Why Calcium Oxide?
Calcium Oxide has two very important properties when it comes to treating root canals—it kills bacteria because of its extremely alkaline pH and it penetrates the tooth’s porous anatomy where bacteria can hide. When calcium oxide comes in contact with the water, it reacts to form calcium hydroxide. Calcium hydroxide is commonly used in dentistry as a disinfectant because of its high alkalinity (pH 10 –11), which is inhospitable to bacteria. Calcium hydroxide also seems to have a stimulatory effect on bone cells. Calcium oxide is also strongly hygroscopic, which means it attracts water and will expand through a water layer. This gives it the ability to actively diffuse through the microscopic spaces of a tooth and penetrate to the outer tooth surface.1-3 The calcium oxide filling material takes 5- 7 days to harden by reacting with carbon dioxide from the surrounding cellular environment to form calcium carbonate. Although a second appointment is required to check the hardness of the fil
