Influence of bleaching agents on surface roughness of sound or eroded dental enamel specimens.
OBJECTIVE
The aim of the present in vitro study was to assess the effect of bleaching agents on eroded and sound enamel specimens.


METHODS
Enamel specimens prepared from human permanent anterior teeth were incubated with different bleaching agents containing active ingredients as 7.5 or 13.5% hydrogen peroxide or 35% carbamide peroxide, ranging in pH from 4.9 to 10.8. The effect of the tooth whitening agents on surface roughness was tested for sound enamel surfaces as well as for eroded enamel specimens. To provoke erosive damage, the enamel specimens were incubated for 10 hours with apple juice (pH = 3.4). Afterwards, pretreated and untreated dental slices were incubated with one of the bleaching agents for 10 hours. The surface roughness (R(a)) of all enamel specimens (N = 80) was measured using an optical profilometric device. A descriptive statistical analysis of the R(a) values was performed.


RESULTS
The study demonstrated that exposure to an acidic bleaching agent (pH = 4.9) resulted in a higher surface roughness (p = 0.043) than treatment with a high peroxide concentration (pH = 6.15). If the enamel surface was previously exposed to erosive beverages, subsequent bleaching may enhance damage to the dental hard tissue.


CONCLUSIONS
Bleaching agents with a high concentration of peroxide or an acidic pH can influence the surface roughness of sound or eroded enamel.
Department of Operative Dentistry, University Medical Center of the Johannes Gutenberg University Mainz, Germany.
Birgül
B
Azrak
Angelika
A
Callaway
Petra
P
Kurth
Brita
B
Willershausen
D000328:Adult; D000368:Aged; D001628:Beverages; D000077463:Carbamide Peroxide; D003743:Dental Enamel / Q000187:drug effects* / Q000473:pathology; D005638:Fruit; D006801:Humans; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D027845:Malus; D008422:Materials Testing; D008875:Middle Aged; D010545:Peroxides / Q000008:administration & dosage / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors; D058205:Tooth Bleaching Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014077:Tooth Erosion / Q000473:pathology*; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology
D010545:Peroxides; D058205:Tooth Bleaching Agents; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide