To compare and evaluate the results of three commonly used nonvital bleach techniques: thermocatalytic, walking bleach, and combination.
- n=39 extracted anterior teeth with intact crowns; in 5.25% NaOCl for 8 hrs
- scaled and polished teeth with pumice
- pre-op shade determined and teeth photographed
- lightest, median, and darkest teeth determined, stored in saline
- lingual accesses made, pulp extirpation, stained with hemolyzed blood
- ranked teeth from lightest to darkest in 3 groups of 12
- 2mm IRM placed in root canal space from CEJ.; chamber freshened with round burs
- thermocatalytic: electric bleaching instrument set to 153 F on facial and in access, heated 35% H202 soln in chamber on cp for 2 min cycles for 12 min total, rinsed, dried, dry cp with cavit placed, repeated at 1 wk, recorded shades at 1wk and 1 mo postops
- walking bleach: H202 and sodium perborate paste placed in chamber, cavit placed, procedure repeated at 1 wk, 1 wk and 1 mo shades postop recorded
- combination: thermocatalytic done then placed walking bleach paste for 1 wk, repeated thermocatalytic, placed cavit and recorded shades at 1 wk and 1 mo postops
- the three techniques are equally effective in bleaching crowns in which pulpal hemorrhage was primary cause of discoloration
- rapidity of walking bleach technique in respect to a decrease of operator time was high significant (P< .0000)
Walking bleach technique is fastest and produces clinically acceptable bleaching.