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.
Abstract A new device was developed to enable the visualization and measurement of canine angulation while at the same time visualizing and measuring the force transmitted to adjacent teeth. This ...study aimed to evaluate the mesiodistal tilt angle of the upper canine brackets, the wire deflection, and its effects on adjacent teeth with five different slot designs of upper canines. Wires (0.020” and 0.019” x 0.025”) were tested on different five bracket types at five different distal angles. The force applied to adjacent teeth was measured as the angle was increased, and its consequences were observed in the posterior and anterior regions as well. The force tension (gf) was measured in a universal testing machine. Data were submitted to a 3-way ANOVA and Tukey’s test (α=0.05). For both arches, regardless of the type of tooth and bracket type, the highest means tension mean values were shown by the 20° angle, followed by the 15°,10°, and 5° angles, which differed statistically among themselves. Overall, for 5°, 10°, and 15° angles, conventional and versatile brackets showed significantly higher force values in all teeth, tip-edge and control brackets showed the lowest. The highest force values were observed in central and lateral incisors with conventional and versatile brackets and on first and second premolar teeth with self-ligating passive and control brackets. Conventional brackets presented the highest forces, tip-edge and control brackets showed the lowest. The teeth that suffered the greatest forces were lateral incisors, and those that suffered the least were second premolars.
Resumo Foi desenvolvido um novo dispositivo para permitir a visualização e medição da angulação canina ao mesmo tempo que se visualiza e mede a força transmitida aos dentes adjacentes. Este estudo avaliou o ângulo de inclinação mesiodistal dos braquetes caninos superiores, a deflexão do fio, e os seus efeitos nos dentes adjacentes com cinco diferentes desenhos de ranhuras dos caninos superiores. Os fios (0,020" e 0,019" x 0,025") foram testados em cinco diferentes tipos de braquetes e ângulos distais. A força aplicada aos dentes adjacentes foi medida a medida que o ângulo era aumentado, e as suas consequências foram observadas também nas regiões posterior e anterior. A tensão da força (gf) foi medida em uma máquina de ensaio universal (Instron). Os dados foram submetidos ao teste ANOVA 3 fatores e Tukey (α=0,05). Para ambos os arcos, independentemente do tipo de dente e tipo de braquete, os valores médios de tensão mais elevados foram mostrados pelo ângulo de 20°, seguido pelos ângulos de 15°, 10°, e 5°, que diferiram estatisticamente entre si. Em geral, para ângulos de 5°, 10° e 15°, os braquetes convencionais e versáteis apresentaram valores de força significativamente mais elevados em todos os dentes, braquetes tip-edge e controle apresentaram os mais baixos. Os maiores valores de força foram observados nos incisivos centrais e laterais com braquetes convencionais e versáteis e no primeiro e segundo pré-molares com braquetes auto-ligantes passivo e controle. Os braquetes convencionais apresentaram as forças mais elevadas, os braquetes controle e tip-edge apresentaram os valores mais baixos. Os dentes que sofreram as maiores forças foram os incisivos laterais, e os que sofreram menos foram os segundos pré-molares.
To compare tooth inclinations in different sagittal skeletal patterns and transverse maxillary relationships three-dimensionally.
A cross-sectional study carried out with 132 three-dimensional ...digital models in the complete permanent dentition divided into six groups (n=22); three groups with maxillary atresia: G1- skeletal class I, G2- skeletal class II and G3-skeletal class III; three groups without maxillary atresia: G4- skeletal class I; G5- skeletal class II and G6- skeletal class III. The comparison between the skeletal pattern was performed by the non-parametric tests of Kruskal Wallis and Dunn and between the groups by the non-parametric test of Mann Whitney.
Subjects with skeletal class II and maxillary atresia had a greater lingual inclination of the maxillary teeth than those with class I and III; Subjects with skeletal class II without atresia had a less lingual inclination of the mandibular molars than the other classes (p<0.05). The maxillary premolars showed no variation in dental inclination with atresia, independent of the skeletal class in G1, G2, and G3 (p>0.05). The mandibular premolars showed that the groups without atresia G4, G5, and G6 presented no significant difference (p>0.05). Lower premolars in skeletal class III malocclusion individuals with atresia had a more negative inclination than the others.
