Radicular penetration of hydrogen peroxide from various intracoronal bleaching agents: an vitro study

External cervical resorption has been reported to occur when bleaching of root filled teeth is done with 30% H2O2 alone or mixed with sodium perborate. H2O2 leakage through dentinal tubules has been speculated as one of the reasons for the resorption. External cervical root resorption has not been reported with the bleaching agent sodium perborate mixed with bidistilled water. Purpose of this study was to comparatively evaluate the H2O, leakage from three bleaching agents i.e. sodiumperborate mixed with 30% H2O2 or bidistilled water or 30% H2O2 alone.21 human freshly extracted premolars were taken and root canal treatment was completed. Pulp chambers were prepared to receive bleaching agents. The teeth were divided into experimental and control groups. Experimental group was again divided into subgroups : A, B, C according to bleaching agents used. Resulls showed that maximum H2O2 leakage occurred from 30% H2O2 while minimum from sodium perborate mixed with bidistilled water.