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1.
J Mech Behav Biomed Mater ; 100: 103390, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31563081

RESUMO

PURPOSE: Digital technology has advanced and changed clinical dentistry. The utility of various thermoplastic materials for 3D dental printing has not been thoroughly explored. The aim of this study was to evaluate mechanical properties of a new thermoplastic elastomer material applicable for a dental 3D printer. MATERIAL & METHOD: Three thermoplastic elastomers: ABS, PLA and an acrylic block copolymer (KUR) and a dental self-curing resin (PMMA) were used in this study. Physical properties were evaluated by measuring water sorption (WS), dimensional accuracy (DA), ultimate tensile strength (UTS) and shear bond strength (SBS) to PMMA. For WS and DA, specimens were measured by weight and length, respectively after desiccation and immersion in 37 °C distilled water for 1 day, 1 week and 1 month. For UTS, the specimens were prepared according to ISO 527-2-5A and loaded to test the UTS at a crosshead speed of 5 mm/min after storage in 37 °C distilled water for 24 h and 1 month. For SBS, MMA self-curing resin was filled in a Teflon ring which was mounted onto polished specimens to make the adhesive area. The prepared specimens were tested for SBS after storage in 37 °C distilled water for 24 h and 37 °C distilled water for 24 h followed by 10000 times thermal cycling. The data were analyzed by repeated measures ANOVA, two-way ANOVA and t-test with Bonferroni correction at 95% confidence level. RESULT: The WS value of PMMA was significantly higher than those of the other materials after 1 day (p < 0.05), while the WS values of KUR were significantly higher than those of the other materials after 1 week and 1 month (p < 0.05). The DA values were influenced by water storage periods except for KUR. There were no significant differences among ABS, PLA and PMMA in SBS before thermal cycling (p > 0.05). The SBS of KUR was the lowest among the materials before thermal cycling (p < 0.05). However, there was no significant difference between PMMA and KUR after thermal cycling (p > 0.05). CONCLUSION: The acrylic block copolymer demonstrated acceptable physical properties, suggesting the potential to be a material to make provisional restorations for a dental 3D printer.


Assuntos
Materiais Dentários/química , Restauração Dentária Permanente/instrumentação , Restauração Dentária Permanente/métodos , Elastômeros/química , Teste de Materiais , Impressão Tridimensional , Acrilatos/química , Resinas Compostas/química , Colagem Dentária , Polímeros/química , Polimetil Metacrilato/química , Cimentos de Resina/química , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , Temperatura , Resistência à Tração
2.
Clin Exp Dent Res ; 5(4): 398-405, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31452950

RESUMO

Objectives: To assess the motivational effect of multi-colored restoration on the anxiety level of pediatric patients at thedental clinic and its motivational effect on their oral hygiene status. Material and methods: A total of 30 participants. Results: Both groups revealed reduction in the anxiety level and improvement in their behavior at the dental office but did not reach significance. Plaque index showed a significant reduction per group and a near significance as compared between test groups. Conclusions: The use of the multicolored restoration could provide a potential advantage to improve the oral health status of children and might aid in enhancing their behavior at dental clinic particularly younger age groups.


Assuntos
Comportamento Infantil/psicologia , Cor , Resinas Compostas , Cárie Dentária/terapia , Restauração Dentária Permanente/instrumentação , Higiene Bucal/psicologia , Ansiedade/etiologia , Ansiedade/prevenção & controle , Criança , Pré-Escolar , Restauração Dentária Permanente/psicologia , Feminino , Seguimentos , Educação em Saúde Bucal/métodos , Humanos , Masculino , Motivação , Resultado do Tratamento
3.
Trials ; 20(1): 530, 2019 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-31445509

