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2.
Am J Orthod Dentofacial Orthop ; 158(2): 166-174, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32624347

RESUMO

Orthodontic treatment with sequential aligners has seen a considerable surge in the last decades, and is currently used to treat malocclusions of varying severity. To enhance tooth movement and broaden the spectrum of malocclusions that can be treated with aligners, composite resin attachments are routinely bonded with the acid-etch technique on multiple teeth, a process known to impose irreversible alterations of the enamel structure, color, gloss, and roughness. Additionally, this clinical setting introduces a unique scenario of different materials applied in a manner that involves the development of friction and attrition between the attachment and the softer aligner material, all performing in the harsh conditions of the oral environment, which impact the aging of these materials. The latter may give rise to alterations of the aligners and the composite attachments and potential intraoral release of Bisphenol A, a known endocrine disrupting agent. Furthermore, at the final stages of contemporary aligner treatment, the removal of multiple, sometimes bulky, composite attachments with a volume and surface far greater than the remnant adhesive after debonding of brackets, through grinding that might be associated with pulmonary effects for the patient or staff. Because of the extensive enamel involvement in bonding, the release of factors from the attachment-aligner complex during service, the aging of these entities in the oral environment, and the laborious debonding/composite grinding process coupled with the hazardous nature of aerosol produced during the removal of these bulky specimens, appropriate risk management considerations should be applied and an effort to confine the application of multiple composite specimens bonded to enamel to the absolutely necessary should be pursued.


Assuntos
Esmalte Dentário , Resinas Compostas , Colagem Dentária , Humanos , Teste de Materiais , Braquetes Ortodônticos , Cimentos de Resina , Propriedades de Superfície , Técnicas de Movimentação Dentária
3.
Niger J Clin Pract ; 23(6): 783-791, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32525112

RESUMO

Background: Microorganisms in the mouth are protected from negative environmental conditions by forming biofilms; however, the use of anti-plaque agents in children is not preferred due to toxic side effects. Green tea has been reported to have anti-microbial and anti-dental caries properties. Aims: The aim of this study was to assess the ability of green tea extract to prevent the formation of biofilm on the teeth of children using space maintainers. Methods: Bacteria were isolated from samples obtained from children aged between 8 and 10 years. The micro-titer plate method and Congo red agar were used to assay biofilm formation. Green tea leaves were obtained from Rize, Turkey. Methanol, hexane and distilled water were used for preparing the extracts. The effects of green tea extract and chlorhexidine on biofilm formation were examined using scanning electron microscopy. Results: Presence of S. mutans 3,3, S. anginosus 2.1.b, S. dysgalactie 6.1.4.1, and E. faecium 10.2. was measured in the biofilm samples. The extracts showed a bacteriostatic effect on the test bacteria, and among the green tea extracts, the methanol extract was found to exhibit the highest efficacy against biofilm formation by S. mutans 3.3. Conclusion: Green tea extract showed good efficacy in controlling bacterial growth, and is recommended as a better-tasting alternative for daily oral hygiene due to a lack of known side effects.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Clorexidina/farmacologia , Cárie Dentária/microbiologia , Braquetes Ortodônticos/microbiologia , Extratos Vegetais/farmacologia , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus mutans/efeitos dos fármacos , Chá/química , Antioxidantes/farmacologia , Carga Bacteriana/efeitos dos fármacos , Criança , Cárie Dentária/tratamento farmacológico , Humanos , Metanol , Testes de Sensibilidade Microbiana , Boca , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Solventes/química , Streptococcus mutans/isolamento & purificação , Streptococcus mutans/fisiologia , Turquia
4.
J Evid Based Dent Pract ; 20(1): 101416, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32381413

RESUMO

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Effectiveness of casein phosphopeptide-amorphous calcium phosphate-containing products in the prevention and treatment of white spot lesions in orthodontic patients: A systematic review. Pithon MM, Baião FS, Sant'Anna LID, Tanaka OM, Cople-Maia L. J Invest Clin Dent 2019;e12391. SOURCE OF FUNDING: No financial support was reported. TYPE OF STUDY/DESIGN: Systematic review.


