Qual a minha sequência preferida de fios ortodônticos durante o tratamento ­ uma escolha baseada em critérios / My favorite sequence of orthodontic wires during the treatment ­ a choice based on criteria

O arco ortodôntico representa o elemento ativo do tratamento e é o principal responsável pela movimentação dentária induzida. O objetivo deste trabalho foi apresentar uma sequência de fios ortodônticos a ser utilizada durante a fase inicial, intermediária e final do tratamento com aparelhos fixos e os critérios a serem observados na seleção destes arcos (AU)

The orthodontic archwire represents the active element for treatment, and it is the main responsible for induced tooth movement. This study aims to present a sequence of orthodontic wires to be used in the early, intermediate and final phases of fixed appliance therapy as well as the criteria to be observed in the selection of these archwires (AU)

Orthodontic Wires: A 12-Year Bibliometric Study.

Aims and Objectives: To perform a bibliometric study to identify and evaluate articles associated with "orthodontic wires" indexed in six databases (PubMed, Embase, Cochrane, Scopus, Lilacs, and Google Scholar) from 2010 to 2022. Materials and Methods: The search strategy in PubMed combined different medical subject heading terms with free-text words and was adjusted for each selected database. The retrieved documents were original English articles containing the keywords used in the search strategies related to orthodontic wires. Collected data consisted of journal name, nationality, field, JIF-2 and JIF-5, SJR, CiteScore, Q and H-index, and categorization of the study. Results: In total, 417 articles were retrieved from the initial search. After the exclusion criteria, 257 articles remained. The most common theme was mechanical properties, with basic studies as the main categorization. Conclusions: This bibliometric survey provides an overview of orthodontic wires publications that might help orthodontists to understand the tendency of the studies on this subject. The retrieved papers were published in 100 journals, including 15 orthodontic journals, mainly in the first and second quartiles. Europe and America were the continents with the highest number of papers. The United States was the country with the highest number of journals on the topic. AJODO presented the highest h-index among the retrieved orthodontic journals. Brazil represented the principal institutions of origin of the listed articles. There was a tendency to increase the number of publications on orthodontic wires over the years. These findings indicate that research on orthodontic wires is still contemporary and relevant.

Alignment efficiency of heat activated and superelastic nickel-titanium archwires in orthodontic patients over three months: A Single-center, randomized clinical trial.

OBJECTIVE: The aim of this 2-arm parallel study was to evaluate the alignment efficiency of heat-activated nickel-titanium (NiTi-TE) and superelastic nickel titanium (NiTi-PSE) archwires over the first 3 months of orthodontic treatment and compare these groups. SETTING AND SAMPLE POPULATION: Randomized, double-blind, controlled, single-center trial in 52 patients with fixed orthodontic appliances from an orthodontic graduate program in the permanent dentition and moderate crowding in the lower arch. MATERIAL AND METHODS: Patients were randomly allocated to one of two interventions: NiTi-TE and NiTi-PSE archwires, 0.014-inch (3M Unitek™, CA, USA) with a follow-up period of 3 months. The primary outcome was the alignment efficiency determined by the reduction in Little's irregularity index (mm), measured in three points, T0: before the start of orthodontic treatment, T1: 1 month later, T2: 2 months later, T3: 3 months later. Data were analyzed using independent sample t tests and repeated measures ANOVA. RESULTS: 52 patients (NiTi-TE n = 26; NiTi-PSE n = 26) were randomized and analyzed (average age: 21.73; standard deviation (SD): 6.07; average lower anterior irregularity: 5.20; SD: 0.76) for intention-to-treat (ITT) analysis. No statistically significant differences between the groups were found (mean of the differences: T1: 0.20; 95% CI: -0.558; 0.958; T2: 0.49: 95% CI: -0.339; 1.319; T3: 0.33; 95% CI: -0.308; 0.968). The resolution of crowding with each of the wires was significant (P < 0.0001) at all times. Twelve participants (2 treated with NiTi-TE and 10 treated with NiTi-PSE) lost follow-up due to face-to-face dental-procedures restrictions during the COVID-19 pandemic, the missing data was imputed. CONCLUSIONS: NiTi-TE and NiTi-PSE wires of 0.014-inch were similar in their clinical efficiency for the resolution of crowding during the first 3 months of orthodontic treatment. REGISTRATION: Clinical Trials NCT03256279.

Does the initial surface roughness of different CuNiTi wires affect the frictional resistance?

Abstract This study aimed to assess and correlate initial surface roughness and frictional resistance of rectangular CuNiTi wires inserted in different self-ligating brackets. The sample consisted of 40 bracket-wire sets (rectangular CuNiTi wires of 0.017" x 0.025" and passive self-ligating brackets) divided into four groups (n=10): metallic self-ligating bracket and metallic CuNiTi wire (G1); metallic self-ligating bracket and rhodium-coated CuNiTi wire (G2); esthetic self-ligating bracket and metallic wire (G3); esthetic self-ligating bracket and rhodium-coated CuNiTi wire (G4). The initial surface roughness of the wires was examined with a Surfcorder roughness meter, model SE1700. Later, frictional resistance was assessed in an Instron 4411 universal testing machine at a speed of 5 mm/min, in an aqueous medium at 35°C. Microscopic analyses of surface morphology were performed with scanning electron microscopy, using an LEO 1430, with magnifications of 1000X. Generalized linear models were applied, considering the 2 x 2 factorial (bracket type x wire type), at a 5% significance level. Regardless of bracket type, the groups with esthetic wires presented higher initial surface roughness than the groups with metallic wires (p<0.05). There was no significant difference between the different bracket-wire sets for frictional resistance and no significant correlation between frictional resistance and initial surface roughness in the environment studied. It is concluded that esthetic wires presented higher initial surface roughness but did not interfere with the frictional resistance between brackets and wires.

