Active application improves the bonding performance of self-etch adhesives to dentin

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Biomaterials Engineering

Background:

• One-step self-etch adhesives simplify dental procedures but their bond durability to dentin requires optimization.
• Application technique, specifically active versus inactive modes, may influence the interfacial integrity of resin-dentin bonds.
• Understanding these effects is crucial for predicting long-term clinical performance of these adhesive systems.

Purpose of the Study:

• To compare the immediate and 6-month microtensile bond strength (microTBS) and nanoleakage (NL) of three one-step self-etch adhesives.
• To evaluate the impact of two application methods (active vs. inactive) on the bond performance of these adhesives.
• To assess the long-term stability of the adhesive interface under different application modes.

Main Methods:

• Human molars were prepared to expose flat dentin surfaces for bonding.
• Three one-step self-etch adhesives (Clearfil S³ Bond, Xeno III, Adper Prompt L-Pop) were applied using active (AC) or inactive (IN) modes.
• MicroTBS and nanoleakage were assessed immediately and after 6 months of water storage; data analyzed using two-way ANOVA.

Main Results:

• Active application (AC) consistently yielded higher microTBS compared to inactive application (IN) at both time points (p=0.001).
• Nanoleakage was reduced with AC application for Xeno III and Clearfil S³ Bond compared to IN.
• Adper Prompt L-Pop showed increased nanoleakage after 6 months regardless of application method, while the other two showed reduced nanoleakage with AC.

Conclusions:

• Active application enhances the bonding performance of one-step self-etch adhesives to dentin.
• This improvement in microtensile bond strength and reduction in nanoleakage is maintained over a 6-month period.
• The active application method is recommended for optimizing the clinical longevity of these adhesive systems.