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Objective: This study aimed to investigate the effect of different disinfection protocols on the mechanical properties of orthodontic elastomeric ligatures (EL), an important issue to biosafety improvement and infection control, and to avoid cross-contamination.Methods: A total of 120 EL were randomly divided into 6 experimental groups (n = 20) according to the disinfection method employed: group 1, EL were not immersed in a disinfectant solution (control group); group 2, EL were immersed in 2% glutaraldehyde; group 3, EL were immersed in 70% alcohol solution; group 4, EL were cleaned in an ultrasound washing (UW) machine by immersion in 0.5% enzyme detergent solution; group 5, UW procedure was performed, followed by immersion in 2% glutaraldehyde; Group 6, UW procedure was performed, followed by immersion in 70% alcohol. After disinfection, EL were subjected to a tensile strength test where the maximum strength, maximum elongation, and work at failure were determined. Data were statistically evaluated using one-way ANOVA and Dunnett’s t-test for multiple comparisons.Results:Statistically significant different (P < .05) values were found between the disinfection methods, and 70% alcohol showed negative changes in all mechanical properties of orthodontic elastomers. By contrast, 2% glutaraldehyde did not show significant alteration in mechanical properties, whereas the UW procedure showed significant alteration in maximum strength and work at failure.Conclusion:Of the tested substances for disinfection, 2% glutaraldehyde was the only substance that did not cause significant changes in the mechanical properties of orthodontic elastics and is considered as an alternative for elastic disinfection before its use.

Objective: The aim of this study was to assess the effects of combined headgear used alone or in association with rapid maxillary expansion, as the first step for Class II malocclusion treatment.Methods:The sample comprised 61 patients divided into three groups: Group 1, combined headgear (CH); Group 2, CH + rapid maxillary expansion (CH + RME); and Group 3, control (CG). In Group 1, patients were treated with combined headgear until Class I molar relationship was achieved. In Group 2, the protocol for headgear was the same; however, patients were previously subject to rapid maxillary expansion.Results:Results showed distal displacement of maxillary molars for both experimental groups (p < 0.001), with distal tipping only in Group 1 (CH) (p < 0.001). There was restriction of forward maxillary growth in Group 2 (CH + RME) (p < 0.05) and clockwise rotation of the maxilla in Group 1 (CH) (p < 0.05).Conclusion: Based on the results, it is possible to suggest that treatment with both protocols was efficient; however, results were more significant for Group 2 (CH + RME) with less side effects.

OBJECTIVE: The objective of this study was to evaluate a sagittal variation on the lower incisors with the use of the lingual arch on the transition from mixed to permanent dentition. METHODS: The sample was constituted of 44 Caucasian patients (26 girls and 18 boys), divided in two groups: CG, control group, monitoring the lower arch space with no orthodontic/orthopedic treatment during the rated period (n = 14); EG, experimental group, presenting anterior inferior mild crowding and installation of the lingual arch for space maintenance (n = 30). The position of the lower incisors was analyzed on computerized cephalometric tracings performed at the beginning of the monitoring (T1) and at the end, on the permanent dentition (T2). In order to evaluate the position of the incisors it was used Tweed and Steiner measurements: IMPA, 1.NB and 1-NB. The alterations were analyzed through the "t" test for paired samples, while the differences between the groups were analyzed through the "t" test for independent samples, as for sexual dimorphism. RESULTS: The values in T2 were greater in relation to T1 for all measurements on EG (IMPA, p = 0.038; 1.NB, p = 0.007 and 1-NB, p < 0.0001). On comparing the differences (T2-T1) between CG and EG, it can be gauged differences significantly superior for measure 1.NB (p = 0.002) and 1-NB (p < 0.0001) on EG. There was no statisticaly significant difference between genres. CONCLUSION: It was concluded that the lower incisors were projected after using the lingual arch to control the space on the transition from mixed to permanent dentition, however, within acceptable standards, not having difference between genres.