Resumo O objetivo deste estudo foi avaliar e correlacionar a rugosidade superficial inicial e a resistência a fricção dos fios CuNiTi retangulares inseridos em diferentes bráquetes autoligados. A amostra foi composta por 40 conjuntos bráquetes-fios (fios retangulares CuNiTi de 0.017" x 0.025" e braquetes autoligados passivos), divididos em 4 grupos (n=10): bráquete autoligado metálico e fio CuNiti metálico (G1); braquete autoligado metálico e fio CuNiti com revestimento de rhodium (G2); bráquete autoligado estético e fio metálico (G3); bráquete autoligado estético e fio CuNiti com revestimento de rhodium (G4). A rugosidade superficial inicial do fio foi examinada com um rugosímetro Surfcorder modelo SE1700. Posteriormente, a resistência a fricção foi avaliada em uma máquina de ensaios universal Instron 4411, a uma velocidade de 5mm/min em meio aquoso à 35oC. Análises microscópicas da morfologia de superfície foram realizadas por microscopia eletrônica de varredura, utilizando um LEO 1430, com ampliações de 1000X. Foram aplicados modelos lineares generalizados, considerando o fatorial 2 x 2 (tipo de bráquete x tipo de fio), com o nível de significância de 5%. Independentemente do tipo de bráquete, os grupos com fios estéticos apresentaram maior rugosidade superficial inicial que os grupos com fios metálicos (p<0,05). Não houve diferença significativa entre os diferentes conjuntos bráquetes-fios quanto a resistência à fricção e não houve correlação significativa entre a resistência a fricção e a rugosidade superficial inicial no ambiente estudado. Conclui-se que os fios estéticos apresentaram maior rugosidade superficial inicial porém não interferiram na resistência a fricção entre os braquetes e os fios.

Comparação da expressão de torque entre fios de níquel titânio convencionais e estéticos / Comparison of torque expression between aesthetic and conventional nickel wires Leniana

Resumo O propósito deste estudo foi comparar a magnitude de torque de fios retangulares de níquel titânio (NiTi) estéticos e convencionais submetidos aos testes de torção. Foram testados fios comerciais de NiTi pré-contornados estéticos e convencionais de 4 marcas comerciais (American Orthodontics, Eurodonto, Orthometric e TP Orthodontics) de secção transversal 0.016" x 0.022". Os testes foram realizados em máquina de torção com rotação de 0° a 90° e foi analisado o comportamento na desativação em 20° e no torque máximo a 90°. Aos 20° no descarregamento, os fios estéticos e convencionais da American Orthodontics tiveram maior expressão de torque, enquanto os fios da Eurodonto convencional e TP Orthodontics estético apresentaram menor torque. No torque máximo a 90°, os fios que tiveram maior expressão foram da TP Orthodontics convencional e American Orthodontics estético, e os fios de menor torque foram da Eurodonto convencional e Orthometric estético. Não foram encontradas diferenças estatisticamente significativas quando os fios estéticos foram comparados entre si. Ao comparar fios estéticos e convencionais de mesma marca comercial, a única que apresentou diferença estatisticamente significativa foi a Eurodonto. Concluiu-se que, quando comparados os torques dos fios estéticos e convencionais de mesma marca, não foram encontradas diferenças estatisticamente significativas, exceto o da marca Eurodonto, que apresentou menor torque para os fios convencionais. (AU)

Abstract The purpose of this study was to compare the torque magnitude of aesthetic and conventional nickel titanium (NiTi) rectangular wires subjected to torsion tests. Commercial esthetic and conventional pre-contoured NiTi wires from 4 brands (American Orthodontics, Eurodonto, Orthometric, and TP Orthodontics) with a cross-section of 0.016" x 0.022" were tested. The tests were carried out in a torsion machine with rotation from 0º to 90° and the behavior in deactivation at 20° and at a maximum torque at 90° was analyzed. At 20° in unloading, American Orthodontics esthetic and conventional wires had higher torque, while conventional Eurodonto and TP Orthodontics esthetic wires had lower torque. At maximum torque (90°), the wires that had the highest torque were conventional TP Orthodontics and aesthetic American Orthodontics, and the wires with the lowest torque were conventional Eurodonto and aesthetic Orthometric. No statistically significant differences were found when the aesthetic threads were compared to each other. When comparing aesthetic and conventional wires from the same brand, the only one that showed a statistically significant difference was Eurodonto. It was concluded that, when comparing the torques of the aesthetic and conventional wires of the same brand, no statistically significant differences were found, except for the Eurodonto brand, which presented lower torque for the conventional wires. (AU)

Influência da pressão dos alicates na rugosidade superficial de fios ortodônticos / Influence of gripping with pliers on the surface rugosity of orthodontic wires

Resumo Proposição: avaliar in vitro a rugosidade superficial de fios ortodônticos antes e após a compressão com pinças ortodônticas. Material E Métodos: 30 fios 0,014" de níckel-titânio termoativados (Neosentalloy, GAC) e 30 fios 0,019 x 0,025" de aço foram usados nos experimentos. Avaliou-se a rugosidade superficial com rugosímetro (NewViewTM 7100, Zygo), antes e após a compressão com alicate Weingart do lado esquerdo e pinça Mathieu do lado direito (Dentaurum). Foram determinados os parâmetros de rugosidade Ra (µm), Rq (µm), PV (µm), Srmax Iso (nm). Testes estat´siticos Wilcoxon foram realizados para analisar a variação dos parâmetros da rugosidade com nível de confiança de 95% e p<0,05. Resultados: Os fios redondos de NiTi apresentaram diferenças significaticas dos parâmetros Ra e Rq antes e após a compressão com pinça Mathieu. O emprego do alicate Weingart não alterou a rugosidade dos fios redondos. Os fios retangulares apresentaram diferenças significativas em todos os parâmetros com uso das duas pinças. As médias das diferenças dos parâmetros entre o alicate Weingart e a pinça Mathieu nos fios redondos, não foram estatisticamente significativos. Os fios retangulares apresentaram maior rugosidade com o emprego do alicate Weingart, com diferenças significativas. Conclusão: O uso do alicate tipo Weingart e da pinça tipo Mathieu aumentam a rugosidade dos fios de NiTi e de aço (AU)

