[Comparative study on the treatment of molar-incisor hypomineralization]

This study aimed to evaluate the efficacy of different treatment methods on local plaque lesions of incisors and the sealing of pits and fissures in first permanent molars in patients with mild molar-incisor hypomineralization (MIH).

Patients clinically diagnosed with mild MIH were selected as research subjects for a prospective clinical comparative study on the treatment of local plaque lesions in incisors and the pits and fissures of first permanent molars. Infiltrative resin and fluoride varnish were used to treat local plaque lesions on incisors. The area of local plaque lesions on incisors and lightness (L), red-green hue (a), and yellow-blue hue (b) of the lesion area were measured before treatment and at 1, 3, and 6 months after treatment. The color difference value (ΔE) and tooth whiteness index (WI_D) were then calculated. Two methods, phosphoric acid etching pit and fissure sealing and self-etching pit and fissure sealing, were used for the treatment of pits and fissures of first permanent molars. The incidence rate of caries, sealant retention rate, and success rate of pit and fissure sealing for the two methods were calculated at 1, 3, and 6 months after treatment.

In patients with mild MIH, local plaque lesions on incisors exhibited a significant reduction in area at 1, 3, and 6 months post-treatment in the infiltrative resin group (P<0.05), whereas no significant change was observed in the fluoride application group (P>0.05). After infiltrative resin treatment, the L value and ΔE value showed a decreasing trend (P<0.05), whereas the L value in the fluoride application group did not change significantly (P>0.05). In patients with first permanent molars, the phosphoric acid etching pit and fissure sealing group exhibited superior success and retention rates at 6 months post-treatment compared with the self-etching pit and fissure sealing group (P<0.05) and a lower loss rate than the self-etching pit and fissure sealing group (P<0.05).

Infiltrative resin treatment can reduce the L value and ΔE value of local plaque lesions on incisors in patients with mild MIH. It demonstrates a significant improvement in plaque lesion area, with relatively stable effects within 6 months. Phosphoric acid etching is recommended for the pit and fissure sealing of first permanent molars in patients with mild MIH.