Hipomineralização Molar-Incisivo (HMI): Consequências Clínicas e Estratégias de Tratamento.

Abstract

The objective of this work was to analyze the clinical consequences and treatments of teeth affected by Molar Incisor Hypomineralization through an overview, systematic literature review and in vitro study. In the first study, an overview of systematic reviews was performed to analyze the quality of available reviews on treatments for MIH. Two reviewers independently performed the selection, the quality assessment using the Assessment of Multiple Systematic Reviews 2 - AMSTAR-2 instrument and the risk of bias assessment using the Risk Of Bias In Systematic reviews (ROBIS) instrument. Study 2 aimed to answer the following research question: “What are the clinical consequences (outcome) of Molar Incisor Hypomineralization (MIH) (exposure) in children and adolescents (population/patient)?”. Cross-sectional studies that identified clinical consequences of MIH were selected. The risk of bias was assessed using the “Joanna Briggs Institute Critical Appraisal Checklist for Cross-sectional studies” protocol. Meta-analyses were performed calculating the prevalence for each of the clinical consequences found, considering both the number of patients and the number of teeth. Higgins and Thompson's I2 statistic was used to describe the proportion of observed heterogeneity due to actual variation in actual effect sizes and the predicted range to assess the dispersion of observed effect sizes, using Comprehensive Meta-Analysis V2.0 software. Study 3 analyzed the penetrability of enamel affected by MIH after treatment with resin infiltrant. The sample consisted of 12 teeth with the presence of opacities suggestive of MIH of different severities. After the clinical examination for diagnosis, the teeth were photographed and separated by severity levels, resulting in mild (white staining) and moderate/severe (yellow-brown staining) categories. Five teeth were randomly selected for analysis by Computerized Microtomography (MicroCT) in order to assess mineral density and confirm the initial clinical diagnosis (two teeth in the mild category and three in the moderate/severe category). After the analysis in MicroCT, qualitative analysis was performed with description of the images and quantitative analysis (Image J software) to evaluate the mineral density of DDEs, and finally the clinical diagnosis was confirmed. After this selection, three samples of each experimental condition were selected for examination under confocal microscopy, with the objective of qualitatively evaluating the penetration of the infiltrant in the opacities. For the accomplishment of this test, before the infiltration, the resinous infiltrant was mixed with 0.0001g of Rhodamina B in order to be detected in the analysis. After this mixing, the infiltration procedures were performed normally and a confocal laser microscope equipped with a 63x/.4 NA oil immersion lens, an Ar/Kr laser in 488-nm excitation mode (Fluorescein excitation), and a He/Ne laser in 568-nm excitation mode (Rhodamine B excitation) was employed for analysis. Study 1 concluded that the evidence supporting the effectiveness of MIH treatments is limited due to the methodological quality and risk of bias of the systematic reviews, as well as the quality of the primary studies included in them, thus, there is still not enough scientific evidence of good quality for the establishment of a clinical protocol for the treatment of this condition. In study 2, of the 903 studies obtained after the search, 41 were selected for qualitative analysis