Clinical, microbiological, and immunological evaluation of patients in corrective orthodontic treatment.

BACKGROUND: The objective was to analyze clinical, microbiological, and immunological periodontal parameters in patients in corrective orthodontic treatment. MATERIALS AND METHODS: Twenty-eight patients were selected. Plaque index (PI), bleeding on probing (BOP), width of keratinized gingiva, levels of 40 bacterial species, and of 3 cytokines (IL-1ß, MMP-8, and TNF-α) in gingival crevicular fluid (GCF) were evaluated at T0, before orthodontic treatment; T1, 6 months; and T2, 12 months post-treatment. Non-parametric, Friedman, Wilcoxon, ANOVA, and Spearman correlation coefficient tests were used for statistical analyses, with the significance level of 5%. RESULTS: No significant difference was found for the width of keratinized gingiva, but PI presented a significant increase at T1 and T2 (p < 0.05) when compared with T0. The percentage of sites with BOP increased significantly from T0 to T1 (p < 0.05); however, at T2, the values decreased and did not differ anymore from T0 (p > 0.05). In the microbiological analysis, red complex pathogens were in significantly greater proportions in T2 compared with T0 (p < 0.05). There was no statistically significant difference in the cytokine levels between the periods but there was a positive correlation between BOP and IL-1ß (r = 0.49 p = .01) and TNF-α (r = 0.39 and p = .05). CONCLUSION: In conclusion, corrective orthodontic treatment caused clinical periodontal alterations regarding biofilm accumulation and gingival bleeding, with alteration of periodontopathogens.

Quantification of Streptococcus mutans in Different Types of Ligature Wires and Elastomeric Chains.

This study aimed to test the hypothesis that Streptococcus mutans contamination levels differ according to the type of the orthodontic ligature. Thirteen patients were selected. Each quadrant was randomly subjected to one of the following ligature-use protocols: I) elastomeric chain, II) steel ligature crossed over the archwire, III) steel ligature crossed under the archwire, and IV) steel ligature in a figure-eight pattern under the archwire. After seven days, the devices were removed and the Streptococcus mutans colony-forming unit count per mg of biofilm weight was determined. Twelve specimens (n=3) were also processed for scanning electron microscopy analysis. ANOVA and Tukey-Kramer test were used for comparisons to assess S. mutans differences between groups at a 5% significance level. There was no statistical difference in detectable levels of S. mutans among the groups (p=0.294). Scanning electron microscopy results showed abundant biofilms and microbial contamination in all groups. In conclusion, S. mutans contamination levels are similar in the different orthodontic ligatures.

Quantification of Streptococcus mutans in Different Types of Ligature Wires and Elastomeric Chains

Abstract This study aimed to test the hypothesis that Streptococcus mutans contamination levels differ according to the type of the orthodontic ligature. Thirteen patients were selected. Each quadrant was randomly subjected to one of the following ligature-use protocols: I) elastomeric chain, II) steel ligature crossed over the archwire, III) steel ligature crossed under the archwire, and IV) steel ligature in a figure-eight pattern under the archwire. After seven days, the devices were removed and the Streptococcus mutans colony-forming unit count per mg of biofilm weight was determined. Twelve specimens (n=3) were also processed for scanning electron microscopy analysis. ANOVA and Tukey-Kramer test were used for comparisons to assess S. mutans differences between groups at a 5% significance level. There was no statistical difference in detectable levels of S. mutans among the groups (p=0.294). Scanning electron microscopy results showed abundant biofilms and microbial contamination in all groups. In conclusion, S. mutans contamination levels are similar in the different orthodontic ligatures.

Resumo Este estudo teve como objetivo testar a hipótese de que os níveis de contaminação de Streptococcus mutans diferem de acordo com o tipo de ligadura ortodôntica. Treze pacientes foram selecionados. Cada quadrante foi submetido aleatoriamente a um dos seguintes protocolos de uso de ligadura: I) ligadura elastomérica, II) ligadura de aço trançada sobre o arco, III) ligadura de aço trançada sob o arco e IV) ligadura de aço em um padrão de "oito" sob o arco. Após sete dias, os dispositivos foram removidos e a contagem das unidades formadoras de colônia de S. mutans por mg de peso de biofilme foi determinada. Doze espécimes (n = 3) também foram processados para análise por microscopia eletrônica de varredura. Análise de variância e teste de Tukey-Kramer foram utilizados para comparações a fim de avaliar as diferenças de níveis de S. mutans entre os grupos com significância de 5%. Não houve diferença estatisticamente significante em níveis detectáveis de S. mutans entre os grupos (p = 0,294). Os resultados da microscopia eletrônica de varredura mostraram biofilmes abundantes e contaminação microbiana em todos os grupos. Em conclusão, os níveis de contaminação de S. mutans são semelhantes nas diferentes ligaduras ortodônticas.