RESUMO

BACKGROUND: Guidelines in pediatric restorative dentistry recommend the use of preformed pediatric stainless steel crowns (SSCs) in cases of severe tooth decay of at least two surfaces. This clinically effective and safe restorative option is frequently refused by parents for esthetic reasons; they prefer conventional restorations using esthetic filling materials (composites, glass ionomer) if lesion severity limited to two surfaces permits. Recently, manufacturers have proposed esthetic preformed pediatric zirconia crowns (ZCs) but these have been assessed in only two randomized clinical trials (RCT) with follow-ups of 6 and 12 months. Only one of these RCTs was carried out on primary molars to test ZCs (NuSmile ZR) without a groove in its inner surface. The primary objective of this proposed RCT is to assess the effectiveness of ZCs compared with SSCs. Our hypothesis is that the effectiveness of ZCs will be equivalent to that of SSCs. METHODS: In this split-mouth, 2-year RCT, pairs of primary molars in 101 child participants will be randomized and restored with SSCs (ESPE, 3M) and ZCs (EZCrowns, Sprig Oral Health Technologies) characterized by grooves on their inner surface. Primary molars will first be allocated to SSCs, and 1 to 2 weeks later the other primary molar of the same pair will be restored by ZC. The primary outcome is the success defined by the "absence of major clinical and radiographic failure" (e.g., pain, pulp infection, dental abscess or periradicular pathology visible on radiographs). The secondary outcomes include the retention and fracture rates, the gingival condition, the wear of the antagonist of the treated teeth, as well as both parental and child satisfaction. DISCUSSION: This study will investigate two types of preformed pediatric crowns for the management of severe decay on primary molars. The results may help practitioners choose the better therapeutic option and to explain to parents the advantages and disadvantages of these two therapies. TRIAL REGISTRATION: NCT03296709 . Registered on  27 September 2017.


Assuntos
Coroas , Assistência Odontológica para Crianças , Cárie Dentária/cirurgia , Restauração Dentária Permanente/instrumentação , Dente Molar/cirurgia , Dente Decíduo/cirurgia , Zircônio , Adolescente , Fatores Etários , Criança , Pré-Escolar , Cárie Dentária/diagnóstico , Planejamento de Prótese Dentária , Falha de Restauração Dentária , Restauração Dentária Permanente/efeitos adversos , Feminino , França , Humanos , Masculino , Estudos Multicêntricos como Assunto , Satisfação do Paciente , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Tempo , Resultado do Tratamento
4.
Niger J Clin Pract ; 22(6): 782-789, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31187762

RESUMO

Objective: The aim of this in vitro study was to investigate the fracture strength and cuspal deflection of endodontically treated premolars restored using different composite resins along with or without fiber post application. Materials and Method: Eighty intact premolars were randomly divided into eight groups (n = 10); CO group: intact teeth (control), OPR group: mesio-occlusal-distal-palatal (MODP) preparation (OPR) + endodontic treatment (ET), TC group: MODP preparation + ET + Tetric N-Ceram, TB group: MODP preparation + ET + Tetric EvoCeram Bulk Fill, SO group: MODP preparation + ET + SonicFill 2, TC-P group: MODP preparation + ET + Hahnenkratt glass fiber post + Tetric N-Ceram, TB-P group: MODP preparation + ET + Hahnenkratt glass fiber + Tetric EvoCeram Bulk Fill, and SO-P Group: MODP preparation + ET + Hahnenkratt glass fiber post + SonicFill 2. After thermocycling, specimens were subjected to a compressive load until fracture. Data were analyzed using analysis of variance and Tukey tests (P < 0.05). Results: The mean fracture strength of groups which received post treatment showed similar fracture strength values [TC-P (931.6 ± 97.9), TB-P (882.0 ± 59.7), SO-P (862.0 ± 143.0) (P > 0.05)] and was significantly higher than OPR (530.6 ± 41.7), TC (841.2 ± 93.1), TB (774.5 ± 101.8), and SO (735.0 ± 178.01) groups (P < 0.05). No significant difference was detected among groups considering cuspal deflection (P > 0.05). The fiber post insertion resulted in more unfavorable fractures. Conclusion: Endodontically treated teeth restored with fiber post and bulk-fill or conventional composite resins demonstrated fracture strength values similar to intact teeth.


