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1.
J Mech Behav Biomed Mater ; 110: 103992, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32750663

RESUMO

It is essential for 3D-printed intra-oral appliances to be able to withstand the mechanical and microbial insult existent in the harsh environment of the oral cavity. Poly(methyl methacrylate) (PMMA)-based appliances are widely used in dentistry. Hence, the present study aimed to evaluate the role of nanodiamonds (NDs) as fillers to enhance the resistance to friction and wear. Using a solution-based mixing technique, 0.1 wt% ND was incorporated into the PMMA, and specimens were 3D-printed for tribological and bacterial analysis. The control specimens without ND fillers were tested against specimens with both amine-functionalized NDs (A-ND) and pure non-functionalized NDs (ND). The surface hardness test revealed a statistically significant increase in the Vickers micro-hardness (p < 0.001) in the nanocomposite groups. There was a significant reduction in the coefficient of friction (COF) (p < 0.01) in both the ND and A-ND nanocomposites compared to the stainless steel (SS) counter surfaces. However, for titanium (Ti)-based specimens, the COF of the control group was similar to that of A-ND but lower than that of ND. The wear resistance evaluation revealed that both the ND and A-ND groups displayed enhanced resistance to surface loss in comparison to the controls for both SS and Ti counter-surfaces (p < 0.001). Furthermore, both A-ND and ND exhibited significantly enhanced resistance to the formation of Streptococcus mutans biofilms after 48 h (p < 0.01) compared to the control group. Hence, we concluded that the addition of 0.1 wt% ND in the PMMA-based resin for 3D printing resulted in significant improvement in properties such as COF, wear resistance, and resistance to S. mutans, without any notable impact associated with the functionalization of the NDs.

2.
Am J Orthod Dentofacial Orthop ; 157(6): 843-851, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32487314

RESUMO

INTRODUCTION: The registration of cone-beam computed tomography (CBCT) images and digital dental models is required for the design and manufacturing of dental devices such as implant guides and surgical wafers. This study aims to register intraoral scan (IS) models and cast scan (CS) models onto CBCT images using 3-dimensional (3D) planning software and evaluate the registration accuracy according to scanning methods and 3D planning software. METHODS: The CBCT image of an artificial skull model with reference markers was taken. The CS model and the IS model were obtained from the same skull model, registered onto the CBCT image using 3D planning software packages providing manual registration (MR) function and point-based registration (PR) functions, and set as the experimental groups. After registration, shell to shell deviations and positional differences between the reference model and the experimental models were evaluated. RESULTS: The shell to shell deviations ranged from 0.03 to 0.18 mm. Deviations in both the maxilla and mandible were significantly different according to scanning methods and software packages. In the anteroposterior direction, the IS-MR and CS-MR groups showed significantly different positions. In the superoinferior direction, the MR and PR groups showed significantly different positions. CONCLUSIONS: The registration using the PR function of the 3D planning software packages was significantly more accurate than the registration using the MR function. There was no significant difference between the registrations using the IS model and the CS model when using the PR functions.

3.
Plast Reconstr Surg ; 2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32590521

RESUMO

BACKGROUND: The traditional method of distraction procedure required a long period of time until the new bone was fully fused. This study aimed to evaluate the effect of cyclic and repetitive compressive force on new bone formation by applying newly designed microactuator-generated distractor comparing with the traditional distraction protocol. METHODS: The distraction devices were applied to the right and left mandibles of eight mature beagles, one of which was allocated as the experimental group and the other as the control group. After a 5-day latency period, the experimental group alternately applied 1.5 mm distraction and 0.5 mm compression every 12 hours, and the control group repeated 0.5 mm distraction every 12 hours to perform a total of 7 mm mandibular lengthening. After an 8-week consolidation period, microstructure analysis using micro-computed tomography and histological evaluations were performed. RESULTS: Bone volume fraction and trabecular number were significantly higher in the experimental group. Trabecular thickness did not show a significant difference. And trabecular separation was significantly higher in the control group. The measurement of new bone area showed significantly higher in the experimental group, but the difference in mineral apposition rate between the experimental and control groups was not statistically significant. CONCLUSIONS: This study has revealed that applying cyclic compressive and tensile forces during the distraction period induces better new bone formation than repetitive distraction alone. In addition, the new distraction device produced reliable distraction results during the experiment.

