Document Classification

Section Type: METHODS

Text: The stained teeth were divided equally into the following experimental groups and subjected to various intra-coronal bleaching regimes : Group 2 --'walking bleach'with 20 microl 30 per cent w/w hydrogen peroxide ; Group 3 -- 20 microl 30 per cent w/w hydrogen peroxide and thermocatalytically activated ; Group 4 -- 20 microl acidified thiourea ; Group 5 -- 20 microl acidified thiourea and 20 microl 30 per cent w/w hydrogen peroxide ; Group 6 -- 20 microl acidified thiourea and 20 microl one per cent sodium hypochlorite ; Group 7 -- 20 microl acidified thiourea, 20 microl one per cent sodium hypochlorite and 20 microl 30 per cent w/w hydrogen peroxide.