Can intra-coronally bleached teeth be bonded safely after antioxidant treatment?

The Effect of Antioxidants on Dentin Bond Strength after Application of Common Endodontic Irrigants: A Systematic Review

The purpose of this systematic review was to evaluate how an antioxidant treatment would influence the immediate bond strength of dental adhesives to endodontically treated dentine. Scientific evidence was researched in five databases using selected descriptors. Two independent reviewers conducted the investigation and assessed the data and methodological quality of the studies. Inclusion and exclusion criteria were specified for article selection; only studies in English and published between 2001 and 2022 were evaluated. A total of 18 studies were selected and analysed. According to most studies, the irrigation procedure and substrate preparation in endodontic therapy may affect the immediate bond strength. Antioxidants can improve bond strength and adhesion following the use of the most frequently used irrigants in root canal treatments. Therefore, antioxidant treatment can be considered a proper technique to enhance the bond strength of endodontically treated teeth.

Use of antioxidants to restore bond strength after tooth bleaching with peroxides

This review compiles the literature on the antioxidants used after tooth bleaching with either low or high-concentrated carbamide and hydrogen peroxide to recover the bond strength. Antioxidants used in bleached teeth are mainly natural and non-enzymatic, except for catalase. Commonly, antioxidants are applied to remove any reactive oxygen species (ROS) residues left from bleaching gels, which adversely affect adhesive procedures, such as restorations or orthodontic brackets bonding. Even though sodium ascorbate, the most thoroughly investigated antioxidant, showed the most efficient bond strength recovery at 10% concentration, its performance depends on the type of solution and the application time. Natural extracts, such as proanthocyanidins and green tea, showed satisfactory results in the reversal of bond strength at 5% and 10% concentrations, respectively. Sodium ascorbyl phosphate, α-tocopherol, and catalase exhibited promising results, but further research is required. The adhesive system type plays an important role in the outcome of enamel bond strength after the antioxidant application. The postponement of either restorations or orthodontic brackets cementation following bleaching procedures seems to be efficiently replaced by antioxidant application prior to bonding procedures. However, the efficacy of using an antioxidant to recover bond strength depends on its type and application time.

Comparative Analysis of Shear Bond Strength of Composites to the Sodium Ascorbate Hydrogel-treated Bleached Enamel Surfaces: An In Vitro Analysis

Aim

To compare the shear bond strength of composites to the sodium ascorbate hydrogel-treated bleached enamel surfaces.

Materials and methods

Sixty-six extracted human maxillary first premolars were sectioned mesiodistally to obtain two nonocclusal surfaces (n = 132). The specimen in the experimental group (n = 80) were divided into four treatment groups depending upon bleaching protocols used: group I (10% FGM home bleach), group II (22% Pola Night home bleach), group III (37% light-activated in-office bleach Pola Office+), and group IV (35% Pola office in-office bleach without light activation). Specimens were subjected to the 1-minute application twice with sodium ascorbate hydrogel and were further divided into two subgroups “a” (acetone-based) and “b”(ethanol-based) depending upon the bonding agents used. The specimens of the control group (n = 52) were further divided into two treatment groups, that is, positive control and negative control. The specimens were tested using universal testing machine.

Results

The result of the present study revealed that the specimens bleached with 10% FGM home bleach showed the greatest shear bond strength and specimens bleached with 35% in-office bleach Pola Office showed the lowest shear bond strength.

Conclusion

A twice 1-minute application of sodium ascorbate hydrogel was effective to reverse the deleterious results of bleaching on enamel shear bond strength. Bonding agent containing acetone as a solvent (Prime and Bond NT) in this present study showed greater shear bond strength values than the bonding agent containing ethanol as a solvent (Adper Single Bond).

Statement of clinical relevance

The shear bond strength of composite restorative materials could be improved by applying sodium ascorbate gel to the bleached enamel surfaces.

