No-waiting dentine self-etch concept-Merit or hype.

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Biomaterials

Background:

• Universal adhesives offer flexible application modes for dental bonding.
• G-Premio Bond allows for a no-waiting self-etch or a 10-second self-etch technique.
• Evaluating in vitro performance under simulated intraoral conditions is crucial.

Purpose of the Study:

• To compare the in vitro performance of G-Premio Bond using two self-etch application modes.
• To assess the impact of thermomechanical cycling on bond strength, hybrid layer integrity, and nanoleakage.
• To examine changes in mineralized dentine composition post-adhesive application.

Main Methods:

• 110 human coronal dentine specimens were bonded using G-Premio Bond in no-waiting and 10-second self-etch modes.
• Specimens underwent thermomechanical cycling (10,000 thermal, 240,000 mechanical cycles).
• Microtensile bond testing, transmission electron microscopy (ultrastructure, nanoleakage), and Fourier transform infrared spectroscopy were employed.

Main Results:

• Both reduced application time and thermomechanical cycling significantly decreased bond strengths.
• Nanoleakage was more extensive after thermomechanical cycling, regardless of application mode.
• The 10-second self-etch application improved bonding compared to the no-waiting mode, but nanoleakage remained a concern.

Conclusions:

• While the no-waiting self-etch mode may achieve sufficient bond strength, it requires further technological advancement for clinical recommendation.
• The 10-second application mode offers better performance but still presents nanoleakage issues.
• Reducing application time for user-friendliness must be balanced with maintaining optimal dentine bonding efficacy.