Abstract Proposition: the surface roughness of orthodontic wires was evaluated in vitro before and after gripping with two different orthodontic pliers. Material And Methods: Units were made of 30 round heat-activated Nickel Titanium alloy wires 0,014" (Neosentalloy, GAC), and another group with 30 rectangular steel wires 0,019 x 0,025". The surface roughness was evaluated with a rugosimeter (NewViewTM 7100, Zygo), before and after gripping with Weingart plier on the left side and Mathieu plier on the right side (Dentaurum), in addition to the average difference in roughness between groups of the same types of wires with parameters Ra (µm), Rq (µm), PV (µm), Srmax Iso (nm). The variation of parameters with different clamps was evaluated (Wilcoxon test); different alloys by the same clamp, 95% confidence level and p<0.05. Results: The round wires showed significant differences (Ra and Rq) before and after being gripped with Mathieu plier. The roughness was higher after being gripped. Weingart pliers and round wires obtained the same results, with greater roughness after being clamped. Rectangular wires showed significant differences in all parameters, with both clamps. The means of the differences in the parameters between the Weingart pliers and the Mathieu forceps on the round wires were not statistically significant. In the rectangular wire, the values between the tweezers showed greater roughness with the grip of the Weingart pliers, with significant differences.Conclusion: After securing the orthodontic wires, the Weingart pliers and the Mathieu tweezers increased the roughness parameters (AU)

Comparison of multistranded wire and fiber-reinforced composite retainers effects on periodontium: A randomized clinical trial

ABSTRACT Introduction: Fixed orthodontic retainers are very important for treatment stability; however, adverse effects on the health of periodontium can be caused as a result of deposition of plaque and calculus. Objectives: To compare and determine the effects of two mandibular fixed lingual retainers on the periodontal status, and to test the null hypothesis that there would be no significant difference on the periodontium health between the patients using fiber-reinforced composite (FRC) or multistranded wire (MSW) fixed retainers. Methods: A total of 60 subjects were recruited, out of which 6 were excluded and 2 dropped out during the study. Hence, 52 subjects with mean age of 21.5 ± 3.6 years were included in the study. The sample was composed by 8 males (15.4%) and 44 females (84.6%). The participants were randomly divided into two groups: Group 1 received fiber-reinforced composite retainer, while Group 2 received multistranded wire retainer. After insertion, plaque index, calculus index, gingival index and bleeding on probing were compared, after three months (T1), six months (T2), nine months (T3) and twelve months (T4), using Mann-Whitney test with p-value ≤ 0.05 as significant. Results: It could be seen that the health of periodontium deteriorated with the passage of time from T1 to T4 in both group of retainers. However, no statistically significant differences were found between the two groups (p> 0.05). Conclusion: The results of the study indicate that there was no significant difference on the health of periodontium between the patients with FRC and MSW fixed retainers, hence, the null hypothesis was accepted.

RESUMO Introdução: As contenções ortodônticas fixas são muito importantes para a estabilidade do tratamento; no entanto, elas podem causar efeitos adversos na saúde do periodonto, como resultado da deposição de placa e cálculo. Objetivos: Comparar e determinar os efeitos na saúde periodontal de duas contenções inferiores coladas por lingual, e testar a hipótese nula de que não haveria diferença significativa na saúde periodontal entre os pacientes usando contenções fixas de compósito reforçado com fibra (FRC) ou de fio multitrançado (MSW). Métodos: No total, 60 indivíduos foram recrutados, dos quais 6 foram excluídos e 2 desistiram durante o estudo. Assim, foram incluídos no estudo 52 indivíduos com média de idade de 21,5 ± 3,6 anos. A amostra foi composta por 8 homens (15,4%) e 44 mulheres (84,6%). Os participantes foram divididos aleatoriamente em dois grupos: O Grupo 1 recebeu contenção de compósito reforçado com fibra, enquanto o Grupo 2 recebeu contenção de fio multitrançado. Após três meses (T1), seis meses (T2), nove meses (T3) e doze meses (T4) da colagem, foram comparados os índices de placa e de cálculo, índice gengival e sangramento à sondagem, usando o teste de Mann-Whitney com p ≤ 0,05 como significativo. Resultados: Pôde-se observar que a saúde periodontal piorou com o passar do tempo, de T1 a T4, em ambos os grupos de contenções. No entanto, não foram encontradas diferenças estatisticamente significativas entre os dois grupos (p> 0,05). Conclusão: Os resultados do estudo indicam que não houve diferença significativa na saúde periodontal entre os pacientes com contenções fixas FRC e MSW; portanto, a hipótese nula foi aceita.

Deflection of tandem archwire in a specific self-ligating metal bracket system: an in vitro study

Abstract The aim of this study was to quantify the force exerted by tandem archwires in a specific system of passive self-ligating bracket. Forty-eight thermo-activated nickel-titanium orthodontic archwires were separated into four groups (n = 12): G1 - two .014" + .014" round archwires; G2 - two .014" + .016" round archwires; G3 - .014" x .025" rectangular archwire; and. G4 - .016" x .022" rectangular archwire. Brackets were fixed onto teeth 1.5 to 2.5 using a device that represented the upper teeth, maintaining an interbracket distance of 6.0 mm. The deflection tests were performed using the structure representative of tooth 1.1 as support on the Instron testing machine at a speed of 2.0 mm/min. The archwires were evaluated at deflections of 0.5 mm, 1.0 mm, and 1.5 mm. The data were analyzed by a generalized linear model, considering values at different deflections as repeated measurements in the same experimental unit (α = 0.5%). At 0.5 mm, higher forces were observed in G2 and G3, which did not differ significantly (p > 0.05). The lowest force was observed in G4 (p < 0.05). At 1.0 mm and 1.5 mm, the highest force was observed in G3, followed by G4 and G2 (p < 0.05). The lowest force was observed in G1 (p < 0.05). In general, tandem archwires (same or different calibers) in a specific passive self-ligating bracket exerted lower force when compared with rectangular archwires.

