It has been reported that bond strength of resin to tooth structure can be reduced when the bonding procedure is carried out immediately after the bleaching treatment. This study evaluated the effect of bleaching of non-vital teeth bleaching on the shear bond strength (SBS) of composite resin/bovine dentin interface and the influence of delaying the bonding procedures for different time intervals following internal bleaching. According to a randomized block design, composite resin cylinders (Z100/Single bond - 3M) were bonded to the flattened dentin surface of two hundred and fifty-six teeth which had previously been subjected to four different treatments: SPH - sodium perborate + 30% hydrogen peroxide; SPW - sodium perborate + distilled water; CP - 37% carbamide peroxide; and CON - distilled water (control), each one followed by storage in artificial saliva for 0 (baseline), 7, 14, and 21 days after bleaching (n = 16). The bleaching agents in the pulp chambers were replaced every 7 days, over 4 weeks. The SBS test of the blocks was done using a universal testing machine. The ANOVA showed that there was no significant interaction between time and bleaching agents, and that the factor time was not statistically significant (p > 0.05). For the factor bleaching treatment, the Student's t-test showed that [CON = CP] > [SPW = SPH]. The bleaching of non-vital teeth affected the resin/dentin SBS values when sodium perborate mixed with 30% hydrogen peroxide or water was used, independently of the elapsed time following the bleaching treatment.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1590/s1806-83242004000100014 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Calprotectin's Protein Structure Shields Ni-N(His) Bonds from Competing Agents.
J Phys Chem Lett
January 2025
State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
The Ni-N(His) coordination bond, formed between the nickel ion and histidine residues, is essential for recombinant protein purification, especially in Ni-NTA-based systems for selectively binding polyhistidine-tagged (Histag) proteins. While previous studies have explored its bond strength in a synthetic Ni-NTA-Histag system, the influence of the surrounding protein structure remains less understood. In this study, we used atomic force microscopy-based single-molecule force spectroscopy (AFM-SMFS) to quantify the Ni-N(His) bond strength in calprotectin, a biologically relevant protein system.
View Article and Find Full Text PDFTuning the lanthanide binding tags for preferential actinide chelation: an all atom molecular dynamics study.
Phys Chem Chem Phys
January 2025
Chemistry Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
The present study focuses on designing mutant peptides derived from the lanthanide binding tag (LBT) to enhance selectivity for trivalent actinide (An) ions over lanthanide (Ln) metal ions (M). The LBT is a short peptide consisting of only 17 amino acids, and is known for its high affinity towards Ln. LBT was modified by substituting hard-donor ligands like asparagine (ASN or N) and aspartic acid (ASP or D) with softer ligand cysteine (CYS or C) to create four mutant peptides: M-LBT (wild-type), M-N103C, M-D105C, and M-N103C-D105C.
View Article and Find Full Text PDFNature and stability of the chemical bond in H3C-XHn (XHn = CH3, NH2, OH, F, Cl, Br, I).
J Chem Phys
January 2025
Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands, https://www.theochem.nl.
We have quantum chemically analyzed the trends in bond dissociation enthalpy (BDE) of H3C-XHn single bonds (XHn = CH3, NH2, OH, F, Cl, Br, I) along three different dissociation pathways at ZORA-BLYP-D3(BJ)/TZ2P: (i) homolytic dissociation into H3C∙ + ∙XHn, (ii) heterolytic dissociation into H3C+ + -XHn, and (iii) heterolytic dissociation into H3C- + +XHn. The associated BDEs for the three pathways differ not only quantitatively but, in some cases, also in terms of opposite trends along the C-X series. Based on activation strain analyses and quantitative molecular orbital theory, we explain how these differences are caused by the profoundly different electronic structures of, and thus bonding mechanisms between, the resulting fragments in the three different dissociation pathways.
View Article and Find Full Text PDFExtending Badger's rule. I. The relationship between energy and structure in hydrogen bonds.
J Chem Phys
January 2025
Department of Chemistry, University of Washington, Seattle, Washington 98185, USA.
We derive a new expression for the strength of a hydrogen bond (VHB) in terms of the elongation of the covalent bond of the donor fragment participating in the hydrogen bond (ΔrHB) and the intermolecular coordinates R (separation between the heavy atoms) and θ (deviation of the hydrogen bond from linearity). The expression includes components describing the covalent D-H bond of the hydrogen bond donor via a Morse potential, the Pauli repulsion, and electrostatic interactions between the constituent fragments using a linear expansion of their dipole moment and a quadratic expansion of their polarizability tensor. We fitted the parameters of the model using ab initio electronic structure results for six hydrogen bonded dimers, namely, NH3-NH3, H2O-H2O, HF-HF, H2O-NH3, HF-H2O, and HF-NH3, and validated its performance for extended parts of their potential energy surfaces, resulting in a mean absolute error ranging from 0.
View Article and Find Full Text PDFDifferent Composite Veneer Surface Preparations for Metal Orthodontic Bracket Bonding: An In Vitro Study.
Int J Dent
January 2025
Department of Orthodontics, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
This research aimed to assess the shear bond strength (SBS) of metal brackets bonded to composite veneers using different surface preparations. One-hundred composite disks were divided into 10 different groups whereby each group combines a surface preparation (roughening or no roughening), etching agent (37% phosphoric or 9.5% hydrofluoric acid), adhesive protocol (self-etch or total-etch), and bonding agent (with or without G-Premio Bond).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!