Assuntos
Resinas Compostas/uso terapêutico , Restauração Dentária Permanente/instrumentação , Vidro , Dente não Vital/terapia , Dente Pré-Molar/lesões , Força Compressiva , Análise do Estresse Dentário , Resistência à Flexão , Humanos , Teste de Materiais , Distribuição Aleatória , Fraturas dos Dentes/etiologia , Preparo do Dente/métodos
5.
J Dent Educ ; 83(4): 407-415, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30745350

RESUMO

Scientific evidence validating the beneficial effect of loupes in preventing musculoskeletal disorders is very scarce. The aim of this study was to assess the impact of dental loupes on dental students' posture during a preclinical restorative dentistry course. Using a randomized crossover design, this study was conducted at the School of Dentistry, University of Nantes, France, in 2017. Forty students in their second year of dental study were randomly divided into two groups of 20 each: group A used loupes, whereas group B did not. The week after, students reversed configurations (each subject served as his or her own treatment and control group). Students were video-recorded during cavity preparation. Trunk, head and neck, and upper arm positions were analyzed using continuous scores based on the modified Posture Assessment Instrument. Additionally, cavities were rated, and students completed a questionnaire on their perceptions of the loupes. On a scale on which lower scores indicated better posture, the results showed significantly higher posture ergonomic scores per minute for students without loupes (146.3±6.64 points/min) than with loupes (123.2±6.77 points/min; p<0.05). The majority of the students (32/39, 82%) showed improvements in ergonomic postures with the use of loupes. Trunk, head, and neck were positively impacted by the use of loupes, but not the upper arms. Cavity preparations were not improved by the use of loupes. The questionnaire revealed negative aspects (pain and difficulty adapting) but underlined the perceived positive impact on posture. This study documented the ergonomic advantages and challenges of introducing magnification near the beginning of the dental training program.


Assuntos
Restauração Dentária Permanente/instrumentação , Educação em Odontologia , Óculos , Postura , Estudos Cross-Over , Ergonomia , Humanos , Estudantes de Odontologia , Gravação em Vídeo
6.
Pediatr Dent ; 40(5): 370-374, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-30355434

RESUMO

Purpose: Polymerization shrinkage stress is determined by shrinkage as well as elastic modulus. Elastic modulus develops during polymerization. This study evaluated how elastic modulus affects shrinkage stresses in a primary molar for three types of restorative materials. Methods: Elastic modulus of resin composite, compomers, and resin-modified glass ionomer (RMGI) were determined using four-point bending of rectangular beams at 10 minutes, 24 hours, and after one to four weeks storage in water (n equals 10). Results were analyzed using twoway analysis of variance and pairwise comparisons (α equals 0.05). The elastic moduli were used with published shrinkage data to calculate stresses at the tooth-restoration interface in finite element models of a cross-sectioned restored primary molar. Results: The elastic modulus ranged between 5.6 to 19.9 gigapascal. Elastic modulus values were lowest at 10 minutes, regardless of material, and increased significantly (43 to 95 percent) in 24 hours; RMGI continued to increase (64 percent) for one week. Shrinkage stresses increased nonproportionally (resin composite 31 percent, compomer 35 percent, RMGI 52 percent) with increasing elastic modulus for sustained volumetric shrinkage. Conclusions: Elastic modulus development is material dependent and an important factor in polymerization shrinkage stress. Maturation of restorative materials can cause long-lasting stress increases if shrinkage is not alleviated by hygroscopic expansion.


