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1.
J Clin Pediatr Dent ; 44(2): 123-126, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32271662

RESUMEN

A modified pontic technique is presented that simplifies the management of patients with missing anterior teeth during the course of comprehensive orthodontic care. This technique demonstrates a lingual arch attached to lingual sheaths with the pontic placed on the lingual arch. Information presented includes appliance design, improved bond strength of the bracket on the pontic tooth, preparing the appliance for use as anchorage, and the incorporation of an anterior biteplate in the appliance. A modified pontic appliance improves esthetics and function when treating patients with missing maxillary anterior teeth.


Asunto(s)
Incisivo , Métodos de Anclaje en Ortodoncia , Dentadura Parcial Fija , Estética Dental , Humanos , Diseño de Aparato Ortodóncico , Alambres para Ortodoncia , Técnicas de Movimiento Dental
2.
J Dent Educ ; 84(3): 377-384, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32176338

RESUMEN

The aims of this study were to evaluate the effects of a live-video teaching tool on the performance of dental students in bending an orthodontic vestibular arch and to assess the students' perceptions of the technology. All 135 fourth-year dental students in the 2018 academic year at Hacettepe Dental School, Ankara, Turkey, were invited to participate in the study; after exclusions, the remaining 116 were randomly divided into two demonstration cohorts. These students had no prior experience bending an orthodontic wire. Cohort 1 (control, N=58) was shown a conventional live demonstration of the orthodontic bending of a vestibular arch, and Cohort 2 (experimental, N=58) was shown a live-video demonstration of the same procedure. Both cohorts saw the demonstration before beginning the exercise and were evaluated afterwards on their performance of the procedure. In addition, the students' perceptions of the demonstration techniques were collected with a questionnaire. The results did not show any significant differences in the students' bending scores between the control and experimental cohorts (p=0.767). The median values on the questionnaire indicated almost no statistically significant difference in responses between the cohorts. The only significant difference was that Cohort 1 had a higher percentage who answered "yes" they would like to rewatch the demonstration than did Cohort 2 (p=0.024). In this study, the live-video technique was found to be as effective as a conventional live demonstration for orthodontic practical education, suggesting that either technique could be used as an appropriate method for training in orthodontic wire bending.


Asunto(s)
Educación en Odontología , Alambres para Ortodoncia , Estudiantes de Odontología , Estudios de Cohortes , Humanos , Facultades de Odontología , Encuestas y Cuestionarios , Grabación en Video
3.
Dental Press J Orthod ; 25(1): 47-55, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32215477

RESUMEN

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.


Asunto(s)
Soportes Ortodóncicos , Alambres para Ortodoncia , Humanos , Incisivo , Diseño de Aparato Ortodóncico , Reproducibilidad de los Resultados
4.
Dental Press J Orthod ; 25(1): 64-69, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32215479

RESUMEN

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.


Asunto(s)
Soportes Ortodóncicos , Catastrofización , Aleaciones Dentales , Humanos , Diseño de Aparato Ortodóncico , Alambres para Ortodoncia , Dolor , Titanio
5.
Am J Orthod Dentofacial Orthop ; 157(3): 320-328, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32115110

RESUMEN

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.


Asunto(s)
Incisivo , Soportes Ortodóncicos , Técnicas de Movimiento Dental , Aleaciones Dentales , Análisis del Estrés Dental , Humanos , Diseño de Aparato Ortodóncico , Alambres para Ortodoncia , Titanio
6.
Am J Orthod Dentofacial Orthop ; 157(1): 128-131, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31901270

RESUMEN

Preservation of the maxillary lateral incisor space after orthodontic treatment in an adolescent patient traditionally requires the use of a retainer with a lateral pontic, commonly referred to as a "flipper," which is minimally effective in the long term. This article illustrates a technique for chairside fabrication of a Maryland bridge retainer for semi-permanent retention. A stainless steel braided palatal wire is bonded to the anterior teeth. A pontic is then built intraorally with flowable composite, using the palatal wire as scaffolding. The retainer is maintained until the patient is of age for a more permanent restoration.


