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1.
Pesqui. bras. odontopediatria clín. integr ; 22: e210044, 2022. tab, graf
Article in English | LILACS, BBO | ID: biblio-1365224

ABSTRACT

ABSTRACT Objective To assess the effects of coloring beverages on the color stability of two types of hybrid ceramics with different surface treatments. Material and Methods 180 specimens of two hybrid ceramics (Vita Enamic and Mazic Duro) and a feldspathic ceramic (Vita Mark II) were prepared (n=60 in each group). Half of the discs in each group were glazed while the other was polished. The specimens were then divided into three subgroups and immersed in distilled water, carrot juice, and coffee. The overall color difference (∆E) was calculated based on CIE L*a*b* color space. Data were analyzed using three-way and one-way ANOVA; Tukey's honest significant difference was also done for pairwise comparisons (α=0.05). Results Vita Mark II specimens revealed less overall color changes compared to other groups. The ∆E of the glazed Vita Enamic specimens was greater than polished specimens following immersion in distilled water (p=0.03) and coffee (p=0.001), but it was not significant for carrot juice. The same results were obtained for polished Mazic Duro specimens. Relatively similar amounts of ∆E were recorded in polished and glazed subgroups of Vita Mark II. Conclusion The ∆E of hybrid ceramics was higher than Vita Mark II. Polishing could be recommended for surface treatment of hybrid ceramics instead of glazing, saving time and facilitating the process.


Subject(s)
Spectrophotometry/instrumentation , Surface Properties , Beverages , Color , Dental Cements , Distilled Water , Ceramics , Analysis of Variance , Dental Prosthesis , Computer-Aided Design/instrumentation , Coffee , Dental Porcelain , Coloring Agents , Fruit and Vegetable Juices , Iran/epidemiology
2.
Pesqui. bras. odontopediatria clín. integr ; 22: e210058, 2022. tab, graf
Article in English | LILACS, BBO | ID: biblio-1365226

ABSTRACT

ABSTRACT Objective To evaluate and compare the effect of 17% Ethylenediaminetetraacetic Acid (EDTA), 9% Etidronic acid (HEDP), and 7% Maleic acid (MA) on the push-out bond strength of NeoMTA Plus sealer to the coronal, middle, and apical thirds of root canal dentin. Material and Methods Forty single-rooted human maxillary central incisors were selected and decoronated to 12 mm long root fragments. Working length was established and root canals were then enlarged up to rotary Protaper F3. After each instrumentation, the root canal was irrigated with 2.5% NaOCl. For the final irrigation regimen, the specimens were divided into 4 groups (n=10) and treated with EDTA, HEDP, MA or Saline. Root canals were coated with NeoMTA Plus sealer, and obturation was done with single cone obturation technique. Subsequently, three horizontal sections were taken from the coronal, middle and apical thirds of each specimen, and POBS was measured using a universal testing machine. The type of bond failures was assessed under a stereomicroscope. Statistical analysis was done with One-way ANOVA with Tukey's Post hoc analysis. Results MA and EDTA showed the highest POBS. There was no significant difference in bond strength between MA and EDTA (p>0.05). HEDP and Saline showed lower POBS. Among all the four groups, the coronal third showed the highest values, followed by middle and apical thirds. Conclusion The type of chelating agent used during the root canal treatment significantly affects the bond strength of NeoMTA Plus to the root canal dentin.


Subject(s)
Humans , Root Canal Filling Materials , Tensile Strength , Chelating Agents/chemistry , Dental Cements , Endodontics , Analysis of Variance , Edetic Acid , Etidronic Acid , Dental Materials/chemistry , Incisor , India , Maleic Hydrazide
3.
Pesqui. bras. odontopediatria clín. integr ; 22: e210114, 2022. tab, graf
Article in English | LILACS, BBO | ID: biblio-1365227

