RESUMO
Objective: To test the shear bond strength and the amount of adhesive remnant on the enamel after debonding of a conventional orthodontic composite system, a flowable composite resin, and a self-adhesive resin cement. Material and Methods: Thirty extracted bovine incisors were allocated in three groups, according to the type of adhesive: Group XT (Transbond XT), Group FL (Flow Z350), and Group RX (RelyX U100). All groups had etching with phosphoric acid. Groups XT and FL received primer before adhesive. Stainless steel metal brackets were bonded using the respective adhesive. Teeth were submitted to shear bond strength (SBS) test, followed by measurement of adhesive remnant. Intergroup comparison of SBS values were performed by one-way Anova and Tukey post-hoc test. Kruskal-Wallis test and the Mann-Whitney U-test were used to compare adhesive remnant. Results: Transbond XT presented higher bond strength than RelyX U100 and Flow Z350; all adhesives exhibited bond failure within the adhesive. All groups showed bond failure occurring within the adhesive. Transbond XT and RelyX U100 left significantly more adhesive remnant on the tooth surface than Flow Z350. Conclusion: All three adhesive systems had bond strength above the minimum for clinical routine use. As regards to bond strength, Transbond XT performed better than the resin cement and the flowable resin. Bond failure occurred within the adhesive in all groups.
Assuntos
Animais , Bovinos , Resinas Compostas , Cimentos Dentários , Ortodontia , Resistência ao Cisalhamento , Análise de Variância , Brasil , Colagem Dentária/métodos , Guias como Assunto , Estatísticas não ParamétricasRESUMO
O objetivo deste estudo foi avaliar se as medidas faciais utilizadas em métodos tradicionais para determinação da Dimensão Vertical de Oclusão estão em Proporção Áurea (1: 1,618) e, por conseguinte, se podem ser utilizadas como método complementar para determinação desta dimensão. Foram selecionados aleatoriamente pacientes entre 20 e 30 anos, da clínica de Odontologia da Universidade Estadual da Paraíba. A amostra foi composta por 30 indivíduos, sendo 15 do gênero masculino e 15 do gênero feminino. Através da análise de fotografias frontais destes indivíduos, e traçados que trespassam pontos cefalométricos, foi possível elucidar novas abordagens nos tratamentos de reabilitação oral. Em relação ao grau da DTM dos pacientes pesquisados, 63,3% (n = 19) apresentavam algum grau de DTM, sendo que 50% (n = 15) apresentavam DTM leve, 10% (n = 3) apresentavam DTM moderada e apenas 3,3% apresentavam DTM severa. O restante, 36,7% (n = 11), não apresentava sinais ou sintomas de disfunções de ATM. Podemos afirmar, através deste estudo, que em pacientes sem DTM tanto os métodos de mensuração facial como os métodos fisiológicos, como o de Litle modificado por Tamaki, são eficientes na determinação da Dimensão Vertical. Porém, em pacientes com disfunções, os métodos se mostraram imprecisos.
The purpose of this study was to evaluate whether the facial measures used in traditional methods of determination of the Occlusion Vertical Dimension are in Divine Proportion (1:1,618) and, subsequently, whether this Proportion can be used as a complementary method for determination of the dimension. For that, 20 to 30 year-old patients were selected at random from Odontology Clinics of the Paraíba State University. The sample was composed by 30 individuals, 15 of male gender and 15 female gender. Through the analysis of frontal photographs of these individuals, and the designs that trespass cephalometric points, it was possível to elucidate new approches on treatements of oral reabilitation. With regard to the degree of the Temple-mandible Disfunction, 63,3% (n=19) of the patients showed some degree of TMD, of whom 50% (n=15) showed mild TMD, 10% (n = 3) showed moderate TMD and only 3.3% showed severe TMD. The rest, 36.7% (n=11), did not show any signs or symptoms of TMA disfunctions. We can state that in patients without TMD, both the methods of facial measures and physiologic methods, such as Litle's Method modified by Tamaki, are efficient in the determination of the Vertical Dimension. However, in patients with TMD the physiologic methods were imprecise.