Asunto(s)
Dentadura Parcial Fija con Resina Consolidada , Adolescente , Humanos , Diseño de Aparato Ortodóncico , Retenedores Ortodóncicos , Alambres para Ortodoncia
7.
Prog Orthod ; 20(1): 46, 2019 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-31840204

RESUMEN

BACKGROUND: To compare the clinical efficiency of premium heat-activated copper nickel-titanium (Tanzo Cu-NiTi) and NT3 superelastic NiTi during initial orthodontic alignment. SUBJECT AND METHODS: A total of 50 patients were randomly allocated to 1 of 2 different archwire types (group 1, Tanzo Cu-NiTi; group 2, NT3 superelastic NiTi). Eligibility criteria included Class I or Class II malocclusion, moderate maxillary anterior crowding, and healthy periodontal condition. Impressions of the upper arches were taken before archwire placement (T0) and at every 4 weeks (T1, T2, T3, and T4). For T1 and T2 stages, 0.014-in., and for T3 and T4 stages, 0.018-in. archwires were used. The primary outcome was the alignment efficiency assessed using Little's irregularity index. The secondary outcomes were arch width and incisor inclination changes. Data were analyzed using independent samples t test, repeated measures ANOVA, and Mann-Whitney U test. Marginal models were established for the estimation of coefficients. RESULTS: The anterior irregularity index reduction was mostly observed between T0 and T2 periods, which were respectively - 7.40 ± 0.50 mm (p < 0.001; 95% CI, - 8.94, - 5.85) and - 6.80 ± 0.55 mm (p < 0.001; 95% CI, - 8.49, - 5.12) for groups 1 and 2 (p < 0.001). With both wires, Little's irregularity index decreased over time, and the difference between the groups was not significant (p = 0.581; estimated effect size, 0.011). No statistically significant difference was found between the groups in terms of intercanine and intermolar width and incisor inclination changes. CONCLUSION: There were no significant between-group differences in alignment efficiency, arch width, and incisor inclination change. There was an increased alignment with 0.014-in. compared with 0.018-in. diameter archwire.


Asunto(s)
Níquel , Titanio , Adolescente , Cobre , Aleaciones Dentales , Calor , Humanos , Alambres para Ortodoncia
8.
Am J Orthod Dentofacial Orthop ; 156(6): 870-877, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31784021

RESUMEN

INTRODUCTION: This study aimed to evaluate the ability of dental clinicians to predict posttreatment dental arch forms in patients with malocclusion with the aid of 3D imaging and digital software in comparison with a conventional method. METHODS: Pretreatment and posttreatment dental plaster casts of 100 patients (200 maxillary models and 200 mandibular models) were selected. Three orthodontists selected the best-fitted archwires among 5 commercially available preformed nickel-titanium archwires using 2 methods. In the conventional method, they fit the archwires to pretreatment casts, and in the digital method, they fit the scanned wire to a 3D digital model, using Ortho-Aid, a locally developed 3D software, using clinical bracket points as reference for wire fitness. The predicted posttreatment archwire in each method was compared with the best-fit archwire on the actual posttreatment model of each patient in both methods, and the level of agreement was calculated. The interobserver agreement between the 3 orthodontists in each method was evaluated using intraclass correlation coefficient and the Dahlberg formula. RESULTS: Orthodontists predicted the final treatment outcome in 50% of cases using the conventional method and 58% using the digital method. However, the range of method error was significantly higher in the conventional method (0.425-3.853 mm for the conventional vs 0.451-0.584 mm for the digital). CONCLUSIONS: Although the clinicians' ability to predict the final dental arch form after orthodontic treatment and the agreement between clinicians increased by the use of digital equipment, orthodontists can predict the final arch form in about 60% of patients.