4.
J Craniofac Surg ; 31(4): e343-e347, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32149967

RESUMO

OBJECTIVE: Maxillary anterior segmental distraction osteogenesis (MASDO) for cleft and palate patients is the alternative treatment option to correct malocclusion with maxillary arch deficiency and severe crowding. After MASDO, prosthetic considerations are crucial for patients with cleft lip and palate because it is related to facial esthetics and occlusal function. The objectives of this study were to investigate the final restoration type for created alveolar space by MASDO. METHODS: Thirteen patients with cleft lip and palate who underwent MASDO and orthodontic treatment from the years 2000 to 2010 in Yonsei University were examined. Final restorations are classified as dental implants, conventional prosthesis, and orthodontic space closure. The relationship between the distracted areas and final restoration type was investigated. The authors evaluated lateral cephalograms obtained at predistraction osteogenesis (pre-DO; T1), postdistraction osteogenesis (post-DO; T2), and debond (T3), and measured changes from T1 to T2 and from T2 to T3. RESULTS: There was no significant difference of final restoration percentage of dental implants, conventional prosthesis, and space closure with orthodontic treatment. However, dental implants and conventional prostheses were applied more frequently in the posterior area and in the anterior area, respectively. The relapse rate was observed as 36.7% and 22.4% in the values of N-A distance and ANB angulation in T2-T3 stage. CONCLUSION: The MASDO site should be decided, based on final restoration goal. Among the created alveolar spaces, implants were applied mainly to the posterior site and the conventional prostheses were mostly restored to the anterior site. For space closure by orthodontic approach, the area could be both anterior or posterior.

5.
Korean J Orthod ; 49(6): 393-403, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31815107

RESUMO

Objective: Sliding mechanics using orthodontic miniscrews is widely used to stabilize the anchorage during extraction space closure. However, previous studies have reported that both posterior segment displacement and anterior segment displacement are possible, depending on the mechanical properties of the archwire. The present study aimed to investigate the effect of archwire stiffness and friction change on the displacement pattern of the maxillary posterior segment during anterior segment retraction with orthodontic miniscrews in sliding mechanics. Methods: A three-dimensional finite element model was constructed. The retraction point was set at the archwire level between the lateral incisor and canine, and the orthodontic miniscrew was located at a height of 8 mm from the archwire between the second premolar and first molar. Archwire stiffness was simulated with rectangular stainless steel wires and a rigid body was used as a control. Various friction levels were set for the surface contact model. Displacement patterns for the posterior and anterior segments were compared between the conditions. Results: Both the anterior and posterior segments exhibited backward rotation, regardless of archwire stiffness or friction. Among the conditions tested in this study, the least undesirable rotation was found with low archwire stiffness and low friction. Conclusions: Posterior segment displacement may be unavoidable but reducing the stiffness and friction of the main archwire may minimize unwanted rotations during extraction space closure.

6.
Mater Sci Eng C Mater Biol Appl ; 105: 110049, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546363

RESUMO

The aim of this study was to evaluate whether combining two treatments to avoid biological aging of the surface of titanium and zirconia implants; i.e., storage in an aqueous solution after ultraviolet light (UV) or non-thermal atmospheric pressure plasma (NTP) treatment, yielded surface bioactivity comparable to that following post-15-min UV or NTP treatment storage under air or immediately after UV or NTP treatment. Grade IV titanium discs modified by large grit sand-blasting and acid-etching (SLA) and smooth zirconia discs were irradiated with UV or NTP and their surface properties were evaluated immediately and after storage for 8 weeks in distilled H2O (dH2O) and a sealed container under air. Approximately 15-30 nm-sized nano-protrusions were formed only on SLA surfaces in dH2O immediately after UV or NTP treatment. Immediate dH2O storage after UV or NTP treatment prevented hydrocarbon contamination and maintained elevated amounts of Ti and Zr. After 8 weeks, unlike zirconia, protein adsorption, cellular adhesion, and cytoskeletal development of MC3T3-E1 cells on SLA surfaces stored in dH2O immediately after UV treatment were further exceeding those immediately after UV or NTP treatments. UV treatment of SLA implants followed by wet storage can not only maintain but also strengthen bioactivity during shelf storage.


