Mechanical properties of NiTi and CuNiTi wires used in orthodontic treatment. Part 2: Microscopic surface appraisal and metallurgical characteristics.

OBJECTIVE: This research aimed at comparing the qualitative chemical compositions and the surface morphology of fracture regions of eight types of Nickel/Titanium (NiTi) conventional wires, superelastic and heat-activated (GAC, TP, Ormco, Masel, Morelli and Unitek), to the wires with addition of copper (CuNiTi 27ºC and 35ºC, Ormco) after traction test. METHODS: The analyses were performed in a scanning electronic microscope (JEOL, model JSM-5800 LV) with EDS system of microanalysis (energy dispersive spectroscopy). RESULTS: The results showed that NiTi wires presented Ni and Ti as the main elements of the alloy with minimum differences in their composition. The CuNiTi wires, however, presented Ni and Ti with a significant percentage of copper (Cu). As for surface morphology, the wires that presented the lowest wire-surface roughness were the superelastic ones by Masel and Morelli, while those that presented the greatest wire-surface roughness were the CuNiTi 27ºC and 35ºC by Ormco, due to the presence of microcavity formed as a result of pulling out some particles, possibly of NiTi4. The fracture surfaces presented characteristics of ductile fracture, with presence of microcavities. The superelastic wires by GAC and the CuNiTi 27ºC and the heat-activated ones by Unitek presented the smallest microcavities and the lowest wire-surface roughness with regard to fracture, while the CuNiTi 35ºC wires presented inadequate wire-surface roughness in the fracture region. CONCLUSIONS: CuNiTi 35ºC wires did not present better morphologic characteristics in comparison to the other wires with regard to surfaces and fracture region.

Mechanical properties of NiTi and CuNiTi wires used in orthodontic treatment. Part 2: Microscopic surface appraisal and metallurgical characteristics

OBJECTIVE: This research aimed at comparing the qualitative chemical compositions and the surface morphology of fracture regions of eight types of Nickel (Ni) Titanium (Ti) conventional wires, superelastic and heat-activated (GAC, TP, Ormco, Masel, Morelli and Unitek), to the wires with addition of copper (CuNiTi 27oC and 35oC, Ormco) after traction test. METHODS: The analyses were performed in a scanning electronic microscope (JEOL, model JSM-5800 LV) with EDS system of microanalysis (energy dispersive spectroscopy). RESULTS : The results showed that NiTi wires presented Ni and Ti as the main elements of the alloy with minimum differences in their composition. The CuNiTi wires, however, presented Ni and Ti with a significant percentage of copper (Cu). As for surface morphology, the wires that presented the lowest wire-surface roughness were the superelastic ones by Masel and Morelli, while those that presented the greatest wire-surface roughness were the CuNiTi 27oC and 35oC ones by Ormco, due to presence of microcavity formed as a result of pulling out some particles, possibly of NiTi. 4 The fracture surfaces presented characteristics of ductile fracture, with presence of microcavities. The superelastic wires by GAC and the CuNiTi 27oC and the heat-activated ones by Unitek presented the smallest microcavities and the lowest wire-surface roughness with regard to fracture, while the CuNiTi 35oC wires presented inadequate wire-surface roughness in the fracture region. CONCLUSION: CuNiTi 35oC wires did not present better morphologic characteristics in comparison to the other wires with regard to surfaces and fracture region. .

OBJETIVO: objetivou-se nessa pesquisa comparar as composições químicas qualitativas e as morfologias das superfícies e das regiões de fratura, após ensaios de tração, de oito tipos de fios de NiTi superelásticos e termoativados convencionais (GAC, TP, Ormco, Masel, Morelli e Unitek) aos fios com adição de cobre (CuNiTi 27°C e 35°C, da Ormco). MÉTODOS: as análises foram realizadas em microscópio eletrônico de varredura (JEOL, modelo JSM-5800 LV) com sistema de microanálise EDS (energy dispersive spectroscopy). RESULTADOS: os resultados mostraram que os fios de NiTi ensaiados apresentaram Ni e Ti como os principais elementos da liga, com diferenças mínimas em suas composições. Os fios de CuNiTi, por sua vez, apresentaram Ni e Ti, com percentual significativo de cobre (Cu). Em relação às morfologias das superfícies, os fios que apresentaram os melhores acabamentos foram os superelásticos da Masel e Morelli, e os que apresentaram os piores acabamentos foram os de CuNiTi 27°C e 35°C, da Ormco, graças à presença de microcavidades formadas devido ao arrancamento de partículas, possivelmente de NiTi 4 . As superfícies de fratura apresentaram características de fratura dúctil, com a presença de microcavidades. Os fios superelásticos da GAC e de CuNiTi 27°C, bem como os termoativados da Unitek, apresentaram as menores microcavidades e os melhores acabamentos à fratura, enquanto os fios de CuNiTi 35° apresentaram acabamentos inadequados das regiões de fratura. CONCLUSÃO: os fios de CuNiTi 35°C não apresentaram características morfológicas mais adequadas das superfícies e das regiões de fratura em relação aos demais fios. .

