Adhesive Dentistry: Understanding the Science and Achieving Clinical Success

A bibliometric and Altmetric analysis of the 100 top most cited articles on dentin adhesives

OBJECTIVE

This study aimed to identify the 100 top-cited articles on dentin adhesives utilizing comprehensive bibliometric and altmetric analyses.

MATERIALS AND METHODS

The Institute of Scientific Information Web of Knowledge database was used to compile the top-cited articles published from 1945 through February 12, 2023. Citation counts were manually retrieved for each article from Scopus, Google Scholar, Dimensions, and Altmetric. The articles were analyzed in terms of their number of citations, year, journal name, author (name, institution, and country), and type and specific field of study. We used descriptive statistics to summarize the results.

RESULTS

The analysis revealed that the top 100 cited articles originated from 18 English-language journals and collectively accumulated a remarkable 34526 citations. The article with the highest number of citations garnered 1288 references. Among authors, Van Meerbeek B. stood out with nine articles and 4650 citations, followed by Pashley D.H. with six articles and 2769 citations. Japan was the leading contributor by country, while the Catholic University of Leuven led in terms of institutions with 20 articles.

CONCLUSION

According to this study, basic research and review articles garnered the most citations, respectively. The citation analysis revealed different trends for researchers, the first being that researchers have focused on basic fields such as the ultramorphology of dentin and adhesive interfaces, followed by bond strength to dentin. Two studies on clinical experiences suggested that studies with high-level evidence, such as systematic reviews, meta-analyses, or randomized controlled clinical trials, are required.

CLINICAL RELEVANCE

It is identified that more studies with high-level evidence-based research are needed in the field of dental adhesives.

The Effect of an Extra Hydrophobic Resin Layer on the Bond Strength and Durability of One-Step Universal Adhesives Used as a Primer

OBJECTIVES

To determine the effect of an extra hydrophobic resin layer (EHL) on the bond strength and durability of three different pH one-step universal adhesives (UAs) utilized in self-etch (SE) mode, and to explore whether UAs can be used as a primer in two-step bonding system.

METHODS

Three different pH UAs were utilized: G-Premio Bond (GPB), Scotchbond Universal (SBU), All-Bond Universal (ABU), while the bonding agent of Clearfil SE Bond 2 (SE2) was selected as the EHL. For the EHL groups, EHL was applied after the air blow of each UA and before light curing. The microtensile bond strength (μTBS), fracture modes, interfacial structures and nanoleakage (NL) were evaluated after 24 h water storage and after 15,000 thermal cycling (TC). Elastic modulus (EM) and hardness (H) was tested by a nanoindenter after 24 h.

RESULTS

Significantly higher μTBS was achieved in the GPB+EHL group compared with GPB both at 24 h and after 15,000 TC, while the additional use of EHL did not improve the μTBS of SBU and ABU significantly both at 24 h and after 15,000 TC. GPB+EHL demonstrated lower NL than GPB. The mean EM and H of the adhesive layer in GPB+EHL was significantly decreased compared with GPB.

CONCLUSIONS

The results indicated that the bond strength and durability of low pH one-step UA (GPB) were significantly improved by additional application of EHL both at 24 h and after 15,000 TC, while no significant improvement was observed for ultra-mild one-step UAs (SBU and ABU).

CLINICAL SIGNIFICANCE

This study indicates that GPB can be used as a primer in a two-step bonding system, while SBU and ABU may not be as effective. These findings may help guide clinicians in selecting the appropriate UAs and bonding techniques for different clinical scenarios.

