Effect of dentin conditioning time on nanoleakage

Area of Science:

• Biomaterials Science
• Dental Materials Science
• Nanotechnology in Dentistry

Background:

• The hybrid layer is crucial for the durability of dental restorations.
• Understanding nanoleakage within the hybrid layer is essential for improving adhesive longevity.
• Dentin adhesives play a key role in forming a stable hybrid layer.

Purpose of the Study:

• To investigate the influence of dentin conditioning time and different dentin adhesives on nanoleakage within the hybrid layer.
• To test the hypotheses that conditioning time and adhesive type do not affect nanoleakage.

Main Methods:

• Class V cavities in human molars were restored using four different dentin adhesives (two total-etch, two self-etch).
• Specimens were subjected to varying conditioning times (15, 30, 60 seconds).
• Nanoleakage was assessed using ammoniacal silver nitrate solution and analyzed via Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM).

Main Results:

• Dentin conditioning time did not significantly affect nanoleakage within the hybrid layer (p>0.926).
• Significant differences in nanoleakage were observed among the different dentin adhesives used (p<0.0001).
• Clearfil SE Bond exhibited the least nanoleakage, while One-Step showed the greatest silver ion penetration; OptiBond SOLO Plus and Adper Prompt L-Pop were intermediate.

Conclusions:

• Extended dentin conditioning times do not increase nanoleakage within the hybrid layer.
• The choice of dentin adhesive is a critical factor influencing the extent of nanoleakage in the hybrid layer.