Breakdown of demarcated opacities related to molar-incisor hypomineralization: a longitudinal study.

Objectives: This prospective longitudinal study aimed to evaluate if the occurrence of post-eruptive breakdown of demarcated opacities in hypomineralized teeth is influenced by the color or location of the opacity.
Materials and Methods: Patients diagnosed with molar-incisor hypomineralization (MIH) between 2012 and 2014 were eligible. Two calibrated examiners performed the initial and follow-up evaluations according to European Academy of Paediatric Dentistry (EAPD) criteria. Sixty-five patients were included. Fifty-eight (89.2%), with a mean age of 8.8 years (SD: 1.4), were reassessed after 1 year. Two hundred and nine of 1155 tooth surfaces were considered for the study: 86 with white opacity (OP-W), 91 with yellow opacity (OP-Y), and 32 with enamel breakdown (EB).
Results: From the OP-W, OP-Y, and EB, 14, 27.5, and 46.9% worsened to breakdown exposing dentin, atypical restoration, or extraction (DB + RA or EXT), respectively. Yellow opacities tended to be more prone to breakdown than white opacities. The occurrence of EB, DB + AR, or EXT was not influenced by the location (p = 0.25).
Conclusions: The color of the opacity seems to play an important role on the occurrence of fracture and should be considered as a potential predictor.
Clinical Relevance: Dentists should be aware that demarcated opacities related to MIH tend to fracture over time. Moreover, children with MIH should be seen at shorter intervals.