Related Experiment Video
Updated: May 31, 2026
Standard Test Method ASTM D 7998-19 for the Cohesive Strength Development of Wood Adhesives
Published on: May 17, 2020
Effect of postbleaching application of an antioxidant on enamel bond strength of three different adhesives
Maryam Khoroushi1, Samaneh Aghelinejad
1Department of Operative Dentistry, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran. khoroushi@dnt.mui.ac.ir
Objectives:
The aim of this study was to compare the shear bond strength (sbs) of three different adhesives on bleached enamel immediately after bleaching, bleached/delayed for 1 week, and bleached/applied antioxidizing agent.
Study Design:
The enamel surfaces of 144 freshly extracted incisors without any caries and restorations were flattened and divided into 12 groups. The following adhesives were investigated: Optibond FL (OFL) (three-step etch&rinse), Optibond Solo Plus (OSP) (two-step etch&rinse), Optibond All-in-One (OA) (one-step self-etch), (Kerr, Orange, USA). Unbleached enamel groups were prepared as negative controls. The remainder surfaces were bleached with 20% Opalescent PF (Ultradent, USA) 6 h/d for 5 consecutive days. Specimens were bonded immediately after bleaching, after 1 week or after using 10% sodium ascorbate gel for 6 hours. After 500 rounds of thermocycling, sbs was measured and data was analyzed with Kruskall-Wallis and Mann-Whitney U-tests ( = 0.05).
Results:
The sbs decreased for the adhesives after bleaching except for OFL. The effect of applying sodium ascorbate subsequent to bleaching was not equal for the studied adhesives. While for OFL, sbs of the sodium ascorbate group was significantly higher than the unbleached control group, for OSP, the sodium ascorbate group had no statistically significant difference with the unbleached control group and for OA, sbs was significantly lower than the unbleached control group.
Conclusions:
Different adhesives demonstrate different degrees of reversed bond strength subsequent to applying antioxidant. It seems the method of application and the chemical composition of the adhesives could affect the antioxidant as a reducing agent.
Related Concept Videos
01:12Bonding and Strength of Aggregate
01:18Effects of EDTA on End-Point Detection Methods
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...