Related Experiment Video
Updated: Jun 1, 2026
08:12
Micro-dissection of Enamel Organ from Mandibular Incisor of Rats Exposed to Environmental Toxicants
Published on: March 29, 2018
Effect of sodium ascorbate on tag formation in bleached enamel
André Luiz Fraga Briso1, Roberta Mariano Toseto, Vanessa Rahal
1Department of Restorative Dentistry, UNESP, São Paulo State University, Araçatuba, São Paulo, Brazil. alfbriso@foa.unesp.br
The Journal of Adhesive Dentistry
|May 20, 2011
Summary
Tooth bleaching with carbamide peroxide (CP) or hydrogen peroxide (HP) reduces resin tag formation. Adding sodium ascorbate (SA) to bleaching agents significantly increases resin tag length in bleached enamel.
Area of Science:
- Dental Materials Science
- Biomaterials
- Restorative Dentistry
Background:
- Dental bleaching agents like carbamide peroxide (CP) and hydrogen peroxide (HP) are widely used for aesthetic improvement.
- The interaction between bleached tooth structure and restorative materials, particularly concerning adhesion, is a critical clinical concern.
- Resin tag formation is a key indicator of micromechanical retention in adhesive dentistry.
Purpose of the Study:
- To investigate the effect of 10% sodium ascorbate (SA) on resin tag formation in enamel after bleaching.
- To compare the influence of different bleaching agents (CP and HP) with and without SA on tag development.
Main Methods:
- Five experimental groups were established: control, bleaching with CP, CP + SA, bleaching with HP, and HP + SA, followed by restoration.
- Teeth were sectioned and decalcified to expose resin tags.
- Resin tag lengths were quantitatively analyzed using optical light microscopy at 400X magnification.
Main Results:
- Control group (G1) showed the longest resin tag length (36.1 µm).
- Bleaching with CP (G2) and HP (G4) significantly reduced tag lengths to 5.8 µm and 1.7 µm, respectively.
- The addition of SA to CP (G3) and HP (G5) increased tag lengths to 14.4 µm and 6.5 µm, respectively, with statistically significant differences observed between groups.
Conclusions:
- Dental bleaching procedures using CP or HP negatively impact resin tag formation, suggesting compromised adhesion.
- Incorporation of sodium ascorbate during the bleaching process can mitigate the adverse effects of bleaching agents on resin tag development.
- SA may serve as a protective agent, enhancing the potential for micromechanical retention in bleached enamel restorations.
Related Concept Videos
01:18Effects of EDTA on End-Point Detection Methods
Different methods, such as visual observance of metal-ion indicators, spectroscopic techniques, and potentiometric methods, can determine the endpoint of an EDTA titration.
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA...
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA...
01:19Masking and Demasking Agents
EDTA titrations may necessitate masking and demasking agents to temporarily protect a particular metal ion in a mixture from the EDTA reaction. These agents facilitate the sequential analysis of the metal ions by forming stable complexes with some—but not all—metal ions during certain steps.
There are many masking agents, such as cyanide, fluoride, triethanolamine, thiourea, and 2,3-bis(sulfanyl)propan-1-ol (formerly 2,3-dimercapto-1-propanol), with the masking agent chosen based on the metal...
There are many masking agents, such as cyanide, fluoride, triethanolamine, thiourea, and 2,3-bis(sulfanyl)propan-1-ol (formerly 2,3-dimercapto-1-propanol), with the masking agent chosen based on the metal...
01:26EDTA: Auxiliary Complexing Reagents
EDTA titrations are usually carried out in highly basic conditions, where the fully deprotonated form of EDTA, Y4−, actively complexes with the free metal ions in the solution. Several metal ions precipitate as hydrous oxide (hydroxides, oxides, or oxyhydroxides) under these conditions, lowering the concentration of free metal ions in the solution. For this reason, auxiliary complexing agents or ligands such as ammonia, tartrate, citrate, or triethanolamine are used in EDTA titrations to...
01:09EDTA: Conditional Formation Constant
Each EDTA molecule has six binding sites: four carboxyl groups and two amino groups. The fully protonated form of EDTA is represented as H6Y2+. However, it can exist in different forms, H5Y+, H4Y, H3Y−, H2Y2−, and HY3−, depending on the pH of the solution. In very basic solutions with pH > 10.17, the fully deprotonated form, Y4−, is the predominant species that readily complexes with metal ions in a 1:1 ratio.
For the equilibrium reaction of the metal with the Y4− form of EDTA, the formation...
For the equilibrium reaction of the metal with the Y4− form of EDTA, the formation...
01:22EDTA: Chemistry and Properties
Polydentate ligands are most widely used in complexometric titrations because they form more stable complexes with the metal ions than mono- or bidentate ligands due to the chelate effect. Examples of polydentate ligands are ethylenediaminetetraacetic acid (EDTA), crown ethers, and cryptands. The most important feature of optimal polydentate ligands is the ability to form 1:1 complexes in a single-step process. Amino carboxylic acid derivatives are frequently used as complexing agents. EDTA is...