Smear layer dissolution by peracetic acid of low concentration

Area of Science:

• Dental materials science
• Biomaterials research
• Endodontic treatment

Background:

• The smear layer is a hybrid layer formed during cavity preparation, potentially hindering adhesion and sealing.
• Effective smear layer removal is crucial for successful endodontic procedures and restorative dentistry.
• Peracetic acid (PAA) is explored as an alternative irrigant for smear layer dissolution.

Purpose of the Study:

• To evaluate the smear layer dissolution efficacy of a noncaustic concentration of peracetic acid (PAA).
• To compare the kinetics of smear layer dissolution by 0.5% PAA with 2.25% PAA and 17% ethylenediaminetetraacetic acid (EDTA).

Main Methods:

• Human dentine discs with standardized smear layers were exposed to 0.5% PAA, 2.25% PAA, or 17% EDTA.
• Image sequences captured smear layer changes over cumulative demineralization times (15, 30, 60, 180 seconds).
• Image analysis quantified the dentine-free area fraction (ΔAF) to assess dissolution.

Main Results:

• Both 17% EDTA and 2.25% PAA showed significantly higher smear layer dissolution (ΔAF) than 0.5% PAA overall.
• No significant differences in ΔAF were found between 15 and 30 seconds for any solution.
• After 60 seconds, all solutions exhibited similar ΔAF; however, EDTA and 2.25% PAA continued to increase ΔAF at 180 seconds.

Conclusions:

• A 0.5% PAA solution demonstrates comparable smear layer dissolution to 2.25% PAA and 17% EDTA after 60 seconds of contact.
• Noncaustic PAA concentrations show potential as effective agents for smear layer removal in dentistry.
• The findings suggest 0.5% PAA could be a viable alternative irrigant for endodontic applications.