Resumo Introdução A movimentação ortodôntica pode causar sintomatologia dolorosa, principalmente nas fases iniciais do tratamento. Objetivo Este estudo teve como objetivo comparar o desempenho da goma de mascar e do ibuprofeno no controle da dor durante o período inicial do tratamento ortodôntico. Material e método Foi desenvolvido um ensaio clínico randomizado cego, com razão de alocação de 1:1, com pacientes com idade ≥18 anos. O tamanho da amostra foi estabelecido considerando um nível de significância de 5% e poder do teste de 80%, resultando em um mínimo de 30 voluntários por grupo (n=90). Os participantes foram pareados quanto ao sexo, idade, gravidade da má oclusão, definida pelo Componente de Saúde Bucal (DHC) do Índice de Necessidade de Tratamento Ortodôntico (IOTN), e apinhamento, determinado pelo índice de irregularidade de Little. A amostra foi distribuída aleatoriamente em três grupos: Grupo I (controle) placebo; Goma de mascar Grupo II; e Grupo III Ibuprofeno. A percepção da dor foi avaliada pela Escala Visual Analógica (EVA) nas primeiras 24, 36 e 48 horas após a ativação do aparelho ortodôntico. Os dados foram analisados por modelos lineares generalizados para medidas repetidas no tempo. Resultado Não foi observada diferença estatisticamente significativa (p>0.05) entre os grupos para os métodos de terapia da dor avaliados em 24, 36 e 48 horas pós-ativação. Conclusão: Não houve diferença entre o método utilizado para controle da dor durante o tratamento ortodôntico.

Abstract Introduction Orthodontic movement can cause painful symptoms, especially in the early stages of treatment. Objective This study aimed to compare the performance of chewing gum and ibuprofen in pain control during the initial period of orthodontic treatment. Material and method A randomized blind clinical trial, with an allocation ratio of 1:1, was developed with patients aged ≥18 years old. The sample size was established considering a significance level of 5% and test power of 80%, resulting in a minimum of 30 volunteers per group (n=90). Participants were paired regarding sex, age, the severity of malocclusion, defined by the Dental Health Component (DHC) of the Index of Orthodontic Treatment Need (IOTN), and crowding, determined by Little’s irregularity index. The sample was randomly allocated to three groups: Group I (control) placebo; Group II chewing gum; and Group III Ibuprofen. Pain perception was evaluated by the Visual Analog Scale (VAS) in the first 24, 36, and 48 hours after activation of the orthodontic appliance. The data were analyzed by generalized linear models for repeated measures in time. Result No statistically significant difference (p>0.05) was observed among the groups for the methods of pain therapy evaluated in 24, 36, and 48 hours post-activation. Conclusion There was no difference among the method used for pain control during the orthodontic treatment.

In order to microscopically analyze the pulpal effects of orthodontic movement, 49 maxillary first molars of rats were submitted to orthodontic appliance composed of a closed coil spring anchored to the maxillary incisors, placed for the achievement of mesial movement. MATERIAL AND METHODS: Ten animals were used as the control group and were not submitted to orthodontic force; the other animals were divided into groups according to the study period of tooth movement, namely 1, 2, 3, 4, 5, 6 and 7 days. The investigation of pulp and periodontal changes included hyalinization, fibrosis, reactive dentin and vascular congestion. Statistical evaluation was performed between control and experimental groups and between periods of observation using non-parametric chi-square, Kruskal-Wallis and Dunn tests. RESULTS: There was no statistically significant difference concerning pulpal changes between control and experimental groups nor between periods of observation. The control group, at 3 and 5 days, revealed greater hyalinization of the periodontal ligament (p<0.05), whereas root resorption was significantly greater at 5 and 7 days (p<0.05). CONCLUSION: No morphological change from the effect of induced tooth movement could be found in the dentin-pulp complex. In addition, no inflammatory or pulp degeneration, detectable in optical microscopy, was found in experimental groups.