Asunto(s)
Arco Dental , Imagenología Tridimensional , Alambres para Ortodoncia , Ortodoncia Correctiva , Aleaciones Dentales , Arco Dental/anatomía & histología , Arco Dental/diagnóstico por imagen , Modelos Dentales , Predicción , Humanos , Mandíbula , Programas Informáticos
9.
Minerva Stomatol ; 68(5): 265-272, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31822051

RESUMEN

BACKGROUND: This study aims to evaluate tension distribution in the anterior region of the mandible during two orthodontic mechanical approaches to treat anterior open bite. METHODS: It was an in-vitro experimental study, that analyzed 5 models of photoelastic resin, simulating a lower dental arch. The anterior teeth underwent orthodontic forces of the Blue Elgiloy® 0.016" x 0.022" (MEAW technique) and Gummetal® 0.018"x 0.022" (GEAW technique) archwires. Tension distribution was assessed on three different points in the lower dental midline and was measured using a reflection polariscope. The archwires were evaluated with and without anterior elastic bands (6 oz, 170 g) installed between lateral incisors and lower canines, as recommended for anterior open bite. RESULTS: The highest magnitudes of tension generated by the archwires were observed in the cervical regions of the teeth (on average 50% higher than those at the most apical point) regardless of the technique used. Comparatively, the GEAW technique showed significantly (P<0.05) lower tension values (16 MPa) than the MEAW technique using Blue Elgiloy (24 MPa). CONCLUSIONS: The GEAW technique showed a more favorable tension distribution pattern than the MEAW approach. The use of elastic bands improved tension distribution, regardless of the technique. The results also suggest that the use of anterior elastic bands in both techniques reduced the tensions released by the intrusive forces generated by the archwires.


Asunto(s)
Mordida Abierta , Humanos , Incisivo , Mandíbula , Diseño de Aparato Ortodóncico , Alambres para Ortodoncia , Técnicas de Movimiento Dental
10.
Indian J Dent Res ; 30(4): 548-552, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31745051

RESUMEN

Aim: The aim of this study was to evaluate and compare the surface characteristics of colored titanium molybdenum alloy archwires (purple-coated TMA and honey dew-coated TMA) and the regular titanium molybdenum alloy archwires. Materials and Methods: The experiment comprised three groups, Group I - regular TMA archwires, Group II - purple-coated TMA archwires, Group III - honey dew-coated TMA wires involving 21 samples each. The surface characteristics were assessed using scanning electron microscopy and optical profilometer. Results: The results were statistically analyzed using analysis of variance wherein Group I regular TMA wires exhibited a root mean square value of 148.071 nm and a standard deviation of 9.0027 nm followed by group II (purple-coated TMA wires) which showed a root mean square value of 84.095 nm with a standard deviation of 2.6005 nm, while group III (honey dew-coated TMA wires) was found to have a root mean square value of 71.681 nm with a standard deviation of 1.4645 nm on subjecting to optical profilometry. Conclusion: The surface roughness is higher for regular TMA wire exhibiting superior characteristic of color-coated TMA wires, especially honey dew-coated TMA wires over the regular and purple-coated TMA wires. This property of the archwires details regarding its application in both sliding and frictionless mechanics in retraction phase of fixed orthodontic treatment.


Asunto(s)
Alambres para Ortodoncia , Titanio , Aleaciones Dentales , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Acero Inoxidable , Propiedades de Superficie
11.
Am J Orthod Dentofacial Orthop ; 156(5): 611-616, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31677669

