Simplified adhesive systems have made restorative dentistry faster and more convenient. But according to a recent narrative review, the long-term success of adhesive procedures still depends far more on protocol execution than on the adhesive bottle alone.
The review revisits several fundamentals of adhesive dentistry, emphasizing that enamel and dentin should not be approached as identical substrates. While enamel bonding remains highly predictable following phosphoric acid etching, dentin bonding continues to be technique-sensitive because of its organic composition, intrinsic moisture, and tubular structure.
Why Substrate Preparation Still Matters
The authors highlight that contamination control, substrate cleaning, and surface conditioning remain critical for adhesive durability.
Although pumice cleaning continues to be effective for superficial debris removal, newer evidence supports the use of air particle abrasion (APA) as a combined cleaning and conditioning method. When performed using particles smaller than 50 μm at controlled pressure, APA was reported to improve surface energy, wettability, and micromechanical retention.
Importantly, the review stresses that substrate preparation should be selected based on:
enamel versus dentin exposure,
restorative indication, and
clinical accessibility.
The Ongoing Challenge of Dentin Bonding
The paper reinforces that dentin remains the more difficult substrate for predictable adhesion.
Overdrying etched dentin may collapse collagen fibers and impair adhesive infiltration, while insufficient solvent evaporation may compromise hybrid layer formation. The review also notes that simplified one-bottle systems continue to demonstrate greater susceptibility to hydrolytic degradation and nanoleakage over time compared with multi-step approaches.
Despite advancements in universal adhesives, the literature reviewed still identifies:
OptiBond FL as a reference total-etch system, and
Clearfil SE Bond as a reference self-etch adhesive with selective enamel etching.
Selective Enamel Etching Continues to Matter
One of the most clinically relevant takeaways is that selective enamel etching remains strongly supported even when universal adhesives are used.
According to the review, phosphoric acid etching continues to provide the most reliable enamel adhesion by creating predictable microretention patterns. Dentin, however, requires greater caution because of its moisture-sensitive nature and dependence on proper primer infiltration.
Immediate Dentin Sealing Gains Further Support
The review also discusses increasing evidence supporting immediate dentin sealing (IDS) in indirect restorations.
Performing adhesive sealing immediately after tooth preparation was reported to:
reduce bacterial penetration,
decrease postoperative sensitivity, and
improve resin–dentin bond stability at final cementation.
The integration of IDS with digital workflows and intraoral scanning under rubber dam isolation was highlighted as a growing clinical trend, particularly for indirect restorations.
Clinical Perspective
The review ultimately reinforces a point many clinicians recognize in practice:
Adhesive failures are often less about the adhesive brand itself and more about moisture control, substrate management, and protocol execution.
While adhesive systems continue evolving toward simplification, the evidence reviewed suggests that multi-step strategies still demonstrate superior long-term reliability, particularly on dentin.
Conclusion
According to the authors, predictable adhesive dentistry continues to rely on three interconnected factors:
effective isolation,
appropriate substrate preparation, and
correct adhesive technique.
The review suggests that modern adhesive success is not achieved simply by selecting newer materials, but by understanding how enamel and dentin respond differently — and adapting clinical protocols accordingly.