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Nanoparticles (NPs) are insoluble particles with a diameter of fewer than 100 nanometers. Two main methods have been utilized in orthodontic therapy to avoid microbial adherence or enamel demineralization. Certain NPs are included in orthodontic adhesives or acrylic resins (fluorohydroxyapatite, fluorapatite, hydroxyapatite, SiO2, TiO2, silver, nanofillers), and NPs (i.e., a thin layer of nitrogen-doped TiO2 on the bracket surfaces) are coated on the surfaces of orthodontic equipment. Although using NPs in orthodontics may open up modern facilities, prior research looked at antibacterial or physical characteristics for a limited period of time, ranging from one day to several weeks, and the limits of in vitro studies must be understood. The long-term effectiveness of nanotechnology-based orthodontic materials has not yet been conclusively confirmed and needs further study, as well as potential safety concerns (toxic effects) associated with NP size. Resumo Nanopartículas (NPs) são partículas insolúveis com diâmetro inferior a 100 nanômetros. Dois métodos principais têm sido utilizados na terapia ortodôntica para evitar a aderência microbiana ou a desmineralização do esmalte: NPs são incluídas em adesivos ortodônticos ou resinas acrílicas (fluoro-hidroxiapatita, fluorapatita, hidroxiapatita, SiO2, TiO2, prata, nanopreenchimentos) e NPs são revestidas nas superfícies de equipamentos ortodônticos, ou seja, uma camada fina de TiO2 dopado com nitrogênio nas superfícies do braquete. Embora o uso de NPs em ortodontia possa tornar acessível modernos recursos, pesquisas anteriores analisaram as características antibacterianas ou físicas por um período limitado de tempo, variando de 24 horas a várias semanas, por isso devem ser compreendidos os limites dos estudos in vitro. A eficácia de longo prazo de materiais ortodônticos com base em nanotecnologia ainda não foi confirmada de forma conclusiva, o que exige mais estudos, bem como potenciais preocupações de segurança (efeitos tóxicos) associadas ao tamanho da NP.

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

The objective of this study was to investigate the characteristics of force degradation and surface morphology of 9 brands of elastic ligatures over 6 weeks, both in vivo and in vitro, to provide some reference for clinical selection of appropriate elastic ligatures and determination of appropriate follow-up visit time.Choosing 9 kinds of brands of elastic ligatures (American Orthodontics, Ormco, 3M Grey, TP Orthodontics, Xihu, Yahong, Creative, Protect, 3M dusty blue), which are common in the market. For the in vivo study, 9 volunteers (5 males, 4 females, aged 22-26 years) were chosen to wear elastic ligature fixators, which were made to fix the elastic ligature in the mouth without bonding brackets on the teeth. The residual force and percentage of force degradation of elastic ligatures were estimated after 0, 1 hour, 2 hours, 8 hours, 1 day, 2 days, 1 week, 2 weeks, 4 weeks, and 6 weeks processed in vivo and in vitro (25°C dry air condition, 37°C artificial saliva, pH = 6.7 and oral environment); A 1-way analysis of variance and t test were used to identify statistical significance (P 0.05). The surface morphology of the initial state and after a 6-week process in vivo and in vitro were observed separately.The characteristics of force degradation and surface morphology of 9 brands of elastic ligatures were different over 6 weeks; With the extension of time, the tensile force declined, and the percentage of force degradation of all groups decreased sharply by about 9.1%-32.3% in the first day, then the rate reduced steadily. In addition, during the first day, the percentage of force degradation declined most sharply in the first hour (4.4%-16.5%). The percentage of force degradation of 9 elastic ligatures was reduced by about 11.3%-37.3% over 6 weeks in all groups. At the same time, the characteristics of force degradation in the same brand are that in vivo artificial saliva air (P 0.05). After a 6-week process, the surface morphologic defects were aggravated under a scanning electron microscope, corresponding to the change of mechanical properties in each brand.The mechanical properties of elastic ligatures are reduced with time extension and decreased greater in vivo than in vitro; According to the characteristics of force degradation of different brands of elastic ligatures, clinicians can choose the proper elastic ligatures at different stages of treatment, and adjust the follow-up visit time appropriately. For example, in alignment and leveling, the elastic ligatures with slow force degradation, such as Ormco, TP, and so on, maybe more suitable to ensure close contact between the archwire and the bracket. In the space-closing stage, the elastic ligatures with fast force degradation may be more appropriate to reduce the friction between the archwire and the bracket, such as 3M Grey, Yahong, Protect, and so on.

To develop a multifunctional orthodontic adhesive (QDA) using ZnO quantum-dots (ZnQDs) as modifier and investigate the antibacterial capability, fluorescence property as well as biocompatibility and bonding property.ZnQDs were synthesized using sol-gel method. XPS, XRD, FT-IR, HRTEM, SAED, DLS and spectrofluorimetry were used to characterize ZnQDs. ZnQDs were incorporated into Transbond XT adhesive paste with 20 %, 30 %, 40 % mass fraction, respectively, to form the multifunctional adhesives (QDAs). Antibacterial capability was evaluated with MTT kit, CFU count and Live/Dead Bacterial Staining Kit. Ultraviolet photography and spectrofluorimetry were used to confirm the fluorescence property of QDAs. Biocompatibility assay was performed on gingival fibroblasts and subcutaneous tissue of rats. Softening in solvent rate, shear bond strength and degree of conversion (DC) were measured.The synthesized ZnQDs presented excellent crystallinity and fluorescence properties. MTT assay, CFU count and CLSM analysis indicated that QDAs had significant antibacterial activity compared with Transbond XT adhesive paste. CCK-8 assay and Live/Dead cell staining analysis denied the cytotoxicity of QDAs and histological analysis proved that QDAs all had no inflammatory irritation to subcutaneous tissue. Softening in solvent, shear bond strength and DC evaluations indicated that 20 % mixing ratio of ZnQDs could enhance the resistance to degradation without influencing the bond strength and DC. Ultraviolet photography and spectrofluorimetry analysis proved the fluorescence capability of QDAs.ZnQDs can impart antibacterial and fluorescence properties to orthodontic adhesives without affecting biocompatibility and bonding performance. QDAs can be multifunctional orthodontic adhesives to reduce bacterial adhesion around brackets and help orthodontists remove residual adhesives precisely when needed.

This split-mouth randomized clinical trial aimed to evaluate the influence of dental enamel deproteinization with sodium hypochlorite on orthodontic accessories breakages using 2 orthodontic adhesives.Forty patients with indications for orthodontic treatment with fixed appliances were randomly divided into 2 groups according to the orthodontic adhesive used: Transbond XT (3M Unitek, Monrovia, Calif) (n = 20) and Orthocem (FGM Dental Products, Joinville, Santa Catarina, Brazil) (n = 20). A split-mouth trial was conducted in the maxillary teeth; the deproteinization process with 5% sodium hypochlorite was performed on the experimental side. The opposite side served as a control without deproteinization. The primary outcome was the number of orthodontic accessories breakages. The randomization was performed using the BioStat software (AnalystSoft Inc, Walnut, Calif). Single-blind was applied for patients. Orthodontic accessories were bonded according to the manufacturer's instructions. The accessories breakages were followed during the first 6 months of treatment. Intergroup comparisons were performed with t tests and 1 and 2-way analysis of variance.Thirty-nine patients concluded the trial. The Transbond XT group comprised 20 patients (9 male, 11 female), with a mean age of 20.77 ± 6.44 years. The Orthocem group included 19 patients (9 male, 10 female), with a mean age of 23.14 ± 7.98 years. The application of sodium hypochlorite before bonding did not influence the number of orthodontic accessories breakages (P = 0.867). The type of adhesive used, associated or not with the deproteinization, did not affect the number of orthodontic accessories breakages (P = 0.929).Enamel deproteinization with 5% sodium hypochlorite did not impact the number of orthodontic accessories breakages. In addition, the 2 bonding adhesives used showed similar clinical results, with or without the enamel deproteinization.The trial was registered at ensaiosclinicos.gov.br, ReBEC (no. RBR-39ntmjk).The protocol was not published before trial commencement.This research did not receive any grant from funding agencies.