Assuntos
Materiais Dentários , Restauração Dentária Permanente/instrumentação , Análise do Estresse Dentário , Módulo de Elasticidade/fisiologia , Dente Molar/cirurgia , Dente Decíduo/cirurgia , Compômeros , Resinas Compostas , Restauração Dentária Permanente/métodos , Análise de Elementos Finitos , Cimentos de Ionômeros de Vidro , Humanos , Polimerização
7.
Folia Med (Plovdiv) ; 60(2): 291-299, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30355813

RESUMO

BACKGROUND: The reduced fracture resistance in endodontically treated teeth requires the use of radicular posts, with their advantages and disadvantages. AIM: To evaluate the clinical performance of teeth restored with or without radicular posts at 6 and 12 months. MATERIALS AND METHODS: The study included 22 patients who received endodontic therapy on premolars with a loss of one or two proximal walls. The premolars were divided into groups according to the restoration method: metal post group (MP), fiber post group (FP), and no post group (NP). For the NP group, a dentinal core of fiber-reinforced composite was used. The McNemar test, marginal homogeneity test and Kruskal-Wallis test were used in the statistical analysis. At the 6 and 12 month recall, both the direct composite restorations and the integrity of the post systems were assessed. RESULTS: At 6-month recall assessment, there was no statistically significant difference in the categories of 'appropriate colour', 'secondary caries' and 'obturation integrity'. That was not the case with 'marginal discoloration', 'marginal adaptation', 'proximal contact' and 'surface smoothness'. The recall at 12 months showed a continuation of this tendency, with significant decrease in the category of 'adequate colour'. Assessment of post longevity at the two recalls did not show any significant changes. The teeth restored without a post showed survival rates comparable to that of teeth restored with a post for the 12-month period of observation. CONCLUSIONS: There were no failures of the different posts used. The observed changes were attributed to the progressive deterioration of the composite restorations.


Assuntos
Dente Pré-Molar , Restauração Dentária Permanente/métodos , Dente não Vital , Adolescente , Adulto , Restauração Dentária Permanente/instrumentação , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
Clin Implant Dent Relat Res ; 20(5): 814-823, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30039915

RESUMO

BACKGROUND: The implant-abutment connection (IAC) is known to be a key factor for the long-term stability of peri-implant tissue. PURPOSE: The aim of the present in vitro study was to detect and measure the mechanical behavior of different IACs by X-ray imaging. MATERIALS AND METHODS: A total of 20 different implant systems with various implant dimensions and IACs (13 conical-, 6 flat-, and 1 gable-like IAC) have been tested using a chewing device simulating dynamic and static loading up to 200 N. Micromovements have been recorded with a high-resolution, high-speed X-ray camera, and gap length and gap width between implant and abutment have been calculated. Furthermore, X-ray video sequences have been recorded to investigate the sealing capacity of different IACs. RESULTS: Out of the 20 implant systems, eight implant systems with a conical IAC showed no measurable gaps under static and dynamic loading (200 N). By contrast, all investigated implant systems with a flat IAC showed measurable gaps under dynamic and static loading. X-ray video sequences revealed that a representative conical IAC had sufficient sealing capacity. CONCLUSION: Within the limits of the present in vitro study, X-ray imaging showed reduced formation of microgaps and consecutive micromovements in implants with conical IAC compared to flat IACs.


Assuntos
Projeto do Implante Dentário-Pivô , Coroas/efeitos adversos , Dente Suporte/efeitos adversos , Projeto do Implante Dentário-Pivô/efeitos adversos , Projeto do Implante Dentário-Pivô/métodos , Restauração Dentária Permanente/efeitos adversos , Restauração Dentária Permanente/instrumentação , Restauração Dentária Permanente/métodos , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Radiografia Dentária , Estresse Mecânico , Torque , Suporte de Carga
10.
Clin Implant Dent Relat Res ; 20(5): 668-673, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30035348