Mechanical properties of NiTi and CuNiTi shape-memory wires used in orthodontic treatment. Part 1: stress-strain tests.

OBJECTIVE: This research aimed to compare, through traction tests, eight types of superelastic and heat-activated NiTi archwires, by six trade companies (GAC, TP, Ormco, Masel, Morelli and Unitek) to those with addition of copper (CuNiTi 27°C and 35°C, Ormco). METHODS: The tests were performed in an EMIC mechanical testing machine, model DL10000, capacity of 10 tons, at the Military Institute of Engineering (IME). RESULTS: The results showed that, generally, heat-activated NiTi archwires presented slighter deactivation loadings in relation to the superelastic ones. Among the archwires that presented deactivation loadings biologically more adequate are the heat-activated by GAC and by Unitek. Among the superelastic NiTi, the CuNiTi 27°C by Ormco were the ones that presented slighter deactivation loadings, being statistically (ANOVA) similar to the ones presented by the heat-activated NiTi archwires from Unitek. When compared the CuNiTi 27°C and 35°C archwires, it was observed that the 27°C presented deactivation forces of, nearly, ⅓ of the presented by the 35°C. CONCLUSIONS: It was concluded that the CuNiTi 35°C archwires presented deactivation loadings biologically less favorable in relation to the other heat-activated NiTi archwires, associated to lower percentage of deformation, on the constant baselines of deactivation, showing less adequate mechanical behavior under traction, in relation to the other archwires.

Mechanical properties of NiTi and CuNiTi shape-memory wires used in orthodontic treatment. Part 1: stress-strain tests

OBJECTIVE: This research aimed to compare, through traction tests, eight types of superelastic and heat-activated NiTi archwires, by six trade companies (GAC, TP, Ormco, Masel, Morelli and Unitek) to those with addition of copper (CuNiTi 27ºC and 35ºC, Ormco). METHODS: The tests were performed in an EMIC mechanical testing machine, model DL10000, capacity of 10 tons, at the Military Institute of Engineering (IME). RESULTS: The results showed that, generally, heat-activated NiTi archwires presented slighter deactivation loadings in relation to superelastic. Among the archwires that presented deactivation loadings biologically more adequate are the heat-activated by GAC and by Unitek. Among the superelastic NiTi, the CuNiTi 27ºC by Ormco were the ones that presented slighter deactivation loadings, being statistically (ANOVA) similar, to the ones presented by the heat-activated NiTi archwires by Unitek. When compared the CuNiTi 27ºC and 35ºC archwires, it was observed that the 27ºC presented deactivation forces of, nearly, ⅓ of the presented by the 35ºC. CONCLUSION: It was concluded that the CuNiTi 35ºC archwires presented deactivation loadings biologically less favorable in relation to the other heat-activated NiTi archwires, associated to lower percentage of deformation, on the constant baselines of deactivation, showing less adequate mechanical behavior, under traction, in relation to the other archwires.

OBJETIVO: o objetivo dessa pesquisa foi comparar, por meio de ensaios de tração, oito tipos de fios de NiTi superelásticos e termoativados, de seis empresas comerciais (GAC, TP, Ormco, Masel, Morelli e Unitek) àqueles com adição de cobre (CuNiTi 27ºC e 35ºC, da ORMCO). MÉTODOS: os ensaios foram realizados em máquina de ensaios mecânicos, da marca EMIC, modelo DL10000, de 10 toneladas de capacidade, no Instituto Militar de Engenharia (IME). RESULTADOS: os resultados mostraram que, de forma geral, os fios de NiTi termoativados apresentaram cargas mais suaves de desativação que os superelásticos. Entre os fios que apresentaram as cargas de desativação biologicamente mais adequadas, estão os termoativados da GAC e da Unitek. Entre os fios de NiTi superelásticos, os de CuNiTi 27ºC da Ormco foram os que apresentaram as cargas mais suaves de desativação, sendo estatisticamente semelhantes (ANOVA) às apresentadas pelos fios de NiTi termoativados da Unitek. Quando comparados os fios de CuNiTi 27ºC aos de 35ºC, observou-se que os primeiros apresentaram forças de desativação de, aproximadamente, ⅓ das apresentadas pelos últimos. CONCLUSÃO: conclui-se que os fios de CuNiTi 35ºC apresentaram cargas de desativação biologicamente menos favoráveis em relação aos demais fios de NiTi termoativados, sendo associadas a percentuais inferiores de deformação, nos patamares constantes de desativação, demonstrando comportamento mecânico, sob tração, menos adequado em relação aos demais fios.