In orthodontics, the torque generated forces from the rectangular archwires refine the teeth position. Literature shows only linear deformation in brackets during torqueing. The objective of this study was to evaluate a new phenomenon of tie wings rotation, an angular deformation in Stainless Steel (SS) brackets with SS and Beta-Titanium (β-Ti) archwires at various angles of twist. Maxillary central incisor SS 0.457 mm × 0.635 mm and 0.558 mm × 0.711 mm brackets, SS and β-Ti archwires of 0.431 mm × 0.635 mm and 0.533 mm × 0.635 mm sizes were used. Finite element analysis was performed in various bracket-archwire assemblies for simulated torque. Palatal root torque was applied and the gingival tie wings rotation was measured at selected points, from 5° to 30° angles of twist. The tie wings rotation for 30° twist with SS 0.533 mm × 0.635 mm archwire in 0.558 mm bracket ranged from 1.32° to 2.55° and with SS 0.431 mm × 0.635 mm archwire in 0.457 mm bracket from 0.71° to 1.73°. Similarly, with β-Ti 0.533 mm × 0.635 mm archwire in 0.558 mm bracket and β-Ti 0.431 mm × 0.635 mm archwire in 0.457 mm bracket, the tie wings rotation ranged from 0.73° to 1.38° and 0.39° to 0.93° respectively. The tie wings rotation were present in all the FE models. Higher archwire size, stiffness, and angles of twist showed increased rotation. Thus, clinicians should be aware of this tie wings rotation during torqueing as an additional factor for torque loss.

This study aimed to evaluate the shear bond strength (SBS) of four bonding agents used to bond metal brackets to zirconia under different storage conditions. Four bonding agents were used [FLC: (Fuji ORTHO LC), XT: (Transbond

This study aims to compare the static friction of untreated and fine particle shot peening (FPSP) treated stainless steel and ceramic bracket slots. A total of 60 pieces of stainless steel and 60 pieces of ceramic brackets (Roth prescription, 0.022×0.028 in

This double in vitro study and randomized clinical trial aimed to investigate the bonding failure rates of orthodontic brackets after enamel pretreatment with agents showing different particle sizes.For the in vitro study, 80 bovine teeth were randomly divided into 4 groups according to the pretreating method used and their particle sizes: erythritol (14 μm), glycine (18-22 μm), sodium bicarbonate (70 μm), and no pretreatment. Scanning electron microscopy microphotographs were performed after pretreatment. Then, brackets were bonded, and shear bond strength was calculated. For the clinical study, agents with low (erythritol) and high (sodium bicarbonate) particle sizes were chosen. Twenty consecutive patients willing to start fixed orthodontic treatment with vestibular stainless steel brackets were enrolled. Patients were randomly divided into 2 groups following a split-mouth design. Group A underwent a 5-second enamel pretreatment procedure with erythritol for teeth belonging to maxillary left and mandibular right quadrants, whereas the remaining quadrants were pretreated for 5 seconds with sodium bicarbonate powder. In group B, quadrants were inverted. Then, brackets were bonded on the vestibular surfaces of teeth, and patients were visited monthly for 12 months to assess bond failures. Periodontal evaluation of probing pocket depth, bleeding on probing, plaque index, and papilla bleeding index was conducted before bonding and after 1, 3, 6, and 12 months.The in vitro study showed that erythritol and control presented significantly higher shear bond strength values for other agents. Bicarbonate showed the lowest values. In the clinical study, 20 patients (aged 16.4 ± 3.9 years) were enrolled, and all completed the study. Erythritol showed a significantly lower failure rate (3%) than sodium bicarbonate (7.5%). Kaplan-Meier survival plots showed statistically significant differences in risk of failure between the 2 groups during the 12-month follow-up.Enamel pretreatment with erythritol can be a viable technique to reduce failure rates of orthodontic brackets.The trial was not registered.The protocol was not published before trial commencement.No funding or grant was received for this research.

The objectives of this study were to simulate long-term orthodontic tooth movement in en-masse retraction using the finite element method and investigate the effects of power arms on tooth movements when using a lingual appliance in comparison with a labial appliance.A 3-dimensional finite element model of the maxillary dentition was constructed with 0.018-in brackets and 0.016 × 0.022-in stainless steel archwire. An en-masse retraction was performed by applying retraction force at various lengths of the power arm (4, 6, 8, and 10 mm) to the second molar tube, and long-term tooth movements with the lingual and labial appliances were analyzed using the finite element method.Although lingual crown tipping of the incisor was more marked with the lingual appliance than with the labial appliance in the early phase of space closure, only a slight difference was evident after space closure. Although the power arm was effective for achieving better-controlled tooth movement and reducing vertical and transverse bowing effects, bodily movement of the incisor could not be achieved, and bowing effects could not be eliminated.To provide better torque control of the incisor or prevent a vertical bowing effect, the incorporation of extra torque into brackets of incisors was recommended, and the use of power arms for the lingual appliance. To prevent a transverse bowing effect, incorporation of the antibowing bend or application of retraction force from both buccal and lingual sides or temporary skeletal anchorage devices was recommended.

Objective: To evaluate the pulp chamber temperature rise (PCTR) in light-cure bonding of brackets with and without primer, in intact and restored mandibular central incisors (M1), maxillary first premolars (Mx4), and mandibular third molars (M8). Material and Methods: Ninety human teeth were included: M1 (n=30), Mx4 (n=30), and M8 (n=30). Light-cure bonding of brackets was performed in intact (n=60) and restored (n=30) teeth, with primer (n=60) or without (n=30) primer. PCTR was defined as the difference between initial (T0) and peak temperatures (T1), recorded with a thermocouple during light-cure bonding. Differences on PCTR between bonding techniques (primer vs. no primer), teeth types (M1 vs. Mx4 vs. M8), and teeth condition (intact vs. restored) were estimated by ANCOVA, with α=5%. Results: PCTR was significantly higher with the use of primer (2.05 ± 0.08oC) than without primer (1.65 ± 0.14oC) (p=0.02), and in M1 (2.23 ± 0.22oC) compared to Mx4 (1.56 ± 0.14oC) (p0.05), and no difference between intact (1.78 ± 0.14oC) and restored (1.92 ± 0.08oC) teeth (p=0.38). There was no influence of dentin enamel thickness in the PCTR (p=0.19). Conclusion: PCTR was higher in light-cure bonding of brackets with primer, especially in M1. Light-cure bonding seems less invasive without primer. RESUMO Objetivo: Comparar o aumento na temperatura da câmara pulpar (ATCP) na colagem de braquetes com fotoativação usando ou não primer, em dentes hígidos versus dentes restaurados, em incisivos centrais inferiores (ICI), primeiros pré-molares superiores (1PMS) e terceiros molares inferiores (3MI). Métodos: Foram incluídos noventa dentes humanos: ICI (n=30), 1PMS (n=30) e 3MI (n=30). A colagem de braquetes com fotoativação foi realizada em dentes hígidos (n=60) ou dentes restaurados (n=30), com primer (n=60) ou sem (n=30) primer. O ATCP foi definido como a diferença entre as temperaturas inicial (T0) e máxima (T1) registradas com um termômetro durante a colagem com fotoativação. As diferenças no ATCP entre as técnicas de colagem (com primer vs. sem primer), diferentes dentes (ICIvs.1PMSvs.3MI) e condição dos dentes (hígidos vs. restaurados) foram estimadas por ANCOVA, com α=5%. Resultados: O ATCP foi significativamente maior com o uso de primer (2,05 ± 0,08oC) do que sem primer (1,65 ± 0,14oC) (p=0,02), e no ICI (2,23 ± 0,22oC) do que no 1PMS (1,56 ± 0,14oC) (p0,05), e não houve diferença entre dentes hígidos (1,78 ± 0,14oC) e restaurados (1,92 ± 0,08oC) (p=0,38). Não houve influência da espessura da dentina e do esmalte no ATCP (p=0,19). Conclusão: O ATCP foi maior na colagem de braquetes com fotoativação usando primer, principalmente no ICI. A colagem com fotoativação parece ser menos invasiva sem primer.

The aim of the work was to develop a new transfer method for indirect bonding of brackets to improve the bond strength by applying a uniform contact pressure over the entire dental arch. This has a great potential to reduce the bracket loss rate during clinical treatment. A suitable shape memory polymer (SMP) was selected and prepared in the chemistry laboratory. This SMP applies a force to the brackets during bonding and thus increases the bond strength by applying uniform contact pressure. Various transfer trays were equipped with SMP platelets and the transfer of brackets from the plaster model to the real human tooth model was performed in vitro. The transfer accuracy and bond strength of the bonded brackets were investigated by 3D-overlay and shear tests, respectively. The transfer accuracy was technique sensitive and showed higher accuracy for the trays with SMPs and self-curing silicones than for the vacuum formed trays with SMPs. The bond strength of the indirectly bonded brackets with SMPs was on average 1–2 MPa higher than the bond strength of the brackets indirectly bonded with a conventional two-layer vacuum formed tray without SMPs. Thus, transfer trays with SMPs can provide a significant improvement in bond strength during indirect bonding after appropriate adjustment.