Assuntos
Cárie Dentária , Braquetes Ortodônticos , Fosfatos de Cálcio , Caseínas , Fluoretos , Humanos , Fosfopeptídeos , Remineralização Dentária
5.
Niger J Clin Pract ; 23(5): 589-595, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32367863

RESUMO

Background: The prevalence of white spot lesions/tooth demineralization during orthodontic fixed appliance therapy ranges widely from 2 to 96% of patients. The purpose of this study was to evaluate measures used by orthodontists practicing in Nigeria to manage demineralization during and after fixed orthodontic treatment and how it compares with the available evidence-based information. Method: Study group comprised of 60 practitioners (21 orthodontists and 39 orthodontic residents) in Nigeria. Self-administered questionnaires were used to obtain information on the measures they use to prevent the occurrence of demineralization at the onset and during orthodontic treatment, as well as the management of its occurrence at treatment completion. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) software, version 17.0. Descriptive statistics were used. Level of significance was set at P < 0.05. Results: Responses obtained showed that 96.7% of orthodontic practitioners routinely advised their patients on tooth cleaning methods; the use of manual orthodontic toothbrush (78.3%) and dental floss (51.7%) being popularly recommended methods. However, 51.7% used a specific demineralization preventive protocol at the start of treatment. Oral hygiene instruction was observed to be the most commonly adopted protocol (51.7%), followed by fluoride rinses (41.7%) (considered relatively ineffective). Extraoral hygiene instruction was the most common treatment protocol used when tooth demineralization occurred during and after treatment (56.7% and 73.3% respectively). Approximately 92% of the orthodontists agreed on the need for the development of a basic protocol to prevent demineralization. Conclusion: The demineralization preventive measures used by Nigerian orthodontists and orthodontic residents are inconsistent and not based on evidence-based information. The development of standardized demineralization prevention protocol was therefore recommended.


Assuntos
Cárie Dentária/prevenção & controle , Higiene Bucal/métodos , Aparelhos Ortodônticos/efeitos adversos , Ortodontia Corretiva/métodos , Ortodontistas , Padrões de Prática Odontológica , Desmineralização do Dente/prevenção & controle , Adulto , Cariostáticos/uso terapêutico , Odontologia Baseada em Evidências/métodos , Feminino , Fluoretos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Nigéria , Braquetes Ortodônticos/efeitos adversos , Inquéritos e Questionários , Escovação Dentária
6.
J Contemp Dent Pract ; 21(3): 227-232, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32434965

RESUMO

AIM: To compare the effect of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser at different irradiation parameters and acid etching on the shear bond strength (SBS) of orthodontic brackets to enamel. MATERIALS AND METHODS: Forty bovine incisors were randomly distributed into groups (n = 10): GI: 37% phosphoric acid etching; GII: Er,Cr:YSGG laser etching 19.1 J/cm2; GIII: Er,Cr:YSGG, 29.3 J/cm2; and GIV: Er,Cr:YSGG, 42.4 J/cm2. After treatments, metallic brackets were bonded using Transbond XT adhesive system. After light curing, the samples were subjected to 500 thermal cycles, debonded with a universal testing machine, and the SBS values were recorded. After debonding, surface morphology was evaluated using scanning electron microscopy (SEM) and optical coherence tomography (OCT). The values of SBS testing were analyzed by one-way analysis of variance (ANOVA) and Tukey post hoc test, at 5% significance level. RESULTS: The mean SBS values of GI, GII, GIII, and GIV groups were 6.2 ± 1.7 MPa, 4.6 ± 2.5 MPa, 7.0 ± 2.2 MPa, and 8.0 ± 3.6 MPa, respectively. Laser irradiation promoted rough surfaces in all parameters used, and the OCT analysis revealed higher optical changes on lased groups when compared with phosphoric acid. CONCLUSION: Er,Cr:YSGG laser irradiation operated at 42.4 J/cm2 and 29.3 J/cm2 is a better alternative for etching enamel prior to the orthodontic treatment than the phosphoric acid. CLINICAL SIGNIFICANCE: Er,Cr:YSGG laser irradiation is better than the phosphoric acid for etching enamel prior to the orthodontic treatment because laser irradiation promotes similar SBSs and preventing demineralization around orthodontic brackets.


