M Beerens

58 CHAPTER 4 More than 97.3% of lesions remained as permanent scars (van der Veen et al. , 2007). Management of WSL should involve methods of both preventing demineralisation and encouraging the remineralisation of existing lesions. In both of these processes the efficacy of fluoride is well established. Fluoride increases the initial rate of remineralisation of early enamel lesions, and then slows down the caries process, arresting the lesion (ten Cate et al. , 2008). However, there are obvious differences between the prevention of WSL during fixed appliance therapy and the curative treatment of existing WSL after debonding. Willmot (Willmot, 2008) and Øgaard (Øgaard et al. , 1988b) warned against treating visible WSL on labial surfaces with concentrated fluoride agents, because this arrests both demineralisation and remineralisation in the lesion by surface hypermineralisation (ten Cate et al. , 1981). These arrested lesions may persist lifelong, exhibiting a white colour, or might become yellowish or dark brown in colour as a result of the uptake of exogenous stains (Bishara and Ostby, 2008). To enhance the natural remineralisation by saliva, bioavailable calcium and phosphate are needed. Products providing calcium and phosphate in bioavailable forms have existed since the 1980s when Reynolds et al . (Reynolds, 1987) introduced casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP). It has been claimed that the multifactorial anticariogenic mechanism for CPP-ACP has a threefold mode of action: 1. it promotes the remineralisation of enamel lesions by maintaining a supersaturated state of the enamel minerals calcium and phosphate in plaque (Reynolds, 1998), 2. it delays the formation of biofilm (Rahiotis et al. , 2008) and inhibits bacterial adhesion to the tooth surface; and 3. it acts as a buffering agent, which may prevent a reduction of pH in the oral micro-environment (Rahiotis et al. , 2008). Casein phosphopeptide amorphous calcium phosphate with fluoride (CPP- ACPF) has the same potential with the additional benefits of the added fluoride (Cross et al. , 2004). Using CPP-ACPF will remineralise subsurface lesions by forming fluorapatite within the lesion (Cochrane et al. , 2008).This concept has led to the production of oral hygiene supporting products, such as chewing gums and tooth creams containing CPP-ACPF, as supplement to normal daily oral hygiene procedure. The remineralisation of enamel subsurface lesions by CPP-ACP complexes has been demonstrated in numerous laboratory,