Matrix metalloproteinases -1, -2, -3, -7, -8, -12, and -13 in gingival crevicular fluid during orthodontic tooth movement: a longitudinal randomized split-mouth study.

This randomized split-mouth study aimed to examine the levels of matrix metalloproteinases (MMPs) -1, -2, -3, -7, -8, -12, and -13 in the gingival crevicular fluid (GCF) at different time points during orthodontic tooth movement. A total of 16 healthy orthodontic subjects (7 females, 9 males; mean age, 17.7 years) who needed their first upper premolars extracted were enrolled. One randomly chosen maxillary canine was subjected to a distalizing force and was considered to be the test side. The contralateral canine, which was not subjected to any force but was included in the orthodontic appliance, was used as a control side. GCF sampling was performed at both the mesial (tension) and distal (pressure) test and control sites at baseline, immediately before applying the orthodontic appliance, and after 1 and 24 hours and 7, 14, and 21 days. A multiplexed bead immunoassay was used to analyse the GCF samples. The mean levels of the MMP-1, -2, -3, -7, -8, -12, and -13 were not significantly different between the test and control groups in each time showed. The comparisons between the tension and pressure sites were also not significantly different at each individual time. A few variations focused on MMP-1 and -3, but the expression of MMP-8 was higher than that of the other MMPs. MMPs are released in sufficient quantities such that tooth movement occurs but with no significant increase in GCF levels.

Assessment of the orthodontic knowledge demonstrated by dental school undergraduates: recognizing the key features of Angle Class II, Division 1 malocclusion

OBJECTIVE: To investigate the ability of undergraduate students in diagnosing Angle Class II malocclusion and evaluate the clinical approach of these students toward a patient displaying this condition. METHODS: The sample consisted of 138 students attending the last semester of 10 dental schools in the State of Rio de Janeiro/Brazil assessed by questionnaires with closed questions. They were presented with photographs and dental casts of a patient in the mixed dentition, with Angle Class II malocclusion, increased overjet and overbite, deviated dental midlines and anterior diastemas in the upper arch. RESULTS: It was found that students easily identified increased overjet (92% of students), followed by the presence of diastemas (89%), midline deviation (84.7%) and increased overbite (77.3%). Conversely, approximately half the sample (n=70 or 51% of the students) were able to identify bilateral Angle Class II malocclusion. Nearly all agreed on the need for treatment and that it should be provided by a specialist (n=131 or 95%), but found it difficult to determine the ideal moment to start orthodontic treatment: 48.9% of the sample would begin treatment at the end of the mixed dentition, 41.7% would indicate treatment during deciduous dentition and 7.9% during permanent dentition. CONCLUSIONS: On completion of their undergraduate courses, students encounter difficulties in diagnosing Class II and even find it hard to articulate ideas about a basic treatment protocol to correct this malocclusion.

Tratamento restaurador em paciente adulto com necessidades multidisciplinares / Restorative treatment in adult patient with multidisciplinary necessities

Este artigo relata a sequência de tratamento odontológico multidisciplinar de uma paciente de 43 anos de idade que apresentava os incisivos inferiores com diastemas generalizados, projetados vestibularmente em relação aos incisivos superiores, além de perdas de elementos dentários. Através de aparatologia ortodôntica, promoveu-se alinhamento e nivelamento dentário, com fechamento de espaços, para que fosse possível a reabilitação protética. A reabilitação protética foi realizada em zircônia, através de um sistema CAD-CAM (Cercon). A conjugação dos tratamentos ortodôntico e protético é apresentada nesse relato de caso que obteve resultados estéticos e funcionais satisfatórios.

Treatment of an anterior open bite with the multiloop archwire technique.

This is a treatment report of a patient with an anterior open bite and predominance of vertical growth. Multiloop edgewise archwire (MEAW) mechanics were used and resulted in an efficient bite closure and good occlusion. For retention, a bonded 3-3 retainer was used in the mandible whereas a wraparound retainer was employed in the maxilla.

Orthodontic treatment needs of Brazilian 12-year-old school children.

