Biodegradação de braquetes ortodônticos: avaliação da liberação iônica in vitro

Dolci, Gabriel Schmidt; Menezes, Luciane Macedo de; Souza, Rodrigo Matos de; Dedavid, Berenice Anina

doi:10.1590/s1415-54192008000300010

Cited by 6 publications

(5 citation statements)

References 22 publications

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“…20 Also, it should be noted that the superficial homogeneity of metal alloy constituent of orthodontic accessories is an important factor in the prevention of the corrosive process, which has become a topic of interest in orthodontic literature. 6 The qualitative analysis of surface characteristics of wires showed no significant differences between the groups studied (Fig 3), which is a result that was confirmed by the analysis of roughness (Table 6). This consistency between the results obtained by the two different methodologies (SEM and the Roughness Tester) confirms the effectiveness of visual analysis regarding surface characteristics by means of Scanning Electron Microscopy, in accordance with the findings of Menezes et al 17 and Chappard et al 23 The standardization of bracket slot sizes seems essential to consolidate certain technological advances, such as the clinical option of using the straight wire technique.…”

Section: Methodssupporting

confidence: 66%

“…5 Preliminary studies indicate that less homogenous surface characteristics of orthodontic wires are those that have greater surface roughness, which generates more friction in the bracket/wire interface. 5 In addition, orthodontic accessories with less homogenous surfaces tend to be more susceptible to corrosion, 6 which increases the risk of tissue damage, esthetic changes (staining of the tooth by corrosive products) and loss of metal properties.…”

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Assessment of the dimensions and surface characteristics of orthodontic wires and bracket slots

Dolci

Spohr

Zimmer

et al. 2013

Dental Press J. Orthod.

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Objective: The purpose of this study was to evaluate the dimensions and surface characteristics of orthodontic wires and bracket slots of different commercial brands. Methods: Thirty metallic brackets (0.022 x 0.028-in and 0.022 x 0.030-in) were divided in three groups: DYN/3M group = Dyna-Lock, 3M/Unitek (stainless steel, or SS); STD/MO group = Slim Morelli (SS); and Ni-Free/MO group = Slim Morelli (Ni-Free). The stainless steel wires (0.019 x 0.025-in) were divided into two groups: MO group = Morelli; and 3M group = 3M/Unitek. The bracket and wire measurements were done by two methods: (a) Surface Electron Microscopy (SEM), and (b) Profile projection. The surface analysis was done qualitatively, based on SEM images and/or by a rugosimeter. The quantitative results were analyzed by ANOVA with Tukey's test (p < 0.05) and Student's t test. Results: A significant difference in the dimensions of slots was observed, and the NiFree/MO group showed the greatest changes when compared to the other groups. The analysis of surface topography of the brackets indicated greater homogeneity of the metallic matrix for DYN/3M and STD/MO groups. As for the dimensions of the wires, groups showed statistically different mean heights. Conclusions: It was concluded that wires and brackets slots can present altered dimensions, which might directly and unintentionally affect the planned tooth movement.Keywords: Orthodontic brackets. Orthodontic wires. Friction.Objetivo: o objetivo desse estudo é avaliar as dimensões e as características superficiais de fios retangulares e slots de braquetes de diferentes marcas comerciais. Métodos: trinta braquetes metálicos (0,022" x 0,028'' e 0,022'' x 0,030'') foram divididos em três grupos: Grupo DYN/3M = Dyna-Lock, 3M/Unitek, aço inoxidável (AI); Grupo STD/MO = Slim Morelli (AI); e Grupo NiFree/MO = Slim Morelli (Ni-Free). Já os fios retangulares (0,019" x 0,025''), de aço inoxidável, foram divididos em 2 grupos: Grupo MO = Morelli; Grupo 3M = 3M/Unitek. As mensurações dos slots dos braquetes e dos fios foram realizadas por dois métodos: (a) microscopia eletrônica de varredura (MEV), e (b) projeção de perfil. A análise da topografia superficial foi realizada qualitativamente, baseada em imagens microscópicas (MEV) e/ou por meio de um rugosímetro. Os resultados quantitativos foram submetidos à análise de variância (ANO-VA) com o teste de Tukey (p < 0,05) ou o teste t de Student. Resultados: observou-se diferença significativa entre as dimensões dos slots dos braquetes, sendo que o Grupo NiFree/MO apresentou a maior alteração quando comparado aos demais Grupos. A análise da topografia superficial dos braquetes indicou maior homogeneidade da matriz metálica nos Grupos DYN/3M e STD/MO. Quanto às dimensões dos fios, os grupos tiveram alturas médias estatisticamente diferentes entre si. Conclusão: concluiu-se que a conformação dos fios e dos slots dos braquetes pode apresentar alterações dimensionais, o que afetará direta e indesejavelmente o movimento dentário planejado.Palavras-chave: Braquetes ortod...