RESUMO

PURPOSE: This study was aimed to investigate, over 5 years, bone response to "one-abutment onetime" (OA-OT) protocol in the restoration of implants inserted in the anterior maxilla. Additionally, influence of soft tissue biotype in the bone remodeling was investigated. MATERIALS AND METHODS: From January 2011 to January 2012, all consecutive patients presented with a hopeless tooth in the maxillary area between canines were enrolled. Post-extraction ridge preservation was performed. After 6 months, implant was midcrestaly inserted and intraoperative impression was taken. Two months thereafter an immediate definitive abutment with a provisional crown was inserted. At final crown connection, patients underwent a standardized periapical radiograph (T0). At 12 (T1), 24 (T2), 36 (T3), 48 (T4), and 60 (T5) months, radiographic follow-up and clinical control were carried out. Independent sample t-test was conducted to compare bone loss at different times. To detect the potential role of biotype, groups (thick TK vs thin TH) were compared by analysis of variance with general linear model. RESULTS: Twenty-five patients were enrolled, but only 22 patients concluded the study. The radiographic analysis showed a stable longitudinal condition of bone levels after the first-year significant increasing (0.17 ± 0.25mm, 0.33 ± 0.25mm, 0.28 ± 0.27mm, 0.25 ± 0.26mm, 0.31 ± 0.35mm, and 0.31 ± 0.29mm, respectively at T1, T2, T3, T4, and T5). No statistical significant differences in bone loss among the two groups TH vs TK over the time (P = 0.952) were demonstrated. CONCLUSION: Results showed that the OA-OT approach allow to obtain stable bone levels.


Assuntos
Projeto do Implante Dentário-Pivô/métodos , Implantes Dentários para Um Único Dente , Restauração Dentária Permanente/métodos , Idoso , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/etiologia , Dente Suporte , Técnica de Moldagem Odontológica , Restauração Dentária Permanente/instrumentação , Estética Dentária , Feminino , Humanos , Masculino , Estudos Prospectivos , Radiografia Dentária
11.
Gen Dent ; 66(3): 68-74, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29714704

RESUMO

The purpose of this study was to compare the depths of cure of a proximal box preparation filled in bulk with various approaches: filled with a bulk-fill or conventional composite; placed with a new perforated metal matrix, a traditional metal matrix, or a clear matrix; and polymerized with either occlusal-only or tri-sited light curing. After tri-sited curing, the use of the new perforated metal matrix band resulted in a depth of cure that was not significantly different from that achieved with the use of metal bands (removed during curing) or transparent matrix bands. Adequate polymerization was obtained at depths of more than 5.0 mm for the bulk-fill composite and more than 4.0 mm for the conventional composite when tri-sited light curing was used. Tri-sited light curing resulted in a significantly greater depth of cure than occlusal-only curing. The perforated metal band may be used as an alternative to the use of solid metal bands or transparent matrix bands to provide similar depths of cure for composite resins, with the possible benefits of malleability and the ability to leave the band in place during tri-sited light curing.


Assuntos
Resinas Compostas/uso terapêutico , Restauração Dentária Permanente/métodos , Preparo da Cavidade Dentária/métodos , Restauração Dentária Permanente/instrumentação , Humanos , Técnicas In Vitro , Bandas de Matriz
12.
Int J Nanomedicine ; 13: 2755-2765, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29780246

RESUMO

Objective: This study investigates the effects of nano-hydroxyapatite (NHA) gel and Clinpro (CP) on remineralization potential of enamel and cementum at the cavosurface area of computer-aided design and computer-aided manufacturing ceramic restoration. Materials and methods: Thirty extracted human mandibular third molars were sectioned at 1 mm above and below the cemento-enamel junction to remove the cemento-enamel junction portions and replaced them with zirconia ceramic disks by bonding them to the crown and root portions with resin cement. The enamel and cementum with an area of 4×4 mm2 surrounding the ceramic disk was demineralized with carbopol. The demineralized surfaces were treated with either NHA or CP, while 1 group was left with no treatment. Vickers microhardness of enamel and cementum were determined before demineralization, after demineralization, and after remineralization. Analysis of variance and Tukey multiple comparisons were used to determine statistically significant differences at 95% level of confidence. Scanning electron microscopy and X-ray diffraction were used to evaluate for surface alterations. Results: The mean ± SD of Vickers microhardness for before demineralization, after demineralization, and after remineralization for enamel and cementum were 377.37±22.99, 161.95±10.54, 161.70±5.92 and 60.37±3.81, 17.65±0.91, 17.04±1.00 for the no treatment group; 378.20±18.76, 160.72±8.38, 200.08±8.29 and 62.58±3.37, 18.38±1.33, 27.99±2.68 for the NHA groups; and 380.53±25.14, 161.94±5.66, 193.16±7.54 and 62.78±4.75, 19.07±1.30, 24.46±2.02 for the CP groups. Analysis of variance indicated significant increase in microhardness of demineralized enamel and cementum upon the application of either NHA or CP (p<0.05). Post hoc multiple comparisons indicated significantly higher remineralization capability of NHA for both enamel and cementum than CP (p<0.05), as evidenced by scanning electron microscopy, indicating NHA particle deposition in the area of remineralization, and crystallinity accumulation, as indicated by X-ray diffraction. Conclusion: NHA gel and CP were capable of remineralization of the enamel and cementum. NHA was more capable in the remineralization process than CP. NHA was extremely capable in the remineralization process for enamel and cementum surrounding the margin of the computer-aided design and computer-aided manufacturing ceramic.


