Antimicrobial Efficacy of 3.8% Silver Diamine Fluoride and Its Effect on Root Dentin

Abstract Introduction This study investigated the use of 3.8% silver diamine fluoride (Ag[NH3 ]2 F) as an antibacterial agent against Enterococcus faecalis biofilms and its ability to penetrate dentinal tubules by the formation of silver salts. Methods Biofims were generated on membrane filter discs and subjected to 15-minute and 60-minute exposure times with 3.8% Ag(NH3 )2 F, saturated Ca(OH)2 , 5.25% NaOCl (negative control), and 0.9% NaCl (positive control). Cleaned and shaped radicular dentin were applied with Ag(NH3 )2 F for 24, 48, and 72 hours. The presence of silver salts on the dentin surface was examined using low-pressure scanning electron microscopy. Results Both NaOCl and Ag(NH3 )2 F were effective against E. faecalis biofilms, with no significant difference in reduction of microorganisms for both exposure times. Silver deposits were present on 66.5% of the radicular dentin surfaces after 72-hour application of Ag(NH3 )2 F as simulated interappointment dressings. Penetration of the silver deposits was observed at most 40 μm into dentinal tubules after smear layer removal. Conclusion Ag(NH3 )2 F has potential to be used as an antimicrobial root canal irrigant or interappointment dressing, especially in locations in which potential browning/blackening of dentin by metallic silver is not a major concern.