How to cite this article

Pathak K, Kumar P, Choudhary A, et al. Comparative Analysis of Shear Bond Strength of Composites to the Sodium Ascorbate Hydrogel-treated Bleached Enamel Surfaces: An In vitro Analysis. Int J Clin Pediatr Dent 2021;14(6):741–747.

Effect of Two-minute Application of 35% Sodium Ascorbate on Composite Bond Strength following Bleaching

AIM

The aim of this study is to assess the effect of 35% sodium ascorbate on microtensile bond strength of dentin immediately after bleaching with 35% hydrogen peroxide.

MATERIALS AND METHODS

A total of 25 sound human 3^rd molars were collected. Teeth were randomly divided into five groups for different treatments: Group I [bleaching + immediate bonding (i.e., restoration)], group II (bleaching + delayed bonding), group III (bleaching + sodium ascorbate + immediate bonding), group IV (bleaching + sodium ascorbate + delayed bonding), and group V (bonding only). After bleaching, but before bonding, groups II and IV were stored for 1 week in deionized water at 37°C. All samples were bonded using OptiBoned FL (Kerr) and Filtek Supreme (3M/ESPE). Teeth were sectioned into 1 × 1 mm 2 bars, and microtensile bond strength was tested with a universal testing machine (Instron 8841) at a cross-head speed of 0.5 mm/minute.

RESULTS

Microtensile bond strength differed significantly across the five groups, with a significant reduction in microtensile bond strength observed for samples in group I relative to samples in any of the other treatment groups (p < 0.05).

CONCLUSION

The application of a high concentration of sodium ascorbate for a shorter time reversed the negative effect of 35% hydrogen peroxide bleaching on composite bonding strength to dentin.

CLINICAL SIGNIFICANCE

The negative effects of bleaching on composite bonding can be neutralized by the application of the reversing agent sodium ascorbate thus, increasing the efficiency of clinic chair time. This is clinically relevant for those patients requiring restorative treatment immediately after in-office bleaching.

Shear bond strength of an orthodontic self-etching adhesive after intracoronary bleaching

OBJECTIVES

To evaluate the effects of intracoronary bleaching on the bond strength of orthodontic brackets using self-etching and total-etch adhesive systems.

MATERIAL AND METHODS

In 60 bovine incisors, a coronal lingual access was made to clean the pulp chamber and standardise the thickness of the dentine. The sample was randomly divided into four groups (each n = 15): (CT), control group, without bleaching and bonded with the total-etch system (Transbond(™) XT-3M); (CTSE), without bleaching treatment and bonded with the self-etching system (Transbond(™) Plus Self-Etching Primer-3M); (BT), treated with 35% hydrogen peroxide for internal bleaching and bonded with the total-etch adhesive system; and (BTSE), treated with 35% hydrogen peroxide and bonded with the self-etching adhesive system. Shear bond strength was measured using a universal testing machine (EMIC). The adhesive remnant index (ARI) score was verified. The data were analysed using a two-way anova and Tukey test (p < 0.05).

RESULTS

Significant differences were found, and the self-etching adhesive groups presented the highest bond strength values (CTSE=11.55 ± 2.85 MPa; BTSE=14.14 ± 2.23 MPa). The ARI scores revealed significant differences among the groups; the greater amount of remaining adhesive was observed in the CTSE group, and the lowest scores were observed in the BT group.

CONCLUSIONS

The use of the self-etching adhesive system, even after intracoronal bleaching, presented satisfactory adhesive strength for the bonding of brackets.

Effect of Epigallocatechin Gallate on shear bond strength of composite resin to bleached enamel: an in vitro study

Objectives

The aim of this study was to determine the effect of epigallocatechin gallate (EGCG) on the shear bond strength of composite resin to bleached enamel.