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PURPOSE: To evaluate the effect of different endodontic irrigating solutions on the micro push-out bond strength of a fiber glass dowel. MATERIAL AND METHODS: Seventy 16-mm long root segments of bovine incisors were prepared and randomly assigned to 7 groups (n=10) according to the type of irrigating solution used prior to the cementation of the intra-radicular fiber glass dowels: G1: 5.25% NaOCl + 17% EDTA; G2: 5.25% NaOCl; G3: 17% EDTA; G4: 2% chlorhexidine gel; G5: 70% alcohol; G6: 11.5% polyacrylic acid; and G7: saline (control). After treatment of intracanal dentin, the glass fibre dowels were cemented with self-adhesive resin cement (RelyX Unicem). Six slices with the thickness of 1.00 ± 0.05 mm were obtained from each tooth at the coronal, middle and apical root thirds (2 slices per third) using a low-speed saw. Micro push-out tests were performed at a crosshead speed of 0.5mm/min and the data (MPa) were analyzed statistically by ANOVA and Tukey's and Dunnett's tests. RESULTS: There were statistically significant differences (p<0.0001) among the irrigating solutions, but no significant difference (p=0.0591) was found among the root thirds. G5 presented the highest bond strength mean of all groups (p<0.0001). The use of 70% alcohol increased the adhesion values by 53% compared to the group control. CONCLUSION: The use of 70% alcohol increased the bond strength of the fiber glass dowel to the dentin walls. However, the push-out bond strength between the dowel and the root dentin was not affected by the root third (coronal, middle and apical).
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OBJECTIVES: The aim of this in vitro study was to investigate the efficacy of in-office bleaching technique combined with the application of a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste (MI Paste-MI) at different moments and its influence on enamel surface properties. METHODS: Eighty bovine dental crowns were randomly allocated into eight groups (n = 10), and bleached with either 35% hydrogen peroxide (HP) or 37% carbamide peroxide (CP). Four different protocols of application of MI were considered: without MI, MI applied before bleaching, MI applied after bleaching, and MI applied both before and after bleaching. Bleaching effectiveness was measured by the VITA EasyShade spectrophotometer utilizing the CIEL*a*b* system (ΔE, ΔL*, Δa*, and Δb*). Color readings were measured at baseline, 7, 14, and 21 days. Hardness and roughness were measured at baseline (T0) and immediately after bleaching (T14). Data were subjected to the two-way ANOVA for repeated measurements and Tukey's test at 5%. RESULTS: HP groups achieved the greatest color change. The application of a CPP-ACP paste did not reduce the efficacy of bleaching peroxides. Samples bleached with CP showed decreased hardness at T14. Samples bleached with HP that received the application of MI before and before/after bleaching did not present hardness decrease at T14. Samples bleached with peroxides only and received MI after bleaching showed increased roughness at T14. CONCLUSIONS: The use of CPP-ACP was able to prevent negative changes in roughness and hardness of bovine enamel when associated to hydrogen peroxide, and might be applied before/after the bleaching protocol.
Assuntos
Caseínas/farmacologia , Esmalte Dentário/efeitos dos fármacos , Clareamento Dental/métodos , Coroa do Dente/efeitos dos fármacos , Análise de Variância , Animais , Peróxido de Carbamida , Bovinos , Esmalte Dentário/patologia , Esmalte Dentário/ultraestrutura , Testes de Dureza , Peróxido de Hidrogênio/farmacologia , Teste de Materiais , Microscopia Eletrônica de Varredura , Peróxidos/farmacologia , Espectrofotometria , Propriedades de Superfície , Fatores de Tempo , Clareadores Dentários/farmacologia , Coroa do Dente/anatomia & histologia , Coroa do Dente/patologia , Descoloração de Dente/patologia , Remineralização Dentária , Ureia/análogos & derivados , Ureia/farmacologiaRESUMO
BACKGROUND: This study evaluated the impact of bleaching teeth using blends of a CPP-ACP paste (MI Paste; MI) and carbamide/hydrogen peroxides in different proportions on surface properties of bleached enamel. METHODS: Ninety bovine incisors were bleached with 7.5% hydrogen peroxide (HP), 16% carbamide peroxide (CP), MI and blends of HP or CP:MI at three proportions (1:1, 2:1, 1:2). Hardness and roughness were measured at baseline and after bleaching. Enamel morphology was evaluated by Scanning Electron Microscopy (SEM). The data were analyzed by two-way ANOVA for repeated measurements and Tukey's test. RESULTS: Most of the samples bleached with MI in combination with peroxides presented increased hardness and roughness which were associated to mineral deposition, as observed by SEM images. Blends with higher fractions of MI did not offer superior benefits. CONCLUSIONS: The use of a CPP-ACP paste mixed to carbamide/hydrogen peroxides can decrease adverse side-effects from tooth bleaching on an enamel surface.