Assuntos
Colagem Dentária , Lasers de Estado Sólido , Braquetes Ortodônticos , Animais , Bovinos , Esmalte Dentário , Propriedades de Superfície
7.
J Contemp Dent Pract ; 21(2): 140-147, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32381817

RESUMO

AIM: The aim of this study was to evaluate the effects of different concentrations of sodium ascorbate (SA), green tea (GT), and chamomile (CM) on the shear bond strength (SBS) of metal orthodontic brackets bonded to teeth bleached with 40% hydrogen peroxide (HP). MATERIALS AND METHODS: Ninety-four sound premolars were divided into eight groups: group I (control + no bleaching), group II (bleaching + immediate bonding), group III (bleaching + 10% SA), group IV (bleaching + 35% SA), group V (bleaching + 0.5% GT), group VI (bleaching + 1% GT), group VII (bleaching + 0.5% CM), and group VIII (bleaching + 1% CM). In groups III-VIII, teeth were treated with the antioxidants for 10 minutes after bleaching with 40% HP, but before bonding. All the specimens were bonded with the resilience adhesive, and the SBS was tested with a universal testing machine (Instron 5965). The cross-head speed to break the bond was 1 mm/minute. The adhesive remnant index (ARI) was tested under 50× magnification. One-way analysis of variance, Tukey's post hoc, and Chi-squared tests were used for analysis (p ≤ 0.05). RESULTS: The differences in SBS among the eight tested groups were highly significant (p < 0.001). Comparison of the eight groups using Tukey's post hoc test revealed significantly lower SBS (p < 0.001) in test groups II, III, IV, and VIII than in group I. Adhesive remnant index scores showed significant intergroup differences (p = 0.005). Most groups had a failure score of 1 (<50% of the bonding material adhering to the tooth), whereas groups II and VIII showed a failure score of 0 (no material adhering to the tooth). CONCLUSION: Bond strength can be enhanced by using 0.5% or 1% GT or 0.5% CM to allow bracket bonding immediately after bleaching. CLINICAL SIGNIFICANCE: The use of antioxidants would allow clinicians to bleach teeth before orthodontic treatment without delaying bonding.


Assuntos
Colagem Dentária , Braquetes Ortodônticos , Clareamento Dental , Antioxidantes , Análise do Estresse Dentário , Humanos
8.
Compend Contin Educ Dent ; 41(5): e11-e16, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32369381

RESUMO

Clear aligner treatment has become popular for many orthodontic cases that ordinarily would have required traditional orthodontic brackets and wires. One of the motivating reasons for patients to use clear aligner therapy is to improve their esthetic appearance, which typically is the same motivation for teeth bleaching, thus a combination of the two treatments may be desirable. The case report presented demonstrates bleaching concurrent with clear aligner (Invisalign®) treatment. A concern about bleaching during such treatment is that the areas on the tooth under the composite attachments, or buttons, used to retain the clear aligner trays may remain unbleached. However, due to the small molecular size of the bleaching material agent and its ability to permeate the tooth, the area under the attachment will be bleached as well. With this understanding, a practitioner can treat patients more efficiently by being able to complete bleaching treatment simultaneously with clear aligner treatment.


Assuntos
Aparelhos Ortodônticos Removíveis , Braquetes Ortodônticos , Clareamento Dental , Assistência Odontológica , Humanos
9.
Head Face Med ; 16(1): 7, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32321577