There is a difference in the inclination of posterior teeth between individuals with and without maxillary atresia and skeletal classes I, II, and III.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Aim: This study aims to evaluate the surface roughness and susceptibility to staining of bleached composite resin with 22% carbamide peroxide, as well as the effect of subsequent prophylaxis with ...NaHCO3 powder. Material and Methods: Forty disk-shaped (2 × 6 mm) specimens of composite resin (Z250 XT) were prepared. Half of the specimens were subjected to bleaching with 22% carbamide peroxide, and the other half were stored in artificial saliva. In sequence, all specimens were immersed in acai juice (Euterpe oleracea) for 4 h for 14 days, and subdivided into two groups. Group 1 samples were subjected to prophylaxis treatment, while group 2 samples were subjected to treatment with artificial saliva. Surface roughness (Ra) and color (ΔE*) were measured after polishing (T0), bleaching (T1), immersion in acai juice (T2), and application of NaHCO3 powder (T3) using a profilometer and a spectrophotometer. Results: Statistical analyses (analysis of variance and Tukey's test, p≤0.05) revealed that regarding color there was statistically significance for the factors in isolation, except for the factor bleaching. For both color and surface roughness there was statistically significant difference for the interaction, except for the interaction between NaHCO3 power and bleaching. Conclusion: The NaHCO3 air-powder polishing decreases the staining of the composite resin; however, it increases the surface roughness. With respect to the color variable, the whitening factor had no significant effect on the tested material; however, it increases surface roughness.
To assess the influence of elastomeric ligatures, subjected to a previous in vitro pigmentation process using different substances, on smile aesthetics during orthodontic treatment, from the ...perception of students and professionals.
Eight elastomeric ligatures of five commercial brands (3M/Unitek, American Orthodontics, Morelli, Ortho Technology, and Orthometric) (n=8) were immersed in coffee, Coca-Cola, and red wine for one minute per day, for 28 days; and another group of ligatures was immersed in artificial saliva. All samples were photographed and subsequently analyzed using the Adobe Photoshop software, by the RGB method. Afterwards, the pigmented ligatures were inserted in a patient wearing orthodontic brackets, and zoomed photographs of the smile were taken and presented to 40 evaluators, who filled in a satisfaction scale sheet to express their opinion on the smile aesthetics of each photograph. The color data were subjected to analysis of variance (ANOVA) and Tukey tests.
The substance with the highest pigmentation potential was coffee (p< 0.05) followed by red wine (p< 0.05). Comparison among the brands used in this study showed that American Orthodontics and Orthometric had the lowest degree of pigmentation when immersed in coffee and red wine (p< 0.05), respectively. However, the brand that showed the highest level of satisfaction among the evaluators was Ortho Technology.
The presence of pigmented elastomeric ligatures affected smile aesthetics, when compared with the control group.
Abstract The present study was evaluated the effect of different light activation and thermocycling methods on the shear bond strength (SBS) and on the adhesive remnant index (ARI) of metal brackets ...bonded to feldspathic ceramic. Hundred metal brackets were bonded to 20 porcelain cylinders, divided into four groups (n=25) based on light activation and thermocycling processes. The cylinders were etched with 10% hydrofluoric acid for 60 s and coated with two layers of silane. The brackets were bonded with Transbond XT composite resin. Light activation in Groups 1 and 3 was performed during 3 s using the VALO Ortho Cordless appliance with irradiance 3,200 mW/cm2 and in Groups 2 and 4 for 40 s using Optilight Max appliance with irradiance 1,200 mW/cm². The samples were stored in deionized water at 37°C for 24 h and the samples from Groups 1 and 2 were submitted to the SBS test at a rate of 1 mm/min, whereas the samples from Groups 3 and 4 were submitted to 7,000 thermal cycles (5°/55°C) before to the SBS test. The data were assessed by two-way analysis of variance and by Tukey’s test (a=0.05). No significant difference was observed between SBS means in the different light activation devices used. The samples subjected to thermocycling revealed lower SBS values (p≤0.05). There was predominance of score 0 for ARI in all groups. Therefore, the different light activation methods did not interfere in SBS, but thermocycling reduced SBS.
Resumo No presente estudo foi avaliado o efeito de diferentes métodos de fotoativação e ciclagem térmica na resistência da união ao cisalhamento (RUC) e no índice de remanescente adesivo (IRA) de braquetes metálicos colados à cerâmica feldspática. Cem braquetes metálicos foram colados em 20 cilindros de porcelana, divididos em 4 grupos (n=25) de acordo com o processo de fotoativação e ciclagem térmica. Os cilindros foram condicionados com ácido fluorídrico 10% por 60s e receberam 2 camadas de silano. Os braquetes foram colados com a resina composta Transbond XT. A fotoativação nos Grupos 1 e 3 foi realizada por 3 segundos usando o aparelho VALO Ortho Cordless com irradiância de 3200 mW/cm2 e nos Grupos 2 e 4 por 40 segundos utilizando o aparelho Optilight Max com irradiância de 1200 mW/cm². As amostras foram armazenadas em água deionizada a 37°C por 24 h, após as amostras dos grupos 1 e 2 foram submetidos ao teste de RUC, velocidade de 1 mm/min, e as amostras dos grupos 3 e 4 foram submetidas a 7.000 ciclos térmicos (5°/ 55°C) antes da RUC. Os dados foram submetidos à Análise de Variância dois fatores e ao teste de Tukey (a=0,05). Não foi encontrada diferença significativa entre as médias da RUC nos diferentes aparelhos de fotoativação. Quando submetidos à ciclagem térmica apresentaram menores valores de RUC (p≤0,05). O IRA mostrou predominância de escore 0 para todos os grupos. Conclui-se que os diferentes métodos de fotoativação não interferiram na RUC, porém a ciclagem térmica reduziu a RUC.