Transient inflammatory surface resorption, referred to as orthodontic induced inflammatory root resorption (OIIRR), is an iatrogenic consequence of orthodontic tooth movement. Systemic fluoride has been associated with a reduction of OIIRR. This study aimed to investigate the effects of water fluoridation levels on OIIRR in a clinically applicable human orthodontic model.Twenty-eight patients who required bilateral maxillary first premolar extraction as part of orthodontic treatment were selected from 2 cities with high and low water fluoridation of ≥2 ppm and ≤0.05 ppm, respectively. Patients were separated into high fluoride (HF) and low fluoride (LF) groups on the basis of water fluoridation levels. Bilateral maxillary first premolar teeth were subjected to 150 g of buccal tipping forces for 12 weeks with reactivation every 4 weeks. Teeth were extracted at the end of 12 weeks. Root resorption crater volume was determined using microcomputed tomography and 3-dimensional reconstruction.HF group showed significantly less mean root resorption volume on the palatal root surface when compared with the LF group (P = 0.025). This difference was specifically displayed at palatal apical regions (P = 0.041). When root resorption volumes from the zones of orthodontic pressure (buccal cervical, palatal apical) were combined, the mean difference between HF and LF groups was statistically significant (P = 0.045).Findings of the present study indicated a positive correlation between water fluoridation and the reduction of OIIRR, especially at the zones of orthodontic pressure, using a clinically relevant human orthodontic model.

The assessment of whether different orthodontic pliers used in bracket debonding have different effects on pain and sensitivity experience.Thirty-three patients (17 females, 16 males) with metal brackets were included in the study. Compressed air and freshly melted ice water were applied to each tooth (6-6) in upper and lower arch before bracket debonding (T0), just after debonding (T1), and 1 week after debonding (T2). Bracket remover plier (BRP) and Weingart plier (WP) were used to debond brackets. A numeric rating scale (NRS) was used to assess sensitivity for each tooth at T0, T1, and T2. Tooth pain was assessed for each tooth using NRS during bracket debonding.Statistically higher pain scores were found in teeth U4 (upper first premolar) (p = 0.017) and L6 (lower first molar) (p = 0.026) in Weingart plier group. No statistically significant difference was found during debonding in the other teeth between groups. Statistically high sensitivity score was found at T1 time point in tooth U3 (upper canine) by applying air stimulus in Weingart plier group (p = 0.024). There was no statistically significant difference between the sensitivity scores measured at T2 time point by applying air and cold stimuli between groups.Although the debonding pain scores were statistically significant in two teeth and the sensitivity score in one tooth, there was no clinical significance between the two pliers in terms of pain and sensitivity.Both debonding pliers gave clinically similar results in terms of pain and sensitivity.

Objectives: The aim of the present study was to evaluate the effects of 1.5 T and 3 T MRI on the adhesion between the orthodontic brackets and the teeth by evaluating the microleakage between the enamel, adhesive and brackets interfaces. Methods: 58 extracted human premolars which were received a standard bracket bonding procedure were randomly divided into three groups; control group (n = 20; no MRI), 1.5 T MRI group (n = 19; 20 min MRI exposure of 1.5 T) and 3 T MRI group (n = 19; 20 min MRI exposure of 3 T). The teeth were kept in distiled water for 2 weeks, and thereafter subjected to 500 thermal cycles. Then, specimens were sealed with nail varnish, stained with 0.5% basic fuchsin for 24 h, sectioned and photographed under a stereomicroscope. Microleakage was scored with regard to the adhesive–enamel and bracket–adhesive interfaces at the occlusal and gingival levels. Statistical analysis was accomplished by Kruskal–Wallis and Bonferroni–Dunn tests. Results: All of the groups exhibited statistically similar microleakage scores in the adhesive–enamel interface along occlusal margins (p>0.05, p = 0.331). The mean microleakage scores along gingival margins in the 3 T MRI group was significantly higher compared to the control group both in the adhesive–enamel and bracket–adhesive interfaces (pConclusions: 3 T MRI may weaken the adhesion between the enamel and the stainless steel orthodontic brackets.

A oclusão dentária normal é constituída fundamentalmente pelos dentes e ossos maxilares. Para iniciar o tratamento ortodôntico, o primeiro passo é a realização de um diagnóstico efetuado de forma correta, a montagem do aparelho ortodôntico fixo é uma etapa no qual deve-se ter muita atenção e destaque para o tratamento ortodôntico adotado, a colagem indireta é dividida em três etapas, sendo duas clínicas e uma laboratorial. A colagem indireta trata-se de um método, onde os bráquetes ortodônticos são desenhados baseados em modelos de gesso e fixados na boca, por meio de um processo de transferência. O objetivo deste trabalho é descrever um caso clínico, acompanhando o emprego da técnica de colagem indireta de bráquetes na superfície vestibular dos incisivos e caninos e pré-molares superiores. O paciente apresentava perfil harmônico, protusão da maxila e mandíbula, classe I esquelética. Após o planejamento do caso, optou-se por utilizar a técnica de colagem indireta. A técnica de colagem indireta requer menor tempo, pois favorece um maior posicionamento de forma correta na confecção da moldeira. levando em consideração os pontos positivos e negativos apresentados e debatidos ao longo de todo o artigo, podemos recomendar a colagem indireta como uma opção a ser considerada aos profissionais de ortodontia que visam a aplicação de trabalhos com excelência em resultados clínicos.

Background The purpose of this study was to evaluate the content and quality of YouTube videos on the topic of adult orthodontics. Methods Four Turkish keywords were searched on YouTube: ``orthodontic treatment in older ages'' (ileri yaslarda ortodonti tedavisi); ``orthodontic treatment in adults'' (yetiskinlerde ortodonti tedavisi); ``braces treatment in older ages'' (ileri yaslarda video information and quality index dis teli tedavisi); and ``braces treatment in adults'' (yetiskinlerde dis teli tedavisi). A total of 184 videos, ranked according to their relevance, were examined; out of these, 52 videos on the topic of adult orthodontics were included in the study. The information content score (with a scoring system consisting of 6 questions), reliability score, (VIQI), interaction index, and viewing rate of the videos were evaluated. The Mann-Whitney U test, Student's t test, and Spearman correlation coefficients were used for statistical analysis. Results Explanations provided on all videos included in the study were given by orthodontists, to inform patients. The average content score of the videos was 2.55 ± 0.99 out of 6, and the reliability score was 3.07 ± 0.92 out of 5. The VIQI score was found to be 16.05 ± 2.76 out of 20. A total of 34 (65%) of the videos were scored as as having poor content, and 18 (35%) had rich content. Rich-content videos were observed to be significantly longer (P Conclusions Although the information provided by YouTube videos about adult orthodontics was only moderately sufficient, this study found that YouTube is a reliable source of information.

Objectives To assess the super-elasticity of CuNiTi wires (Ormco, Glendora, Calif) according to their Austenite finish temperature (Af) and to the imposed displacement. The secondary objective was to compare the wire dimensions with the stated measurements and to study interbatch variability. Materials and Methods 10 types of CuNiTi wires (Ormco, Glendora, Calif) (n = 350) were investigated at 36 ± 1°C, with conventional brackets (Victory Series, 3M Unitek, Monrovia, Calif). Tensile test with coronoapical displacement ranging from 1 to 5 mm of the canine bracket was imposed. The wire dimensions were initially measured from two batches (n = 10). Results Dimensional heterogeneity varied by ± 2.00% compared to the manufacturer's data, and even up to 5.54% for 0.014-inch CuNiTi (P = .00069). However, all unloading forces were reproducible. In decreasing order, the forces delivered by a CuNiTi 27 were greater than those with CuNiTi 35 and 40. The super-elasticity was expressed only for displacements of 1 to 2 mm, at best up to 3 mm for 0.014-inch CuNiTi 27. Conclusions The value of Af as well as the amount of imposed displacement seem to influence the expression of the super-elasticity of CuNiTi wires and the amount of corrected malocclusion. Among the tested wires, under these experimental conditions, 0.014-inch wire could be suitable as a first archwire. CuNiTi 35, therefore, seems to offer the best compromise among the force level, the expression of super-elasticity and the amount of malocclusion correction.