Alignment efficiency and three-dimensional assessment of root resorption after alignment with conventional and copper-nickel-titanium archwires: A randomized controlled trial

ABSTRACT Objective: To compare alignment efficiency and root resorption between nickel-titanium (NiTi) and copper-nickel-titanium (CuNiTi) archwires after complete alignment in mandibular anterior region. Methods: In this two-arm parallel single-blind randomized controlled trial, forty-four patients with Class I malocclusion with mandibular anterior crowding were recruited form orthodontic clinic of All India Institute of Medical Sciences (Jodhpur, India). Patients were randomly allocated into NiTi and CuNiTi groups, with a 1:1 allocation. Alignment was performed using 0.014-in, 0.016-in, 0.018-in, 0.019x0.025-in archwire sequence in the respective groups, which terminated in 0.019 x 0.025-in stainless-steel working archwire. The primary outcome was alignment efficiency, measured on study models from baseline (T0) to the first, second, third, fourth and fifth-month (T5). Secondary outcome was root resorption, measured from CBCT scans taken at T0 and T5. Mixed-factorial ANOVA was used to compare Little's Irregularity Index (LII). For assessing the proportion of patients with complete alignment at the end of each month, Kaplan-Meier survival curve was built and time to treatment completion was compared between groups using log rank test. Paired t-test was used to assess external apical root resorption (EARR) within groups, whereas independent t-test was used to evaluate LII and EARR between the groups. Results: Twenty-two patients were recruited in each group. One patient was lost to follow-up in the CuNiTi group. No statistically significant differences were observed in alignment efficiency between the groups (p>0.05). Intergroup comparison revealed that the changes in root measurement in three-dimensions were not statistically significant (p>0.05), except for mandibular right central incisor, which showed increased resorption at root apex in NiTi group (p<0.01). Conclusion: The two alignment archwires showed similar rate of alignment at all time points. Root resorption measurement did not differ between the NiTi and CuNiTi groups, except for the mandibular right central incisor, which showed more resorption in NiTi group.

RESUMO Objetivo: Comparar os fios de níquel-titânio (NiTi) e de cobre-níquel-titânio (CuNiTi) quanto à eficiência do alinhamento e quantidade de reabsorção radicular, após alinhamento completo dos dentes da região anterior inferior. Métodos: Neste estudo clínico randomizado, cego, paralelo, de dois braços, quarenta e quatro pacientes com má oclusão Classe I e apinhamento anterior inferior foram recrutados na clínica ortodôntica do All India Institute of Medical Sciences (Jodhpur, India). Os pacientes foram alocados aleatoriamente nos grupos NiTi e CuNiTi, na proporção de 1:1. O alinhamento foi realizado usando a sequência de fios 0,014", 0,016", 0,018" e 0,019" x 0,025" nos respectivos grupos, finalizando com o arco de trabalho 0,019" x 0,025" de aço inoxidável. O desfecho primário foi a eficiência do alinhamento, medida nos modelos de estudo nos tempos inicial (T0) e após um, dois, três, quatro e cinco meses (T5). O desfecho secundário foi a reabsorção radicular, medida a partir de tomografias computadorizadas realizadas em T0 e T5. ANOVA fatorial mista foi utilizada para comparar o Índice de Irregularidade de Little (IIL). Para avaliar a proporção de pacientes com alinhamento completo ao fim de cada mês, foi construída uma curva de sobrevida pelo método de Kaplan-Meier, e o tempo até o fim do tratamento foi comparado entre os grupos por meio do teste log-rank. Um teste t pareado foi utilizado para avaliar a reabsorção radicular apical externa (RRAE) dentro dos grupos, enquanto um teste t independente foi utilizado para avaliar o IIL e a RRAE entre os grupos. Resultados: Vinte e dois pacientes foram recrutados em cada grupo. Um paciente perdeu o acompanhamento no grupo CuNiTi. Não foram observadas diferenças estatisticamente significativas entre os grupos quanto à eficiência do alinhamento (p>0,05). A comparação intergrupos revelou que as alterações na RRAE medida em três dimensões não foram estatisticamente significativas (p>0,05), exceto para o incisivo central inferior direito, que apresentou aumento da RRAE no grupo NiTi (p<0,01). Conclusão: Os dois tipos de fios de alinhamento apresentaram taxa de alinhamento semelhante em todos os momentos. A medida da reabsorção radicular não diferiu entre o grupo NiTi e CuNiTi, exceto para o incisivo central inferior direito, que apresentou maior reabsorção no grupo NiTi.

In vitro wearing away of orthodontic brackets and wires in different conditions: A review.

Introduction: The release of metallic ions from orthodontic brackets and wires typically depends on their quality (chemical composition) and the medium to which they are exposed, e.g., acidic, alkaline, substances with a high fluoride concentration, etc. This review examines corrosion and wear of orthodontic brackets, wires, and arches exposed to different media, including: beverages (juices), mouthwashes and artificial saliva among others, and the possible health effects resulting from the release of metallic ions under various conditions. Objective: This review aims to determine the exposure conditions that cause the most wear on orthodontic devices, as well as the possible health effects that can be caused by the release of metallic ions under various conditions. Sources: A search was carried out in the Scopus database, for articles related to oral media that can corrode brackets and wires. The initial research resulted in 8,127 documents, after applying inclusion and exclusion criteria, 76 articles remained. Conclusion: Stainless steel, which is commonly used in orthodontic devices, is the material that suffers the most wear. It was also found that acidic pH, alcohols, fluorides, and chlorides worsen orthodontic material corrosion. Further, nickel released from brackets and wires can cause allergic reactions and gingival overgrowth into patients.

Comparison of the friction forces delivered by different elastomeric patterns and metal ligature on conventional metal brackets with a NiTi arch wire versus a self-ligating system: An in vitro study.

OBJECTIVES: The aim of this study was to measure the frictional resistance of different types of ligatures used on conventional and self-ligating brackets. MATERIALS AND METHODS: Monoblock (conventional) and Portia (self-ligating) brackets were used and the archwire used was nickel-titanium. On conventional brackets the ligatures tested were the Elastomeric type and steel 0.30 tie-wire. The groups were divided according to the ligature types (n=8): (1) conventional elastomeric ligature; (2) relaxed conventional elastomeric ligature; (3) elastomeric ligature in shape-8; (4) double vertical elastomeric ligatures; (5) double-crossed elastomeric ligatures; (6) crossed ligature; (7) steel wire ligature; and (8) self-ligating ligature (self-ligating bracket). A segment of five brackets, each ligature types, was mounted. The archwire, between the bracket and the ligature, was connected on Instron® Universal test machine to simulate the frictional resistance. The maximum frictional resistance was obtained, and the mean values were submitted to the analysis of variance (ANOVA) and the Tukey's post-hoc test (α=0.05). RESULTS: The elastomeric ligature in shape-8 showed the highest value compared with other groups (P<0.05). Although the crossed elastomeric ligature presented the lowest mean value and it was not statistically different regarding relaxed conventional elastomeric ligature, steel wire ligature and self-ligating (P≥0.05). CONCLUSIONS: The frictional resistance was influenced by ligature types. Elastomeric Ligature in shape-8 showed the highest frictional force. Crossed Elastomeric Ligature had the lowest frictional force value.

