use a hydrophilic primer during bonding procedures to maintain shear/peel bond strength.
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http://dx.doi.org/10.1034/j.1600-0854.2003.c242.x | 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.
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