Objectives To evaluate the effect of nitrogen (N)-doped titanium dioxide (TiO2) coated stainless steel brackets activated with natural visible light and dental operating lights on Streptococcus mutans concentration in the plaque of orthodontic patients at 30 and 60 days. Materials and Methods A total of 30 patients were recruited for this split-mouth study; 60 upper lateral incisor brackets constituted the study sample. A total of 30 brackets (15 right and 15 left) were coated with N-doped TiO2 using the (radio frequency) magnetron sputtering method. Plaque samples were collected at 30 days and 60 days after appliance placement. S mutans concentration was evaluated using real-time polymerase chain reaction. Results At both time intervals, the concentration of S mutans in the control group was greater than that in the study group (P = .005). In both the study and the control groups, the S mutans concentrations significantly increased from 30 to 60 days (P = .005). Conclusions N-doped TiO2, on exposure to natural visible light and dental operating light, was effective in reducing the plaque concentration of S mutans in orthodontic patients. The efficacy was better at 30 days than at 60 days after placing the orthodontic appliances.

Failure of brackets is a common problem in orthodontics. This affects the treatment time, cost, and compliance of the patient. This study was conducted to estimate the bracket failure rate and the related factors for the long term. Methodology. This ambidirectional cohort study included 150 nonsyndromic orthodontic patients undergoing fixed appliance therapy for the last two years. The same patients were followed for 7 months. Different variables related to bracket failure were evaluated. The available data were analyzed descriptively, and the Kaplan-Meier estimate was used to measure the bracket survival rate from the date of bonding to failure. Results. A total of 180 bracket bond failures in the 150 included patients (52.2% males and 47.8% females) with a median age of 17 years (range 10-25 years). 69% of brackets failures were reported within the first 6 months after bonding. About 58.3% of bracket failure was noticed in adolescent patients before the age of 18 years. The majority of the cohort (81.1%) has good oral hygiene. The failure rate in patients with normal overbite was 41.1%, in decreased overbite cases was 15%, while in deep bite cases the failure rate was 43.9% with a statistically significant difference. Adults show less bracket failure (41.7%) than adolescent patients (58.3%). More bracket failure was noted in the lower arch (55%) than the upper arch (45%), and there were more bond failures posteriorly (61%) than on the anterior teeth (39%). Majority (41.1%) of the bracket failed on round NiTi wires. Conclusion. The bracket failure rate was 6.4%, with most bracket failure occurring in the first 6 months after bonding with individual difference. There was more incidence of bond failure in an increased overbite, adolescents, lower arch, posterior teeth, and lighter alignment wires.

Made available in DSpace on 2022-04-29T08:32:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Introduction: Fixed orthodontic appliances create areas of stagnation for dental biofilms and make it difficult to clean the teeth; therefore, there is a risk of developing incipient caries lesions during the orthodontic treatment. The objective of this study is to determine if the combination of 2 different therapies, phototherapy by blue light (BL) and the antimicrobial 0.12% chlorhexidine (CHX) on enamel, orthodontic brackets, and elastics, would reduce or inhibit mature Streptococcus mutans biofilms and their regrowth on these substrates 24 hours after the application of the treatment; and if this treatment would interfere with bracket adhesion to the enamel. Methods: Biofilms of S. mutans UA159 were formed for 5-days over samples composed of a bovine enamel, orthodontic bracket, and orthodontic elastic. Then, the specimens were treated with 0.89% NaCl for 1 minute, BL for 12 minutes (72 J/cm2), 0.12% CHX for 1 minute, and BL for 12 minutes, followed by 0.12% CHX for 1 minute (BL+CHX). Biofilm was evaluated by colonies forming units and dry weight immediately after treatments and 24 hours after treatments (regrowth). The pH of the spent media was measured on the fifth and sixth days. Biofilm formation on the samples after the treatments and regrowth was visually evaluated by confocal laser scanning microscopy. Shear bond strength (SBS) between bracket and enamel was evaluated using a universal testing machine at a crosshead speed of 1 mm/min. After bonding, specimens were thermocycled (500× at 5-55°C), treated, and thermocycled again. Results: After 5 days of biofilm formation, BL+CHX significantly reduced the bacterial viability on enamel compared with NaCl (P = 0.004) and BL (P = 0.014). For bracket and elastic, all the treatments resulted in similar bacterial viability (P ≥0.081). In the regrowth, CHX and BL+CHX significantly reduced the bacterial viability in the enamel compared with the NaCl (P ≤0.015) and BL (P ≤0.013). For bracket, BL+CHX significantly reduced the bacterial viability compared with NaCl (P = 0.008) and BL (P = 0.009). For the elastic, BL+CHX eliminated the biofilms from the substrate. CHX and BL+CHX significantly reduced the bacterial viability 24 hours after treatment for all substrates (P ≤0.05). The media pH significantly increased when samples were treated with CHX and BL+CHX (P ≤0.001). Confocal laser scanning microscopy images visually showed an abundant quantity of red cells in the samples treated with BL+CHX. There was no difference in the SBS between the treatments (P ≥0.932). Conclusions: The association between BL and CHX reduced S. mutans biofilm and its regrowth on an in vitro orthodontic model and did not influence the bonding strength between bracket and enamel. Department of Cariology Operative Dentistry and Dental Public Health Indiana University School of Dentistry Department of Orthodontics and Pediatric Dentistry School of Dentistry at Araraquara UNESP São Paulo State University Department of Biomedical Sciences and Comprehensive Care Indiana University School of Dentistry Department of Orthodontics and Pediatric Dentistry School of Dentistry at Araraquara UNESP São Paulo State University

Introduction As a result of the rapid spread of the disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the World Health Organization (WHO) declared a global pandemic on March 11, 2020. Governments around the world adopted various measures to stop or slow the spread of coronavirus disease 2019 (COVID-19). One widely used measure was “lockdown”; workers who could work from home were instructed to do so, and nonessential businesses – including dental clinics -- were closed for weeks or months. The purpose of this investigation was to document the incidence of fixed orthodontic appliance failures and the periodontal health status of patients undergoing fixed orthodontic treatment during and after the lockdown period. Methods The sample comprised 350 orthodontic patients (mean age 16.85 ± 2.59 years; 249 female, 101 male) who underwent orthodontic and periodontal examinations in Adıyaman, Turkey after a mean lockdown period of 103.7 ± 21.3 days. Frequencies of orthodontic bracket, elastic ligature, molar band, and miniscrew failures and of oral ulcers were recorded and periodontal parameters were assessed. The effects of sex, age, and the bracket systems used in the patients on the frequencies of these failures were analyzed. Results It was revealed that 15.42% (n=54) of all patients had at least one bracket bonding failure and 8.16% (n=4) of the patients with miniscrew implantation had at least one miniscrew failure. The incidence of bracket bonding failure was significantly higher in men than in women. No significant relationship was found between periodontal parameters and bracket bonding failure. Plaque and gingival scores were higher than those reported for a similar population before a lockdown. Conclusions The results indicated that orthodontic appliances may have higher frequencies of failure during a lockdown when compared with normal times and lockdown periods may worsen the periodontal health status of the patients.

An effective adhesion of the orthodontic brackets on the tooth surface is one of the factors that influence the outcome and duration of the orthodontic treatment, as it is one of the reasons of bracket debonding that lead to additional unplanned appointments, increasing the length of the treatment. In recent years there has been an increase in the demand for bleaching treatments, which are based on the use of acid agents that affect the enamel in order to eliminate stains and improve the aesthetics of the teeth. The modifications on the structure of the enamel caused by the bleaching agents might have an effect on the adhesion of the bonding agents used in orthodontics. The aim of this systematic review is to analyze the effects of the different bleaching agents (hydrogen peroxide and carbamide peroxide) on the the shear bond strength (SBS) of samples which are subjected to orthodontic treatments and how the type of the brackets, the adhesive techniques and the bleaching agents could affect each other and the SBS value.