Assessment of frictional resistance and surface roughness in orthodontic wires coated with two different nanoparticles.

Several mechanical and biological factors may change the orthodontic wire frictional resistance (FR). Titanium dioxide (TiO2 ) and silica dioxide (SiO2 ) nanoparticle (NP) coatings may be used to improve the characteristics of materials, reducing FR between archwire and bracket. This in vitro study aimed to evaluate the FR of orthodontic wires with and without coating in both dry and wet environments and measure the surface roughness (SR). One hundred and eighty segments of rectangular Cr-Ni orthodontic wires (Morelli Co, Brazil) were divided into three groups according to the NP coating applied: TiO2 group; SiO2 group; and control group. The SR parameters were measured in an optical profilometer, the surface morphology was analyzed with scanning electron microscopy (SEM), and FR was performed in a universal testing machine in dry and wet environments (n = 30). The statistical analysis was performed using the Generalized Estimated Equations model with a Bonferroni post-test (α = 0.05). It was observed that SiO2 NP coating decreased FR significantly when compared to the TiO2 and control groups, in both environments (p < .001). The SiO2 and TiO2 groups presented statistically lower SR than the control group and were similar to each other (p < .001). The SiO2 group presented the lower depth of Valley parameter than the TiO2 group (p < .001). The SEM showed that the TiO2 coating had the most heterogeneous surface morphology than the SiO2 and control groups. The orthodontic wires with NP coating modified the FR and morphology. The SiO2 coating reduced FR in both dry and wet environments and decreased SR. Titanium dioxide (TiO2 ) and silica dioxide (SiO2 ) nanoparticles coatings may be used to reduce frictional resistance (FR) between archwire and bracket as well as to improve surface morphology. The SiO2 coating reduced FR in both dry and wet environments and decreased the SR of Cr-Ni orthodontic wire. The TiO2 coating promoted the most heterogeneous surface morphology of Cr-Ni orthodontic wire.

Avaliação da resistência à deformação plástica dos fios redondos de níquel-titânio / Evaluation of plastic deformation resistance of nickeltitanium round wires

Resumo As ligas de níquel-titânio (NiTi) possuem elasticidade elevada sem sofrer deformações plásticas permanentes, sendo amplamente indicadas nas primeiras fases do tratamento ortodôntico. O Objetivo deste estudo é avaliar a resistência de fios ortodônticos de NiTi termoativados em relação à deformação plástica. Foram avaliados fios de 6 marcas comerciais (GAC®, Morelli®, American Orthodontics®, Infinity®e 3M®). Primeiramente a partir de modelos prototipados foi simulada a relação entre deformação plástica e deflexão pela distância interbráquetes em 4 níveis de força a 37°C por 30 dias. Um segundo experimento foi realizado através da análise de fotografias padronizadas com diagramas observando o antes e depois de aplicada uma deformação ao fio a diferentes temperaturas. Os resultados do primeiro teste mostraram que todas as marcas comerciais testadas retornaram a sua forma original após sofrer deflexão por 30 dias. O segundo experimento mostrou que os fios da marca GAC® e American Orthodontics® não apresentaram diferenças estatisticamente significativas comparando as medidas do fio antes da deformação, deformado e após aquecimento (fio aquecido). Já os fios das marcas 3M®, Orthometric® e Infinity®, Morelli apresentaram diferenças significantes entre os fios novos e os fios deformados, e entre os fios deformados e os fios aquecidos, porém, não houve diferenças significantes entre os fios novos e aquecidos. Concluiu-se que nenhum fio, em nenhuma magnitude de deflexão aplicada, sofreu deformação plástica (permanente). Assim, todos os fios das marcas comerciais testadas foram considerados satisfatórios para a prática clínica da Ortodontia no que diz respeito à resistência a deformação plástica. (AU)

Abstract Nickel-titanium (NiTi) alloys have high elasticity without suffering permanent plastic deformations, widely indicated in the early stages of orthodontic treatment. This study aims to evaluate the heat-activated NiTi orthodontic wires' resistance to plastic deformation. The wire from 6 commercial brands (GAC®, Morelli®, American Orthodontics®, Infinity®, and 3M®) was evaluated first from prototype models, simulating the relationship between plastic deformation and deflection by the inter bracket distance at four levels of force at 37° C for 30 days. A second experiment was carried out by analyzing standardized photographs with diagrams observing the before and after deformation was applied to the wire at different temperatures. The first test showed that all tested trademarks returned to their original shape after deflecting for 30 days. The second experiment showed that GAC® and American Orthodontics® wires did not present statistically significant differences comparing the wire measurements before deformed deformation and after heating (heated wire). On the other hand, 3M®, Orthometric® and Infinity®, Morelli wires showed significant differences between new and deformed wires and between twisted and heated wires; however, there were no significant differences between new and heated wires. It was concluded that no wire, at any magnitude of applied deflection, suffered plastic (permanent) deformation. Thus, all wires of the commercial brands tested were considered satisfactory for the clinical practice of Orthodontics in terms of resistance to plastic deformation.(AU)

Verticalização de molares com a utilização do bráquetes Duplo Slot ­ relato de caso / Molar uprighting using Double Slot brackets ­ case report