ABSTRACT

ABSTRACT Objective To compare the cytotoxicity of commercial reparative endodontic cements on human periodontal ligament stem cells (hPDLSCs). Material and Methods The culture of hPDLSCs was established. Cell density was set at 2 × 104 cells/well in 96-well plates. Extracts of Biodentine, Bio-C Repair, Cimmo HD, MTA Repair HP and White MTA were prepared. Then, the extracts were diluted (pure, 1:4 and 1:16) and inserted into cell-seeded wells for 24, 48, and 72 h to assess cell viability through MTT assay. hPDLSCs incubated with culture medium alone served as a negative control group. Data were analyzed by Two-Way ANOVA and Tukey's test (α=0.05). Results At 24 h, pure extract of MTA Repair HP and Biodentine 1:16 presented higher cell viability compared to control. Lower cell viability was found for pure extract of Cimmo HD, MTA Repair HP 1:4 and 1:16, and White MTA 1:16. At 48 h, pure extract of Bio-C Repair and MTA Repair HP presented higher cell viability compared to control. At 72 h, only the pure extract of MTA Repair HP led to higher cell proliferation compared to control. Conclusion Biodentine, Bio-C Repair and MTA Repair HP were able to induce hPDLSCs proliferation. Cimmo HD and White MTA were found to be mostly cytotoxic in hPDLSCs.


Subject(s)
Periodontal Ligament/anatomy & histology , Root Canal Filling Materials , Stem Cells/immunology , Cytotoxicity Tests, Immunologic/instrumentation , Dental Cements , Immunologic Tests/instrumentation , Brazil , Cell Count , Analysis of Variance , Endodontics , Primary Cell Culture
4.
Braz. dent. sci ; 25(1): 1-9, 2022. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1354535

ABSTRACT

Objective: This study aimed to determine the push-out-bond-strength(PBS) of mineral trioxide aggregate (BIOMTA+) and calcium-enriched-mixture-cement (CEM) in retrograde cavities prepared using Er: YAG laser and stainless-steel bur. Material and Methods: The root canals of 60 extracted single-rooted human teeth were prepared, filled and their apical portion of 3-mm were resected using a diamond bur and randomly divided into four groups according to technique of retrograde preparation and filling material as follows(n=15): Group1: bur/ BIOMTA+ ,Group2: bur/ CEM, Group3: Er:YAG laser/ BIOMTA+, Group4: Er:YAG laser/ CEM. PBS test were performed to specimens and failure modes were evaluated. The data were statistically analyzed with ANOVA, Post-Hoc Tukey and t tests (p< 0.05). Results: CEM was exhibited higher than bond strength compared to BIOMTA+ in retrograde cavity prepared using laser (p= 0.021) and BIOMTA+ in retrograde cavity prepared using bur was exhibited higher than bond strength compared to in retrograde cavities prepared using laser (p= 0.024). Failure modes were dominantly cohesive in all groups tested and one representative specimen each failure mode was examined in SEM and the general characteristics of the failure modes were confirmed. Conclusion: With in the limitations of the present study, when used CEM, Er: YAG laser-assisted retrograde cavity preparation positively affected the bond strength values compared to BIO MTA+. Considering its optimal adhesion, the calcium-enriched-mixture-cement (CEM) might be a good option as a filling material in retrograde cavities in clinical use. (AU)


Objetivo: O objetivo deste estudo foi determinar a força de união (PBS) de cimento de agregado trióxido mineral (BIO MTA+) e cimento enriquecido com cálcio (CEM) em preparos cavitários retrógrados realizados com: Laser Er-YAG e brocas de aço inoxidável. Material e Métodos: Canais radiculares de 60 dentes unirradiculares extraídos foram preparados, preenchidos e 3 mm de suas porções apicais foram ressecadas usando uma broca diamantada e divididos randomicamente em quatro grupos de acordo com a técnica de preparação retrógrada e o material de preenchimento (n=15): Grupo 1: Broca/BIO MTA+, Grupo 2: Broca/CEM, Grupo 3: Laser Er-YAG/BIO MTA+, Grupo 4: Laser Er-YAG/CEM. O teste de PBS foi realizado para as amostras e os modelos de falha foram avaliados. Os dados foram analisados estatisticamente pelos testes de ANOVA, Post-Hoc Tukey e testes t (p< 0.05). Resultados: CEM apresentou maior força de união que BIO MTA+ em cavidades retrógradas preparadas com laser (p= 0.021) e BIO MTA+ em cavidades retrógradas preparadas com brocas apresentou maior força de união quando comparado à cavidades retrógradas preparadas com laser (p= 0.024). Os modelos de falha foram predominantemente coesos em todos os grupos testados e um espécime representativo de cada modelo de falha foi examinado em MEV e as características gerais dos modelos de falha foram confirmadas. Conclusão: Com as limitações do presente estudo, quando usou-se CEM, o preparo de cavidades retrógradas através de Laser Er-YAG afetou positivamente os valores da força de união quando comparados com BIO MTA+. Considerando sua ótima adesão, o cimento enriquecido com cálcio (CEM) pode ser uma boa opção como um material de preenchimento em cavidades retrógradas no uso clínico.