RESUMO

BACKGROUND/OBJECTIVE: To reproduce the methods and results of the study by Alobeid et al. (2018) in which the efficacy of tooth alignment using conventional labial and lingual orthodontic bracket systems was assessed. MATERIALS/METHODS: We used the identical experimental protocol and tested (i) regular twin bracket (GAC-Twin [Dentsply]) and lingual twin bracket systems (Incognito [3M]), (ii) together with NiTi 0.014" wires (RMO), and (iii) a simulated malocclusion with a displaced maxillary central incisor in the x-axis (2 mm gingivally) and in the z-axis (2 mm labially). RESULTS: The method described by Alobeid et al. (2018) is not reproducible, and cannot be used to assess the efficacy of tooth alignment in labial or lingual orthodontic treatment. Major flaws concern the anteroposterior return of the Thermaloy-NiTi wire ligated with stainless steel ligatures. The reproduced experimental setting showed that a deflected Thermaloy-NiTi wire DOES NOT move back at all to its initial stage (= 0 per cent correction) because of friction and binding (see supplemented video), neither with the tested labial nor with the lingual brackets. Furthermore, an overcorrection of up to 138 per cent, which the authors indicate for some labial bracket-wire combinations and which deserves the characterization "irreal", stresses the inappropriateness of the method of measurement.Further flaws include: a) incorrect interpretation of the measurement results, where a tooth tripping around (overcorrection) is interpreted as a better outcome than a perfect 100 per cent correction; b) using a statistical test in an inappropriate and misleading way; c) uncritical copying of text passages from older publications to describe the method, which do not correspond to this experimental protocol and lead to calculation errors; d) wrong citations; e)differences in table and bar graph values of the same variable; f) using a lingual mushroom shaped 0.013" Thermaloy-NiTi wire which does not exist; g) drawing uncritical conclusions of so called "clinical relevance" from a very limited in vitro testing. CONCLUSIONS: Clinical recommendations based on in vitro measurements using the Orthodontic Measurement and Simulation System (OMSS) should be read with caution.


Assuntos
Desenho de Aparelho Ortodôntico , Braquetes Ortodônticos , Fios Ortodônticos , Análise do Estresse Dentário , Teste de Materiais , Aço Inoxidável , Estresse Mecânico , Titânio , Técnicas de Movimentação Dentária
12.
Am J Orthod Dentofacial Orthop ; 157(3): 320-328, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32115110

RESUMO

INTRODUCTION: This study compared three-dimensional forces delivered to the displaced tooth and its adjacent teeth between passive self-ligation (PSL) and conventional elastic ligation (CL) in simulation of mandibular lateral incisor linguoversions. METHODS: A multisensor system was used to measure three-dimensional forces delivered to brackets attached to the mandibular left central incisor, lateral incisor, and canine (FDI tooth numbers 31, 32, and 33, respectively). Two ligation methods (PSL and CL), 3 nickel-titanium (0.014-inch) archwires similar to the arch form of normal occlusion, and 2 displacements (1 and 4 mm) were tested. RESULTS: In 1-mm displacement, forces were significantly smaller in CL than in PSL at 32 in the labial direction and larger at 31 in the mesial direction for all 3 types of archwires (P <0.01 for both). For 2 of 3 archwires, forces were larger in CL than in PSL at 33 in the lingual direction (P <0.01). In 4-mm displacement, forces were significantly larger in CL than in PSL at 31 in the mesial direction and significantly smaller in CL than in PSL at 33 in the distal direction for all 3 archwires (P <0.05 and P <0.01, respectively). Mean forces in the vertical direction were small, ranging from -0.05 to 0.05 N. CONCLUSIONS: Under a small amount of displacement, force magnitude in PSL was smaller than that in CL at the displaced tooth in labial-lingual directions. Under a large amount of displacement, a more "open coil spring effect" was significantly obtained in CL than PSL at both adjacent teeth of the displaced tooth.


Assuntos
Incisivo , Braquetes Ortodônticos , Técnicas de Movimentação Dentária , Ligas Dentárias , Análise do Estresse Dentário , Humanos , Desenho de Aparelho Ortodôntico , Fios Ortodônticos , Titânio
13.
Braz Dent J ; 31(1): 52-56, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32159706

RESUMO

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.


Assuntos
Colagem Dentária , Braquetes Ortodônticos , Cimentos Dentários , Porcelana Dentária , Análise do Estresse Dentário , Teste de Materiais , Cimentos de Resina , Resistência ao Cisalhamento , Propriedades de Superfície
14.
Dental Press J Orthod ; 25(1): 28-35, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32215475

