pH changes of self-etching primers mixed with powdered dentine

Area of Science:

• Dental Materials Science
• Biomaterials Chemistry

Background:

• Self-etching primers are widely used in dental restorations.
• Their acidity can potentially affect dentine properties.
• Understanding the interaction between primers and dentine is crucial for clinical success.

Purpose of the Study:

• To investigate the pH changes in self-etching primers when mixed with dentine powder.
• To assess the buffering capacity of dentine against acidic dental adhesives.

Main Methods:

• Four self-etching primer systems (Clearfil SE Bond, Imperva Fluoro Bond, Mac Bond II, Unifil Bond) were tested.
• Pulverized bovine dentine was mixed with diluted primer solutions.
• pH measurements were taken using a solid-state pH sensor over 600 seconds.

Main Results:

• Baseline primer pH ranged from 1.83 to 2.34.
• After mixing with dentine powder, pH increased significantly to 6.95–7.37 within 600 seconds.
• No significant pH differences were observed among primers post-mixing; Clearfil SE Bond showed precipitate formation.

Conclusions:

• Dentine exhibits a strong buffering capacity against the acidity of self-etching primers.
• This buffering effect is significant and rapid, suggesting minimal risk of acid-induced damage to dentine during bonding.