Assuntos
Cemento Dentário/efeitos dos fármacos , Esmalte Dentário/efeitos dos fármacos , Restauração Dentária Permanente/métodos , Durapatita/farmacologia , Remineralização Dentária/métodos , Cerâmica/química , Resinas Compostas/farmacologia , Desenho Assistido por Computador , Cemento Dentário/fisiologia , Esmalte Dentário/fisiologia , Desgaste de Restauração Dentária , Restauração Dentária Permanente/instrumentação , Géis , Humanos , Dente Molar , Dente Serotino , Selantes de Fossas e Fissuras/farmacologia , Zircônio/química
14.
Oper Dent ; 43(5): 467-471, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29570028

RESUMO

Given the increasing incidence of root caries in the elderly population, clinicians frequently must isolate and restore subgingival preparations. This article demonstrates a technique utilizing a modified Tofflemire matrix band that creates a preparation free of crevicular fluid and blood for restoration with resin-modified glass ionomer cement.


Assuntos
Restauração Dentária Permanente/métodos , Bandas de Matriz , Cárie Radicular/cirurgia , Restauração Dentária Permanente/instrumentação , Humanos , Incisivo/cirurgia , Masculino , Pessoa de Meia-Idade
15.
Dent Mater ; 34(5): e83-e88, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29402539

RESUMO

OBJECTIVE: Dental restoration aesthetics, particularly the translucency of modern dental restorative filling materials depends on the refractive index (RI) match between the different components in the material. In the case of dental composites (DC), the RI of the polymer must match the RI of the filler otherwise the material is optically opaque and has limited depth of cure. In the case of glass ionomer cements (GICs), the RI of the ion-leachable glass must match the RI of the polysalts to engineer a smart material with a tooth-like appearance. The RI of oxide glasses can be calculated by means of Appen factors. However, no Appen factors are available for the fluoride components in dental glasses. Therefore, the objective of this study is to empirically derive composition-specific Appen factors for the metal fluorides in complex multicomponent glasses for use in dentistry. METHODS: Two series of bioactive glasses and two series of ionomer-type glasses were produced for this study. Refractive indices of all glasses were then measured by the Becke Line technique. Thereafter, composition-specific factors for the metal fluorides were derived. RESULTS: It was found that increasing metal fluoride content reduces the RI of multicomponent dental glasses linearly. A series-specific Appen factors for the metal fluorides were successfully derived and allow RI calculation to within 0.005. SIGNIFICANCE: This paper proposes a modified Appen Model with composition-specific Appen factors for the metal fluorides for the development of dental restoratives with enhanced aesthetics and improved depth of cure of dental composites.