AIM: To assess the orthodontic treatment need of 12-year-old Brazilian school children using the Index of Orthodontic Treatment Need (IOTN). METHODS: One experienced examiner evaluated the IOTN's dental health component (DHC) and its esthetic component (EC) in 1,182 individuals from 50 randomly selected state schools of Rio de Janeiro. He also requested that these students score their own EC (self-perception). RESULTS: The DHC showed that 51.1% of the children had no/little need, while 26.7% had a need/high need/priority for orthodontic treatment. There was no significant difference between the two sexes (P=.156). According to the EC, esthetics were good in 59.1% of the children, borderline in 32.7%, and unattractive in 8.1%. The self-perception of the EC showed that 89.0% judged themselves as having good esthetics, with girls significantly more critical than boys (P=.035). The statistical correlation between EC (examiner) and EC (children) was low (kappa coefficient=.13). CONCLUSIONS: About half of the scored Brazilian 12-year-old schoolchildren had no/little need for treatment. Orthodontists were more critical in their esthetic evaluation than the children themselves, with girls being more critical in self-perception than boys.

Diagnóstico de má oclusão de Classe III por alunos de graduação / Class III malocclusion diagnosis by graduation students

OBJETIVO: verificar a capacidade de alunos de graduação diagnosticarem a má oclusão do tipo Classe III de Angle, assim como avaliar a possível indicação para tratamento ortodôntico e o momento ideal de iniciá-lo, levando em consideração as idades dentária e esquelética do paciente. MÉTODOS: a amostra foi composta por 138 alunos do último período de graduação de 10 faculdades de Odontologia do estado do Rio de Janeiro, avaliados por meio de questionários com perguntas fechadas. Foram-lhes apresentados fotografias e modelos de estudo de um paciente portador de má oclusão Classe III de Angle unilateral e, ainda, outras más posições dentárias. RESULTADOS: constatou-se facilidade por parte dos estudantes em identificar o desvio de linha média (n = 124 ou 90 por cento) e a mordida cruzada anterior (n = 122 ou 89 por cento). Em contrapartida, aproximadamente metade da amostra (n = 63 ou 46 por cento dos alunos) foi capaz de reconhecer, no caso clínico, a existência da má oclusão Classe III de Angle unilateral. Apenas 46 por cento deles (n = 63) identificaram a ausência precoce do dente decíduo. Quanto ao tratamento, quase a totalidade concordou com a sua necessidade, porém encontraram dificuldade em reconhecer o momento ideal da indicação ao especialista, com a finalidade de que este realize o tratamento ortodôntico. CONCLUSÃO: os estudantes terminam o curso de graduação com dificuldade no diagnóstico de Classe III e nem mesmo articulam idéias sobre um protocolo básico de tratamento para correção desta anormalidade.

AIM: The aim of this article was to check the ability of undergraduate students to identify Class III malocclusion and also recognize the correct timing for referring them for orthodontic treatment, taking into consideration the patient's dental and skeletal ages. METHODS: The sample included 138 senior students of 10 Dental Schools in the State of Rio de Janeiro, which answered a written questionnaire with objective questions. It was also presented to them the facial photographs and study models of a unilateral Class III patient, which also included other dental irregularities. RESULTS: It could be observed that it was easy for most of the students to identify the dental midline deviation (n = 124 or 90 percent) and the anterior crossbite (n = 122 or 89 percent). However, approximately half of the sample (n = 63 or 46 percent of the students) was able to classify the studied clinical case as a unilateral Class III. Only 46 percent of the group (n = 63) could identify the early loss of a deciduous tooth. Almost the totality of the sample agreed on the orthodontic treatment need, however, it was hard for them to agree on the best timing for referring the case to the specialist and the beginning of this therapy. CONCLUSION: The students graduate in Dental School with difficulties on the correct diagnosis of Class III cases and are not fully aware of a basic protocol for the treatment of this abnormality.

Extrusão ortodôntica como auxiliar na obtenção da excelência estética de prótese sobre implante / Orthodontic extrusion as an assistant on obtaining esthetic excellence of prosthesis over implant

Este artigo relata a seqüência de extrusão forçada de um incisivo central superior, através de aparotologia ortodôntica, previamente à colocação de implante osseointegrado e à realização de prótese sobre implante. Havia indicação de exodontia e a extrusão ortodôntica foi realizada com objetivo de fornecer área adequada para inserção do implante. A conjugação dos tratamentos ortodôntico, periodontal e protético é apresentada nesse relato de caso, que obteve resultado estéticos satisfatórios.