RESUMEN

INTRODUCTION: This study aimed to compare the microorganism adhesion on coated, partially coated, and uncoated orthodontic archwires after clinical use. The correlation between surface roughness (SR) and bacterial colonization was also evaluated. METHODS: A total of 48 archwire segments (0.016 × 0.022-in) were equally divided into 4 groups: nickel-titanium coated, nickel-titanium partially coated, uncoated stainless steel, and uncoated nickel-titanium. The archwires were randomly inserted in a split-mouth study design. After 4 weeks of clinical use, the total number of microorganisms adhering to the archwire was quantified and transformed into colony-forming units. SR was evaluated using a profilometer. A one-way and two-way ANOVA, post-hoc Tukey test, paired-samples t test, and Pearson correlation coefficient were used for statistical analysis. RESULTS: All the archwires presented microorganism adhesion, with the nickel-titanium-coated group demonstrating the highest value (P < 0.001). A statistically significant increase in SR was observed after clinical use for all groups (P < 0.05). No correlation between SR and bacterial adhesion was detected. CONCLUSIONS: Microorganism adhesion occurred on all of the archwires tested, especially on the esthetic fully coated. Because SR was not correlated with microorganism adhesion, future studies should evaluate the effect of surface free energy and superficial chemical changes on in-vivo microorganism adhesion.


Asunto(s)
Estética Dental , Soportes Ortodóncicos , Alambres para Ortodoncia , Aleaciones Dentales , Humanos , Ensayo de Materiales , Estudios Prospectivos , Acero Inoxidable , Propiedades de Superficie , Titanio
12.
Microsc Res Tech ; 82(12): 2049-2053, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31587442

RESUMEN

Orthodontic brackets, specifically in their slots, are responsible for receiving active orthodontic forces and transferring them to the teeth to be moved. The presence of an altered slot or inaccurate dimensions can influence the mechanical relationship between the bracket and archwire, interfering with the biomechanics of tooth movement. The objective of this study was by comparing the accuracy of slot placement of upper right lateral incisor metal brackets for Bioprogressive Ricketts therapy from five trademarks. The following characteristics were evaluated: height, torque, and internal parallelism of the walls of the slot. The sample included 75 brackets, 15 each from the following trademarks: 3M Abzil, Forestadent, Morelli Rocky Mountain Orthodontics, and Tecnident. Images of the slot profiles were obtained through standardized techniques using scanning electron microscopy, measured by the AutoCAD 2017 software, and compared to Ricketts prescription, respecting standard deviation with the technical and tolerance parameters present in standard ISO 27020. The results indicated that most of the evaluated characteristics were in accordance with the standard parameters, considering the tolerance adopted. There were exceptions found to this pattern of precision in the 3M Abzil brackets with regard to torque variation, and the Morelli brackets in relation to height variation and parallelism between the walls of the slot. Considering the measured dimensional characteristics, the metal brackets used in Bioprogressive Ricketts therapy has satisfactory pattern accuracy; however, there are still some specific inaccuracies in brackets from certain brands that can require more attention during the detailing phase.


Asunto(s)
Análisis del Estrés Dental/métodos , Incisivo/fisiología , Soportes Ortodóncicos , Ortodoncia/métodos , Humanos , Ensayo de Materiales , Alambres para Ortodoncia , Acero Inoxidable , Estrés Mecánico , Propiedades de Superficie , Torque
13.
J Orofac Orthop ; 80(6): 304-314, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31552447

RESUMEN

PURPOSE: Torque control in lingual orthodontics is key to obtain optimal esthetic results. The aim of this in vitro experimental study was to verify the efficiency of the ligature-archwire-slot system in torque control using a customized lingual appliance. METHODS: An idealized cast with eight extracted human teeth was created and a set of customized lingual brackets was obtained. Tests were performed with the following wires: 0.016â€³â€¯× 0.022″ nickel-titanium (NiTi), 0.016â€³â€¯× 0.024″ stainless steel (SS), 0.017â€³â€¯× 0.025″ ßIII titanium (ßIIITi), 0.0182â€³â€¯× 0.0182″ ßIIITi, 0.018â€³â€¯× 0.025″ SS, 0.018â€³â€¯× 0.025″ NiTi, 0.018â€³â€¯× 0.025″ ßIIITi, and three types of ligatures were tested using a universal testing machine to calculate the efficiency in torque control. A blind statistical analysis was performed. RESULTS: Based on post hoc multiple comparisons, differences were found for two of the three ligatures when using the 0.016â€³â€¯× 0.022″ NiTi wires (p < 0.001 for both ligatures). When considering all ligatures, 0.018â€³â€¯× 0.025″ SS and 0.018â€³â€¯× 0.025″ ßIIITi were significantly different from all other wires (p < 0.001 in all cases). With a moment of 5 Nmm, the 0.016â€³â€¯× 0.022″ NiTi wire developed median angles of 26.7, 29.8, and 38.7° with the three ligatures, respectively, while the 0.018â€³â€¯× 0.025″ SS developed median angles of 12.9, 10.7, and 12.7°, respectively. CONCLUSIONS: The ligature type and geometry did not affect the efficiency of torque control, except for the 0.016â€³â€¯× 0.022″ NiTi wire. The wires generating the greatest moments were the 0.018â€³â€¯× 0.025″ SS and 0.018â€³â€¯× 0.025″ ßIIITi.


