Concentrations of hydrogen peroxide used in professional and over the counter teeth whitening processes don't cause significant changes to tooth enamel, according to US researchers.
Conversely the researchers found that an everyday practice such as drinking acidic fruit juices can have significant negative effects on the hardness and the roughness of tooth enamel.
The scientists, led by YanFang Ren at the Eastman Institute for Oral Health at the University of Rochester, investigated the effects of hydrogen peroxide 6 percent on tooth enamel.
According to the team, when compared to orange juice the hydrogen peroxide did not lead to any significant changes in the hardness of surface enamel.
After 20 minutes of daily exposure for five days to eBright Tooth Whitening Accelerator (6 percent hydrogen peroxide) provided by Beyond Dental Health which part funded the study, surface hardness was reduced by 5.6 percent.
Insignificant when compared to orange juice
However, compared to 20 minutes exposure to orange juice which reduced surface enamel by 84.4 percent, the researchers concluded the teeth whitening was insignificant.
"Enamel surface becomes significantly softer and rougher after the orange juice challenge," wrote the authors.
"The acid is so strong that the tooth is literally washed away," said lead author Ren.
Furthermore, softened and roughened enamel surfaces may predispose the tooth to the development of dental caries and non-carious lesions such as abrasion and attrition, according to the study.
The authors discussed the potential of fluoride to protect against the assault of acidic soft drinks on the teeth as it has been shown to help harden the enamel surface after whitening treatments; however, they were unsure as to fluoride's potential to fight against the dangers of acidic soft drinks.
"In contrast, the effectiveness of fluoride treatments on erosion caused by soft drinks has not been firmly established. Some studies have indicated that fluoride treatment had limited effect_but others have show that higher concentrations of fluoride could indeed reduce the erosive effects of soft drinks on surface enamel."
The researchers conclude that the results provide dentists with a unique perspective on the relative impact of tooth whitening on dental hard tissues.