Bonding of self-etching adhesives on dehydrated dentin

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Biomaterials

Background:

• Dentin bonding is crucial for dental restorations.
• Understanding the effect of substrate hydration on adhesive bond strength is essential.
• Self-etching adhesives offer simplified application but their performance can be sensitive to moisture.

Purpose of the Study:

• To investigate how dentin pretreatment with acetone or ethanol affects the bond strength of one-bottle versus two-step self-etching adhesives.
• To evaluate the influence of dentin dehydration on the performance of different types of self-etching dental adhesives.
• To determine the relationship between adhesive hydrophilicity and bond strength on pretreated dentin substrates.

Main Methods:

• Two types of one-bottle and two types of two-step self-etching adhesives were tested.
• Adhesives were applied to either normally wet dentin (control) or dentin pretreated with 95% acetone or ethanol for 30 seconds.
• Solvent evaporation and adhesive phase separation were analyzed to assess hydrophilicity and bonding efficacy.

Main Results:

• One-bottle self-etching adhesives showed significantly increased bond strengths on acetone- or ethanol-pretreated dentin compared to the control.
• Two-step self-etching adhesives exhibited significantly lower bond strengths on pretreated dentin compared to the control.
• Analysis indicated that dentin dehydration positively impacted one-bottle adhesives while negatively affecting two-step adhesives.

Conclusions:

• Dentin bond strength is significantly influenced by substrate wetness, with varying effects depending on the adhesive system.
• Dehydrating dentin with acetone or ethanol can enhance the adhesion of hydrophilic one-bottle self-etching adhesives.
• The findings suggest that optimizing dentin surface moisture is critical for maximizing the bond strength of different self-etching dental adhesive systems.