Effect of various surface treatments on the microleakage and ultrastructure of resin-tooth interface

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.

Adhesive Dentistry: Understanding the Science and Achieving Clinical Success

Successful adhesive dentistry begins with correct placement and polymerization of the bonding agent. Although numerous agents exist, all abide by certain key principles, including the newest group, the universal adhesives. Fundamental steps also exist in the application process that require the operator to understand the chemistry of the adhesive being used. Modalities exist that can help preserve the durability of the bond achieved, thus slowing down the degradation process. However, no material or agent can overcome poor technique. Thus, it is of the utmost importance that the practitioner respects the technique sensitivity of adhesives, and follows the manufacturer's instructions.

Bonding efficacy of etch-and-rinse adhesives after dentin biomodification using ethanol saturation and collagen cross-linker pretreatment

Aim:

To evaluate whether the application of two simplified etch-and-rinse adhesives to biomodified dentin using ethanol-wet bonding (EWB) and collagen cross-linker (CCL) pretreatment improves their sealing ability.

Materials and Methods:

In 176 extracted human molars, the pulp-chambers were deroofed, and teeth were sectioned horizontally. Samples were randomly divided into eight groups according to four bonding techniques using two simplified etch-and-rinse adhesives; Adper Single Bond 2 (ASB) and XP Bond (XPB). The bonding protocols included: (a) Water-wet bonding (WWB); (b) EWB; (c) WWB and CCL application; (d) EWB and CCL application. After composite resin restorations, dye leakage evaluation and scanning electron microscope analysis were done. Leakage scores were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests at a significance level of P < 0.05.

Result:

For both ASB and XPB adhesives, least dye leakage was observed in EWB groups (b and d) (P = 0.918 and P = 0.399 respectively) which showed no significant difference, while maximum leakage scores were seen in WWB groups (a and c). Regardless of CCL application and adhesives used, EWB technique depicted (P = 0.003 and P = 0.004) significantly greater sealing ability than WWB.

Conclusion:

Bonding of ASB and XPB using EWB significantly improved their sealing ability. Biomodification using CCL pretreatment had no significant effect on the sealing ability of adhesives bonded with either WWB or EWB.

Influence of double application technique on the bonding effectiveness of self-etch adhesive systems

AIM

To evaluate and compare the effect of double-application of single-step self-etch adhesives using microleakage study and to analyze the dentin-adhesive interfacial micromorphology.

METHODS

In total, 72 extracted human premolars were divided into three groups for different self-etch adhesives (G Bond, GC [GB], Optibond, Kerr [OB], and Xeno V Plus, Dentsply [XV]). Class V cavities were prepared. Each group was further divided into two subgroups (n = 10) according to the placement technique of the adhesive, using the single-application [subgroup (a)] or double-application method [subgroup (b)]. Resin composite (Z 250, 3M ESPE, St. Paul, MN) was used to restore the cavities and light cured for 40 s. Twenty samples from each group were subjected to microleakage study. Two samples from both the subgroups of the three adhesives were used for scanning electron microscopic examination of the resin-dentin interfacial ultrastructure. Dye leakage scores were subjected to statistical analysis using Kruskal-Wallis and Mann-Whitney U-tests at significance level of P < 0.05.

RESULTS

GB depicted significantly more microleakage which was significantly greater than OB and XV. The double application led to significant decrease in microleakage of GB with no significant effect on the microleakage scores of other two all-in-one adhesives, that is OB and XV.

CONCLUSION

Double application of all-in-one self-etch adhesives improves the marginal sealing ability in dentin although it appears to be product dependent.

Adhesive bonding to pulp chamber dentin after different irrigation regimens

AIM

The aim of the present study was to determine the effect of ethylenediaminetetraacetic acid (EDTA) and NaOCl irrigation on the microleakage and interfacial morphology of adhesives bonded to pulp chamber dentin.

METHODS

The pulp chamber roof of 72 extracted permanent molars was removed. Samples were equally divided into six groups. Pulp chamber dentin was bonded with either Adper Easy One (group 1), Adper Prompt L-Pop (group 2), or Adper Single Bond 2 (Group 3), after irrigation with either normal saline (groups 1a, 2a, 3a) or 17% EDTA and 5.25% NaOCl (groups 1b, 2b, 3b). Composite resin restorations were placed in the pulp chamber. Ten samples per group were subjected to microleakage test and scanning electron microscopic analysis was done in two samples from each group. Data were statistically analyzed using Mann-Whitney and Kruskal Wallis tests at a significance level of P < 0.05.

RESULTS

EDTA and NaOCl irrigation of the pulp chamber significantly reduced microleakage in Adper Easy One. However, it had no significant effect on the microleakage of Adper Prompt L-Pop and Adper Single Bond 2.

CONCLUSIONS

EDTA and NaOCl irrigation of the pulp chamber was not deleterious to the bonding of any of the adhesives tested. While this irrigation regimen had no significant effect on the microleakage of Adper Prompt L-Pop and Adper Single Bond 2, it significantly reduced the microleakage scores in Adper Easy One.

Effect of 10% sodium ascorbate hydrogel and delayed bonding on shear bond strength of composite resin and resin-modified glass ionomer to bleached enamel

OBJECTIVE

The aim of this study was to comparatively investigate the neutralizing effect of antioxidant treatment and delayed bonding after bleaching with hydrogen peroxide on the shear bond strength of a composite resin (CR) and resin-modified glass ionomer (RmGI) to enamel.

MATERIALS AND METHODS

Ninety-six freshly extracted human 3rd molars with flat enamel surfaces were divided into six experimental groups (n=12/group) and two control groups (n=12/group). After initial preparation, specimens in Groups 1 and 5 (control groups) were not bleached and the buccal enamel surface of specimens were bonded immediately with CR and RmGI. The samples of the remaining groups were all bleached six hours a day for seven days consecutively. Immediately after bleaching, groups two and six specimens were bonded with CR and RmGI. Groups 3 and 7 specimens were immersed in distilled water at 37°C for 7 days and the specimens in Groups 4 and 8 were treated with 10% sodium ascorbate as an antioxidant agent after bleaching. Specimens in Groups 3 and 4 were bonded with CR and Groups 7 and 8 specimens were bonded with RmGI immediately. After specimens were bonded, the shear bond strength (SBS) was measured. The SBS data analyses were subjected to one-way analysis of variance (ANOVA) followed by Tukey test for comparison of specific mean values.

RESULTS

The mean SBS value in Group 2 (immediately bonded with CR after bleaching) was significantly lower than other CR groups (P=0.045). RmGI did not bond to buccal enamel surface of specimens in group 6. There was no significant difference between other groups bonded with RmGI (P>0.05).

CONCLUSIONS

Applying 10% sodium ascorbate hydrogel and one week delay before bonding resulted in reversal of reduced bond strength of CR and RmGI to bleached enamel.