double antibiotic paste

Double antibiotic paste (DAP) is an intracanal medicament used primarily in regenerative endodontics and the management of root canal infections. It is a combination of two antibiotics—metronidazole and ciprofloxacin—mixed in equal proportions, typically with saline or another vehicle to form a paste[3][5][7]. DAP was developed as an alternative to triple antibiotic paste (TAP), which also contains minocycline but can cause tooth discoloration. By omitting minocycline, DAP avoids this side effect while maintaining broad-spectrum antimicrobial activity against both Gram-positive and Gram-negative bacteria commonly found in endodontic infections[2][5][7]. The mechanism of action involves inhibition of bacterial DNA synthesis (ciprofloxacin) and disruption of anaerobic bacterial metabolism (metronidazole). DAP is used for disinfection during regenerative procedures, treatment-resistant apical infections, external inflammatory root resorption, and symptomatic irreversible pulpitis. However, prolonged use may reduce dentin microhardness[1][3][7].

Other names

DAPdouble antibiotic paste