Resumo Atualmente, muitos pacientes procuram tratamento ortodôntico por motivos funcionais, não apenas estéticos. A perda de um elemento dental leva a um desequilíbrio tanto oclusal quanto periodontal, caracterizados por diversos malefícios aos dentes e estruturas de suporte, tais como perdas ósseas, contatos prematuros e falta de espaço para confecção de próteses. Por isso, a verticalização do molar é de suprema importância pois leva à normalização da condição funcional, periodontal e oclusal. O objetivo desse trabalho é relatar um caso clínico, em que a verticalização foi realizada com o objetivo de estabelecer a função e estética. Para isso, um novo bráquete com a presença de dois slots foi utilizado. Com a utilização desse dispositivo, conseguiu-se minimizar os efeitos indesejados, reduzir o número de acessórios de ancoragem, maior controle de movimento e simplificar a mecânica ortodôntica de verticalização. (AU)

Abstract Patients seek orthodontic treatment not only for aesthetics, but also for functional reasons. The loss of a posterior tooth leads to occlusal and periodontal imbalance, characterized by several risks to teeth and supporting structures such as bone loss, premature occlusal contact, and lack of space for prosthetic rehabilitation. Therefore, the uprighting of a molar is of paramount importance as it leads to the normalization of the functional, periodontal, and occlusal status. The objective of this work is to report a clinical case of molar uprighting with the objective of establishing proper function and occlusion using a new bracket with two separate slots. The use of this bracket minimizes the undesirable effects of regular braces, reduces the number of anchoring accessories, optimizes control of tooth movement, and simplifies orthodontic mechanics.(AU)

Comparison of the High Cycle Fatigue Behavior of the Orthodontic NiTi Wires: An in Vitro Study

Abstract Objective: To compare the high-cycle fatigue behavior of four commercially available NiTi orthodontic wires. Material and Methods: Twelve NiTi orthodontic wires, round, 0.016-in, three per brand, were selected and divided into four groups: G1 - Heat-activated NiTi, G2 - Superelastic NiTi, G3 - Therma-Ti, and G4 - CopperNiTi. The atomic absorption spectrometry method was used to determine the chemical composition of investigated NiTi wires. We also performed a fatigue test at three-point bending using a universal testing machine for 1000 cycles in a 35 °C water bath. For the first and thousandth cycle, the average plateau load and the plateau length were determined in the unloading area of the force versus displacement diagram. In addition, we calculated the difference between the average plateau load of the first and thousandth cycle (∆F), as well as the difference between the plateau length of both cases (∆L). Results: According to our results, there were no significant differences between the average plateau load of the first and thousandth cycles of each group (p>0.05) and in the plateau length of the first and thousandth cycles of the groups (p>0.05). Conclusion: There were no significant differences between the groups changing the superelasticity property after high-cycle fatigue.

Caracterização mecânica, termodinâmica e química de fios CuNiTi ­ um estudo comparativo clínico e laboratorial / Mechanical, thermodynamic and chemical characterization of CuNiTi wires ­ a clinical and laboratory comparative study

Introdução: Os fios Copper Ni-Ti (CuNiTi) possuem indicações de uso clínico específicas, permanecendo no ambiente bucal por um longo período. Por esse motivo suas características mecânicas, termodinâmicas e estruturais devem ser preservadas durante todo o período de uso. Objetivos: Investigar se ocorrem alterações no comportamento mecânico, termodinâmico, estrutura e composição química superficial em fios CuNiTi 35°C submetidos ao envelhecimento in vivo (uso clínico) e in vitro (termociclagem), evidenciando as possíveis diferenças entre os métodos de envelhecimento. Material e Métodos: A amostra total foi constituída de 30 arcos pré-contornados 0.016", termodinâmicos com adição de cobre, e temperatura austenítica final (Af) de 35°C, da marca Ormco®. As análises destes fios resultaram em dois capítulos. Para o experimento clínico, 10 unidades de fios foram instaladas em 05 pacientes e permaneceram em meio bucal durante 30, 60 e 90 dias, e 05 fios foram analisados como recebidos (CR). A cada período, um hemiarco completo mais 1/3 (um terço) do hemiarco inferior direito foi retirado para análises. Para o experimento in vitro os 15 fios restantes foram submetidos à termociclagem para simulação do envelhecimento em ambiente oral durante 30 (600 ciclos), 60 (1200 ciclos) e 90 dias (1800 ciclos) com variação de temperatura entre 5°C e 55°C, com banhos de 90 segundos em cada temperatura, e transição de 15 segundos entre os banhos. Após cada período de envelhecimento in vivo e in vitro, os fios foram submetidos a um teste de padronização das suas dimensões através da medição dos diâmetros com paquímetro, Microscopia Eletrônica de Varredura (MEV), Espectrometria por Raios X Fluorescentes (FRX), ensaios de tração uniaxial e ensaio de Varredura Diferencial de Calorimetria (DSC). Resultados: No capítulo 1 a comparação entre os fios CR e os envelhecidos revelou que não houve diferença significativa entre os diâmetros das amostras, das forças obtidas ou mesmo das temperaturas Af, independentemente do tempo de permanência em boca. Foram encontrados predominantemente Ni, Ti, Cu e Al nas amostras, além de outros elementos químicos em concentrações variadas. No capítulo 2 não houve diferença significativa entre os diâmetros das amostras, das forças obtidas ou mesmo das temperaturas Af entre as amostras, independentemente do tempo ou do método de envelhecimento. Conclusão: As análises laboratoriais dos fios envelhecidos in vivo e in vitro foram comparadas, evidenciando que as características mecânicas, termodinâmicas e químicas dos fios permanecem estáveis mesmo até 90 dias de uso clínico ou 1800 ciclos de termociclagem. O método de envelhecimento in vitro se mostra uma alternativa viável para a análise destes parâmetros, em substituição aos métodos in vivo (AU).

