Influence of photobiomodulation on pain perception during initial orthodontic tooth movement / Influência do fotobiomodulação na percepção da dor durante o movimento ortodôntico inicial

Introduction: Laser in low intensity (LLI) has been used to reduce the discomfort and pain that is triggered by the forces applied during orthodontic treatment. Objective: To evaluate the effect of LLI application in the pain perception of periodontal ligament initial compression, during orthodontic tooth movement; and to compare the effect of this therapy between men and women. Material and method: The sample consisted of 30 volunteers, who needed orthodontic band placement on mandibular first molars. After insertion of the elastic separators, LLI was applied to the mesial and distal apical region (wavelength 808nm, energy 2J, time 20s and fluency of 8.32J/cm2) and at three points on the root region (wavelength 808nm, energy 1J, time 10s and fluency of 4.16J/cm2) of the first molar (irradiated side) and compared to the contralateral first molar (non-irradiated side), in three time intervals: 0hs, 24hs and 48hs. Pain perception was evaluated by the Visual Analog Scale (VAS), at 0hs, 24hs and 48hs after insertion, with significance of 5%. Result: The pain level was observed to be significantly lower (p<0.05) on the irradiated side, irrespective of gender and time. Women presented a significantly higher pain level (p<0.05) than men, irrespective of time and side. There were no significant differences between the time intervals (p>0.05). Conclusion: It was concluded that LLI reduced the perception of initial pain in patients in whom compression of the periodontal ligament was promoted by elastic separation, and that women had a greater perception of pain sensitivity in the time intervals studied.

Introdução: O tratamento com Laser em Baixa Intensidade (LBI) tem sido utilizado para reduzir o desconforto e a dor desencadeados pelas forças aplicadas durante o tratamento ortodôntico. Objetivo: Avaliar o feito da aplicação de LBI na percepção da dor na compressão inicial do ligamento periodontal durante o movimento dentário ortodôntico; e comparar o efeito desta terapia entre os sexos. Material e método: A amostra foi composta por 30 voluntários, que necessitavam de bandagem dos primeiros molares inferiores. Após a instalação dos elásticos separadores, aplicou-se o LBI infravermelho na região apical mesial e distal (comprimento de onda 808nm, energia 2J, tempo 20s e fluência de 8,32J/cm2) e em três ponto na região radicular (comprimento de onda 808nm, energia 1J, tempo 10s e fluência de 4,16J/cm2) no lado irradiado e comparou-se com o primeiro molar contralateral não irradiado (lado controle), em três tempos: 0hs, 24hs e 48hs. A percepção de dor foi avaliada pela interpretação da Escala Visual Analógica (EVA) em 0hs, 24hs e 48hs após a instalação, com nílvel de significância de 5%. Resultado: Observou-se que o nível de dor foi significativamente menor (p<0,05) no lado irradiado, independentemente do sexo e do tempo. O sexo feminino apresentou nível de dor significativamente maior (p<0,05) que o sexo masculino, independentemente do tempo e do lado. Não houve diferença significativa entre os tempos (p>0,05). Conclusão: Concluiu-se que o LBI diminui a percepção de dor inicial em pacientes onde se promoveu a compressão do ligamento periodontal por meio de separação elástica, e que o sexo feminino apresentou maior percepção da sensibilidade dolorosa nos tempos observados.

Comorbidity of TMD and malocclusion: impacts on quality of life, masticatory capacity and emotional features

Aim: to evaluate the synergic impact of muscular TMD and malocclusion on quality of life, masticatory capacity and emotional features of young adults. Methods: this cross-sectional study comprised 4 groups (n= 15): G1, individuals without TMD or malocclusion; G2, with TMD and malocclusion; G3, with TMD and without malocclusion, and G4, without TMD and with malocclusion. Muscular TMD was diagnosed by RCD/TMD. Data included quality of life (OHIP-14), masticatory capacity test (X50), emotional stress (PSS-14), depression (MDI), pain intensity and salivary cortisol. Comparative statistical analysis included One-way ANOVA and Tukey post hoc test (X50, stress and cortisol) and GENMOD followed by Wald test (OHIP-14 and pain data). Fisher's and Pearson's association analysis were carried out. Results: Comorbidity of muscular TMD and malocclusion leads to significant lower masticatory capacity (p<0.05). TMD groups independently of the occlusal condition had considerably lower OHIP-14 scores and higher stress levels (self-perceived and hormonal) (p<0.05). There was no statistically significant difference of emotional depression among groups. A significant positive correlation was observed among quality of life, stress and pain perception. Conclusion: muscular TMD in the overlap of malocclusion potentializes their negative effect on masticatory capacity. In addition, the hindering effect of the comorbidity is variable, however, TMD has a greater negative impact on quality of life and stress, whilst malocclusion on mastication