Aim: To evaluate the influence of social capital on self-perception related to orthodontic treatment need. Methods: A cross-sectional study was conducted with a sample of 578 11-16 years-old ...adolescents from a city in southern Brazil. Social capital was evaluated using the Social Capital Questionnaire for Adolescent Students (SCQ-AS). Index of Orthodontic Treatment Need (IOTN) assessed malocclusion and self-perception related to orthodontic treatment need. Sociodemographic aspects of adolescents were also evaluated. Individual analyses were performed, relating the study variables to the outcome, estimating the odds ratio with the respective confidence intervals of 95%. The variables with p<0.20 in the individual analyses were tested in the multiple logistic regression models, and those with p<0.10 remained in the model. Results: Social capital did not influence the self-perception related to orthodontic treatment need. Adolescents with high orthodontic needs were 5.35 (CI 95%: 2.68 to 10.65) times more likely to perceived orthodontic treatment need (p <0.05). Crowding and dental absence were associated with self-perception related to orthodontic treatment need (p <0.05). Conclusions: Social capital did not influence the self-perception related to orthodontic treatment need.
Aim: The aim of this study was to verify the frictional force during sliding mechanics in orthodontic tooth movement, using conventional metal brackets of the active and passive self-ligating types ...with stainless steel and copper nickel titanium archwires. Methods: This experimental in vitro study was conducted with conventional metal (Morelli, Sorocaba, SP, Brazil) brackets, active self-ligated (SLI Morelli, Sorocaba, SP, Brazil) and passive self-ligated (SLP Morelli, Sorocaba, SP, Brazil), with slot 0.022 x 0.028 inches and Roth prescription. The brackets were tested with rectangular section 0.019 x 0.025 inch copper nickel titanium and stainless steel archwires. For each type of bracket, 10 sets of plate/bracket/archwire segment (n=10) were fabricated. Non-parametric Kruskal Wallis and Dunn tests were used for comparison between types of brackets and Wilcoxon tests for comparison between types of archwires. Results: The results showed that the frictional force values were higher with copper nickel titanium than with stainless steel archwires (p<0.05). When copper nickel titanium archwires were used, the active self-ligating brackets showed higher frictional force values than the other types, followed by the conventional brackets. Lower frictional force values were observed with passive self-ligating brackets. For stainless steel archwires, no difference was observed between conventional and active self-ligating brackets, the passive self-ligating type presented lower frictional force values than the others. Conclusion: It was concluded that the higher frictional force was observed when active self-ligating brackets were associated with copper nickel titanium archwires. Lower frictional force was verified between passive self-ligating brackets combined with stainless steel archwires.
The aim of this study was to determine the influence of mouthrinses on the surface roughness of a nanofilled composite resin after toothbrushing. One hundred nanofilled composite resin specimens were ...prepared and randomly distributed into two groups-brushed and non-brushed-and then assigned to five subgroups, according to the mouthrinse solutions (n = 10): Colgate Plax Fresh Mint, Oral B, Cepacol, Colgate Plax, and artificial saliva. Each sample was immersed in 20 mL of the mouthrinses for 1 minute, 5 days per week, twice a day, for a 3-week period. The control group used in the study was one in which the specimens were not subjected to brushing and remained only in artificial saliva. Toothbrushing was performed once a week for 1 minute, for 3 weeks. Surface roughness measurements (Ra) were performed after the immersion period and toothbrushing, by means of a profilometer. Data were analyzed by two-way ANOVA and Tukey's test. Analysis revealed that the association between toothbrushing and Colgate Plax Fresh Mint produced the lowest surface roughness (p < 0.05). All other groups tested (Oral B, Cepacol, Colgate Plax, artificial saliva) exhibited no statistically significant differences between surfaces, whether subjected to toothbrushing or not (p < 0.05). It was concluded that the surface roughness of the nanofilled composite resin tested can be influenced by the mouthrinse associated with toothbrushing.
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