Using 10% carbamide peroxide or 10% hydrogen peroxide bleaching agents in conjunction with an abrasive dentifrice can lead to a significant increase in enamel roughness when combined with an abrasive dentifrice, according to a study in Acta Odontologica Scandinavica (May-July 2013, Vol. 71:3-4, pp. 488-497).
Researchers from Ankara University, Near East University, and Drexel University examined the effects of the two bleaching agents on enamel at different times. They also looked at the effect of different superficial cleaning treatments when they are used after these agents.
The researchers divided 140 flat enamel samples into 14 groups, half of which were treated with 10% carbamide peroxide and half with 10% hydrogen peroxide. One group from each half was set aside as the control. Then one group from each was brushed with Ipana toothpaste, Clinomyn toothpaste, Moos Dent toothpaste, Signal toothpaste, Colgate toothpaste, and without a dentifrice, respectively.
The bleaching sessions lasted six hours each day, while the brushing phase took place three times a day for two minutes at a time over a four-week period. At each seven-day interval, the researchers measured average roughness values with a profilometer.
Bleaching with either peroxide agent did not alter the enamel surface roughness, but when the bleaching treatment was combined with abrasive dentifrices, a significant increase in roughness values was observed, the study authors concluded