WOS:000920098500003 Duration of orthodontic treatment becomes major concern. The present study compared shear bond strength (SBS) and adhesive remnant index (ARI) values of different adhesive systems with different application methods on rebonding process of retrieved orthodontic brackets. Eighty premolar teeth were equally divided into five groups. Transbond XT (TXT) which belongs to total-etch system was used in Group 1 as the control group. Nova Compo-SF (NC) and Vertise Flow (VF) (Kerr Dental, Italy) which are self-adhering flowable composites were used in Group 2 (NC+etch) and Group 3 (VF+etch) respectively with additional etching before application. Group 4 (NC) and Group 5 (VF) were used by following instructions of each brand. The brackets were debonded with a bracket removing plier and rebonded with the same procedures after sandblasting of the bracket and surface cleaning of the enamel. SBS and ARI were measured for each sample. Comparison between all groups was performed by Kruskal-Wallis test and chi-square test. The highest SBS was observed in NC+etch (median = 11.44, mean = 13.49±9.42), followed by NC (median = 10.17, mean = 11.35±6.55), TXT (median = 6.36, mean = 8.06±6.33), VF+etch (median = 5.68, mean = 6.75±4.58), and VF (median = 2.62, mean = 2.92±2.57), respectively. ARI 1 was observed in 81.3% of TXT whereas 62.5% of NC+etch. ARI 1, 2, and 3 were equally distributed in VF+etch group (31.3%). ARI 5 was observed in 37.5% of NC and 62.5% of VF. Analyses referred to statistically significant differences between five groups regarding both SBS and ARI (p < 0.001). As NC showed the highest SBS on rebonding process, it can be a promising alternative to TXT which is the gold standard. © Penerbit Universiti Sains Malaysia. 2022 This work is licensed under the terms of the Creative Commons Attribution (CC BY) (http://creativecommons.org/licenses/by/4.0/). All Rights Reserved.

Orthodontic treatment with fixed mechanotherapy using appliances and permanent retainers bonded after treatment is a routine procedure performed in clinical dentistry. Patients with braces or retainers sometimes need to undergo magnetic resonance imaging (MRI) for various reasons. Radiologists do not know the exact impact of the materials used in orthodontics on the diagnostic image quality of MRI scans.The aim of the study was to evaluate the influence of different types of orthodontic brackets and permanent retainers on the diagnostic image quality of MRI scans.Twenty patients with bonded brackets (stainless steel buccal/labial, stainless steel lingual, ceramic self-ligating with metal slots, ceramic, and polycarbonate) and 18 patients with bonded fixed retainers (titanium, fiber-reinforced composite, multi-stranded stainless steel, and different combinations of permanent retainers) participated in the study. The same adhesive was used for bonding. Cranial MRI scans of 6 regions were acquired for each subject, using a 1.5T MAGNETOM machine. Six radiologists evaluated the images and provided scores based on the modified receiver operating characteristic (ROC) analysis of distortion. The paired Wilcoxon signed-rank test was used to assess differences between the materials and the anatomic sites with regard to the distortion rating scale. Cohen's kappa coefficient (κ) was applied to establish the interrater reliability.A statistically significant difference was found between stainless steel brackets (both buccal/ labial and lingual) and all other experimental materials in terms of mean distortion scores (p = 0.020 or p = 0.024). The interrater reliability proved to be high.Stainless steel buccal/labial and lingual brackets caused maximum distortion of the images, which became non-diagnostic; hence, such brackets should be removed before MRI. Ceramic and polycarbonate brackets as well as fiber-reinforced composite retainers did not distort the images; thus, they need not be removed. Ceramic self-ligating brackets with metal slots, titanium retainers, multi-stranded stainless steel retainers, and combinations of fixed retainers caused minimal distortion; however, the images were still diagnostic. Hence, patients using these materials may not need to have them removed before MRI.

Fluoride has been shown to be shown to be an effective agent in the prevention of caries during orthodontic treatment. Resin modified glass ionomer cements possess therapeutic anticariogenic properties acting as a fluoride reservoir and releasing fluoride into the environment, particularly at low pH where there is a threat of enamel demineralisation and white spot lesions (WSL's). Patient compliance to instructions in standard oral hygiene measures limits the success of caries prevention and the routine use of glass-ionomer cements can mitigate the lack of compliance, although RMGIC's are not a panacea against WSL's. The adhesion of GIC's to the enamel surface is a physico-chemical bond rather than a mechanical bond which reduces the risk of iatrogenic damage to the enamel when bonding and debonding attachments. RMGIC's can be recommended as a bonding adhesive for all attachments but one needs to be selective when bonding molar attachments to avoid occlusal interferences as masticatory forces can be high in these areas.

Background: This study aimed to evaluate the effect of the combination of zinc oxide nanoparticles (NPs) and chitosan NPs on the shear bond strength (SBS) of composites used for orthodontic bonding. Methods: Four groups of composites (n = 10), containing 0%, 1%, 5%, and 10% w/w NP fillers, respectively, were used to bond brackets to the surfaces of 40 intact bovine incisors. After 1000 rounds of thermal cycling at 5°C–55°C, all specimens were mounted in acrylic blocks. The SBS was tested using a universal testing machine, and the adhesive remnant index scores were registered using a stereomicroscope. Data were statistically analyzed using a 1-way ANOVA and the Kruskal–Wallis test. Results: The highest value of mean SBS was found in the control group, and the lowest value was found in the group with composite containing 10% NPs. The adhesive remnant index did not differ significantly among the groups (P = 0.823). Conclusions: Incorporation of 1% and 5% zinc oxide and chitosan NPs had no effect on the SBS of composite, and the obtained SBS values were similar to that of the control group.

Summary Aim To test the null hypothesis that there was no difference in treatment efficiency between therapies undertaken with conventional (CBs), passive self-ligating (PSLBs) or active self-ligating (ASLBs) brackets. Materials and methods An electronic search was performed in 3 data bases (Pubmed, Web of Science, Cochrane Library) from their origin up to January 2019. Additional references were hand searched. Search was strictly restricted to randomized controlled trials (RCTs) and split-mouth design studies (SMDs). RCTs and SMDs were initially processed separately and subsequently combined in a network meta-analysis. The following variables were evaluated: treatment duration, number of visits, occlusal outcomes, alignment rate, transverse arch dimensional changes, incisor position modification, rate of space closure, anchorage loss, bond failure, root resorption, perception of discomfort during the initial phase of alignment, time to ligate in or to untie an archwire, periodontal variables, quality of life. Results On 229 papers, 30 RCTs and 9 SMDs were finally included in this study. Out of 85 comparisons, 16 only revealed statistically significant differences. It was quicker to untie and ligate an 0.014 NiTi arch from/in 6 ASLBs anterior ceramic brackets compared to 6 ceramic CBs. It was also more painful to insert and remove an 0.019 × 0.025 SS wire in/from PSLB's brackets compared to CB's attachments. Compared to conventional brackets, there was less maxillary incisor proclination with PSLBs in non-extraction cases. Moreover, there was less bleeding on probing 4-5 weeks after bonding with PSLBs compared to CBs brackets. The only significant difference between ASLBs and PSLBs was that alignment was 10 days faster with active self-ligating braces compared with passive self-ligating braces even if treatment duration between ASLBs and PSLBs was not significantly different. The network meta-analysis revealed that IMPA was greater in extractions cases with CBs compared with both ASLBs (+2,5°) and PSLBs (+1,6°). Conclusions The vast majority of the studied variables did not show any significant differences between the three types of brackets. The most significant findings were that it was quicker to insert and remove archwires from ASLBs compared to CBs, and it was more painful to insert and remove an 0.019 × 0.025” stainless steel wire in/from PSLBs compared to CBs. The major difference between ASLBs and PSLBs was that alignment was 10 days faster with active self-ligating braces compared with passive self-ligating braces even if treatment duration between ASLBs and PSLBs was not significantly different. Most of the claims put forward by the suppliers were not substantiated by our network meta-analysis.

Purpose: This study sought to compare enamel surface morphology and orthodontic bracket re-bonding strength after phosphoric acid- or erbium-doped yttrium aluminum garnet (Er:YAG) laser-mediated re...