Introduction: Copper Ni-Ti wires (CuNiTi) have specific indications for clinical use, remaining in the oral environment for a long period. For this reason, their mechanical, thermodynamic and structural characteristics must be preserved throughout the period of use of these materials. Objectives: To investigate whether there are changes in the mechanical, thermodynamic, structure and surface chemical composition of CuNiTi 35°C wires subjected to in vivo aging (clinical use) and in vitro (thermocycling), highlighting the possible differences between the aging methods. Material and Methods: The total sample was obtained from 30 pre-contoured Ormco® 0.016 thermodynamic archwires with copper addition and austenitic final temperature (Af) of 35°C. The analysis of these archwires resulted in two articles. For the clinical experiment, 10 units of wires were installed in 05 patients and remained in the oral environment for 30, 60 and 90 days, and 05 wires were analyzed as received. At each period, a complete hemiarch plus 1/3 of the right lower hemiarch was removed for analysis. For the in vitro experiment, the 15 remaining wires underwent thermocycling to simulate the aging of the oral environment for 30 (600 cycles), 60 (1200 cycles) and 90 days (1800 cycles) with a temperature range between 5°C and 55°C, with 90 second baths at each temperature, and 15 second transition between baths. After each in vivo and in vitro aging period, the wires underwent to a standardization test of their dimensions, by defining the diameters with a caliper, Scanning Electron Microscopy (SEM), Fluorescent X-Ray Spectrometry (FRX), tests of Uniaxial traction and Differential Scanning Calorimetry (DSC) test. Results: In chapter 1, the comparison between CR and aged wires revealed that there was no significant difference between the sample diameters, the forces obtained or even the temperatures Af, regardless the time spent in the mouth. Predominantly Ni, Ti, Cu and Al were found in the samples, in addition to other chemical elements in different concentrations. In chapter 2 there was no significant difference between the diameters of the samples, the forces obtained or even the temperatures Af between the samples, regardless of time or aging method. Conclusion: The comparison of the laboratoral analyzes of the archwires aged in vivo and in vitro showed that the mechanical, thermodynamic and the surface chemical characteristics were stable, even up to 90 days of clinical use or 1800 thermocycling cycles. The in vitro aging method is a viable alternative for the analysis of these parameters, replacing the in vivo methods (AU).

Can we expect similar behavior among CuNiTi 35°C wires?

ABSTRACT Objective: This paper aims to verify the thermodynamic, mechanical and chemical properties of CuNiTi 35ºC commercial wires. Methods: Forty pre-contoured copper-nickel-titanium thermodynamic 0.017 x 0.025-in archwires with an Af temperature of 35°C were used. Eight wires from five different manufacturers (American Orthodontics® [G1], Eurodonto® [G2], Morelli® [G3], Ormco® [G4] and Orthometric® [G5]) underwent cross-sectional dimension measurements, tensile tests, SEM-EDS and differential scanning calorimetry (DSC) tests. Parametric tests (One-way ANOVA and Tukey post-test) were used, with a significance level of 5%, and Pearson's correlation coefficient test was performed between the Af and chemical elements of the wires. All sample tests and statistical analyses were double-blinded. Results: All wires presented standard dimensions (0.017 x 0.025-in) and superelastic behavior, with mean plateau forces of: G1 = 36.49N; G2 = 27.34N; G3 = 19.24 N; G4 = 37.54 N; and G5 = 17.87N. The Af means were: G1 = 29.40°C, G2 = 29.13°C and G3 = 31.43°C, with p>0.05 relative to each other. G4 (32.77°C) and G5 (35.17°C) presented statistically significant differences between each other and among the other groups. All samples presented Ni, Ti, Cu and Al in different concentrations. Conclusions: The chemical concentration of the elements that compose the alloy significantly influenced the thermodynamic and mechanical properties.

RESUMO Objetivo: O presente artigo teve como objetivo verificar as propriedades termodinâmicas, mecânicas e químicas de fios CuNiTi 35°C comerciais. Métodos: Foram utilizados 40 arcos termodinâmicos pré-contornados de cobre-níquel-titânio de 0,017" x 0,025" e temperatura Af de 35°C. Oito fios de cinco fabricantes diferentes (American Orthodontics® [G1], Eurodonto® [G2], Morelli® [G3], Ormco® [G4] e Orthometric® [G5]) foram submetidos a medições de suas secções transversais, testes de tração, MEV-EDS e calorimetria diferencial (DSC). Foram utilizados testes paramétricos (One-way ANOVA e pós-teste de Tukey), com nível de significância de 5%, e foi realizado o teste do coeficiente de correlação de Pearson entre a temperatura Af e os elementos químicos dos fios. Todos os testes das amostras e análises estatísticas foram duplo-cegos. Resultados: Todos os fios apresentavam dimensões padronizadas (0,017" x 0,025") e comportamento superelástico, com forças médias de platô de G1 = 36,49 N; G2 = 27,34 N; G3 = 19,24 N; G4 = 37,54 N; e G5 = 17,87 N. As médias de Af foram: G1 = 29,40°C, G2 = 29,13°C e G3 = 31,43°C, com p> 0,05 entre si. G4 (32,77°C) e G5 (35,17°C) apresentaram diferenças estatisticamente significativas entre si e entre os demais grupos. Todas as amostras apresentaram Ni, Ti, Cu e Al em diferentes concentrações. Conclusões: A concentração química dos elementos que compõem a liga influenciou significativamente as propriedades termodinâmicas e mecânicas.

Effect of fluoride on mechanical properties of NiTi and CuNiTi orthodontic archwires: an in vitro study

ABSTRACT Introduction: After debonding, white spot may appear on the area below the bracket, which is the early clinical sign of carious lesion. There is increased caries risk underneath and adjacent to orthodontic bands and brackets, which call for maximum use of caries preventive procedures using various fluoride application methods. Objective: The aim of the study was to evaluate alterations in the mechanical properties (modulus of elasticity and yield strength) in loading and unloading phases for different orthodontic archwires (nickel-titanium [NiTi] and copper-nickel-titanium [CuNiTi]) when exposed routinely to fluoride prophylactic agents for a predetermined period of time. Methods: Preformed rectangular NiTi and CuNiTi wires were immersed in fluoride solution and artificial saliva (control) for 90 minutes at 37ºC. After immersion, specimens were tested using a 3-point bend test on a universal testing machine. Results: There is a significant reduction in the unloading yield strength when the NiTi and CuNiTi wires were exposed to APF gel. Conclusion: The result suggests that use of topical fluoride agents affect the mechanical properties of the wires, leading to increase in treatment duration. Fluoride prophylactic agents must be used with caution in patients undergoing orthodontic treatment. Injudicious use of these agents may cause corrosive effects on the orthodontic wire surfaces, with alteration in their mechanical properties.