RESUMO

OBJECTIVE: The purpose of this study was to evaluate the effect of the Yd:YAG laser irradiation on orthodontic bracket base surface. Shear bond strength (SBS) values and sites of the bonding failure interfaces were quantified. METHODS: Brackets were divided into two groups: OP (One Piece - integral sandblast base) and OPL (One Piece - laser irradiation). The brackets were randomly bonded on an intact enamel surface of 40 bovine incisors. The SBS tests were carry out using a universal test machine. A stereomicroscopy was used to evaluate the adhesive remnant index (ARI), and surface characterization was performed by scanning electron microscopy (SEM). Student's t-test was used to compare the SBS between the two groups (p< 0.05). Frequencies and chi-square analysis were applied to evaluate the ARI scores. RESULTS: OPL group showed higher value (p< 0.001) of SBS than OP group (43.95 MPa and 34.81 MPa, respectively). ARI showed significant difference (p< 0.001) between OPL group (ARI 0 = 100%) and OP group (ARI 0 = 15%). SEM showed a higher affinity between the adhesive and the irradiated laser base surface. CONCLUSIONS: Yd:YAG laser irradiation on bracket base increased SBS values, showing that bonding failure occurs at the enamel/adhesive interface. Laser-etched bracket base may be used instead of conventional bases in cases where higher adhesion is required, reducing bracket-bonding failure.


Assuntos
Colagem Dentária , Lasers de Estado Sólido , Braquetes Ortodônticos , Animais , Bovinos , Humanos , Metais , Resistência ao Cisalhamento , Propriedades de Superfície
15.
Dental Press J Orthod ; 25(1): 47-55, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32215477

RESUMO

INTRODUCTION: Several advantages have been established regarding the efficiency of self-ligating brackets (SL). In spite of some controversy surrounding this question in the literature, clinical results confirm that "arch development" requires fewer extractions. OBJECTIVE: The objective of this study was to compare changes in the transverse and sagittal planes in patients treated with conventional ligating brackets (CL)as well as in patients treated with SL brackets and oversized arches. METHODS: A sample was selected from a pool of 300 consecutive cases treated by a single clinician: 51 patients with SL brackets and oversized wires, and 55 with CL brackets. These two groups were compared with a control group of 20 patients. All plaster models were scanned and dental landmarks were measured to identify changes from commencement (T0) to conclusion (T1) of treatment. Lateral cephalograms were analyzed for changes in the lower incisor (IMPA) and the first lower molar distal angulation (MAng). Intraoperator reliability was tested with linear regression analysis. To assure all groups were comparable at T0, an ANOVA test with a 95%confidence interval (CI) was performed for all values. To assess changes from T0 to T1 in all groups, a Student's t-test with 95% CI was used. Finally, results from the three groups were compared using an ANOVA-test (95% CI) and a post-hoc test. RESULTS: Increases in all the transverse variables were recorded in the two groups treated (SL and CL), except for the lower intercanine distance in the SL group. IMPA difference from T0 to T1 was higher in the CL group, and molar distal angulation (MAng) took place in the SL group. CONCLUSIONS: Self-ligating brackets with oversized arches and conventional ligating brackets showed increases in all variables in the transverse plane, except for the SL group at the mandibular intercanine distance. In comparison with the CL group, fewer different IMPA values were observed in the SL group, in which distal molar angulation occurred.


Assuntos
Braquetes Ortodônticos , Fios Ortodônticos , Humanos , Incisivo , Desenho de Aparelho Ortodôntico , Reprodutibilidade dos Testes
16.
Dental Press J Orthod ; 25(1): 64-69, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32215479

RESUMO

OBJECTIVE: This study proposed to investigate the influence of catastrophizing and others factors related to pain during orthodontic treatment. METHODS: 27 patients with 0.022 x 0.028-in Straight-wire brackets were evaluated during alignment and leveling phase with nickel-titanium wires. Visual Analog Scales measured the intensity of orthodontic pain at six moments after a clinical appointment: 6 first hours; 1, 2, 3, 5, and 7 days. Multiple linear regression and stepwise approach assessed the influence of the following variables on pain: catastrophizing, sex, age, duration of treatment, clinical appointment time (morning or afternoon), and wire diameter. RESULTS: The highest pain intensity was reported 24 hours after activation. These data were used to analyze factors associated with pain level. Age (r = 0.062, p= 0.7586), sex (p= 0.28), catastrophizing (r = -0.268, p= 0.1765), and orthodontic wire diameter (r = 0.0245, p= 0.2181) were not correlated with orthodontic pain in the univariate statistics. Catastrophizing was included in the multiple regression model because it was of great interest. Duration of orthodontic treatment (r = 0.6045, p= 0.0008) and the time when orthodontic appliance was activated (p= 0.0106) showed statistical significant associations with pain, and were also included in the multivariate regression, which showed that about 32% of orthodontic pain could be explained by the duration of treatment (R2= 0.32, p= 0.0475). Catastrophizing (R2= 0.0006, p= 0.8881) and clinical appointment time were not significantly associated with pain (R2= 0.037, p= 0.2710). CONCLUSIONS: Pain after activation of fixed orthodontic appliance is not associated with catastrophizing as well as age, sex, orthodontic wire diameter, and period of activation.