Summary Objective This study aimed to evaluate the failure incidence of brackets with at least six months follow-up between self-etch primer and conventional etch/primer, as well as to investigate the clinical duration of the bonding process and the amount of adhesive remnant index (ARI). Methods Electronic search was conducted in databases including PubMed, Scopus, Web of Science, ProQuest, ClinicalTrials.gov, and ICTRP (International Clinical Trials Registry Platform). The electronic search targeted only randomized clinical trials and was limited from January 2000 to June 2021. Delphi list is used to evaluate the risk of bias and Stata Version14.2 software was used. This systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and recorded on the Ethics Committee of Research Institute of Dental Sciences, SBMU (IR.SBMU.DRC.REC.1398.240). Results Out of 2288 extracted studies, 30 of them entered the full-text evaluation process. According to the inclusion criteria, 15 studies entered this systematic review. Containing 607 participants and 10,563 brackets/teeth. All the included studies were of randomized clinical trials (RCT) design with either parallel or split-mouth design. Comparing the two groups, the risk difference effect (RD) = 0.007 CI 95% (−0.004,0.018) indicated a neglectable difference in the risk of bracket failure during treatment between the two groups. The index I2 = 53.9% indicated moderate heterogeneity in the results. Furthermore, the P-value = 0.007 indicated statistical insignificance between the two interventions in terms of failure rate. The clinical duration of bonding time analysis were equal to SMD _Cohen = −2.67 CI95% (−3.49, −1.85), which indicated a statistically significant reduction in clinical process time, using the self-etch primer. Data synthesis for adhesive remnant index could not be conducted due to heterogeneity among included studies. Conclusions There was no difference between the self-etch primer and conventional etch/primer in bracket debonding at a medium level of evidence, However, there was statistically significant reduction in clinical bonding time using self-etch primer.

The aims of this clinical study were to evaluate the Color change - ΔE (based on spectrophotometry and visual analysis) and luminosity - L* (based on spectrophotometry) of dental enamel surface (after orthodontic treatment) around the area where orthodontic brackets were fixed, based on different cementing materials such as a resin (R group) and resin-modified glass ionomer cement (RMGIC group). The split-mouth study initially comprised 14 patients. Orthodontic brackets were fixed to the upper central incisors with resin or RMGIC. The color of the buccal surface of each tooth was measured through spectrophotometry and visual examination before the bracket-fixation process. Four individuals were excluded during the follow-up; thus 10 patients were evaluated (n=10). Brackets were removed after 12 months of orthodontic treatment, tooth color measurement and visual examination were performed again, and Adhesive Remaining Index (ARI) was also measured. ΔE and L* results were subjected to Student's t-test and by repeated-measures analysis of variance, respectively (α=0.05). ARI data were analyzed in percentages. There was statistically significant difference in ΔE between groups; the R group showed statistically higher values of L* after orthodontic treatment. ARI of 2 and 3 prevailed in the RMGIC group, whereas the R group presented 0 and 1. After orthodontic treatment, the RMGIC group presented smaller changes in ΔE, and the increase in the white scale was observed on the enamel surface around the area where brackets were fixed in the R group. The visual analysis did not show color change on the evaluated teeth. Resumo Os objetivos deste estudo clínico foram avaliar a alteração de cor - ΔE (baseada em espectrofotometria e análise visual) e luminosidade - L* (baseada em espectrofotometria) da superfície do esmalte dentário (após tratamento ortodôntico) ao redor da área onde os braquetes ortodônticos foram fixados, com base em diferentes materiais de cimentação, como resina (grupo R) e cimento de ionômero de vidro modificado por resina (grupo RMGIC). Estudo boca dividida foi inicialmente composto por 14 pacientes. Os braquetes ortodônticos foram fixados nos incisivos centrais superiores com resina ou RMGIC. A cor da superfície vestibular de cada dente foi mensurada por espectrofotometria e avaliada por exame visual antes do processo de fixação dos braquetes. Quatro indivíduos foram excluídos durante o acompanhamento; assim, 10 pacientes foram avaliados (n=10). Os braquetes foram removidos após 12 meses de tratamento ortodôntico, a mensuração da cor do dente e o exame visual foram realizados novamente, e o Índice de Remanescente do Adesivo (IRA) também foi mensurado. Os resultados ΔE e L* foram submetidos ao teste t de Student e à análise de variância para medidas repetidas, respectivamente (α=0.05). Os dados do ARI foram analisados em porcentagens. Houve diferença estatisticamente significativa no ΔE entre os grupos; o grupo R apresentou valores estatisticamente maiores de L* após o tratamento ortodôntico. O IRA 2 e 3 prevaleceu no grupo RMGIC, enquanto o grupo R apresentou 0 e 1. Após o tratamento ortodôntico, o grupo RMGIC apresentou menores alterações no ΔE e o aumento da escala branca foi observado na superfície do esmalte ao redor da área onde os braquetes foram fixados no grupo R. A análise visual não mostrou mudança de cor nos dentes avaliados.

Objective The study aims to investigate the shear bond strength (SBS) between silicate ceramic restorations and ceramic brackets after different pretreatments and aging methods. Material and methods Leucite (LEU) and lithium disilicate (LiSi) specimens were pretreated with (i) 4% hydrofluoric acid + silane (HF), (ii) Monobond Etch&Prime (MEP), (iii) silicatization + silane (CoJet), and (iv) SiC grinder + silane (SiC). Molars etched (phosphoric acid) and conditioned acted as comparison group. SBS was measured after 24 h (distilled water, 37 °C), 500 × thermocycling (5/55 °C), and 90 days (distilled water, 37 °C). Data was analyzed using Shapiro–Wilk, Kruskal–Wallis with Dunn’s post hoc test and Bonferroni correction, Mann–Whitney U, and Chi2 test (p Results LEU pretreated with MEP showed lower SBS than pretreated with HF, CoJet, or SiC. LiSi pretreated with MEP resulted in lower initial SBS than pretreated with HF or SiC. After thermocycling, pretreatment using MEP led to lower SBS than with CoJet. Within LiSi group, after 90 days, the pretreatment using SiC resulted in lowest SBS values. After HF and MEP pretreatment, LEU showed lower initial SBS than LiSi. After 90 days of water storage, within specimens pretreated using CoJet or SiC showed LEU higher SBS than LiSi. Enamel presented higher or comparable SBS values to LEU and LiSi. With exception of MEP pretreatment, ARI 3 was predominantly observed, regardless the substrate, pretreatment, and aging level. Conclusions MEP pretreatment presented the lowest SBS values, regardless the silicate ceramic and aging level. Further research is necessary. Clinical relevance There is no need for intraoral application of HF for orthodontic treatment.

Background Direct orthodontic bracket bonding consumes significantly more chairside time in comparison to indirect bonding. The primary drawback of indirect bonding is incomplete penetration of the curing light through transfer trays, leading to bracket bond failure. The primary objective in a clinical setting is to minimize the chairside time. This technique of indirect bonding reduces chairside time, is economical, utilizes minimum armamentarium, and provides adequate light penetration and accuracy. Technique Impressions were made, casts were poured and marked for the desired bracket position as per MBT prescription. Bonding agent was used to stabilize the brackets on the working model. A 3D printing pen and polylactic acid (PLA) filament were used to fabricate transfer trays for indirect bonding. The tray with brackets held in the desired position was transferred to the oral cavity and cured. Conclusions Fabrication of complete or partial transfer trays for indirect bonding using PLA with the help of a 3D printing pen is a precise, easy-to-use, economical, and reliable method that reduces chairside time. Clinical significance When compared with other methods of indirect bonding, the PLA transfer tray made with a 3D printing pen was easy to fabricate with brackets held firmly in the tray for a precisely desired position. The tray fit snugly and permitted light curing of composite from all surfaces of brackets and removal of flash. This method significantly reduced the overall time of the indirect bonding procedure.

Aim of the Study: The aim of the present study was to analyze the accuracy of 0.022 inch slot of stainless steel and ceramic orthodontic brackets marketed by different manufacturers. Materials and Methods: An in vitro study was done on upper left central incisor bracket of MBT 0.022 slot of American orthodontics (AO), 3M Unitek, Ormco with each 20 of stainless steel and ceramic brackets divided into six groups, and the total sample was 120. The brackets were scanned with stereo microscope of Magnus Company and Image Pro plus analysis software was used to evaluate the mesial face and base, distal face and base. Results: Comparison in between the groups of stainless steel showed that 3M Unitek brackets showed higher slot widths as compared to AO and Ormco which was statistically significant (P < 0.05). Comparison in between the groups of ceramic brackets of AO brackets showed higher slot widths as compared to Ormco and 3M Unitek ceramic brackets which was statistically significant (P < 0.05). Conclusion: By this study, there was a difference between stated values and measured values of brackets displaying inaccuracies in dimension. A clear impreciseness about the appliance could be needed during the finishing and detailing stage to avoid loss of torque control due to slot oversize and the divergence of slot walls.

