Effect of simplified ethanol-wet bonding on dentin bonding durability of etchand-rinse adhesives

Effects of carbodiimide combined with ethanol-wet bonding pretreatment on dentin bonding properties: an in vitro study

Purpose

This study evaluated the combined effects of Carbodiimide (EDC) and ethanol-wet bonding (EWB) pretreatment on the bond strength and resin-dentin surface.

Methods

Phosphoric acid-etched dentin specimens were randomly divided into five groups based on the following pretreatments: deionized water (control), EWB, 0.3M EDC in water (EDCw), EDC water solution combined EWB (EDCw + EWB), and 0.3M EDC in ethanol (EDCe). A scanning electron microscope (SEM) was used to observe the morphology of collagen fibrils on the demineralized dentin matrix in each group after pretreatment. The adhesives Prime & Bond NT (PB) (Dentsply De trey, Konstanz, Germany) or Single bond 2 (SB) (3M ESPE, St. Paul, MN, USA) was applied after pretreatments, and a confocal laser scanning microscope (CLSM) was used to evaluate the quality of resin tags. The degree of conversion (DC) of the adhesive was investigated by Fourier transform infrared spectroscopy (ATR-FTIR). The dentin was first bonded with resin and bathed in water at 37 °C for 24 h. Half of them were subjected to 10, 000 cycles in a thermocycler between 5 °C and 55 °C before a microshear bond strength (µSBS) test. The statistical methods were Analysis of Variance (ANOVA) and a Tukey post hoc test at α = 0.05.

Results

The µSBS was significantly affected by pretreatments (p < 0.001), adhesives (p < 0.001), and aging conditions (p < 0.001) as revealed by the three-way ANOVA. The EDCw, EDCw + EWB, and EDCe groups significantly increased the µSBS; the EDCw + EWB and EDCe groups produced the highest µSBS. In the EDC-containing groups, the SEM showed at the collagen fibrils in the dentin matrix formed a three-dimensional network structure in the tubules after cross-linking into sheets, and the hybrid layer formed thicker resin tags under a CLSM. In the EDC-containing groups, the CLSM observed an increase in the length of resin tags. PB showed a higher DC and bonding strength than SB, and the five pretreatment groups tested did not affect the DC of the two adhesives.

Conclusions

In etch-and-rinse bonding system, EDC combined with EWB pretreatment can improve the quality of the hybrid layer and enhance the mechanical properties of demineralized dentin matrix. Pretreatment with EDC-ethanol solution may be a new clinically friendly option for enhancing dentin bonding durability.

Effect of dentin biomodification techniques on the stability of the bonded interface

Aim:

The aim of this study is to evaluate the effect of different bonding techniques ethanol wet bonding and dimethyl sulfoxide (DMSO) wet bonding and a novel collagen cross-linker Quercetin application on the durability of resin-dentin bond and observe the bonded interface under the scanning electron microscope (SEM).

Materials and Methods:

For shear bond strength testing, flat coronal dentin surfaces were prepared on 110 extracted human molars. Teeth were randomly divided into five experimental groups according to different surface pretreatments techniques. Group A was control group without any surface pretreatment. In Group B, ethanol wet bonding pretreatment was done before the application of adhesive. In Group C, DMSO wet bonding was done before the application of adhesive and in Groups D and E, Quercetin along with ethanol and Quercetin along with DMSO pretreatment, respectively, were done before adhesive application. Composite restorations were placed in all the samples. Twenty samples from each group were subjected to immediate and delayed (9 months) shear bond strength evaluation. In addition, two samples per group were subjected to the scanning electron microscopic analysis for the observation of resin-dentin interface.

Statistical Analysis:

Data collected were subjected to the statistical analysis using the one-way analysis of variance and post hoc Tukey's test at a significance level of P < 0.05.

Results:

Dentin pretreatment with all the techniques resulted in significantly higher resin-dentin bond strength after 9 months storage with DMSO group showing the highest bond strength values.

Conclusion:

It can be concluded that these biomodification techniques can improve the durability of the resin-dentin bond.

Bond Strength to Microtraction and Nanofiltration Using Ethanol Wet Bonding Technique in Fresh Extracted Teeth: An Ex Vivo Study

Objective

The objective of this study was to evaluate the bond strength to microtraction and nanofiltration using ethanol wet bonding technique in fresh extracted teeth.

Materials and Methods

This quasi-experimental ex vivo study evaluated 48 teeth that had an indication of premolar extraction due to orthodontic reasons. The protocol of dental preparation and restorative procedure was carried out to evaluate the adhesion resistance by means of the universal testing machine at a loading speed of 0.5 mm/min and 500MPa. To evaluate the nanofiltration, matches were made that were immersed in ammoniac silver nitrate for 24h, and then the specimens impregnated with silver were washed thoroughly in distilled water and placed in a photo-developer solution for 8h under a fluorescent light. All statistical analyses were statistically evaluated with a level of significance P < 0.05.