RESUMO Introdução: Após a remoção dos braquetes, manchas brancas podem aparecer na área embaixo deles, as quais são o sinal clínico inicial da lesão cariosa. Existe um maior risco de cáries embaixo e ao redor das bandas e braquetes ortodônticos, o que exige a máxima utilização de procedimentos preventivos de cárie, usando diferentes métodos com aplicação de flúor. Objetivo: O objetivo do presente estudo foi avaliar alterações nas propriedades mecânicas (módulo de elasticidade e resistência ao escoamento), nas fases de carregamento e descarregamento de diferentes fios ortodônticos (níquel-titânio [NiTi] e níquel-titânio com adição de cobre [CuNiTi]), quando expostos rotineiramente a agentes profiláticos fluoretados, utilizados durante um período de tempo predeterminado. Métodos: Os fios pré-contornados retangulares de NiTi e CuNiTi foram imersos em solução fluoretada e saliva artificial (controle) durante 90 minutos a 37°C. Após a imersão, as amostras foram testadas utilizando-se um teste de flexão em três pontos, em uma máquina universal de testes. Resultados: Houve uma redução significativa na resistência ao escoamento na fase de descarregamento quando os fios de NiTi e CuNiTi foram expostos ao gel fluoretado. Conclusão: O resultado sugere que o uso tópico de agentes fluoretados afeta as propriedades mecânicas dos fios, levando a um aumento na duração do tratamento. Os agentes profiláticos fluoretados devem ser utilizados com cautela em pacientes submetidos a tratamento ortodôntico. O uso indiscriminado desses agentes pode causar efeitos corrosivos na superfície dos fios ortodônticos e consequente alteração das suas propriedades mecânicas.

Comparative Analysis of Stiffness of Lingual Appliances: An in Vitro Study

ABSTRACT Objective: To analyze and compare the stiffness of different lingual appliances with different archwires. Material and Methods: The three-point bending test was used to analyze the stiffness of the lingual archwires for the different lingual systems: eBrace, Harmony, Incognito, and STb. The deflection load curve of each archwire was obtained to evaluate how the section, the material and the manufacturer affect the elasticity and stiffness characteristics of the wires. The comparison of the stiffness between different systems was carried out through a factor variance analysis with three factors (manufacturer, cross-section, and material), followed by the post-hoc Tuckey test. Results: An increase in the system's rigidity was reported as the wire section increases, regardless of the manufacturer. The stainless steel archwires have ever higher stiffness values than NiTi and TMA. The STb wires of CuNiTi material, by virtue of the characteristics of the thermal wires, have flatter and lower load-deflection curves than the NiTi wires of other manufacturers. Conclusion: Archwires section and material showed a significant influence on the stiffness of the lingual systems. Archwires of the same section and material but different manufacturers show different load-deflection curves of stiffness.

Avaliação do grau de corrosão de fios ortodônticos submetidos a desafio de pH / Evaluation of the corrosion degree of orthodontic wires subjected to pH challenge

Introdução: a movimentação dentária requer a aplicação de um sistema de forças que é orientado com o uso de acessórios, incluindo fios ortodônticos. Existem diversos materiais e fabricantes disponíveis no mercado, por isso é importante que o profissional conheça a composição deste material, uma vez que estará em contato com a mucosa oral, podendo sofrer corrosão e liberação de íons metálicos. Objetivo: avaliar, in vitro, o grau de corrosão de duas ligas metálicas que compõem fios ortodônticos de três fabricantes diferentes, submetidos à ciclagem de pH. Metodologia: 60 corpos de prova foram confeccionados com dois tipos de ligas metálicas (NiTi e CrNiaço 302) produzidas por três fabricantes diferentes, divididos em 6 Grupos de Testes com 10 unidades cada. Os corpos-de-prova foram submetidos à ciclagem ácida de pH 4,3, diariamente, e mantidos em estufa a 37 ° C por 14 dias. A massa foi pesada antes e após a ciclagem, por meio de balança analítica de precisão. A avaliação das características visuais dos fios foi realizada por um único observador em lupa estereomicroscópica. Resultados: a ciclagem de pH dos fios ortodônticos não promoveu perda significativa de massa ou corrosão, apesar da análise das características visuais terem mudado após a ciclagem. Conclusão: com base nos resultados do protocolo experimental estabelecido no presente estudo, a análise do comportamento das ligas de aço NiTi e CrNi ­ 302 que compõem os fios ortodônticos, frente ao desafio ácido de pH 4,3, por duas semanas, concluiu-se que esses materiais não apresentaram perdas de massa, opacidade, brilho e lisura consideradas significativas. Outros estudos são recomendados para fornecer maiores esclarecimentos sobre o tema.

Introduction: the tooth movement requires the application of a force system that is guided with the use of accessories, including orthodontic wires. There are several materials and manufacturers available on the market, so it is important that the professional knows the composition of this material, since it will be in contact with the oral mucosa, and may suffer corrosion and release metal ions. Objective: to evaluate, in vitro, the degree of corrosion of two metal alloys that make up orthodontic wires from three different manufacturers, submitted to pH cycling. Methodology: 60 specimens were made from two types of metal alloys (NiTi and CrNi ­ steel 302) produced by three different manufacturers, divided into 6 Test Groups with 10 units each. The specimens were subjected to acid pH 4.3 cycling, daily, and kept in an oven at 37 ° C for 14 days. The mass was obtained before and after cycling, using a precision analytical balance. The evaluation of the visual characteristics of the wires was performed by a single observer using a stereomicroscopic loupe. Results: the pH cycling of orthodontic wires did not promote significant loss of mass or corrosion, despite the analysis of visual characteristics having changed after cycling. Conclusion: based on the results of the experimental protocol established in the present study, the analysis of the behavior of the NiTi and CrNi ­ 302 steel alloys that make up the orthodontic wires, facing the acid challenge of pH 4.3, for two weeks, it was concluded that these materials did not present loss of mass, opacity, brightness and smoothness considered significant. Other studies are recommended to provide further clarification on the topic.