Objectives: The aims of this study were to investigate the effect of the working archwire intra-aging on the rate of upper first premolar space closure and to measure frictional resistance during space closure. Methods: A total of 28 subjects participated in this study. All patients were treated by upper first premolar extraction. Subjects were subdivided into 2 groups: non-replacement side: consisted of the right or left sides of the upper arch where space closure was done using the same 0.019 × 0.025-inch SS; replacement side: comprised the other side of the subjects where the working archwire was replaced with a new one each visit. The working archwire in the upper arch was split into 2 halves (new archwire on one side and old one on the other side); each one-half was connected to the other in the midline by a joining shim. Elastomeric chain was used to close extraction spaces. The amount of space closure (mm) was recorded each visit for 3 months. Results: In the non-replacement side, the rate of upper space closure was 0.80 mm/month coronally and 0.75 mm/month gingivally. In the replacement side, it was 0.69 mm/month coronally and 0.67 mm/month gingivally (p > 0.05). Mean frictional force for the non-replacement side was 3.58 ± 1.20 N, and it was 2.43 ± 1.21 N for the replacement side (p < 0.01). Conclusions: Intraoral archwire aging has no effect on the rate of upper premolar space closure/month although frictional resistance of the aged archwire was higher than of the new one. Clinical relevance No need to replace 0.019 × 0.025-inch SS every visit during space closure to overcome corrosion and frictional resistance. The study was supported by the Deanship of Research at Jordan University of Science and Technology (research grant number 53/2019).

Made available in DSpace on 2022-04-28T19:42:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Introduction: This split-mouth randomized clinical trial aimed to compare the enamel surface roughness (SR) and color alteration after bracket debonding and polishing using 2 systems. Methods: After removal of excess adhesive using a 12-blade tungsten carbide bur on a low-speed handpiece, a randomized polishing procedure using Sof-Lex discs was applied on 1 side (n = 36) and Sof-Lex Spiral Wheels on the contralateral side (n = 36). Dental replicas were obtained with epoxy resin before bracket bonding and after tooth polishing. The SR was evaluated using a profilometer. The color was assessed using an Easyshade spectrophotometer before bracket bonding, immediately after tooth polishing, and 30 days after polishing. Two-way analysis of variance and t tests were applied for statistical analysis. Results: The SR of enamel showed similar results between the polishing systems (P = 0.309) and between moments (before bracket bonding and after tooth polishing) (P = 0.317). The color change was also similar between the polishing systems (P >0.05). Conclusions: The Sof-Lex discs and Sof-Lex Spiral Wheel polishing systems used after removal of excess adhesive using a 12-blade tungsten carbide bur on a low-speed handpiece did not appear to significantly damage the enamel surface, and the color change was similar between them. Division of Orthodontics University Ceuma Department of Orthodontics State University of São Paulo Department of Orthodontics Uninga University Center

Objective: The purpose of this review is to systematically assess the existing literature and summarize the evidence regarding the effect of erbium-doped yttrium aluminum garnet (Er:YAG) laser on e...

This study aims to evaluate the feasibility of chlorhexidine (CHX)-loaded poly-L-glycolic acid (PLGA) nanoparticles as a modifier of a commercial orthodontic adhesive via the assessment of physicochemical, biological, and mechanical properties at tooth-bracket interface. CHX-loaded PLGA nanoparticles were synthesized using double emulsion-solvent evaporation method and characterized using transmission electron microscopy and Raman analysis. CHX-loaded PLGA nanoparticles in Transbond XT orthodontic adhesive were prepared using two different concentrations of the CHX (25 and 50%) and characterized for degree of conversion (DC), antimicrobial, and cytotoxicity testing. Bonded specimens were tested for shear bond strength (SBS) and adhesive remnant index (ARI) at tooth-bracket interface. The synthesized PLGA nanoparticles averaged between 60 and 80 nm in size. After loading CHX inside PLGA nanoparticles, the morphology of the PLGA nanoparticles was considerably changed. Orthodontic bracket bonded with 25% CHX-loaded PLGA-modified adhesive demonstrated DC scores similar to control group. Both 25 and 50% CHX-loaded PLGA-modified adhesive specimens showed higher antibacterial activity against S. mutans compared to control group. The least mean SBS values were exhibited by 50% CHX-loaded PLGA-modified adhesive samples, while a statistically significant difference was observed in the mean ARI values among all study groups at all-time points (p = .018). This study indicates that the addition of CHX-loaded PLGA nanoparticles in Transbond XT achieved stable bonds with enhanced antimicrobial and mechanical properties.

Objectives To compare the efficacy of casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP) MI Varnish (GC America, Inc, Alsip, IL) and ProSeal (Reliance Orthodontic Products, Itasca, IL) sealant in preventing the development of white spot lesions (WSLs) in orthodontic patients. Materials and Methods This prospective randomized clinical trial included 40 orthodontic patients 12–17 years of age. One group had sealants placed on their anterior maxillary teeth, with reapplications every 3 months. The other group had MI Varnish applied every 4–6 weeks. WSL formation and oral hygiene were evaluated at the initial appointment before bonding (T1) and 12 months later (T2). Standardized digital photographs were analyzed using the enamel decalcification index (EDI). Statistical comparisons were made using independent and paired-sample t-tests as well as chi-square tests. Results In this trial, 43% of patients and 15% of teeth developed new WSLs. Lateral incisors showed the highest incidence of decalcification and WSL formation. WSL formation and EDI score increases during treatment were significantly greater in the gingival region than in the mesial, distal, or incisal regions. Of the EDI scores at T2, 93.8% were 0 and 5.5% were 1. Poor oral hygiene at T2 showed a high positive predictive value (76%) for the development of WSLs. There were no statistically significant between-group differences for the development of WSLs. Conclusions MI Varnish and ProSeal sealant provided similar levels of protection during the first 12 months of fixed orthodontic treatment. The severity of the WSLs that developed was minimal. WSLs were most likely to develop on lateral incisors and in the gingival regions of teeth, especially among patients with poorer oral hygiene.

Objectives To compare the treatment and posttreatment effects of Invisalign aligners that incorporated SmartForce features and attachments to traditional fixed appliances. Materials and Methods This randomized controlled trial included 66 patients, 32 aligners, and 34 fixed-appliance patients. The median ages of the aligner and braces patients were 26.7 (interquartile range [IQR]: 9.8) and 25.9 (IQR: 16.6) years, respectively. Pretreatment occlusion was assessed using the ABO Discrepancy Index. Posttreatment (T1) and 6-month retention (T2) occlusions were quantified using the ABO Objective Grading System (OGS) scores. Results The braces group finished treatment significantly (P < .001) earlier (0.4 years) than the aligner group. The median DI scores for the aligner and braces groups were 4.5 and 7.0, respectively, which was a statistically significant (P = .015), but clinically insignificant, difference. There were no statistically significant between-group differences for the total OGS scores or any of the individual component scores at debond (T1) or after 6 months of retention (T2). During the posttreatment period, alignment and overjet worsened significantly in the aligner group, while buccolingual inclinations and occlusal relations improved. Over the same period, alignment worsened in the braces group and buccolingual inclinations improved. There was no statistically significant between-group difference in posttreatment changes of the total OGS scores. Conclusions While patients with simple malocclusions require 4.8 months longer treatment times with aligners than traditional braces, the treatment and 6-month posttreatment occlusal outcomes are similar.

Digital technology advancements have been introduced into the orthodontic specialty in the last few years. Three-dimensional (3D) surface scanning, 3D volume scanning, computer-aided design (CAD) software, and 3D manufacturing have irreversibly altered and refined processes that were previously performed more conventionally. As a result, customized fixed orthodontic appliance production has been made possible by a few manufacturing companies. An attempt at implementing the in-house designing and manufacturing of customized fixed orthodontic appliances using dedicated orthodontic CAD software has never been undertaken until now. Our case report used a novel orthodontic CAD software named UBrackets to design in-house customized orthodontic brackets. Three-dimensional printing was performed in the orthodontic office using a permanent crown ceramic resin. The complete customized fixed appliance's design, printing, postprinting, and bonding workflow are also presented.

The wear behaviour and chemical composition of orthodontic components influence the mechanical characteristics of a fixed orthodontic treatment. The purpose of this paper is to evaluate the surface alterations of different types of brackets (aesthetic, metallic, and conventional self-ligating) and archwires (superelastic and thermal) subjected to wear tests through optical microscopy and, subsequently, to identify the chemical elements of accessories by X-ray fluorescence. The cycles (5000 for each bracket and 10,000 for each wire) of the tribological test were carried out in dry conditions inside a machine that allows alternating sliding. The results of the study highlighted different wear behaviours even within the same type of brackets and archwires. The monocrystalline sapphire brackets maintain their aesthetic properties despite traces of wear inside the slots and contain minimal amounts of nickel. Superelastic NiTi archwires have a better overall rating than thermal wires, as they do not show significant surface wear alterations.