Asunto(s)
Soportes Ortodóncicos , Alambres para Ortodoncia , Aleaciones Dentales , Análisis del Estrés Dental , Estética Dental , Humanos , Ensayo de Materiales , Diseño de Aparato Ortodóncico , Titanio , Torque
14.
Am J Orthod Dentofacial Orthop ; 156(3): 401-411, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31474270

RESUMEN

A 24-year-old man presented with a severe skeletal class III malocclusion, associated with an anterior and posterior crossbite in the left side, upper and lower lip eversion, skeletal asymmetry, midline discrepancy, diastemas in the maxillary and mandibular dental arches, and agenesis of maxillary lateral incisors and canines with retained deciduous teeth. Treatment was performed with the use of the Win Lingual System. When the 0.016 × 0.022-inch NiTi archiwire was applied, the deciduous teeth were extracted and replaced with temporary crowns connected to the appliance. After the aligning, leveling, and diastema closure phases, a modified Le Fort II osteotomy, a mandibular setback with a bilateral sagittal split osteotomy and a genioplasty were performed. Implants were placed in the canine site through a flapless guided surgery, and cantilevered temporary bridges were delivered. Final prosthetic rehabilitation included veneers for the central incisors and zirconia-ceramic cantilevered bridges for the canine and lateral incisors. After 36 months of active treatment, the patient showed an Angle Class I molar and canine relationship and an ideal overbite and overjet. His profile had improved, lips were competent, and gingival levels were acceptable. The lateral radiograph and cephalometric analysis showed a good balance of the skeletal pattern, a good profile of the soft tissue, and proper inclinations of the maxillary and mandibular incisors in relation to maxilla and mandible. After 2 years of follow-up, the patient had a pleasant smile and no relapse, or joint or muscular pain.


Asunto(s)
Anodoncia/complicaciones , Maloclusión de Angle Clase III/terapia , Diseño de Aparato Ortodóncico/instrumentación , Diseño de Aparato Ortodóncico/métodos , Aparatos Ortodóncicos , Adulto , Cefalometría , Diente Canino , Implantación Dental Endoósea , Implantes Dentales , Modelos Dentales , Diastema/cirugía , Diastema/terapia , Estética Dental , Humanos , Incisivo , Labio , Masculino , Maloclusión de Angle Clase I/complicaciones , Maloclusión de Angle Clase III/diagnóstico por imagen , Maloclusión de Angle Clase III/rehabilitación , Maloclusión de Angle Clase III/cirugía , Mandíbula/cirugía , Maxilar/cirugía , Diente Molar , Métodos de Anclaje en Ortodoncia/instrumentación , Métodos de Anclaje en Ortodoncia/métodos , Soportes Ortodóncicos , Alambres para Ortodoncia , Osteotomía , Sobremordida/terapia , Radiografía Panorámica , Técnicas de Movimiento Dental/instrumentación , Técnicas de Movimiento Dental/métodos , Adulto Joven
16.
J Clin Orthod ; 53(4): 234-242, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31390610
17.
Dent Mater J ; 38(6): 909-920, 2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31366769