Internal and Marginal Adaptation of Adhesive Resin Cements Used for Luting Inlay Restorations: An In Vitro Micro-CT Study

Adequate internal adaptation and marginal sealing of resin luting cements are of particular importance for the success of cemented ceramic inlays. The purpose of this study was to investigate the initial adaptation of different resin cements at the tooth-inlay restoration interface at enamel versus dentin surfaces. Thirty-two extracted human molars were allocated to four groups. One Class II cavity was prepared in each tooth. In each group, half of the cavities’ gingival floors were on enamel while the other halves were on cementum. Lava Ultimate CAD/CAM inlays were luted to the cavities using the following adhesive systems: RelyX Unicem, RelyX Ultimate, eCement, and Variolink Esthetic DC. After staining teeth with silver nitrate solution, marginal and internal gap volumes were determined using micro-CT images. Statistical analyses were conducted by independent t test and one-way ANOVA followed by post hoc Tukey test (p < 0.05). The internal and marginal gap volume values were the highest for Variolink Esthetic DC at the dentin surface (0.629 ± 0.363) and (2.519 ± 1.007), respectively, and the lowest for RelyX Unicem at the enamel surface (0.005 ± 0.004) and (0.009 ± 0.003), respectively. The internal and marginal adaptation on the enamel surface for RelyX Unicem and RelyX Ultimate resin cements were comparable to each other and to eCement but significantly better than Variolink Esthetic DC cement. Regardless of the adhesive resin system used, adaptation on enamel is superior to that on dentin surfaces.

The effect of different application modes of a 1-step self-etch adhesive on the clinical performance of Class I composite restorations: A randomized controlled clinical trial

OBJECTIVE

To evaluate the clinical performance of a 1-step self-etch dentin adhesive that was applied according to the manufacturers' recommendations, doubling the adhesive application time and layer in Class I cavities with a composite resin.

MATERIALS AND METHODS

A total of 39 patients aged between 14 and 43 (mean age: 19.1) years were enrolled in the study. Each patient received three restorations. In these three restorations, a 1-step self-etch adhesive was applied according to the manufacturer's recommendations (control group), by doubling the adhesive application time, and with double layers. The restorations were evaluated according to modified USPHS criteria at baseline, and 1, 2, 3, and 4-year recalls.

RESULTS

After 4 years, the success rate was 100% for restorations with the adhesive applied according to the manufacturers' recommendations, 96.9% for restorations applied by doubling the adhesive application time, and 93.8% for restorations applied with double adhesive layers. There was no significant difference between the three application methods among all the evaluation periods regarding the evaluation criteria.

CONCLUSIONS

The 4-year success rates of a 1-step self-etch dentin adhesive that was applied according to the manufacturers' recommendation, by doubling the adhesive application time, and with double layers were excellent.

CLINICAL SIGNIFICANCE

It is not recommended to double the adhesive application time nor apply a double layer of a 1-step self-etch adhesive because it does not improve the clinical performance of Class I composite restorations.

Resin Cement Residue Removal Techniques: In Vitro Analysis of Marginal Defects and Discoloration Intensity Using Micro-CT and Stereomicroscopy

The objective was to compare marginal defects and evaluate discoloration for adhesively cemented veneers in vitro when using two cement removal techniques. Twenty premolars were prepared with chamfer and borders in enamel. IPS e.max CAD veneers were cemented using Panavia V5 and divided in two groups (n = 10): cement excess removed with a probe after tack-curing for 3–5 s, or cement excess removed with a brush, then completely polymerized. All teeth were stored in alginate gel until micro-CT examination. Scanning was performed twice: directly after cementation and after thermocycling (5000 cycles, between 5 and 55 °C). To analyze discoloration, teeth were colored using 0.5% basic fuchsine and examined under a stereomicroscope. Depth of dye infiltration was scored 0 (no discoloration) to 5 (discoloration along the entire margin). Statistically significant differences of cement defects before thermocycling were reported, where brushing showed more defects than probing (p = 0.0161). After thermocycling, the defects increased for both groups. Extensive discoloration was the most common (55.56%) when removing excess by probing; by brushing, 90% of the specimens exhibited slight discoloration (p = 0.008). Regression analysis showed no relationship between type of defect and degree of discoloration. Removing cement with a brush causes more marginal defects, however less discoloration after thermocycling.