Results

The ethanol technique without premature failure (PF) group had an average of 31.26 ± 10.26MPa, whereas the lowest value was found in the water technique group with PF, which had 22.59 ± 12.27MPa. When performing inferential statistics, it was evidenced that there were statistically significant differences between both techniques with a value of P < 0.05.

Conclusion

According to the results in both cases, the adhesive strength showed superiority in the ethanol wash group. It determines that this technique presents greater tolerance to the residual presence of water. Finally, in relation to nanofiltration we found that there were no significant differences between the groups evaluated.

Effect of diode laser irradiation on the bond strength of polymerized non-simplified adhesive systems after 12 months of water storage

Objectives:

The aim of this in vitro study was to evaluate the bonding strength of non-simplified dentin bonding systems (DBS) to dentin irradiated with a diode laser (970 nm) immediately and after 12 months of water storage following either primer or bond application.

Material and methods:

The experimental design included three different factors: DBS type [Adper^TM Scotchbond Multipurpose (MP) and Clearfil™ SE Bond (CSE)], irradiation [without irradiation - control (C), irradiation after primer application (AP), and irradiation after bond application (AB)], and time [initial (I) and after 12 months of water storage (12 m)]. Sixty sound human third molars (n = 10) were obtained, and their flat occlusal dentin areas were prepared and standardized. Laser irradiation was performed in the contact mode perpendicular to the dental surface over an automatically selected scanning area at a pulse energy of 0.8 W, frequency of 10 Hz, and energy density of 66.67 J/cm². After 7 days of treatment, the specimens were cut, and half of them were subjected to microtensile testing (500 N/0.05 mm/min), whereas the remaining sticks were examined after 12 months of water storage. The obtained data were analyzed by three-way analysis of variance (ANOVA) followed by a Tukey test (p<0.05). The observed fracture modes were investigated using a portable digital microscope with a magnification of 40x.

Results:

Among the utilized DBS, MP generally exhibited higher bond strengths, but did not always differ from CSE under similar conditions. The irradiation factor was statistically significant only for the MP/AB groups. After 12 months of storage, all groups demonstrated a significant reduction in the bond strength, whereas the results of fracture analysis showed a predominance of the adhesive type.

Conclusions:

The laser treatment of non-simplified DBS was not able to stabilize their bonding characteristics after 12 months.

Influence of ethanol-wet dentin, adhesive mode of application, and aging on bond strength of universal adhesive

The aim of this study was to evaluate the effect of ethanol on the bond longevity of a universal adhesive system to bovine dentin, under different modes of adhesive application and artificial aging. Bovine dentin was exposed, and the smear layer was standardized by sandpaper polishing. Specimens were randomly divided into 2 groups: ethanol (E) and non-ethanol (N). Groups were subdivided according to adhesive mode of application into etch-and-rinse (Er) and self-etching (S). Resin blocks were built onto the treated surface, and the specimens were stored in deionized water at 37°C for 48 h. Half of the specimens (n = 10) were subjected to thermomechanical aging (A for aged and Na for non-aged). Resin/dentin beams were obtained and subjected to microtensile test in a universal testing machine. Data were analyzed using a three-way ANOVA and Tukey's tests (α = 5%). There was interaction among the three factors (p=0.0003). The use of ethanol resulted in higher values, except for the Er and Na groups (E_Er_Na = N_Er_Na). The mode of application was similar, except for the N and A groups (N_S_A > N_Er_A). For the A groups, the values were lower, except in the cases using ethanol, in which the results were not affected. The study concluded that the use of ethanol resulted in higher microtensile bond strength values, even after aging. The mode of adhesive application did not influence the results.

Influence of Polishing Methods on the Bonding Effectiveness and Durability of Different Resin Cements to Dentin

The purpose of this study was to investigate the impact of polishing methods on the bonding effectiveness and durability of different resin cements to dentin. The dentin surfaces were either treated with a fine-grit diamond bur (polishing A) or further polished by polishing disks (polishing B), and then they were bonded with any one of the three resin cements, namely, etch-and-rinse, self-etch, and self-adhesive resin cements. After 24-hour or 2-year water storage, a microtensile bond strength (μTBS) test was performed. A scanning electron microscope (SEM) was used to observe the morphology of the smear layer as well as the resin-dentin bonding interface. The results indicated that a thinner smear layer thickness was created by polishing B compared with polishing A. Although self-etch and self-adhesive resin cements achieved a relatively high primary bond strength before water degradation, etch-and-rinse resin cement obtained a stable bond strength during water degradation. The application of an additional polishing procedure could improve the bond strength of self-etch and self-adhesive resin cements.

A review of ethanol wet-bonding: Principles and techniques

Conventional water wet-bonding technique has been advocated by many scientists, but the excess water will induce suboptimal polymerization of dental adhesives, phase separation, and nanoleakage, which will influence the longevity of resin-dentin interfaces. Recent studies have put forward a new concept, ethanol wet-bonding. This technique can increase in dentin bond durability. This review focuses on the principles of ethanol wet-bonding, its surface treatment methods.