RESUMEN

Corrosion of metallic materials in the oral cavity could trigger metal allergy in patients. To clarify the risk elevation of magnetic fields (MFs) exposure on metallic corrosion when combined with fluoride-containing dental care products and indigenous oral bacteria, we investigated electric toothbrush-derived MF-induced corrosion of orthodontic stainless steel (SUS) and nickel titanium (Ni-Ti) wires in the presence of fluoride and oral bacteria, i.e. Streptococcus (S) mutans and S. sanguinis. MFs induced an electric current in the wires under both environments. Oral bacteria corroded SUS wires, and fluoride corroded SUS and Ni-Ti wires as previously reported; however, no additive or synergistic effects of MF exposure on fluoride- and microbiologically-induced metallic corrosion were observed. These results suggest that the MFs from electric toothbrushes do not increase the risk of corrosion of metallic appliances, given that the oral environment of patients is exposed to oral bacteria and fluoride-containing products.


Asunto(s)
Fluoruros , Alambres para Ortodoncia , Bacterias , Corrosión , Aleaciones Dentales , Humanos , Campos Magnéticos , Ensayo de Materiales , Propiedades de Superficie , Titanio
18.
Am J Orthod Dentofacial Orthop ; 156(2): 210-219, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31375231

RESUMEN

INTRODUCTION: More patients are choosing customized orthodontic appliances because of their excellent esthetics. It is essential that clinicians understand the biomechanics of the tooth movement tendency in customized lingual orthodontics. This study aimed to evaluate the tooth movement tendency during space closure in maxillary anterior teeth with the use of miniscrew anchorage in customized lingual orthodontics with various power arm locations. METHODS: Three-dimensional finite element models of the maxilla were created with miniscrews and power arms; the positions were varied to change the force directions. A retraction force (1.5 N) was applied from the top of the miniscrews to the selected points on the power arm, and the initial displacements of the reference nodes of the maxillary teeth were analyzed. RESULTS: After applying force in different directions, power arms located at the distal side of the canines led to larger initial lingual crown tipping and occlusal crown extrusion of the maxillary incisors compared with power arms located at the midpoint between the lateral incisors and canines, and caused a decreasing trend of the intercanine width. CONCLUSIONS: In customized lingual orthodontic treatment, power arms located at the distal side of the canines are unfavorable for anterior teeth torque control and intercanine width control. Power arms located at the midpoint between the lateral incisors and canines can get better torque control, but still cannot achieve excepted torque without extra torque control methods, no matter whether its force application point is higher than, lower than, or equal to the level of the top of the miniscrews.


Asunto(s)
Tornillos Óseos , Análisis de Elementos Finitos , Métodos de Anclaje en Ortodoncia/instrumentación , Métodos de Anclaje en Ortodoncia/métodos , Cierre del Espacio Ortodóncico , Técnicas de Movimiento Dental/instrumentación , Técnicas de Movimiento Dental/métodos , Adulto , Fenómenos Biomecánicos , Simulación por Computador , Diente Canino/patología , Humanos , Imagenología Tridimensional/métodos , Incisivo/patología , Maxilar , Modelos Biológicos , Diseño de Aparato Ortodóncico , Aparatos Ortodóncicos , Soportes Ortodóncicos , Cierre del Espacio Ortodóncico/instrumentación , Cierre del Espacio Ortodóncico/métodos , Alambres para Ortodoncia , Planificación de Atención al Paciente , Estrés Mecánico , Corona del Diente , Torque , Resultado del Tratamiento
19.
Am J Orthod Dentofacial Orthop ; 156(2): 266-274, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31375237

