ABSTRACT
Aim: To evaluate the force decay of orthodontic elastomeric chains after immersion in disinfecting solutions. Methods: One-hundred and fifty segments of elastomeric chains were divided in 3 groups: Control group - no disinfection; Chlorhexidine group - disinfection in 0.12% chlorhexidine digluconate solution; and Peracetic acid group - disinfection in 0.2% peracetic acid solution. Elastomeric chains of 14 mm were stretched up to 20 mm and the given force (kgf) was evaluated in an Instron universal testing machine at the following intervals: 1 h, 1 day, 7, 14, 21 and 28 days after the immersion in the disinfecting solutions. Data (kgf) were analyzed statistically by Analysis of Variance and Tukey's test at a 5% significance level. Results: Both groups presented similar force decay along 7 days and remained stable up to 28 days. Force degradation was observed in the first hours of activation (~50%). Conclusions: It may be concluded that there were no significant differences among the investigated groups, in most interval times, indicating that both chemical solutions can be used for previous disinfection of orthodontic elastomeric chains.
Subject(s)
Peracetic Acid , Chlorhexidine , Disinfection , Orthodontic Space ClosureABSTRACT
A grande dependência da colaboração do paciente quanto ao uso de acessóriospara o tratamento das más-oclusões da Classe II tem gerado a procura por dispositivos mecânicos fixos que excluam esse fator. O ressurgimento do aparelho de Herbst, no finalda década de 1970, impressionou os profissionais da área pelos resultados obtidos com o mesmo, apesar da complexidade de sua instalação, do envolvimento laboratorial e doseu custo. Devido a isto, foram lançadas várias propostas de dispositivos de conceito mecânico semelhante, entre as quais a de Coelho Filho, com o seu Aparelho de Protração Mandibular (APM), que reunia características bastante atraentes como custo baixo, possibilidade de fabricação pelo próprio ortodontista ou seus auxiliares, fácil e rápida instalação e não necessitar de envolvimento laboratorial especializado, além de poder ser utilizado concomitantemente com o aparelho ortodôntico pertencente a qualquer técnica. Entre as alterações dentoalveolares e esqueléticas que possam ser responsáveis pela correção das más-oclusões da Classe II com os aparelhos ortopédicos fixos, somente o aspecto sagital foi extensivamente estudado, existindo carência de trabalhos de avaliação do aspecto vertical, com ênfase especial na divergência facial, cujo aumento é a constante preocupação no tratamento da Classe II. O presente trabalho avaliou as alterações lineares e angularesrelacionadas à divergência facial ocorridas após o tratamento com o Aparelho de Protração Mandibular em 33 pacientes adultos, de ambos os gêneros, após um tempo médio de nove meses de utilização, concluindo-se que o APM não interfere na divergência facial.
The need for patient compliance in wearing accessories during the treatment of Class II malocclusions has led professionals to look for appliances that may exclude such factor. The reappearance of the Herbst appliance in the 70's impressed for the resultsobtained, regardless of its difficult installation, laboratory need and its cost. Hence, several other appliances were proposed to override those aspects, among which was the MandibularProtraction Appliance by Coelho Filho, that included appealing characteristics such as low cost, option of being fabricated by the professional himself or his auxiliary personnel, besides compatibility with fixed appliances belonging to any technique. Most studies on the skeletal and dentoalveolar alterations resultant from the use of orthopedic fixed appliances were directed mainly to the sagital aspect, with very little focus on the vertical modifications and their rettex on facial divergence, which constitutes one of the main concerns during the treatment of Class II malocclusion. The present study analyzed the linear and angular cephalometric alterations linked to facial divergence that occurred after the use of the Mandibular Protraction Appliance in thirty-three adult patients of both sexes after an average period of nine months. It was concluded that the MPA do not compromise facial divergence.