Assuntos
Caseínas/farmacologia , Esmalte Dentário/efeitos dos fármacos , Dentifrícios/farmacologia , Clareadores Dentários/farmacologia , Clareamento Dental/métodos , Análise de Variância , Animais , Peróxido de Carbamida , Bovinos , Esmalte Dentário/ultraestrutura , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Dureza/efeitos dos fármacos , Peróxido de Hidrogênio/administração & dosagem , Peróxido de Hidrogênio/farmacologia , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Peróxidos/administração & dosagem , Peróxidos/farmacologia , Propriedades de Superfície/efeitos dos fármacos , Chá/efeitos adversos , Clareadores Dentários/administração & dosagem , Descoloração de Dente/etiologia , Ureia/administração & dosagem , Ureia/análogos & derivados , Ureia/farmacologiaRESUMO
CONTEXT: The effect of different curing units on bond strength of orthodontic brackets is still unclear when utilizing nanofilled composites in comparison with traditional Transbond-XT. AIM: To evaluate the influence of two adhesive promoters and two curing-light units on the shear bond strength (SBS) of orthodontic brackets. SETTINGS AND DESIGN: The factors under study were adhesive promoters (nanofilled composite - Filtek-Z350 flowable restorative and conventional orthodontic adhesive - Transbond XT) and curing-light units (halogen lamp - Ultralux and LED device - Radii-Call). MATERIAL AND METHODS: Forty lower bovine incisors were utilized. The teeth were distributed in four groups (n = 10) according to the combination between adhesive promoters and curing-light units. Scotchbond Multipurpose-Plus and Transbond-XT primer were used to bond Filtek-Z350 Flowable Restorative and Transbond-XT, respectively. After storage in distilled water for 24 h, the brackets were subjected to SBS test at a speed of 0.5 mm/min until bracket debonding. The Adhesive Remnant Index (ARI) was assigned at fractured specimens. STATISTICAL ANALYSIS USED: Analysis of variance and Tukey test were utilized. The Kruskal-Wallis test was used to compare ARI scores between the groups (p<0.05). RESULTS: There was statistically significant difference between the adhesive promoters tested. Transbond-XT showed higher SBS means than Filtek-Z350. There was no statistically significant difference between both curing-light units tested in this study, neither between ARI scores. CONCLUSIONS: The conventional orthodontic adhesive presented higher bond strength than the nanofilled composite, although both materials interacted similarly to the teeth. The curing-light devices tested did not influence on bond strength of orthodontic brackets.
Assuntos
Resinas Compostas/química , Lâmpadas de Polimerização Dentária/classificação , Colagem Dentária , Braquetes Ortodônticos , Cimentos de Resina/química , Condicionamento Ácido do Dente/métodos , Adesividade , Animais , Bovinos , Análise do Estresse Dentário/instrumentação , Cura Luminosa de Adesivos Dentários/instrumentação , Nanocompostos/química , Ácidos Fosfóricos/química , Polimerização , Distribuição Aleatória , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , Fatores de Tempo , Água/químicaRESUMO
Este estudo in vitro teve como objetivo avaliar a profundidade de polimerização de duas resinas compostas com diferentes tamanhos de partículas de carga. Foram selecionadas duas resinas compostas micro-híbridas (Opallis (FGM) e Charisma (Heraeus Kulzer) e uma nanoparticulada Z350 (3M ESPE), todas na cor A3. Corpos de prova nas espessuras de 2, 3 e 4mm foram confeccionados (n=5) por meio do aparelho emissor de luz por diodos LED (Radii SDI). Após 24h de armazenamento dos espécimes em recipientes livre de luz, realizou-se a leitura da dureza Vickers nas superfícies de topo e base. Os dados foram submetidos aos testes estatísticos ANOVA a dois critérios e Tukey (p=0,05). Houve diferenças entre os compósitos, entre as profundidades bem como na interação de ambos os fatores, de forma que, de modo mais frequente, a resina Z350 mostrou valores superiores aos outros materiais. O material nanoparticulado mostrou maior profundidade de polimerização do que as resinas microhíbridas.
