Use of a Glass Ionomer Sealant in Molar Incisor Hypomineralization

Molar Incisor Hypomineralization (MIH) is a worldwide widespread qualitative developmental defect of the dental enamel with a multifactorial aetiology defined in 2001 as an "hypomineralization of systemic origin affecting one or more permanent molars, usually first permanent molars (FPMs), with or without the involvement of one or more affected permanent incisors". Clinically MIH lesions appear as demarcated opacities with a creamy-white to yellow-brown colour depending on the severity of the defect that is classified as mild or severe (levels of severity) according to the European Academy of Pediatric Dentistry (EAPD) severity criteria. The distribution of the lesions is asymmetrical and their severity varies from a patient to another and also within the mouth of the same patient. Due to its porous structure with an altered prism organization and an increased content of proteins, the hypomineralized enamel has reduced mechanical properties and a lower refractive index if compared to the sound enamel. MIH is associated to a large number of objective and subjective problems as an altered aesthetics, an increased risk of plaque accumulation, caries, post-eruptive breakdown (PEB), reduced retention rates of adhesive materials, hypersensitivity and difficulty in anesthetizing the affected teeth making its management a challenging condition. Among preventive measures, pit-and-fissure sealants are a valuable and effective treatment to prevent occlusal caries in FPMs when they are still intact. However, since their efficacy is closely related to the sealant retention, they have to be monitored over time. When the molar to be sealed is fully erupted and isolation is adequate, resin-based sealants are indicated while if the moisture control is inadequate and/or the tooth is hypersensitive and patient is not sufficiently cooperative, low-viscous glass ionomer cements (GICs) are suggested as a temporary measure until the eruption is completed and both symptoms and cooperation are improved. To date, the scientific knowledge regarding the use of different type of sealants in MIH affected molars is insufficient to draw exhaustive conclusions and further studies are needed to deepen the knowledge on this topic. The aim of this study is to assess, by clinical examination, the survival rate of a glass ionomer sealant in MIH affected FPMs at 12 months of follow-up.