Assuntos
Implantes Experimentais , Teste de Materiais , Gases em Plasma/química , Titânio , Raios Ultravioleta , Zircônio , Animais , Pressão Atmosférica , Linhagem Celular , Camundongos , Propriedades de Superfície , Titânio/química , Titânio/farmacologia , Zircônio/química , Zircônio/farmacologia
7.
Am J Orthod Dentofacial Orthop ; 156(3): 375-382, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31474267

RESUMO

INTRODUCTION: The aim of this work was to compare the skeletal and dental outcomes of 1- versus 2-phase treatment in Class II subjects with difficult-to-treat high-angle severe Class II malocclusions. METHODS: The sample of 120 cases was collected from the private offices of 3 experienced clinicians. The following selection criteria were used: (1) ANB ≥6°, (2) SN-GoGn ≥37° or mandibular plane to Frankfort horizontal plane ≥30°; and (3) overjet ≥6 mm. Patients were classified into either the early or the late treatment group according to dental age (early Tx: ≥5 primary teeth; late Tx: otherwise). Thirty-four angular, linear, and proportional measurements were determined for each patient. Statistical significance was assessed with the use of a 2-tailed t test, analysis of covariance test, and chi-square test. RESULTS: The results showed that early 2-phase treatment for severe Class II high-angle patients offered no skeletal anteroposterior advantages over late 1-phase treatment. Severe high-angle Class II patients also showed similar dental anteroposterior outcomes with the use of both approaches. Vertically there was a higher frequency of increased mandibular plane angles and extrusion of upper incisors and lower molars in the late treatment group. CONCLUSIONS: Early 2-phase treatment for severe Class II high-angle patients offered no skeletal or dental advantage over late 1-phase treatment.


Assuntos
Má Oclusão de Angle Classe II/terapia , Ortodontia Corretiva/métodos , Adolescente , Cefalometria/métodos , Criança , Feminino , Humanos , Incisivo , Masculino , Mandíbula , Maxila , Dente Molar , Sobremordida/terapia , Fatores de Tempo , Resultado do Tratamento
8.
Angle Orthod ; 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30920867

RESUMO

When considering camouflage orthodontic treatment for Class III malocclusion with skeletal facial asymmetry, it is crucial to preserve the favorable compensated posterior occlusion. Once the inclination of the compensated occlusion is changed during orthodontic treatment, unstable occlusion, such as crossbite or scissor bite may occur. A 23-year-old female patient had anterior spacing with Class III malocclusion and a mandibular asymmetry. A nonsurgical approach was adopted. The treatment objectives were to establish a Class I molar relationship with compensated inclination of the posterior dentition and to correct the midline deviation. To achieve these goals, the computer-aided design/computer-aided manufacturing (CAD/CAM) orthodontic system plus customized brackets was applied, and miniscrews were used to distalize the left mandibular dentition for midline correction. The results suggested that the CAD/CAM-based customized brackets can be efficiently used in camouflage treatment to achieve a correct final occlusion.

9.
Cleft Palate Craniofac J ; 56(6): 827-830, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30453769

RESUMO

Patients with cleft lip and palate sometimes have a retruded maxilla. Here, we describe the case of a young man in whom crowding of the maxillary teeth and an anteroposterior discrepancy of the maxilla were resolved by premaxillary distraction osteogenesis (DO) using 3 individual intraoral distractors. Our experience in this patient confirms that premaxillary DO with 3 intraoral distractors and preoperative simulation can achieve stable maxillary advancement and arch expansion without impairing velopharyngeal incompetence.

10.
Korean J Orthod ; 48(6): 384-394, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30450331

RESUMO

Objective: This study was performed to investigate an appropriate degree of prestretch for orthodontic synthetic elastomeric chains focusing on time-dependent viscoelastic properties. Methods: Orthodontic synthetic elastomeric chains of two brands were prestretched to 50, 100, 150, and 200% of the original length in one and three cycles, and the hysteresis areas of the obtained stress-strain curves were determined. Acrylic plates were employed to maintain constant strain during the experiment. A total of 180 samples were classified into nine groups according to brand, and their stresses and permanent deformations were measured immediately after prestretch (0 hour), after 1 hour and 24 hours, and after 1, 2, 3, 4, 5, 6, 7, and 8 weeks. The relationship between stress relaxation and permanent deformation was investigated for various degrees of prestretch, and the estimated stress resulting from tooth movement was calculated. Results: The degree of prestretch and the stress relaxation ratio exhibited a strong negative correlation, whereas no correlation was found between the degree of prestretch and the average normalized permanent strain. The maximal estimated stress was observed when prestretch was performed in three cycles to 200% of the original length. Conclusions: Although prestretch benefited residual stress, it did not exhibit negative effects such as permanent deformation. The maximal estimated stress was observed at the maximal prestretch, but the difference between prestretch and control groups decreased with time. In general, higher residual stresses were observed for product B than for product A, but this difference was not clinically significant.