This in vitro study aimed to evaluate the depth of two composites' cure with different filler particles sizes. Two micro-hybrid composites (Opallis FGM) and Charisma (Heraeus Kulzer)] and a nanofiller one Z350 (3M ESPE) were selected with A3 shade. Specimens with thicknesses of 2, 3 and 4 mm were made (n = 5) using the light emitting diode LED device (Radii SDI). After 24 h storage of specimens in containers free of light, hardness readings on the top and bottom surfaces were executed. Data were subjected to two-way ANOVA and Tukey tests (p = 0.05). There were differences between the composites, among the depths, as well as in the interaction of both factors. Z350 composite resin showed higher values than other materials in the most experimental conditions. The nanofiller material showed higher polymerization depth than those microhybrid ones.
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Dental caries on tooth surfaces is still a problem in many industrialized countries. For many years, dentistry was influenced by a mechanical approach characterized by the use of high-speed rotary cutting instruments, and dentists predominantly used surgical methods to address caries. This included radical removal of diseased portions of the tooth, along with material-driven geometric extensions to areas that were assumed to be caries-resistant. This concept of extension for prevention was introduced by G. V. Black and influenced dentists for more than 120 years. Recently, a new paradigm of operative conservatism, sometimes referred to as "minimally invasive dentistry," has gained popularity. This paradigm is designed to promote maximum preservation of healthy dental structures over a lifetime. The aim of this review is to discuss the efficacy of current nonsurgical treatments for non-cavitated caries lesions in permanent teeth. Based on results obtained from clinical trials, this review evaluates treatments such as consumption of CPP-ACP added gums, resin infiltration and fissure sealing. Although in a few cases an invasive approach is needed to arrest caries progression, the non-surgical approach generally provides potential benefits that include conserving structure by delaying intervention or minimizing the operative procedure. All current non-invasive methods are effective in treating non-cavitated caries lesions. The adoption of non-invasive approaches in the management of these lesions can preserve dental tissues, thus increasing tooth longevity.
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Although supervised night-guard bleaching has proved successful for whitening teeth, both mineral loss and tooth sensitivity are still common problems. The present study introduces a novel remineralizer as well as describes the utilization of a possibly low sensitivity supervised night-guard vital tooth bleaching technique. A 22% carbamide peroxide gel was mixed with the casein phosphopeptide-amorphous calcium phosphate-containing MI Paste. The peroxide/MI Paste mixture was prepared with 1 ml of each material until obtaining a homogeneous paste. Five patients were instructed to follow a home bleaching protocol for 3 weeks. The outcome was assessed visually with a Vitapan scale. All subjects presented reduction of at least two Vitapan scale units after bleaching and no sensitivity was reported. The concomitant use of MI Paste and peroxide might not affect the gel effectiveness and still reduce hypersensitivity levels.
Assuntos
Fosfatos de Cálcio/química , Caseínas/química , Fosfopeptídeos/química , Clareadores Dentários , Descoloração de Dente/terapia , HumanosRESUMO
AIM: The aim of this study was to evaluate the effect of indirect restorative materials (IRMs) and light-curing units (LCUs) on the micro hardness of dual-cured resin cement. MATERIALS AND METHODS: A total of 36 cylindrical samples (2 mm thick) were prepared with dual-cured resin cement (Relyx ARC) photo-activated with either a QTH (Optilight Plus) for 40s or a LED (Radii) light-curing unit for 65s. Photo-activation was performed through the 2-mm- thick IRMs and the samples were divided into six groups (n=6) according to the combination of veneering materials (without, ceramic and indirect resin) and LCUs (QTH and LED). In the control group, the samples were light-cured with a QTH unit without the interposition of any restorative material. Vickers micro hardness test was performed on the top and bottom surfaces of each sample (load of 50 g for 15 secs). The data were statistically analyzed using a three-way ANOVA followed by Tukey x s post-hoc test ( P < 0.05). RESULTS: There were no statistically significant differences on the top surface between the light curing-units ( P > 0.05); however, the LED provided greater hardness on the bottom surface when a ceramic material was used ( P < 0.05). The mean hardness in photo-activated samples, in which there was no interposition of indirect materials, was significantly greater ( P < 0.01). CONCLUSIONS: It may be concluded that the interposition of the restorative material decreased the micro hardness in the deeper cement layer. Such decrease, however, was lower when the ceramic was interposed and the cement light-cured with LED.