Actacal Paste - Calcium Hydroxide (2) 2 Gram Syringe + 10 Tips ActaCal is an industry-leading, high-concentration (45%), calcium hydroxide, antibacterial treatment paste. With best in class concentration of calcium hydroxide, ActaCal provides long-lasting hydroxyl and calcium ion release exhibiting a high PH value (>12) which has a pronounced bactericidal effect, i.e killing of bacteria. It is recommended for routine use between office visits to disinfect canals and prevent flare ups, and for use in complicated cases when extended calcium hydroxide treatment is indicated.