11.
PLoS One ; 13(9): e0202952, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30204811

RESUMO

Based on three-dimensional scanning and computer-aided design and computer-aided manufacturing (CAD/CAM) techniques, customized bracket systems are increasingly used. However, data remain limited regarding customized bracket design, characteristics, and stability. This study was undertaken to evaluate the design, bond strength, and residual adhesives of four different CAD/CAM customized brackets that were attached to human tooth specimens by indirect bonding. Thirty extracted human upper premolars were divided into five groups: Group 1, preadjusted self-ligating labial metal bracket; Group 2, lingual self-ligating metal injection molding customized bracket; Group 3, gold-casted lingual customized bracket; Group 4, labial self-ligating milled customized bracket; Group 5, labial customized resin base bracket. Except in Group 1, premolar specimens were scanned via model scanner, and the images were sent to each manufacturing company to fabricate customized brackets and transfer trays/jigs. Debonding force (DF; N) was measured by Instron universal testing machine and shear bond strength (SBS; MPa) was calculated via dividing DF by bonding area. Adhesive remnants were analyzed via stereo microscopic images. Group 2 (196.90±82.75 N) exhibited significantly higher DF than Group 1 (62.77±12.65 N); other groups exhibited similar DFs, compared with Group 1. No customized bracket groups exhibited significant differences in SBS, relative to Group 1 (6.73±1.36 MPa). However, SBS in Group 5 (11.46±7.22 MPa) was significantly higher than in Group 3 (3.58±2.14 MPa). Group 3 had significantly lower ARI scores than other groups (P<0.05). Customized brackets exhibited large deviations in DF and SBS; all customized bracket systems exhibited DF that was equivalent or superior to that of preadjusted brackets, even when placed by indirect bonding.


Assuntos
Desenho Assistido por Computador , Colagem Dentária , Braquetes Ortodônticos , Dente Pré-Molar , Análise do Estresse Dentário , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina , Resistência ao Cisalhamento
12.
Korean J Orthod ; 48(5): 283-291, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30206527

RESUMO

Objective: This study was conducted to perform histomorphometric evaluations of the bone surrounding orthodontic miniscrews according to their proximity to the adjacent tooth roots in the posterior mandible of beagle dogs. Methods: Four male beagle dogs were used for this study. Six orthodontic miniscrews were placed in the interradicular spaces in the posterior mandible of each dog (n = 24). The implanted miniscrews were classified into no loading, immediate loading, and delayed loading groups according to the loading time. At 6 weeks after screw placement, the animals were sacrificed, and tissue blocks including the miniscrews were harvested for histological examinations. After analysis of the histological sections, the miniscrews were categorized into three additional groups according to the root proximity: high root proximity, low root proximity, and safe distance groups. Differences in the bone-implant contact (BIC, %) among the root proximity groups and loading time groups were determined using statistical analyses. Results: No BIC was observed within the bundle bone invaded by the miniscrew threads. Narrowing of the periodontal ligament space was observed in cases where the miniscrew threads touched the bundle bone. BIC (%) was significantly lower in the high root proximity group than in the low root proximity and safe distance groups. However, BIC (%) showed no significant differences among the loading time groups. Conclusions: Regardless of the loading time, the stability of an orthodontic miniscrew is decreased if it is in contact with the bundle bone as well as the adjacent tooth root.