Assuntos
Braquetes Ortodônticos , Catastrofização , Ligas Dentárias , Humanos , Desenho de Aparelho Ortodôntico , Fios Ortodônticos , Dor , Titânio
17.
Orthod Craniofac Res ; 23(3): 291-299, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32011803

RESUMO

OBJECTS: To simulate and compare salivary flow patterns over a tooth surface bonded with different orthodontic appliances using computational fluid dynamics (CFD) and investigate the impact of bracket design on salivary flow in relation to peri-bracket bacterial accumulation. SETTING AND SAMPLE POPULATION: The models were constructed using computed tomography (CT) data of 81 patients scheduled for fixed orthodontic treatment: 27 patients (10 males, 17 females) for the metal Victory MBT™ bracket; 27 patients (seven males, 20 females) for the ceramic Clarity MBT™ bracket; 27 patients (15 males, 12 females) for the Mini Uni-Twin (MUT) bracket. METHODS: The salivary flow patterns were simulated by CFD and compared between the groups and the model predictions were validated using a bacteriological experiment. RESULTS: The MUT bracket was associated with the greatest number of low salivary velocity areas, as it is designed with a connector between double tie wings and a right contact angle between tooth surface and bracket base. After archwire placement, the centred slot in the bracket and the bilateral sites around the bracket had higher bacterial retention and needed special oral hygiene measures. The obtuse contact angle of the ceramic bracket formed a pocket structure in the tie-wing area, retarding salivary flow and contributing to bacteria retention. CONCLUSION: With the evaluation of CFD models, we demonstrate that salivary flow patterns over a tooth surface with a bracket vary with bracket designs and further promote bacterial retention in specific locations, suggesting the need for additional oral hygiene measures for specific bracket types.


Assuntos
Braquetes Ortodônticos , Bactérias , Feminino , Humanos , Hidrodinâmica , Masculino , Teste de Materiais , Desenho de Aparelho Ortodôntico , Fios Ortodônticos
18.
Dent Mater J ; 39(4): 593-600, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32092724

RESUMO

We investigated the surface modification of orthodontic stainless steel wire using electrophoretic deposition (EPD) of bioactive glass (BG). BG coatings were characterized by spectrophotometry, three-dimensional (3D) focal laser scanning microscopy and scanning electron microscopy. The mechanical properties of the BG-coated wires were estimated nanoindentation, three-point bending and drawing friction tests. BG-coated specimens prepared at higher voltage showed higher values for both reflectance and L* compared to those prepared at lower voltage. Specimens coated at higher voltage had significantly lower surface roughness than those coated at lower voltage, and their BG layers had higher hardness and elastic modulus values. In the three-point bending test, BG-coated wires produced significantly lower elastic modulus than non-coated wires. Most BG-coated specimens produced similar frictional forces to those produced by non-coated specimens. The surface modification technique applying EPD and BG coating to orthodontic stainless steel wire could be used to develop new esthetical orthodontic wire.


Assuntos
Braquetes Ortodônticos , Fios Ortodônticos , Ligas Dentárias , Fricção , Vidro , Teste de Materiais , Aço Inoxidável , Propriedades de Superfície , Titânio
19.
Am J Orthod Dentofacial Orthop ; 157(2): 269-277, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32005479

RESUMO

INTRODUCTION: A protocol was introduced to achieve accurate bracket placement in vivo, which consisted of operative procedures for precise control, and a computer-aided design and computer-aided manufacturing-guided bonding device. To evaluate the accuracy of this protocol, a 3-dimensional assessment was performed. METHODS: Ten consecutive patients were enrolled. Strictly following the protocol, from December 2017 to March 2018, brackets were placed on the teeth of each patient using the device. To evaluate the accuracy, deviations of positions and orientations for bracket placement were measured. Each patient was followed up after 3 months regarding bracket failures. RESULTS: The guided bonding device was used in all cases, and a total of 205 brackets were successfully bonded and evaluated. Except for 15.12% brackets with torque deviation over 2°, the deviations in mesiodistal, buccolingual, vertical, rotation, and angulation were below the clinical acceptable range (0.5 mm in translation or 2° in orientation) for all brackets. In the 3-month follow-up, there was no bracket failure in any patient. CONCLUSION: This protocol transferred the planned bracket position from the digital setup to patient's dentition with generally high positional accuracy.


