Avaliação de fatores preditores, do perfil microbiológico salivar e da ocorrência de fratura pós-eruptiva do esmalte em pacientes com hipomineralização de molares e incisivos

Abstract

The aim of the present study was to evaluate the etiology, microbiological profile and longitudinal follow up to observe molar-incisor hypomineralization (MIH) related factors, caries risk and clinical evolution of enamel defects. In the study 1 (case-control), the presence of deciduous molar hypomineralization (DMH) as a predictor for MIH was analyzed in 162 patients (65 case and 97 controls), with age between 5-12 years old, as well as the association between HMI and risk factors as low birth weight and antibiotics intake during the first year of life. As a result, DMH plays an important role as a predictor, increasing in 2.77 times de chance of MIH occurrence (95% CI: 1.20 6.39). Although MIH is more frequent in children with low birth weight (p: 0.0036), this factor could not increase significantly the chance of MIH occurrence (OR: 2.82; 95% CI: 1.00 7.66). Antibiotics intake during the first year of life showed an increased chance of MIH occurrence in 2.97 times (95% CI: 1.43 6.16). In the study 2, the analysis of caries risk in 20 patients with severe MIH (7-1 years old) was made to observe the association between Streptococcus mutans (SM) and Lactobacillus spp. counts, salivary flow and caries experience in deciduous teeth with DMF index. The study group showed 2.8 (SD: 1.1) and 7.3 (SD: 4.7) DMF-T and DMF-S, respectively. Each caries tooth had 2.5 (SD: 1.1) affected surface. Analyzing only the decayed component of DMF index, a mean of 1.9 (SD: 2.0) of decayed surface was observed. All patients showed good salivary buffer capacity and there were no statistical difference between DMF-T and DMF-S related to the variables. In study 3, MIH longitudinal evaluation was performed in 58 children with mean age of 8.8 years, observing the color, location and force incidence to estimate the risk of post-eruptive fracture in those affected teeth. Considering dentine fracture (FD) as outcome, 14% of white-cream (OP-BC), 26.9% of yellow-brown (OP-AM) opacities and 46.9% of enamel fracture broke. Progression was significantly frequent in OP-AM, compared to OP-BC, and highly significant when fracture was considered from FE (p<0.0003). Progression to FE was not statistically different between surfaces under masticatory forces or not for OP-BC (p=0.15), and for OP-AM (p=0.51). The same happened considering progression to FD in OP-BC (p=0.36), OP-AM (p=0.82) or FE (p=0.27). The chance of fracture occurrence from demarcated opacities was 3.55 (95% CI: 1.75 7.20) and 2.27 (95% CI: 1.06 4.86) times higher when OP-AM, considering FE and FD, respectively. Based on these results, MIH remains a challenge in clinical dentistry and the knowledge of these factors can help to establishment appropriated treatments and good prognosis.