13.
Korean J Orthod ; 48(5): 316-325, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30206530

RESUMO

Objective: The aim of this systematic multiscale analysis was to evaluate the effects of thermoforming on the physical and mechanical properties of thermoplastic materials used to fabricate transparent orthodontic aligners (TOAs). Methods: Specimens were fabricated using four types of thermoplastic materials with different thicknesses under a thermal vacuum. Transparency, water absorption and solubility, surface hardness, and the results of three-point bending and tensile tests were evaluated before and after thermoforming. Data were analyzed using one-way analysis of variance and Student's t-test. Results: After thermoforming, the transparency of Duran and Essix A+ decreased, while the water absorption ability of all materials; the water solubility of Duran, Essix A+, and Essix ACE; and the surface hardness of Duran and Essix A+ increased. The flexure modulus for the 0.5-mm-thick Duran, Essix A+, and eCligner specimens increased, whereas that for the 0.75-/1.0-mm-thick Duran and eClginer specimens decreased. In addition, the elastic modulus increased for the 0.5-mm-thick Essix A+ specimens and decreased for the 0.75-mm-thick Duran and Essix ACE and the 1.0-mm-thick Essix ACE specimens. Conclusions: Our findings suggest that the physical and mechanical properties of thermoplastic materials used for the fabrication of TOAs should be evaluated after thermoforming in order to characterize their properties for clinical application.

14.
Am J Orthod Dentofacial Orthop ; 153(6): 808-817, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29853238

RESUMO

INTRODUCTION: The aim of this study was to investigate the level of satisfaction for orthodontic treatment among adult patients. In addition, the influencing host factors were monitored for their associations with satisfaction. METHODS: A questionnaire was designed to measure the level of satisfaction in 10 items; overall satisfaction, tooth alignment, facial appearance, eating and chewing, confident smile and self-image, retention state, treatment duration, treatment costs, intention to recommend, and relief of previous concerns, using a 5-point Likert scale. Total satisfaction was calculated by averaging the Likert scores from the 10 items. The survey was conducted, and the results from 298 adults were evaluated. RESULTS: For the overall satisfaction item, 45.0% were very satisfied, and 39.9% were satisfied, resulting in a satisfaction ratio of 84.9%. Total satisfaction score was 3.9. The level of satisfaction for tooth alignment and confident smile and self-image were significantly higher than facial appearance and eating and chewing (P <0.001). Patients aged 50 and above were more satisfied than the younger ones, and men were more satisfied than women (P <0.05). CONCLUSIONS: Overall, adult patients were highly satisfied with orthodontic treatment. Age, sex, motivation, expected concern, and discomfort influenced the level of satisfaction.


Assuntos
Ortodontia Corretiva , Satisfação do Paciente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Autorrelato , Adulto Jovem
15.
Biomed Res Int ; 2018: 8414605, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29568766

RESUMO

Objective: We investigated the suitability of intraoral-scan models for measuring tooth dimensions and the amount of crowding in patients with severe tooth crowding. Materials and Methods: Fifty-eight patients who had undergone intraoral scans for diagnosis were included. Cast models were divided into two groups depending on the amount of crowding, as determined by initial caliper-based measurements (mild crowding [MC] group: <3.0 mm; severe crowding [SC] group: >4.5 mm). Twenty maxillary models and 20 mandibular models were used in this study. For the three types of models (i.e., IS digital model, C cast model, and CS digital model), the reproducibility and the precision of linear measurements were evaluated. Results: We found that linear measurements made using digital calipers on a plaster model and on the relevant software were reproducible. There was no significant difference in most linear measurements between digital models and the C model. There were differences in the amount of crowding (p < .05), although these were not clinically significant. There was no relationship between the precision of crowding in the three types of models and the severity of crowding. Conclusions: Digital models can be used for measuring crowding in both mild and severe crowding cases. However, crowding measured by digital models tends to be lesser than that measured by cast models, and this should be considered during clinical application.


Assuntos
Má Oclusão/diagnóstico , Mandíbula/fisiopatologia , Maxila/fisiopatologia , Técnica de Moldagem Odontológica , Modelos Dentários , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Reprodutibilidade dos Testes , Software
16.
Am J Orthod Dentofacial Orthop ; 153(1): 144-153, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29287640