Subject(s)
Dental Cements , Dental Pulp Cavity , Lasers, Solid-State
5.
Braz. dent. sci ; 25(1): 1-11, 2022. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1352726

ABSTRACT

Objective: To evaluate the influence of immediate dentin sealing (IDS) and mechanical methods for removing the temporary cement on the bond strength between dentin and resin cements. Material and Methods: Bovine incisors were ground until dentin exposure and divided according to two factors: "dentin surface treatment"' - cleaning with manual dental excavator (DE), with Robinson bristle brush and pumice paste (PP) or IDS application with Single Bond 2 (IDS/SB+PP) or Single Bond Universal (IDS/SBU+PP) plus cleaning with PP; and "resin cement" - Self-adhesive (RelyX U200) or conventional cement with self-etching adhesive (Multilink Automix). Simulating provisional restoration, acrylic resin plates were cemented onto the dentin surface (with or without IDS) with a non-eugenol temporary cement, and stored in distilled water (37 ºC; 7 days). The acrylic plates were removed, the dentin surface was cleaned (PP or DE), and starch tubes were positioned on the dentin where the resin cements were applied. After 24 h, the specimens were submitted to a microshear test (wire-loop method). Results: Two-way analysis of variance showed statistically significant influence of dentine surface treatments (p< 0.001) and resin cement (p= 0.001) in the bond strength values. The IDS/SBU+PP/U200 (7.24 MPa) and IDS/SBU+PP/MULTI (6.40 MPa) groups presented higher values when compared to cleaning with DE (DE/U200= 4.60 MPa; DE/MULTI= 1.45 MPa) and PP (PP/U200= 3.74 MPa; PP/MULTI= 3.14 MPa). Statistical difference was also found between the cements when dental excavator treatment was used (RelyX U200 ˃ Multilink Automix). The IDS/SBU+PP protocol presented a higher percentage of cohesive failures. The micrographs showed differences in dentin surface characteristics among the groups. Conclusion: Immediate dentin sealing increased the bond strength of the resin cements to dentin compared to mechanical cleaning only, regardless the resin cement. (AU)


Objetivo: Avaliar a influência do selamento dentinário imediato (IDS) e dos métodos mecânicos de remoção do cimento provisório na resistência de união entre dentina e cimentos resinosos. Materiais e Métodos: Incisivos bovinos foram desgastados até a exposição da dentina e divididos de acordo com dois fatores: "tratamento da superfície dentinária" - limpeza com cureta dentária manual (DE), com escova de cerdas Robinson e pasta de pedra-pomes (PP) ou aplicação de IDS com Single Bond 2 (IDS/SB +PP) ou Single Bond Universal (IDS/SBU+PP) mais limpeza com PP; e "cimento resinoso" - autoadesivo (RelyX U200) ou cimento convencional com adesivo autocondicionante (Multilink Automix). Simulando a restauração provisória, placas de resina acrílica foram cimentadas na superfície dentinária (com ou sem IDS) com um cimento provisório sem eugenol e armazenadas em água destilada (37 ºC; 7 dias). As placas de acrílico foram removidas, a superfície dentinária foi limpa (PP ou DE) e tubos de amido foram posicionados na dentina onde os cimentos resinosos foram aplicados. Após 24 h, os corpos-de-prova foram submetidos ao ensaio de microcisalhamento (método wire-loop). Resultados: A análise de variância de dois fatores mostrou influência estatisticamente significativa dos tratamentos de superfície dentinária (p< 0,001) e cimento resinoso (p= 0,001) nos valores de resistência de união. Os grupos IDS/SBU+PP/U200 (7,24 MPa) e IDS/SBU+PP/MULTI (6,40 MPa) apresentaram valores maiores quando comparados à limpeza com DE (DE/U200= 4,60 MPa; DE/MULTI= 1,45 MPa) e PP (PP/U200= 3,74 MPa; PP/MULTI= 3,14 MPa). Uma diferença estatística também foi encontrada entre os cimentos quando o tratamento com cureta dentária foi usado (RelyX U200 ˃ Multilink Automix). O protocolo IDS/SBU+PP apresentou maior percentual de falhas coesivas. As micrografias mostraram diferenças nas características da superfície dentinária entre os grupos. Conclusão: O selamento dentinário imediato aumentou a resistência de união dos cimentos resinosos à dentina em comparação com a limpeza mecânica apenas, independentemente do cimento resinoso.(AU)