RESUMEN

Adult orthodontic treatment involving maxillary transverse deficiency is a challenge for an interdisciplinary team. Surgically assisted rapid palatal expansion to segment the maxilla was once the treatment of choice, but the invasiveness, bone deficiency, and gingival recession hindered its acceptance. Corticotomy-assisted rapid maxillary arch expansion with ridge augmentation has the advantage of augmenting alveolar bony housing to accommodate and facilitate tooth movement. This approach was used to correct a severely constricted maxilla with bilateral posterior crossbite and anterior crowding in a 46-year-old man. Treatment time was 14 months. The accelerated arch expansion overcame the crossbite in 7 months, increasing intercanine distance by 5.2 mm and intermolar distance by 9.8 mm. Subsequent implant prosthesis was able to be restored in a functional normal occlusion. Satisfactory and stable clinical outcome was followed for 7 years. Corticotomy-assisted rapid maxillary arch expansion with alveolar bone augmentation is a novel and effective interdisciplinary approach for correcting adult maxillary transverse deficiency. Well controlled prospective clinical trails are warranted for further investigation.


Asunto(s)
Aumento de la Cresta Alveolar/métodos , Maloclusión/terapia , Técnica de Expansión Palatina , Técnicas de Movimiento Dental/métodos , Cefalometría , Modelos Dentales , Oclusión Dental , Estudios de Seguimiento , Humanos , Masculino , Maloclusión/diagnóstico por imagen , Maloclusión/patología , Maloclusión/cirugía , Maloclusión de Angle Clase II/diagnóstico por imagen , Maloclusión de Angle Clase II/patología , Maloclusión de Angle Clase II/cirugía , Maloclusión de Angle Clase II/terapia , Maloclusión de Angle Clase III/diagnóstico por imagen , Maloclusión de Angle Clase III/patología , Maloclusión de Angle Clase III/cirugía , Maloclusión de Angle Clase III/terapia , Maxilar/anomalías , Maxilar/patología , Maxilar/cirugía , Persona de Mediana Edad , Aparatos Ortodóncicos , Soportes Ortodóncicos , Alambres para Ortodoncia , Paladar (Hueso)/cirugía , Planificación de Atención al Paciente , Estudios Prospectivos , Resultado del Tratamiento
20.
J Orofac Orthop ; 80(5): 223-235, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31410493

RESUMEN

OBJECTIVE: In vitro testing of archwires in a multibracket model may provide estimates of force-moment (F/M) systems applied to individual teeth in a realistic geometry. Such investigations have mostly been performed by continuous wire deflection, leading to frictional forces biasing the pure deflection forces. Aim of this study was to quantify this bias and the pure deflection forces for leveling archwires. MATERIALS AND METHODS: Three nickel-titanium (NiTi) and two multistranded wires were tested in a three-bracket model simulating vertical movement of an upper incisor with a typical interbracket distance of 8 mm (intercenter). To determine pure deflection forces, the middle bracket was first leveled incrementally from its vertical malposition to neutral position with repeated wire insertion at each step (so-called "static leveling mode"). For comparison, forces at the middle bracket were also determined during dynamic leveling with or without ligation of the wire at the lateral brackets by either elastic, tight or loose steel ligatures. RESULTS: The dynamic mode resulted in significantly lower mean leveling forces for all the tested wires (ANOVA [analysis of variance], p < 0.01) compared to the static mode. Expressed in numbers, dynamic wire unloading resulted in mean force underestimation of 53 ± 9% (loose steel ligatures), 56 ± 11% (elastic ligatures) or 91 ± 29% (tight steel ligatures). CONCLUSIONS: Orthodontic tooth movement is quasi-static. This concerns the initial hyalinization phase in particular. Thus, especially static testing of archwires provides valid reference data for the peak forces exerted directly after clinical insertion of a leveling wire. In dynamic wire testing, significant underestimation of actual forces exerted on individual teeth may occur due to experimental friction, which might considerably differ from that occurring during clinical therapy. This aspect has to be taken into account in the interpretation of published stiffness values for orthodontic wires, and in the selection of the appropriate archwire for leveling of the present tooth malposition, respectively.


Asunto(s)
Soportes Ortodóncicos , Análisis del Estrés Dental , Fricción , Ensayo de Materiales , Diseño de Aparato Ortodóncico , Alambres para Ortodoncia , Titanio , Técnicas de Movimiento Dental
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