Removal of surgical smear layer

Area of Science:

• Endodontic Microsurgery
• Dental Materials Science
• Scanning Electron Microscopy

Background:

• A smear layer forms on dentinal surfaces during apicoectomy and retrograde cavity preparation, potentially harboring microorganisms.
• This smear layer can impede effective disinfection and healing.
• Understanding smear layer removal is crucial for successful endodontic treatment outcomes.

Purpose of the Study:

• To compare the efficacy of 35% orthophosphoric acid and 24% ethylenediaminetetraacetic acid (EDTA) in removing the smear layer from retrocavities.
• To evaluate smear layer removal using scanning electron microscopy (SEM).

Main Methods:

• Twenty-eight single-rooted teeth underwent apicoectomy and retrograde cavity preparation using ultrasonic retrotips.
• Group A teeth were treated with 35% orthophosphoric acid gel for 15 seconds.
• Group B teeth were treated with 24% EDTA gel for 2 minutes.
• Samples were analyzed via SEM to assess smear layer presence.

Main Results:

• Eighty percent of teeth treated with orthophosphoric acid exhibited open dentinal tubules and optimal cleanliness.
• The majority of samples treated with EDTA showed remaining smear layer covering dentinal tubules.
• Orthophosphoric acid demonstrated superior smear layer removal compared to EDTA.

Conclusions:

• 35% orthophosphoric acid is more effective than 24% EDTA for surgical smear layer removal in retrocavities.
• Orthophosphoric acid achieved better results in less application time.
• These findings suggest orthophosphoric acid as a preferred agent for smear layer management in endodontic microsurgery.