• Chalermkwan Phuvoravan D.D.S., M.Sc.
• Patchara Posrithong D.D.S.
• Tipanan Yanisarapan D.D.S.
• Sopida Sumleerat D.D.S.

Objective To compare the bleaching outcomes of the three different bleaching materials in order to
bleach nonvital tooth discolored after intracanal medication with triple antibiotic mixture.

Materials and methods Thirty two human permanent maxillary central incisors were used. The root
apices were cut. Coronal accesses and root canal preparation were performed. Root apices were sealed
with sealant in order to allow 3 mm of root canal space for reservoir of bleaching agent and triple
antibiotic mixture. All teeth were artificially stained using triple antibiotic mixture. After 7 days,
the color change was measured by colorimeter on the labial surface of the crown. The teeth were
divided into four groups (n = 8): group 1 control (without bleaching material), group 2 (35% carbamide
peroxide), group 3 (35% hydrogen peroxide), group 4 (sodium perborate + sterile water = 2:1 g/ml).
The bleaching agents were replaced every 7 days. The shade of teeth was evaluate again at 7, 14, 21 days.

Results Group 3 (35% hydrogen peroxide) showed the highest mean of shade alteration, followed
closely by group 2 (35% carbamide peroxide), while group 4 (sodium perborate) had the lowest mean
of shade alteration. Statistic analysis revealed that group 2 and group 3 showed significant difference
from control group. When considering time as variation factor, group 3 is the only group that showed
significant difference from control group at day 7. Whereas group 2 can provide significant difference
at day 14, and group 4 had significant difference only at day 21.

Conclusion Thirty-five percent carbamide peroxide and 35% hydrogen peroxide were more effective
than sodium perborate for intracoronal bleaching of teeth discolored with triple antibiotic therapy.

(CU Dent J. 2013;36:153-64)