RESUMO

INTRODUCTION: In this study, we assessed the precision and trueness of dental models printed with 3-dimensional (3D) printers via different printing techniques. METHODS: Digital reference models were printed 5 times using stereolithography apparatus (SLA), digital light processing (DLP), fused filament fabrication (FFF), and the PolyJet technique. The 3D printed models were scanned and evaluated for tooth, arch, and occlusion measurements. Precision and trueness were analyzed with root mean squares (RMS) for the differences in each measurement. Differences in measurement variables among the 3D printing techniques were analyzed by 1-way analysis of variance (α = 0.05). RESULTS: Except in trueness of occlusion measurements, there were significant differences in all measurements among the 4 techniques (P <0.001). For overall tooth measurements, the DLP (76 ± 14 µm) and PolyJet (68 ± 9 µm) techniques exhibited significantly different mean RMS values of precision than the SLA (88 ± 14 µm) and FFF (99 ± 14 µm) techniques (P <0.05). For overall arch measurements, the SLA (176 ± 73 µm) had significantly different RMS values than the DLP (74 ± 34 µm), FFF (89 ± 34 µm), and PolyJet (69 ± 18 µm) techniques (P <0.05). For overall occlusion measurements, the FFF (170 ± 55 µm) exhibited significantly different RMS values than the SLA (94 ± 33 µm), DLP (120 ± 28 µm), and PolyJet (96 ± 33 µm) techniques (P <0.05). There were significant differences in mean RMS values of trueness of overall tooth measurements among all 4 techniques: SLA (107 ± 11 µm), DLP (143 ± 8 µm), FFF (188 ± 14 µm), and PolyJet (78 ± 9 µm) (P <0.05). For overall arch measurements, the SLA (141 ± 35 µm) and PolyJet (86 ± 17 µm) techniques exhibited significantly different mean RMS values of trueness than DLP (469 ± 49 µm) and FFF (409 ± 36 µm) (P <0.05). CONCLUSIONS: The 3D printing techniques showed significant differences in precision of all measurements and in trueness of tooth and arch measurements. The PolyJet and DLP techniques were more precise than the FFF and SLA techniques, with the PolyJet technique having the highest accuracy.


Assuntos
Modelos Dentários/normas , Impressão Tridimensional
17.
Biomed Res Int ; 2018: 3936918, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30598994

RESUMO

Objective: The aim of this study was to evaluate the morphological characteristics of the palatal rugae in Korean subjects to determine whether the palatal rugae can be used as an appropriate reference area for three-dimensional digital model superimpositions. Materials and Methods: In total, 343 patients (110 men, 233 women; mean age, 25.6±8.2 years) who had a digital model taken at their initial visit were included, and the numbers and types of right and left palatal rugae were investigated according to the primary, secondary, and fragmentary rugae. Finally, the differences in the positions of the third primary ruga were investigated according to the presence of additional rugae posterior to the third primary ruga. Results: The number of primary palatal rugae ranged from one to six, with 43.5% of the subjects having three primary rugae and 36.1% having four primary rugae; there were no significant differences between sexes. Except for the fragment rugae, the numbers of primary and secondary rugae were not significantly different between the left and right sides. The third primary ruga was located more significantly anteriorly when there was an additional ruga posterior to the third primary ruga (P < 0.001). Conclusions: The numbers of the palatal rugae vary greatly among individuals, and this affects the anteroposterior position of the third primary ruga. When the third primary ruga is located anteriorly, care should be taken when using it as a reference area for superimposition with a digital model before and after orthodontic treatment.


Assuntos
Palato Duro/fisiologia , Adulto , Modelos Dentários , Feminino , Humanos , Masculino , Mucosa Bucal/fisiologia
18.
Angle Orthod ; 88(1): 82-90, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29016190

RESUMO

OBJECTIVE: To investigate the effect of flapless osteoperforation on the tissue response of the atrophic alveolar ridge affected by orthodontic tooth movement (OTM). MATERIALS AND METHODS: An atrophic alveolar ridge model was established in the mandibular quadrants of eight beagle dogs. As a split-mouth design, the quadrants were randomly divided into group C (OTM only) and group OP (OTM with flapless osteoperforation). The rate of OTM for 10 weeks was compared between groups, and micro-CT-based histomorphometric analysis and RNA-sequencing-based gene-enrichment analysis were performed targeting the atrophic ridge. RESULTS: Group OP displayed more rapid tooth movement with lower bone mineral density and higher trabecular fraction in the atrophic ridge than did group C, showing no intergroup difference of total ridge volume. As contributing biological functional pathways in group OP, the genes related to osteoclast differentiation and TNF signaling pathway were up-regulated and those associated with Wnt signaling pathway and AMPK signaling pathway were down-regulated. CONCLUSIONS: Flapless osteoperforation facilitated the rate of OTM toward the atrophic ridge, maintaining low bone density, whereas it did not increase the volume of the atrophic ridge.