Microhardness of Enamel Adjacent to Orthodontic Brackets After CO2 Laser Irradiation and Fluoride Application

This study evaluated the effectiveness of carbon dioxide (CO2) laser combined or not with fluoride application on the surface microhardness of enamel adjacent to orthodontic brackets. Fifteen human molars were selected from which 30 enamel fragments measuring 4 mm2 were obtained. The fragments were embedded in PCV tubes with acrylic resin and prepared using water abrasive paper, felt disks and alumina. Orthodontic brackets cut in half were bonded to enamel and 3 microhardness readings were performed on the adjacent surface, as follows: initial, after cariogenic challenge and final. The specimens were divided into the following 3 groups (n=10): Group C: control, Group L: irradiated with CO2 laser, and Group FL: topical fluoride application and CO2 laser irradiation. After initial reading, the specimens were placed in a demineralizing solution for 32 h and the second reading was to verify if demineralization was uniform in all groups. After the treatments, the specimens were submitted to DES-RE cycling for 8 days followed by final surface microhardness reading. The data were analyzed statistically using ANOVA and Duncan test (α=0.05). At the final measurement Group FL obtained higher microhardness value than Groups C and L (p<0.05). Groups L and FL were statistically superior to Group C (p<0.05). Irradiation with CO2 laser around orthodontic brackets combined or not with topical fluoride application was effective to increase the surface microhardness of enamel.

Este estudo avaliou a eficácia do laser de CO2, associado ou não à aplicação de flúor na microdureza superficial do esmalte dentário adjacente a bráquetes ortodônticos. Foram selecionados 15 molares humanos, dos quais 30 fragmentos de esmalte com 4 mm2 foram obtidos. Os fragmentos foram incluídos em tubos de PVC, contendo resina acrílica, preparados usando lixas d'água e discos de feltro e alumina. Bráquetes ortodônticos cortados ao meio foram colados no esmalte e 3 leituras de microdureza foram realizadas na superfície adjacente: inicial, após desafio cariogênico e final. Os espécimes foram divididos em 3 grupos (n=10): Grupo C - Controle, Grupo L - irradiado com laser de CO2 e Grupo FL - aplicação tópica de flúor e irradiação com laser de CO2. Após leitura inicial, os espécimes foram colocados em solução desmineralizadora por 32 h e a segunda leitura foi realizada para verificar se desmineralização foi uniforme em todos os grupos. Após os tratamentos, os espécimes foram submetidos a ciclagem DES-RE durante 8 dias seguida da leitura da microdureza superficial final. Os dados foram analisdos estatisticamente utilizando ANOVA e o teste de Duncan (α=0,05). Na mensuração final o grupo FL obteve maior valor de microdureza que os grupos C e L (p<0,05). Os grupos L e FL foram estatisticamente superiores ao grupo C (p<0,05). A irradiação de laser de CO2 ao redor de bráquetes ortodônticos combinadas ou não à aplicação tópica de flúor foi eficaz no aumento da microdureza superficial do esmalte.

Tratamento da má oclusão de Classe II subdivisão com distalização assimétrica de molares superiores / Treatment od Class II malocclusion, subdivision with asymmetric distalization of upper molars

A má oclusão de Classe II é caracterizada pela posição distal da arcada inferior em relação à superior, com o centro da cúspide mesiovestibular do primeiro molar permanente superior ocluindo mesialmente ao sulco vestibular do primeiro molar permanente inferior. Sua origem pode ser esquelética, dentária ou uma combinação dos dois fatores. Essa má oclusão é dividida em divisão 1 e 2 e pode apresentar subdivisão. A Classe II subdivisão é encontrada em, aproximadamente, 50% dos casos de classe II de Angle, e é caracterizada pela distoclusão de somente um lado da arcada dentária, com o outro em relação de Classe I de molar. O diagnóstico dessa má oclusão deve ser criterioso para a elaboração de plano de tratamento adequado. Diante de uma má oclusão de Classe II subdivisão, deve-se verificar se a assimetria é dentária ou esquelética, e, quando dentária, se está localizada na arcada inferior ou superior. O tratamento das más oclusões de Classe II subdivisão é abrangente e pode envolver extrações, distalizações ou stripping - dependendo da idade do paciente, do tipo das características da má oclusão. Um dos fatores mais importantes no tratamento da Classe II subdivisão, além de finalizar com os caninos em chave de oclusão, é coincidir as linhas médias dentárias entre si, e elas com a linha média facial. O objetivo desse trabalho foi abordar as principais características da má oclusão de Classe II subdivisão com ênfase no diagnóstico e tratamento, e ilustrá-lo com o relato de dois casos clínicos.

Microhardness of enamel adjacent to orthodontic brackets after CO2 laser irradiation and fluoride application.

This study evaluated the effectiveness of carbon dioxide (CO2) laser combined or not with fluoride application on the surface microhardness of enamel adjacent to orthodontic brackets. Fifteen human molars were selected from which 30 enamel fragments measuring 4 mm2 were obtained. The fragments were embedded in PCV tubes with acrylic resin and prepared using water abrasive paper, felt disks and alumina. Orthodontic brackets cut in half were bonded to enamel and 3 microhardness readings were performed on the adjacent surface, as follows: initial, after cariogenic challenge and final. The specimens were divided into the following 3 groups (n=10): Group C: control, Group L: irradiated with CO2 laser, and Group FL: topical fluoride application and CO2 laser irradiation. After initial reading, the specimens were placed in a demineralizing solution for 32 h and the second reading was to verify if demineralization was uniform in all groups. After the treatments, the specimens were submitted to DES-RE cycling for 8 days followed by final surface microhardness reading. The data were analyzed statistically using ANOVA and Duncan test (α=0.05). At the final measurement Group FL obtained higher microhardness value than Groups C and L (p<0.05). Groups L and FL were statistically superior to Group C (p<0.05). Irradiation with CO2 laser around orthodontic brackets combined or not with topical fluoride application was effective to increase the surface microhardness of enamel.