MIH hypoplstic enamel treated with a novel bioactive light-curing calcium-silicate material:SEM and case report

Objectives: MIH (molar-incisor-hypoplasia) is a frequent disease affecting the erupting permanent molars and incisors showing low level of calcium and phosphate. Clinical remineralizing therapies are required and tried out by clinicians (Baroni et al, 2010). Calcium-silicate materials has been recently proposed as dentine remineralizing materials. They are able to induce apatite deposits formation (Gandolfi et al, 2009, 2010). A novel bioactive light-curing calcium-silicate material has been recently designed (Gandolfi & Prati). This material adhere to the etched enamel surface and proved the ability to release calcium and to form apatite (Gandolfi et al, 2010). The goal of the study was to evaluate the effectiveness of the novel material in reducing incisors defects and improving the mineralization of MIH enamel lesion in children Materials and Methods: 8 children aged 6-9 with hypoplasic incisors (identified as white-yellow-brownish spots) were selected. The spots enamel surface were gently polished and etched with H3PO4 gel for 20 seconds, washed with water and air dried. A thin layer of the bioactive light-curing calcium-silicate material was applied on the spots with a small brush to completely cover the entire surface of the spot lesion, then light-cured for 120 seconds with a photo-curing unit (Anthos, Italy) and finally covered by orthodontic wax. The patients were recalled after 15 days. Clinical pictures and polyvinylsiloxane impressions were taken before and after the treatment and acrylic resin replicas were taken and observed by SEM. Results: SEM analysis before treatment shows a very clear demarcation between normal and hypoplasic enamel. At 35x magnification affected surfaces are overall characterized by porosities. At 500x the prismatic structure is present, but crystal organization in the affected tissue is lacking connections, resulting looser and less organized. At 35x magnification MIH affected incisor enamel treated with bioactive agent showed a smoother surface profile, difficult to distinguish from normal enamel. At 500x no porosities and irregularities were observed on enamel surface. After the treatment the white spots appeared clinically less evident. Conclusions: The calcium releasing of the novel material may create the local condition for the apatite formation inside the enamel porosities that is responsible for the reduction of the spot lesions with aesthetic and clinical advantage.