M Beerens

108 CHAPTER 6 as remineralisation enhancing agents. However, the commercially available MI Paste Plus ® , with CPP-ACPF as active ingredient, did not show this intended effect as was concluded in this thesis. After natural remineralisation has been given time to occur, a second step is to camouflage the inactive WSL by external bleaching. Inactive WSL are visible as permanent scars and vulnerable to staining (Sonesson et al. , 2017). External bleaching may camouflage such WSL (Knösel et al. , 2007). External bleaching, however, increases caries susceptibility in patients that have poor oral hygiene (Flaitz and Hicks, 1996). If bleaching is not conclusive or satisfying to the patient, acid micro-abrasion (Ardu et al. , 2007) or micro abrasion with pumice powder (Akin and Basciftci, 2012) will provide aesthetical improvement. Micro-abrasion aims to remove the hypermineralised surface layer. Resin infiltration (Icon technique) (Knösel et al. , 2007; Senestraro et al. , 2013) may be considered combined with micro abrasion (Abdelaziz et al. , 2016). The Icon technique provides an immediate improved esthetical appearance of the WSL compared with untreated lesions. A downside of resin is that this material may discolour over time (Ceci et al. , 2017). The last phase is restorative treatment, by applying resin fillings or even veneers. During the retention phase, directly after orthodontic bracket removal, it is appropriate for the orthodontist to control the first phase. Secondary steps and beyond should be left to the dentist. Future perspective In general, fluoride is effective in reducing enamel caries decay (Feyerskov and Kidd, 2008). The prevention of WSL is considered crucial. Despite available scientific evidence to prevent WSL with fluoride, clinical guidelines have not been formulateduntil now.Orthodontistsandotherdental healthprofessionals should formulate and accept guidelines in their treatment strategies for orthodontic patients having WSL. Also the social health reimbursement system should include preventive measures in their tariff rates to prevent WSL during orthodontic treatment (Kerbusch et al. , 2010). If preventive measures are not effective and WSL appear, promoting remineralisation should be the preferred approach for active WSL that have