Evaluation of friction in metal, ceramic and self-ligating brackets submitted to sliding mechanics / Avaliação do atrito em braquetes metálicos, cerâmicos e autoligados submetidos à mecânica de deslizamento

Objective: With the purpose of evaluating the best results for a proposed orthodontic treatment, the aim of this research was to verify the frictional force between archwires and orthodontic brackets in sliding mechanics. Material and method: Three different types of brackets were used: conventional metal, self-ligating metal and conventional polycrystalline esthetic type (n=10), totaling 30 brackets and .019 x .025 inches stainless steel rectangular wire. An acrylic plate was used. The wire was fixed to the brackets (conventional metal and conventional polycrystalline esthetic) with esthetic elastomeric ligation. The acrylic plate together with the 019 x 0.025 inches wire fitted to it was attached to the base plate of the Instron 4411 universal test machine so that it was positioned perpendicular to the ground. The bracket was drawn through the archwire segment at a speed of 5 mm / minute for a distance of 5 mm. For each type of bracket, ten tests were performed, with the bracket and archwire set being changed for each repetition. Data were analyzed by one-way Analysis of Variance (p <0.0001) and the Tukey Test (p <0.05). Result: Convencional metal and self-ligating brackets presented similar friction (p>0.05), while ceramic bracket presented higher frictional resistance during sliding test (p<0.05). Conclusion: It was concluded that the type of bracket influenced the frictional force value obtained, and better results were found when the metal and self-ligating brackets were used. The ceramic bracket presented a higher frictional force value.

Objetivo: Visando avaliar os melhores resultados para um tratamento ortodôntico de premissa, esta pesquisa teve como objetivo verificar a força de atrito entre fio e braquetes ortodônticos na mecânica de deslizamento. Material e método: Foram utilizados três diferentes tipos de braquetes, sendo metálico convencional, metálico autoligado e estético policristalino convencional (n=10), totalizando 30 braquetes e fio retangular de aço inoxidável .019 x .025 polegadas. Foi utilizada uma placa de acrílico. O fio foi fixado aos braquetes (metálico convencional e estético policristalino convencional) com ligadura elastomérica estética. A placa de acrílico juntamente com o fio .019 x .025 polegadas montado foi fixada ao mordente da base da máquina de ensaio universal Instron 4411, de maneira que ficou posicionada perpendicular em relação ao solo. O braquete foi tracionado à velocidade de 5 mm/minuto através do segmento do fio por uma distância de 5mm. Para cada tipo de braquete foi realizado dez testes havendo a troca do conjunto braquete e fio em cada repetição. Os dados foram analisados por Análise de Variância um fator (p<0,0001) e Teste de Tukey (p<0,05). Resultado: Braquetes metálicos convencionais e autoligáveis apresentaram atrito similar (p>0,05), enquanto braquetes cerâmicos apresentaram maior resistência ao atrito durante o teste de deslizamento (p<0,05). Conclusão: Conclui-se que o tipo de braquete influenciou no valor de atrito obtido, sendo que melhores resultados foram encontrados quando foram utilizados os braquetes metálicos e autoligados. O braquete cerâmico apresentou maior atrito.

Evidence of Heterokaryon compatibility on Candida albicans biofilm

Aims: Candida species, especially Candida albicans, are frequently found associated with biomaterials and immunosuppressed patients, and have been described as the most virulent yeasts in human fungi diseases. These yeasts have recently been isolated from periodontal pockets, revealing the penetration of hyphae into the periodontal connective tissue. Methods: In this study, 7 periodontal C. Albicans strains were applied individually in biofilm development on titanium discs and the samples were thereafter analyzed as for the number of colony forming units per milliliter (CFU/mL), dry-weight and scanning electron microscopy (SEM). Results: Counting of CFU/ mL and determination of dry-weight showed that all samples formed biofilm. SEM analysis showed the development of a polymorphic network in the biofilms and the presence of hyphal anastomosis in the sites where fusion between the hyphae occurred. Conclusion: periodontal C. albicans strains present heterokaryon compatibility.