Internal bleaching with calcium oxalate and laser irradiation for managing discolorations induced by mineral trioxide aggregate.

Aim: This in vitro study investigated the effects of incorporating 1%, 3%, and 5% calcium oxalate into 15% hydrogen peroxide (HO), with and without laser activation, on the whitening of teeth discolored by mineral trioxide aggregate (MTA).

Methods: The pulp tissue of 80 bovine incisors was removed, and an MTA plug was placed at 2 mm below the cementoenamel junction. After nine months, the samples were randomly divided into eight groups (n = 10).