Introduction Torque in orthodontics is the activation of the archwire for the third-order movement of teeth. During this force transfer mechanism from the twisted archwire, the bracket is prone to deformation. This study aimed to compare the deformation in tie wings and the slot region of the bracket during torque using finite element analysis. Methods Three-dimensionally modeled 0.017 × 0.025-in and 0.019 × 0.025-in stainless steel (SS) and titanium molybdenum alloy archwires were assembled in 0.018-in and 0.022-in solid modeled SS edgewise brackets, respectively. The finite element model of the bracket-archwire combinations was developed with contact boundary conditions. The deformation between tie wings and the slot was analyzed for various angles of twist. Results For SS archwires at 30° angle of twist, the tie wings deformation in 0.018-in and 0.022-in brackets were 48.67 μm and 34.87 μm, respectively. The slot deformations of 0.018-in and 0.022-in brackets were 66.33 μm and 45.69 μm, respectively. Similarly, the amount of deformation in the bracket—titanium molybdenum alloy archwire combinations were also presented. Conclusions The slot deformation was more than the tie wings deformation as the slot walls bear the immediate torque force. Thus, orthodontic researchers should know that the torque-relevant bracket deformation should ideally be evaluated in the slot region rather than the tie wings.

The purpose of this report is to introduce a digital indirect bonding technique that uses a customized virtual orthodontic bracket setup and 3-dimensional printing technology. The main advantages of this methodology compared with the conventional method of indirect bonding, are a reduction in fabrication steps and optimization of bracket positioning offered by the computer-aided design–computer-aided manufacturing technology. Errors in bracket placement can be prevented by checking and confirming the simulated setup. This digital method of indirect bonding allows for more accurate bracket positioning that is achieved by scanning the patient's dentition directly without the need for recording impressions, for virtual positioning of the brackets in the desired position, and simulated orthodontic movement of teeth according to the bracket positions in real-time.

Purpose To evaluate bonding quality for orthodontic bracket bonding with different component combinations of self-etch primers in vitro. Methods Metallic brackets were bonded to bovine lower incisors and assigned to groups. Group 1: comparison of self-etch (Transbond™ Plus, 3M™ Unitek, Neuss, Germany, n = 30; BrackFix® primer SE, VOCO®, Cuxhaven, Germany, n = 20) and etch-and-rinse bonding systems (Transbond™ XT, n = 20; BrackFix®, n = 20); group 2: comparison of different self-etch primer (Transbond™ Plus; BrackFix® primer SE) and adhesive (Transbond™ XT, n = 20; BrackFix®, n = 20) product combinations; group 3: testing cyclic fatigue bond strength of self-etch bonding systems (Transbond™ Plus, n = 20; BrackFix® primer SE, n = 20). All teeth were tested for shear bond strength according to the DIN-13990 standard, the adhesive remnant index (ARI) and enamel fractures were determined microscopically (10 × magnification). Results The mean shear bond strength of the self-etch (Transbond™ Plus: 16.38 ± 3.68 MPa; BrackFix® primer SE: 16.24 ± 1.73 MPa) and etch-and-rinse bonding systems (Transbond™ XT: 18.45 ± 2.56 MPa; BrackFix®: 17 ± 5.2 MPa) were of a clinically adequate order of magnitude (≥ 6-10 MPa) and were not statistically different. The component combination BrackFix® primer SE/Transbond™ XT adhesive led to a significantly lower shear bond strength (11.99 ± 3.68 MPa). There were no significant differences between static and fatigue shear bond strengths of self-etch bonding systems. Mean ARI scores mostly ranged between 4 and 5. The combination of the self-etch primer Transbond™ Plus with the BrackFix® adhesive led to a significantly increased enamel fracture rate. Conclusions Based on the present findings bond strength of self-etch primers was equal to etch-and-rinse primers for bracket bonding. Combining different self-etch bonding systems might alter the clinical performance.

This study aimed to evaluate the impact of fluoride-releasing 4-META/MMA-TBB resin on the degree of enamel demineralization typically detected around orthodontic brackets using μCT. Enamel-dentin blocks were prepared from bovine teeth. Brackets were attached with either 4-META/MMA-TBB resin (SBC), fluoride-releasing 4-META/MMA-TBB resin (SBF), or fluoride-releasing RMGIC (FLC). The specimens were subjected to demineralization (pH 4.5, 21 days) and scanned by μCT (0, 7, and 21 days). Fluoride ion release under the experimental conditions was measured. The degree of demineralization detected in SBF and FLC was significantly lower than that in SBC; there were no significant differences in the degree of demineralization detected in SBF and FLC. The level of fluoride ion detected in FLC was significantly higher than that detected in SBC. Fluoride-releasing 4-META/MMA-TBB resin protected against enamel demineralization around orthodontic brackets when compared to the results from the fluoride-free resin.

The purpose was to determine the effect of different environments (artificial saliva, human saliva, distilled water, dry storage) on frictional forces between various tribological systems made from self-ligating brackets in combination with stainless-steel wires (dimensions: 0.016″×0.022″, 0.018″×0.025″ and 0.019″×0.025″). An universal testing-machine applied a normal force of 1 N. Two-way ANOVA and Tukey post-hoc tests (α=5%) were used. Saliva had significantly higher frictional forces (p

Objective: Comparative evaluation of antibacterial and anti-adherent properties of surface-modified stainless steel (SS) orthodontic brackets against Streptococcus mutans ( S. mutans). Materials and Methods: The study was conducted on 120 SS orthodontic McLaughlin, Bennett, Trevisi (MBT) 0.022″ slot by Leone, Italy. Orthodontic brackets that constituted the sample size were divided into 6 groups, consisting of 20 samples each in two control (non-surface coated) and four experimental groups. The experimental group’s surface coatings were photocatalytic zinc oxide (ZnO) and photocatalytic titanium oxide (TiO2), which were carried out by radiofrequency (RF) magnetron sputtering method for surface modification. Brackets were subjected to microbiological tests against S. mutans. For anti-adherence, weight change, pre- and postexposure, was evaluated to gauge the adherence of bacteria and colony-forming units/milliliter (CFU/mL) count measuring the survival rate of bacterial cells for antibacterial activity. Results: The TiO2-coated group showed statistically significant anti-adherence ( P-value < .05) against S. mutans than control and ZnO groups. The CFU count of TiO2 group was lower than control as well as ZnO group. Conclusion: TiO2 is superior to ZnO and should be continued to be considered for surface modification of orthodontic brackets against White Spot Lesions (WSLs) and gingivitis.

Summary Objective The aim of this in vitro study was to evaluate the effects of enamel deproteinization on the shear bond strength of a self-etching primer Transbond Plus™(TBP), with different application times of sodium hypochlorite (NaOCl 5.25%), primarily and secondarily on the adhesive remnant index score. Materials and methods One hundred twenty-five freshly extracted human premolars were randomly and blindly divided into five groups according to the enamel surface preparation, as follows (n = 25): group 1(control): Etching with 37% phosphoric acid for 15 seconds + Bonding; group 2 (control): TBP™ without NaOCl, group 3: 60 seconds NaOCl + TBP™, group 4: 30 seconds NaOCl + TBP™, group 5: 15 seconds NaOCl + TBP™. The same composite resin was used (Transbond XT™) to bond the orthodontic metal brackets. After the immersion of the teeth in distilled water at 37 °C for 24 hours the shear bond strength was measured using the universal testing machine and the adhesive remnant index score (ARI) was evaluated under an optical microscope (25 × ). Results The mean SBS values (in MPa) of the groups were respectively: group 1: 13.03 ± 5.36; group 2: 12.28 ± 3.06; group 3: 12.38 ± 4.55; group 4: 12.98 ± 5.76; and group 5: 11.73 ± 5.67. Enamel deproteinization increased the SBS for groups 3 and 4, but no statistically significant difference was found between the five groups (P = 0.883). Group 1 showed the highest ARI scores, with 52% of the teeth retaining all the adhesive (score 3). However, for all the other groups, scores 0 and 1 were predominant, with less than half of the adhesive or no adhesive at all remaining on the teeth. Conclusions Enamel deproteinization with sodium hypochlorite (5.25%) and the variation of its application time has no effect on the SBS of the self-etching primer Transbond Plus ™.