Assuntos
Perda do Osso Alveolar/patologia , Processo Alveolar/patologia , Técnicas de Movimentação Dentária , Proteínas Quinases Ativadas por AMP/genética , Perda do Osso Alveolar/diagnóstico por imagem , Processo Alveolar/diagnóstico por imagem , Animais , Atrofia , Densidade Óssea , Remodelação Óssea , Diferenciação Celular/genética , Modelos Animais de Doenças , Cães , Mandíbula/diagnóstico por imagem , Mandíbula/patologia , Osteoclastos , Transdução de Sinais , Fator de Necrose Tumoral alfa/genética , Via de Sinalização Wnt/genética , Microtomografia por Raio-X
19.
Dent Mater ; 33(12): 1426-1435, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29033191

RESUMO

OBJECTIVE: We evaluated whether the biological activity of the surface of titanium, when stored in an aqueous solution, in low vacuum, and under ambient conditions after ultraviolet light (UV) treatment is comparable to that of the surface immediately after UV treatment for 15min and that after dielectric barrier discharge (DBD) plasma treatment for 15min. METHODS: Grade IV titanium discs with machined surfaces were irradiated with UV and their surface properties were evaluated immediately and after storage for 28days in distilled H2O (dH2O), a vacuum desiccator (31.325kPa), and a sealed container under air. Their surface characteristics were evaluated by atomic force microscopy, X-ray diffraction, contact angle analysis, and X-ray photoelectron spectroscopy. Biological activities were determined by analyzing the albumin adsorption, MC3T3-E1 cell adhesion, and cytoskeleton development. RESULTS: Hydrophilicity of titanium surfaces stored in dH2O was comparable to that immediately after UV treatment and higher than that immediately after DBD plasma treatment (P<0.001). Storage in dH2O and in low vacuum immediately after UV treatment prevented hydrocarbon contamination and maintained elevated amounts of titanium and oxygen. After 28 days, protein adsorption, cellular adhesion, and cytoskeletal development of MC3T3-E1 cells on the titanium surfaces stored in dH2O were significantly enhanced compared to those stored in low vacuum and under ambient conditions while being comparable to those immediately after UV and DBD plasma treatments. SIGNIFICANCE: UV treatment of the titanium implants followed by wet storage is useful for maintaining enhanced biological activity and overcoming biological aging during shelf storage.


Assuntos
Osteoblastos/efeitos da radiação , Titânio/química , Ar , Albuminas/metabolismo , Animais , Adesão Celular , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Microscopia de Força Atômica , Espectroscopia Fotoeletrônica , Propriedades de Superfície , Fatores de Tempo , Raios Ultravioleta , Vácuo , Água , Difração de Raios X
20.
Korean J Orthod ; 47(5): 306-312, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28861392

RESUMO

OBJECTIVE: The purpose of this study was to examine the effect of commercially available fluoride-containing oral rinses on the corrosion behavior of titanium alloys, which are the main components of orthodontic miniscrews. METHODS: Four commercially available oral rinses (solution A, pH 4.46/260 ppm fluoride; solution B, pH 4.41/178 ppm fluoride; solution C, pH 6.30/117 ppm fluoride; and solution D, pH 4.17/3.92 ppm fluoride) were tested on titanium alloy (Ti-6Al-4V) circular plates, and saline was used as the control. The open-circuit potential and potentiodynamic polarization of these materials were measured. Thereafter, all samples were evaluated under a field-emission scanning electron microscope. RESULTS: Among the tested oral rinses, except solution D, the more the fluoride content was, the greater was the corrosion potential downtrend; the corrosion resistance of the titanium alloy sample was also lowered significantly (p < 0.05). Field-emission scanning electron microscopic analysis of the surface morphology of the titanium alloy samples revealed that all samples had some defects, crevices, or pitting after exposure to the oral rinses than before treatment. In particular, the samples in solution A showed the most changes. CONCLUSIONS: Commercially available oral rinses having a high fluoride concentration and a low pH may reduce the corrosion resistance of titanium alloys used in dental appliances such as orthodontic titanium miniscrews and brackets.

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