Effectiveness of methods for cleaning arch wire: an in vitro study

The aim of this study was to evaluate various methods of removing bacterial and fungus biofilm, to simulate orthodontic arch wires cleaning before reinsertion in the patients appliance. Rectangular Nickel Titanium (NiTi), Stainless Steel (SS) and Titanium Molybdenum (TMA) wires were divided into five groups, then contaminated with strains of Streptococcus mutans and Candida albicas. Four segments of each group served as control and were not contaminated. Six cleanings methods were used to remove the biofilm: cotton roll and a chemical agent (chlorhexidine, sodium hypochlorite, 70% alcohol), cotton roll and water, steel woll and immersion on enzymatic detergent. There was a control group not decontaminated Then wires were placed in broth separately, and after an incubation period the optical density (OD) was measured, observing whether there was microbial growth. A wire segment of each subgroup of SS 3M® was taken to the Scanning Electron Microscope (SEM) for visualization of the treatment response. The results were submitted to one-way ANOVA test and Tukey post-test. With the exception of 70% alcohol, the disinfection means behaved similarly regardless the type of wire. Two percent Chlorhexidine and 1% Sodium Hypochlorite totally removed the microorganisms while other agents left a high microbial concentration. Chemical cleaning is necessary to remove biofilm in orthodontic wires; 1% Sodium Hypochlorite and 2% Chlorhexidine are good disinfectants for this purpose.

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.

Monitoreo bacteriológico del instrumental utilizado en la práctica clínica de ortodoncia / Bacteriologic monitoring of the instruments used in orthodontic clinical practice

El objetivo del trabajo fue verificar la efectividad de procedimientos de esterilización en el instrumental de ortodoncia el objetivo del trabajo fue verificar la efectividad de procedimientos de esterilización en instrumental de ortodoncia. Seesterilizaron 10 juegos de instrumentos compuestos por alicates How recto, alicates Weingart, alicates de corte, retractores acrílicos, bastones de ligaduras elastoméricas y rollos decadenas elastoméricas. esterilización previa al trabajo: en autoclavelos alicates, en óxido de etileno los elementos plásticos y elastoméricos. Post esterilización in situ: alicates enesterilizador a bolitas de cuarzo; elementos elastoméricos y plásticos aerolizados en glutaraldehido al 2 por ciento. Se tomaron muestras con tubos de hisopos estériles, en dos momentos, 1: previo a la atención al paciente y 2: después de esterilización in situ. los tubos con turbidez macroscópica se colorearon con gram y cultivaron en medios de maC ConKey y Clde. Para cuantificar la carga microbiana, se realizaron tres siembras por estrías con ansa calibrada. momento 1: se encontrócontaminación con Corynebacterium en alicates Weingart y con Staphylococcus coagulasa negativo en los rollosde cadena.momento 2: contaminación con Corynebacterium en retractores; con Staphylococcus coagulasa negativo en alicates de corte, en retractores acrílicos, en bastones de ligadura;con Micrococcus en alicates How rectos. La presencia de cargas bacterianas no satisfactorias sugiere que los procedimientos habituales de esterilización no fueron eficaces.