Orthodontic appliances and enamel demineralization. Part 1. Lesion development.

A clinical trial was conducted to investigate carious lesion development associated with fixed orthodontic therapy. Specially designed orthodontic bands for plaque accumulation were attached to premolars scheduled to be extracted as part of an orthodontic treatment. Visible white spot lesions were seen within 4 weeks in the absence of any fluoride supplementation. Both microradiographic and SEM examinations showed surface softening of the enamel surface--that is, a surface layer was not seen in the lesions. The clinical significance of the present study is that enamel demineralization associated with fixed orthodontic therapy is an extremely rapid process caused by a high and continuous cariogenic challenge in the plaque developed around brackets and underneath ill-fitting bands. Careful inspection of the appliance at every visit and preventive fluoride programs are therefore required.