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Section: Methodssupporting

confidence: 66%

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Assessment of the dimensions and surface characteristics of orthodontic wires and bracket slots

Dolci

Spohr

Zimmer

et al. 2013

Dental Press J. Orthod.

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“…15,19 Variation on chemical composition and superficial aspect of metallic brackets 2 and their biodegradation before different stimulus 5,10 have been described in literature. Studies have shown that, in an acid environment and in presence of fluoride ions the resistance to corrosion of certain materials may deteriorate.…”

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Evaluation of ionic degradation and slot corrosion of metallic brackets by the action of different dentifrices

Brandão

Simas²,

Almeida³

et al. 2013

Dental Press J. Orthod.

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How to cite this article: Brandão GAM, Simas RM, Almeida LM, Silva JM, Meneghim MC, Pereira AC, Almeida HA, Brandão AMM. Evaluation of ionic degradation and slot corrosion of metallic brackets by the action of different dentifrices. Dental Press J Orthod. 2013 Jan-Feb;18(1):86-93. » The authors report no commercial, proprietary or financial interest in the products or companies described in this article. Objective: To evaluate the in vitro ionic degradation and slot base corrosion of metallic brackets subjected to brushing with dentifrices, through analysis of chemical composition by Energy Dispersive Spectroscopy (EDS) and qualitative analysis by Scanning Electron Microscopy (SEM).Methods: Thirty eight brackets were selected and randomly divided into four experimental groups (n = 7). Two groups (n = 5) worked as positive and negative controls. Simulated orthodontic braces were assembled using 0.019 x 0.025-in stainless steel wires and elastomeric rings. The groups were divided according to surface treatment: G1 (Máxima Proteção Anticáries introduction Deterioration and corrosion of orthodontic appliances is a concern for orthodontists in their clinical practice. This attention is focused in two main questions: If the corrosion by products, whether they are produced, are absorbed by the organism and can cause local or systematic effects; and which effects the corrosion has on the physical properties and clinical performance of orthodontic appliances. There are evidences that support the deleterious effects of the buccal environment on structural alterations of metallic biomaterials.23 Eliades et al 6,7 tested orthodontic materials and did not find ion release by nickel-titanium alloys, but observed levels of nickel and chromium released by stainless steel alloys. No material was mentioned as cytotoxic, probably due low quantity of released ions or for the way they link.The several appliances (brackets, arch wires, etc.) used during orthodontic treatment to obtain the dental movement are composed of materials with distinct physical integrity, structural compositions and mechanical properties. Their requirements are complex for they are put under many stresses in the oral environment. This includes immersion in saliva and ingested liquids, temperature variation, mastication efforts and the loading submitted to the appliances. The combination of these materials and hostile conditions provided by the environment can result in corrosion, ion release and deterioration of these appliances. The interactions that these corrosion by products can have on the manifestation of local or systematic problems in the individual's health is not well corroborated and comprehended in literature, 3,4,11 despite numerous case reports of hypersensitivity to nickel 13,21 and alterations on the ionic concentration of body fluids.

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“…Na literatura, é grande a diversidade de trabalhos com enfoque na liberação de íons metálicos de braquetes ortodônticos -principalmente ferro, cromo e níquel, que representam os principais produtos da corrosão do aço inoxidável 8,19,44,53,64,74 . Entretanto, de acordo com o International Register of Potentially Toxic Chemical of United Nations Environment Program, outros íons metálicos, presentes na solda de prata utilizada na aparelhagem ortodôntica -como o cádmio, o cobre e o zinco -podem ser liberados na cavidade bucal e já são considerados produtos químicos potencialmente perigosos, sendo incluídos na lista de substâncias e processos considerados de grande risco para a vida humana.…”

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