Assuntos
Materiais Dentários/química , Restauração Dentária Permanente/instrumentação , Estética Dentária , Fluoretos/química , Cimentos de Ionômeros de Vidro/química , Vidro/química , Teste de Materiais , Refratometria
17.
J Prosthodont ; 27(8): 771-774, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28067979

RESUMO

PURPOSE: To compare two fiber post removal techniques in terms of fracture resistance and time required for post removal. MATERIALS AND METHODS: Post space was prepared to a 9-mm depth in each root canal. The roots were randomly divided into three groups of 15 specimens each. D.T. Light-Posts were cemented in all groups. In group 1, fiber posts were removed using the D.T. Light-Post-removal kit; in group 2, Start-X stainless-steel ultrasonic tips were used. In group 3, fiber posts were left without removal (the control group). For all groups, fracture resistance (N) value was measured and recorded using a universal testing machine. Times required for fiber post removal were also recorded for the two study groups. RESULTS: There was no significant difference between the control and removal kit groups for fracture resistance values (p = 0.233). The fracture resistance value of the ultrasonic group was found to be significantly lower than that of the control group (p = 0.001) as well as that of the removal kit group (p = 0.032). The fiber post removal time for the ultrasonic group was significantly longer than that for the removal kit group (p < 0.001). CONCLUSION: Compared to the removal kit, removal of the fiber posts with an ultrasonic tip decreases the fracture resistance of the roots, although significantly more time is required.


Assuntos
Restauração Dentária Permanente/métodos , Técnica para Retentor Intrarradicular , Dente não Vital/cirurgia , Falha de Restauração Dentária , Restauração Dentária Permanente/efeitos adversos , Restauração Dentária Permanente/instrumentação , Análise do Estresse Dentário , Humanos , Técnica para Retentor Intrarradicular/instrumentação , Fatores de Tempo , Procedimentos Cirúrgicos Ultrassônicos/métodos
18.
Vet J ; 230: 30-35, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29208213

RESUMO

An ex-vivo study was performed on vertically mounted equine maxillary cheek teeth that had caries of 30 infundibulae, using high and low speed contra-angle dental drills and Hedstrom files to debride infundibular food debris and carious dental tissues. This technique effectively debrided 27/30 infundibulae with a mean depth of 19mm (range 9.4-34.3mm) as assessed by computed tomographic (CT) imaging. The debrided infundibulae were treated with sodium hypochlorite, EDTA and a bonding agent, and then then filled in layers with endodontic restoration materials. Further CT imaging and direct examination of sectioned restored teeth showed 6/30 infundibulae, including three that were incompletely debrided, to have defects between the restoration and the infundibular wall/apex. Twenty-one of the remaining 24 infundibulae contained air bubbles, largely within restorations. It is concluded that the use of drills and Hedstrom files is effective in debriding carious infundibulae but improved techniques and materials are required to more effectively fill infundibulae with restorative material.


Assuntos
Cárie Dentária/veterinária , Restauração Dentária Permanente/veterinária , Doenças dos Cavalos/cirurgia , Desbridamento Periodontal/veterinária , Animais , Cárie Dentária/patologia , Cárie Dentária/cirurgia , Restauração Dentária Permanente/instrumentação , Restauração Dentária Permanente/métodos , Cavalos , Maxila , Desbridamento Periodontal/instrumentação , Desbridamento Periodontal/métodos , Dente/patologia , Dente/cirurgia
19.
Cochrane Database Syst Rev ; 12: CD009606, 2017 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-29261853

