Efeitos da colagem do esporão lingual no microambiente periodontal e liberação de subprodutos de materiais resinosos no tratamento de mordida aberta anterior em crianças

Abstract

Introduction: The passive spur orthodontic appliance is a method used in children to correct anterior open bite. To fix these teeth accessories, it is necessary to use resinous materials that can release toxic by-products such as BisGMA and TEGDMA. In addition, orthodontic tooth movement can increase the concentration of interleukins in the gingival crevicular fluid (FCG). The release of resinous by-products in the treatment of open bite and the behavior of interleukin expression are not yet elucidated in the literature. Objective: (1) to evaluate the expression of cytokines in the FCG in children with open bite who received spur fixation as treatment and (2) to quantify the BisGMA and TEGDMA in the saliva of these patients; and (3) evaluate the migration and viability of human ketarinocytes exposed to the resin. Methods: Patients from the FO-UFMG clinic who presented anterior open bite were selected. The spurs were bonded and the excess resin was removed. Clinical and periodontal examinations were performed on the upper and lower incisors, collections of the FCG (before bonding - baseline, 24 h and 7 d after) and saliva (baseline, 30 min, 24 h and 7 d after bonding). The FCG cytokines were analyzed using the BD ™ Cytometric Bead Array and the saliva samples, using the high performance liquid chromatography method. For in vitro analysis, immortalized HaCat cells were treated with culture medium conditioned with increments of the resin system in 3 different dilutions and then the viability and cell migration tests were performed. Results: The in vivo study showed that there was an increase in gingival bleeding in the lower incisors after 7d when compared to the baseline and that this index was higher in the lower than in the upper teeth. At 24h and 7d after spur fixation, IL-8 levels in the upper incisors were increased. At 7d, the concentration of IL-1β was increased compared to the baseline in the two groups of teeth. Comparing the upper and lower incisors, the levels of IL-8, IL-1β and IL-6 were higher in those above 24h. Cytokine production could be positively correlated with increased FCG volume. There was an increase in the levels of BisGMA and TEGDMA in saliva in 30 minutes, with a reduction in levels in 24h and 7d. The in vitro results demonstrated an increase in cell migration in keratinocytes exposed to conditioned media even in low concentrations. Conclusion: It was identified that after the gluing of the tongue spur there was an increase in the expression of interleukins in the FCG. In addition, it was possible to identify the release of resinous by-products in children's saliva. Although they can interfere with cell migration, there are no studies that quantify the minimum exposure capable of inducing changes in the individual. Therefore, the benefits of spur bonding override its adverse effects.