Assuntos
Desenho Assistido por Computador , Colagem Dentária , Braquetes Ortodônticos , Modelos Dentários , Humanos
20.
Rev. ADM ; 77(1): 22-27, ene.-feb. 2020. ilus, graf
Artigo em Espanhol | LILACS | ID: biblio-1087921

RESUMO

Introducción: Hoy en día, la mayoría de los pacientes requieren tratamiento de ortodoncia fija convencional, la cual utiliza procedimientos adhesivos afines con la superficie amelodentinaria. Aunque existen diferentes técnicas adhesivas que pueden ofrecer adecuados niveles de resistencia al desalojo, el uso del hipoclorito de sodio (NaClO) como agente desproteinizante no ha sido bien definido en materiales de cementación en aparatología ortodóncica convencional. Objetivo: El objetivo de este estudio fue determinar los niveles de resistencia al desalojo con pruebas de microtensión y análisis topográfico con microscopia electrónica de barrido. Material y métodos: 20 bloques de esmalte bovino fueron expuestos superficialmente a soluciones acondicionadoras (ácido ortofosfórico al 37%) con y sin agente desproteinizante (NaClO al 5.25%); finalmente, brackets individuales de ortodoncia fueron cementados con sistemas adhesivos y resinas compuestas de casas comerciales (Ormco y 3M). Las pruebas de resistencia al desalojo fueron realizadas con una máquina de fuerzas universales y el análisis topográfico con microscopia electrónica de barrido. Resultados: El uso del NaClO al 5.25% y la marca Ormco tuvieron estadísticamente los mejores niveles de adhesión que el grupo sin desproteinización y la casa comercial 3M, respectivamente. La topografía adamantina expuesta al agente desproteinizante mostró características de superficie relacionadas con el patrón de grabado tipo I. Conclusión: El uso de un agente desproteinizante (NaClO 5.25%) así como una marca comercial (Ormco) en particular podrían definir el aumento en los niveles de adhesión en superficies adamantinas con aparatología ortodóncica convencional (AU)


Introduction: Nowadays, patients require conventional fixed orthodontic treatment, which uses adhesive procedures related to the dentinal denture surface. Although there are different adhesive techniques that can offer adequate levels of bonding resistance, the use of NaClO as a deproteinizing agent has not been well defined in cementing materials in conventional orthodontic appliances. Objective: The objective of this study was to determine the levels of bond resistance using micro tension tests and topographic analysis with scanning electron microscopy. Material and methods: Twenty-blocks of bovine enamel were exposed superficially to conditioning solutions (37% orthophosphoric acid) with and without deproteinizing agent (5.25% NaClO); finally, individual orthodontic brackets were cemented with adhesive systems and resin composites of different trademarks (Ormco and 3M). Bonding resistance tests were performed with a universal force machine and topographic analysis was made with scanning electron microscopy. Results: The use of 5.25% NaClO and the Ormco brand had statistically better levels of adhesion than the group without deproteinization and the 3M brand, respectively. Adamantine topography exposed to the deproteinizing agent showed surface characteristics related to the type I etching pattern. Conclusion: The use of a deproteinizing agent (NaClO 5.25%) as well as a trademark (Ormco) in particular conditions could define the increase in adhesion levels on adamantine surfaces with conventional orthodontic appliances (AU)


Assuntos
Hipoclorito de Sódio/química , Condicionamento Ácido do Dente , Colagem Dentária , Braquetes Ortodônticos , Esmalte Dentário/efeitos dos fármacos , Ácidos Fosfóricos , Propriedades de Superfície , Resistência à Tração , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Estudos Transversais , Análise Estatística , Resinas Compostas
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