OBJECTIVE: To evaluate the mechanical properties of three glass ionomers cements (GICs) used for band cementation in Orthodontics. METHODS: Two conventional glass ionomers (Ketac Cem Easy mix/3M-ESPE and Meron/Voco) and one resin modified glass ionomer (Multi-cure Glass ionomer/3M-Unitek) were selected. For the compressive strength and diametral tensile strength tests, 12 specimens were made of each material. For the microhardness test 15 specimens were made of each material and for the shear bond strength tests 45 bovine permanent incisors were used mounted in a self-cure acrylic resin. Then, band segments with a welded bracket were cemented on the buccal surface of the crowns. For the mechanical tests of compressive and diametral tensile strength and shear bond strength a universal testing machine was used with a crosshead speed of 1,0 mm/min and for the Vickers microhardness analysis tests a Microdurometer was used with 200 g of load during 15 seconds. The results were submitted to statistical analysis through ANOVA complemented by Tukey's test at a significance level of 5%. RESULTS: The results shown that the Multi-Cure Glass Ionomer presented higher diametral tensile strength (p < 0.01) and compressive strength greater than conventional GICs (p = 0.08). Moreover, Ketac Cem showed significant less microhardness (p < 0.01). CONCLUSION: The resin-modified glass ionomer cement showed high mechanical properties, compared to the conventional glass ionomer cements, which had few differences between them.OBJETIVO: avaliar as propriedades mecânicas de três cimentos de ionômero de vidro (CIVs) utilizados para cimentação de anéis ortodônticos. MÉTODOS: foram utilizados dois CIVs convencionais (Ketac Cem Easy mix/3M-ESPE e Meron/Voco) e um CIV modificado por resina (Multi-Cure Glass ionomer/3M-Unitek). Para os testes de resistência à compressão e tração diametral, foram confeccionados 12 corpos de prova de cada material. Para os testes de microdureza, foram confeccionados 15 corpos de prova de cada material; para os testes de resistência de união ao cisalhamento, foram utilizados 45 dentes bovinos incluídos em resina acrílica, sobre os quais foi cimentada uma lâmina de anel ortodôntico com braquete soldado a ela para a realização dos ensaios. Para os testes de compressão, tração diametral e cisalhamento, foi utilizada uma máquina universal de ensaios a uma velocidade de 1mm/min; para os testes de microdureza Vickers, foi utilizado um microdurômetro com 200g de carga durante 15 segundos. Os resultados foram submetidos à análise estatística ANOVA, complementada pelo teste de Tukey ao nível de significância de 5%. RESULTADOS: os resultados demonstraram que o Multi-Cure Glass Ionomer apresentou resistência à tração diametral significativamente maior (p < 0,01) e maior resistência à compressão (p = 0,08) em relação aos CIVs convencionais. Além disso, o Ketac Cem apresentou microdureza significativamente maior que os demais materiais (p < 0,01). CONCLUSÃO: o CIV modificado por resina apresentou propriedades mecânicas superiores às dos CIVs convencionais, que, por sua vez, apresentaram poucas diferenças entre si.

Ao analisarmos os diversos agentes etiológicos do diastema mediano superior, foi encontrado, por eliminação destes agentes, que o freio é apenas uma entre as várias causas de diastema. Este freio é chamado de freio teto labial persistente. Um roteiro específico para diagnóstico do freio patológico foi elaborado, tendo por base a cronologia de desenvolvimento e características físico-clínicas associadas a diferentes imagens radiográficas de suturas palatinas medianas.

ABSTRACT Objective: The aim of this in vitro study was to evaluate and compare the effects of grinding, drilling, sandblasting, and ageing prefabricated teeth (PfT) on the shear bond strength (SBS) of orthodontic brackets, as well as the effects of surface treatments on the adhesive remnant index (ARI). Methods: One-hundred-ninety-two PfT were divided into four groups (n = 48): Group 1, no surface treatment was done; Group 2, grinding was performed with a cylindrical diamond bur; Group 3, two drillings were done with a spherical diamond bur; Group 4, sandblasting was performed with 50-µm aluminum oxide. Before the experiment, half of the samples stayed immersed in distilled water at 37oC for 90 days. Brackets were bonded with Transbond XT and shear strength tests were carried out using a universal testing machine. SBS were compared by surface treatment and by ageing with two-way ANOVA, followed by Tukey’s test. ARI scores were compared between surface treatments with Kruskal-Wallis test followed by Dunn’s test. Results: Surface treatments on PfT enhanced SBS of brackets (p< 0.01), result not observed with ageing (p= 0.45). Groups II, III, and IV showed higher SBS and greater ARI than the Group 1 (p< 0.05). SBS was greater in the groups 3 and 4 (drilling, sandblasting) than in the Group 2 (grinding) (p< 0.05). SBS and ARI showed a positive correlation (Spearman’s R2= 0.57; p< 0.05). Conclusion: Surface treatment on PfT enhanced SBS of brackets, however ageing did not show any relevance. Sandblasting and drilling showed greater SBS than grinding. There was a positive correlation between SBS and ARI.