Treatment of Postorthodontic White Spot Lesions

Dental caries is the destruction of the tooth structure in the presence of organic acids produced by cariogenic bacteria located in the dental biofilm (Dowker et al., 1999 and Robinson et al., 2000).Tooth enamel comprises 90% substituted hydroxyapatite (Ca10 (PO4)6(OH) 2), which is subjected to consecutive cycles of demineralization and remineralization. This is an interrupted process, with periods of remineralization and demineralization occurring, depending on the state of the oral environment in terms of the prolonged accumulation and retention of bacterial plaque on the enamel surface (Aoba, 2004). Oral bacteria ferment carbohydrates to produce organic acids which lower the pH and cause the subsurface dissolution of the hydroxyapatite crystals. Under normal physiological conditions (pH7), saliva is supersaturated with calcium and phosphate ions which diffuse into the vacancies created during acid-mediated demineralization episodes (Dowker et al., 1999 and Robinson et al., 2000). The demineralization of enamel (white spot lesions) is a significant problem during and after orthodontic treatment with prevalence 71.1% and various preventive measures have been suggested to minimize the incidence (Derks et al., 2004 and Al Maaitah et al., 2011).