Materials and Methods

Ninety enamel surfaces of maxillary incisors were randomly divided into 9 groups as follows: G1: control (no bleaching); G2: bleaching; G3: bleaching and storage for seven days; G4 - 6: bleaching and application of 600, 800 and 1,000 µmol of EGCG-containing solution for 10 minutes, respectively; G7 - 9: bleaching and application of 600, 800 and 1,000 µmol of EGCG-containing solution for 20 minutes, respectively. The specimens were bleached with 30% hydrogen peroxide gel and a composite resin cylinder was bonded on each specimen using a bonding agent. Shear bond strength of the samples were measured in MPa. Data was analyzed using the two-way ANOVA and Tukey HSD tests (α = 0.05).

Results

The maximum and minimum mean shear bond strength values were observed in G1 and G2, respectively. Time and concentration of EGCG showed no significant effects on bond strength of the groups (p > 0.05). Multiple comparison of groups did not reveal any significant differences between the groups except for G2 and all the other groups (p < 0.05).

Conclusions

There is a significant decrease in bond strength of composite resin to enamel immediately after bleaching. A delay of one week before bonding and the use of EGCG increased bond strength of composite resin to bleached enamel.

Antioxidant agents and their effects on shear bond strength of bleached enamel

AIM

The goal of this study was to fnd a method to eliminate bond strength reduction after vital bleaching.

MATERIALS AND METHODS

Sixty fat surfaces of enamel central human incisors were prepared by diamond disks. In the frst group, the samples immediately bonded to the tooth after bleaching. For the second group, the bleached samples were treated by sodium ascorbate for 1 hours. In the third and fourth groups the treatment was down using a new antioxidant agent for 1 hour and 15 minutes respectively. For the ffth group no bleaching was done. Cylindrical composite resin (Z 100) with a Single Bond adhesive system was bonded to the enamel with a special metal mold. After thermocycling, the samples were loaded at a crosshead speed of 0.5 mm/min. The mode of failures was inspected by the Dino Lite microscope and the microstructure of the debonding surfaces was observed by SEM. Considering normal data, statistical analysis was conducted by ANOVA and Tukey tests (p = 0.05).

RESULTS

The fourth group had maximum (21.82), while the frst group had the least (9.0971) shear bond strength. The ANOVA test showed a signifcant difference among the fve groups (p = 0.0002). There was not any signifcant statistical difference between the three types of debonding (p = 0.165).

CONCLUSION

The usage of sodium ascorbate or sodium ascorbate with detergent after vital bleaching are effective methods for reducing the damaging effects of bleaching agents on the shear bond strength of composite resin restoration to enamel. CLINICAL SIGNIFCANCE: Using antioxidants is necessary post bleaching and before resin bonding.

Effects of different intracoronal bleaching methods on shear bond strengths of orthodontic brackets

OBJECTIVE

To evaluate the effects of different intracoronal bleaching methods on the shear bond strengths (SBS) of orthodontic brackets.

MATERIALS AND METHODS

Sixty freshly extracted mandibular incisors were randomly divided into four groups (n = 15 per group). After filling the root canals, root fillings were removed 2 mm apical to the cementoenamel junction, and a 2-mm-thick layer of zinc-phosphate cement base was applied. Group 1 served as the control. Intracoronal bleaching was performed with hydrogen peroxide (Opalacence Endo, Ultradent products Inc, South Jordan, Utah) in group 2, sodium perborate (Sultan Healthcare, Englewood, NJ) in group 3, and 37% carbamide peroxide (Whiteness Super Endo, Dentscare, ltda, Joinville, Brazil) in group 4. Orthodontic brackets were bonded with a light cure composite resin and cured with an LED light. After bonding, the SBS of the brackets was tested with a Universal testing machine.

RESULTS

Analysis of variance indicated a significant difference between groups (P < .001). The highest values for SBS were measured in group 1 (10.15 ± 1.15 MPa). The SBS was significantly lower in groups 2, 3, and 4 than in group 1 (P < .001). The lowest values for SBS were measured in group 3 (6.17 ± 0.85 MPa). SBS was significantly higher in group 4 than in group 3 (P < .05).

CONCLUSIONS

Intracoronal bleaching significantly affected the SBS of orthodontic brackets on human enamel. Bleaching with sodium perborate affects SBS more adversely than does bleaching with other agents.