There are established, successful concepts for the prophylaxis of caries. It is based on few but effectively proven strategies: oral hygiene to reduce the cariogenic biofilm; fluoridation to improve tooth structure; and appropriate diet to reduce sucrose exposure.1
Prophylactic concepts for molar incisor hypomineralization (MIH) must be considered in a more differentiated way. Preventing the development of the disease is not possible – at present at least – because the etiological factors have not been adequately clarified. Consequently, primary prevention in the true sense is not feasible. Therefore, the current focus should be on secondary prevention, ie, detecting the disease at an early stage with the aim of preventing its progression, at least to some extent, through targeted treatments and promoting remineralization. Essential for this is, first of all, knowledge of the presence of an MIH problem and its particularities, understanding of the possible occurrence of hypersensitivities, and recognition of new enamel defects. Nevertheless, even in the case of MIH, the generally known caries risk factors must not be disregarded. Their additional reduction should be intended, as this at least achieves a concomitant preventive effect.
The present chapter highlights the options for prophylaxis and desensitization in MIH-affected patients.
10.1 General recommendations for prophylaxis
Effective prophylaxis in children affected by MIH implies the development of an individually adapted therapeutic concept immediately after diagnosis, depending on the severity of the affected teeth.2 The caries risk, the severity and extent of MIH, any posteruptive enamel breakdown, and the clarification of pain symptoms must be taken into account (Fig 10-1).
On the basis of these findings, recall appointments can then be made for check-ups and close monitoring so that any enamel breakdown or complications can be detected immediately without much loss of time. This will only work, however, if the patient and parents are fully informed about the disease and the possible consequences and also report for check-ups themselves if necessary. Ideally, prevention will then be so successful that no secondary caries and no enamel loss will have occurred at the check-up appointments.3
10.1.1 Prophylaxis at home
At home, the recommendations applicable from caries prophylaxis should first be adopted: according to these, teeth should be brushed twice a day from the age of 6 with a fluoride toothpaste containing at least 1450 ppm fluoride.4 In addition to particularly careful oral hygiene, attention should also be paid to a tooth-healthy diet.
Some authors recommend the additional home use of a CPP-ACP (casein phosphopeptide amorphous calcium phosphate) paste or sugar-free chewing gum as a source of bioavailable calcium and phosphate for erupting MIH teeth and to support mineralization and desensitization.5–7 Clinical information in this regard is limited.4 The exact effect and the current study situation on this are described in Section 10.2.2.
10.1.2 Prophylaxis in practice
In children with an increased caries risk, a high-dose fluoride varnish is applied to the teeth in a dental practice at risk-dependent time intervals.8 Application is recommended two to four times a year; in individual cases, this may be more frequent.9,10 The main advantage of fluoride varnishes is the slow release of fluoride, but also the ease of application and the independence of the method from patient compliance.
The indication of additional measures (eg, professional tooth cleaning, chlorhexidine, and/or xylitol to reduce the infection level of caries-relevant bacteria) results from the respective findings of the individual risk diagnostics. Furthermore, regular professional plaque removal is important, as plaque accumulation may increase on the partially rough enamel surfaces (Fig 10-2).
In the case of intact surfaces, fissure sealants can be applied as part of caries prophylaxis or also for the therapy of hypersensitivities (see Chapter 11).
10.2 Remineralization and therapy of hypersensitivity
aboratory and clinical studies indicate that remineralization of MIH teeth after eruption appears to be clinically possible, but complete elimination of symptoms is not always achievable due to the extent, depth, and thickness of the lesions.6,7,11 In an effort to remineralize MIH-affected teeth and reduce hypersensitivity (if any), a variety of materials have been investigated. However, scientific evidence of the efficacy of these therapeutic approaches is still limited to date.
10.2.1 Fluorides
Treatment with fluoride still represents the “gold standard” in caries prophylaxis.12 A significant mechanism of action lies in the formation of a calcium fluoride covering layer on the tooth surface. Calcium ions originating from the tooth react with fluoride – preferably at acidic pH values. The resulting calcium fluoride or calcium fluoride-like material is precipitated on the tooth surface in the form of globules.13 The surface layer gains its great importance from the fact that it dissolves again when the pH value is low. It releases calcium and fluoride. The fluoride can then develop its remineralizing effect.14
The promotion of remineralization due to fluoride and its importance in posteruptive enamel maturation naturally also occur in MIH-affected teeth.
The effect of fluoride has additionally been proven in the therapy of tooth hypersensitivity.15 For this reason, it can be assumed that fluoride also helps in the treatment of hypersensitivity in MIH. However, the study situation in this regard is still insufficient. An in vivo study that focused on the treatment of hypersensitive MIH molars failed to observe any effect of fluoride.16