Microhardness evaluation of root dentin after using resin sealer solvents

Area of Science:

• Dental Materials Science
• Biomaterials Research
• Endodontics

Background:

• Resin sealers are crucial in endodontic treatments.
• Solvents used in resin sealers can affect surrounding tooth structure.
• Understanding solvent effects on dentin microhardness is vital for material selection.

Purpose of the Study:

• To evaluate the impact of methyl ethyl ketone (MEK) and ethyl acetate (EA) on dentin microhardness.
• To compare MEK and EA with chloroform and saline as resin sealer solvents.
• To assess the influence of exposure time and ultrasonic agitation on these effects.

Main Methods:

• Eighty single-rooted teeth were divided into four groups: MEK, EA, chloroform, and saline.
• Vickers microhardness testing was performed at three root levels.
• Solvents were applied for 5 or 15 minutes, or 1 minute with ultrasonic agitation.
• Data analyzed using repeated-measures ANOVA and Bonferroni tests.

Main Results:

• All tested solvents, except saline, significantly decreased dentin microhardness (P < 0.05).
• Microhardness reduction increased with prolonged exposure times.
• Chloroform caused the most substantial decrease in microhardness.
• Ultrasonic agitation significantly amplified the reduction in microhardness.

Conclusions:

• MEK and EA demonstrate a less detrimental effect on dentin microhardness compared to chloroform.
• MEK and EA do not dissolve gutta-percha, unlike chloroform.
• MEK and EA are potentially safer solvent alternatives for resin sealers.