RESUMO

BACKGROUND: Fixed prosthodontic treatment (crowns, fixed dental prostheses (FDPs), complete arch prostheses) involves the use of several different materials to replace missing tooth structure. Traditionally full metal or metal frameworks veneered with ceramic (metal-ceramic (MC)) have been used. In recent years several different metal-free systems have become available to clinicians and patients. In general, metal-free restorations should allow practitioners to better reproduce natural tooth colour, avoiding shortcomings of MC restorations. The comparative in service clinical performance of fixed prosthodontic treatments of different materials is unclear. OBJECTIVES: To assess the effects of metal-free materials for prosthodontic restorations compared to metal-ceramic or other conventional all-metal materials. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (searched 3 May 2017), Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 4) in the Cochrane Library (searched 3 May 2017), MEDLINE Ovid (1946 to 3 May 2017), and Embase Ovid (1980 to 3 May 2017). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials (searched 3 May 2017). No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Randomised controlled trials (RCTs) in which the clinical performance of metal-free fixed prosthodontic restorations was compared with metal-ceramic (MC) or other conventional restorations in adult patients requiring prosthodontic treatment. RCTs in which the clinical performance of different kinds of metal-free systems were compared among themselves were also considered. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted independently and in duplicate. Trial authors were contacted for missing information. Available results for the outcomes of interest of the systematic review of the studies included were tabulated as they could not be included in a formal meta-analysis. MAIN RESULTS: Nine trials involving a total of 448 participants were included. We judged two trials to be at unclear risk of bias and seven to be at high risk of bias. The majority of items of risk of bias were evaluated to be at unclear or high risk level in more than 50% of the included trials. Each trial except two was addressing a different type of intervention. All evidence was rated as being of very low quality due to problems with risk of bias and imprecision of results, the latter being due to very small sample sizes, low event rates, 95% confidence intervals including the possibility of benefit for both the test and control groups, or combinations of these problems. This means that we are very uncertain about all of the results presented in this review.One trial compared metal-free single crowns (full contour zirconia) to cast gold single crowns in 224 participants and found insufficient evidence of a difference in failure rate after one year, but after five years there was some evidence of a benefit for the gold crowns. There was insufficient evidence of a difference for crown complications at either time of assessment.One trial compared three-unit metal-free FDPs (lithium disilicate) to three-unit metal-ceramic FDPs in 37 participants. There was insufficient evidence of a difference in bridge failure at one and six years, but some evidence of a benefit for the lithium disilicate group in terms of bridge complications at six years. One trial compared zirconia-ceramic FDPs to metal-ceramic FDPs in 34 participants but found insufficient evidence of a difference in bridge failures (i.e. no failures in either treatment group), bridge complications or patients' aesthetic evaluation at any time of assessment up to three years.One trial compared metal-free cantilevered FDPs to metal-ceramic cantilevered FDPs in 21 participants. There was insufficient evidence of a difference for any primary outcome: bridge failures (i.e. no failures in either treatment group), bridge complications, or patients' aesthetic evaluation at any time of assessment up to three years.One trial compared metal-free implant-supported screw retained single crowns (zirconia veneered with feldspathic ceramic) to metal-ceramic implant-supported screw-retained single crowns in 20 participants. There was insufficient evidence of a difference for any primary outcome: crown failures (i.e. no failures in either treatment group), crown complications, or satisfaction/aesthetic evaluation at any time of assessment up to two years.Two trials compared metal-free implant abutments (zirconia) to metal implant abutments both supporting single crowns in 50 participants. There was insufficient evidence of a difference in abutment failure at one year.One trial compared metal-free implant-supported FDPs made of two different types of zirconia ceramic in 18 participants. There was insufficient evidence of a difference in failures at any time of assessment up to 10 years (i.e. no failures in either treatment group). There was some evidence of a benefit for the zirconia-toughened alumina group in terms of complications (chipping).One trial compared metal-free tooth-supported FDPs made with two different veneering techniques (pressed versus layered) in 40 participants. There was insufficient evidence of a difference for failures (i.e. no failures in either treatment group) or complications at any time of assessment up to three years. AUTHORS' CONCLUSIONS: There is insufficient evidence to support or refute the effectiveness of metal-free materials for fixed prosthodontic treatment over metal-ceramic or other type of standard restorations. The overall quality of existing evidence was very low, therefore great caution should be exercised when generalising the results of the included trials. Until more evidence becomes available clinicians should continue to base decisions on which material to use for fixed prosthodontic treatment on their own clinical experience, whilst taking into consideration the individual circumstances and preferences of their patients. There is urgent need of properly designed RCTs.


Assuntos
Coroas , Materiais Dentários/uso terapêutico , Restauração Dentária Permanente/instrumentação , Ligas Dentárias/uso terapêutico , Restauração Dentária Permanente/métodos , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Zircônio/uso terapêutico
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