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.

Relationship between maxillary canine intra-alveolar position and maxillary incisor angulation: a cone beam computed tomography study

The aims of the present study were to evaluate the angulation and inclination of permanent maxillary incisors and to correlate the results to the intra-alveolar permanent maxillary canine position during mixed dentition, using cone beam computed tomography (CBCT). The subjects were 30 children aged 7 to 10 years in the inter-transitory period of mixed dentition (permanent incisors and first molars erupted; primary canines, first and second molars erupted; and permanent canines intraosseous). The CBCT scans were obtained and, using the Dolphin Imaging® software - version 11.0, 3D images were reconstructed and the measurements were performed. The angulation of the right and left lateral and central maxillary incisors was measured in relation to the sagittal plane and their inclination was measured in relation to the coronal plane. The intra-alveolar height of the right and left maxillary canines was measured from the cusp tip to the axial plane. Pearson's correlation at 5 percent significance level showed positive correlation between the canine height and the lateral incisor angulation. It was concluded that the intra-alveolar position of the maxillary canines has a direct influence on the angulation of maxillary incisors, especially the lateral incisors.

Os objetivos deste estudo foram avaliar, por meio de tomografia computadorizada de feixe cônico (TCFC), a inclinação mésio-distal e vestíbulo-lingual dos incisivos permanente superiores e correlacionar os resultados com o posicionamento intra-ósseo do canino permanente superior na dentição mista. Foram selecionadas 30 crianças, entre 7 e 10 anos de idade, no período inicial de dentição mista, apresentando incisivos e primeiros molares permanentes erupcionados, caninos, primeiros e segundos molares decíduos presentes na cavidade bucal e caninos permanentes intra-ósseos. Foi realizada TCFC e com o software Dolphin Imaging®, versão 11.0 foi realizada a reconstrução em 3D destas imagens e feitas as medidas. A inclinação dos incisivos centrais e laterais superiores direito e esquerdo foi medida em relação ao plano sagital (angulação mésio-distal) e ao plano coronal (inclinação vestíbulo-lingual). A altura intra-óssea dos caninos superiores direito e esquerdo foi medida da ponta da cúspide ao plano axial. Para análise da correlação entre a angulação dos incisivos e altura dos caninos foi utilizado o teste de correlação de Pearson, ao nível de significância de 5 por cento. Pode-se concluir que a posição intra-óssea dos caninos superiores sugere influência direta na inclinação dos incisivos superiores, principalmente nos incisivos laterais.