Subject(s)
Cattle , Resin Cements , Dental Cements , Dentin
6.
Braz. dent. sci ; 25(2): 1-6, 2022. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1363727

ABSTRACT

Objective: The aim of this study was to evaluate the effects of material and processing methods on the bond strength of orthodontic brackets. Material and Methods: Five types of brackets were tested: Conventional metallic (CM), metallic sandblasted (SB), ceramic (C), polycarbonate (PC), and metallic fabricated by melting injection molding (MIM). Shear bond strength (SBS) was conducted to check bond strength of the brackets bonded to bovine teeth (n=10/group), and tensile bond strength (TBS) (20 brackets/group) to check bracket retention to bonding material (n=20/group). Both, SBS and TBS were conducted with 1mm/min crosshead speed in a universal testing machine. Bond strength was calculated in Megapascal (MPa) based on force (N) and bracket area (mm 2). Data normality was verified, and One-way ANOVA was the statistical test with Tukey post-hoc (α=0.05). Results: SB and MIM presented higher SBS compared to C, PC, and CM (p<0.05). SB and MIM also presented significantly higher TBS compared to CM and PC (p<0.05). However, MIM was not different of C for TBS. Conclusion: The type of material and method of fabrication are determinant factors that affect bond strength of orthodontic brackets and melting injection molding (MIM) is a remarkable technology to improve brackets retention during the orthodontic treatment. (AU)


Objetivo: O objetivo deste estudo foi avaliar os efeitos dos materiais e métodos de processamento na resistência de união de bráquetes ortodônticos. Material e Métodos: Cinco tipos de bráquetes foram testados: Convencionais metálicos (CM), metálicos jateados (SB), cerâmico (C), policarbonato (PC), e metálico fabricado por injeção de metal fundido em molde (MIM). A resistência de união ao cisalhamento (SBS) foi conduzida para verificar a resistência de união dos bráquetes aderidos a dentes bonivos (n=10/grupo) e a resistência à tração (TBS) (20 bráquetes/grupo) para verificar a retenção do bráquete ao material adesivo (n=20/grupo). SBS e TBS foram conduzidas com relação carga/velocidade de 1mm/min em uma máquina de ensaios universal. A resistência de união foi calculada em Megapascal (MPa) com base na força (N) pela área do bráquete (mm 2). A normalidade dos dados e a estatística foi realizada utilizando One-way ANOVA e Tukey post-hoc (α=0.05). SB e MIM apresentaram os maiores valores de SBS comparados com C, PC e CM (p<0.05). Resultados: SB e MIM também apresentaram valores significativamente maiores de TBS comparados com CM e PC (p<0.05). Contudo, os valores de TBS para o grupo MIM não foram significativamente diferentes de C. Conclusão: O tipo de material e o método de fabricação são fatores determinantes que afetam a resistência de união de bráquetes ortodônticos e a injeção de metal fundido em molde (MIM) é uma tecnologia relevante para melhorar a retenção dos bráquetes durante o tratamento ortodôntico. (AU)


Subject(s)
Animals , Cattle , Orthodontic Brackets , Dental Cements , Shear Strength
7.
Braz. dent. sci ; 25(1): 1-9, 2022. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1361885

ABSTRACT

Objetivo: O objetivo foi avaliar a resistência de união de seis adesivos experimentais contendo sistemas fotoiniciadores binários ou ternários, associados a três diferentes concentrações de MDP (0-12% em peso) após 12 meses de armazenamento em água destilada. Material e Métodos: Adesivos experimentais foram preparados com: bis-GMA, UDMA, bis-EMA, TEGDMA, HEMA, BHT e etanol, contendo sistemas fotoiniciadores binários (CQ/amina) ou ternários (CQ/amina/DPIHFP ­ 0,5% em peso). Foi adicionado a esta composição 0%, 6% ou 12% em peso de MDP. Os sistemas adesivos foram aplicados seguindo o protocolo com condicionamento ácido. Moldes cilíndricos transparentes foram colocados sobre a dentina hibridizada, preenchidos com resina composta e fotopolimerizados. Os corpos-de-prova foram armazenados em água destilada a 37oC por 24h ou 12 meses e submetidos ao ensaio de microcisalhamento (n=6). Os dados foram analisados por ANOVA de três fatores e teste de Tukey (α=5%). Resultados: Para o sistema binário, após 12 meses de armazenamento, todos os valores de resistência de união foram semelhantes. Em relação à degradação da resistência de adesão ao longo do tempo, as formulações de MDP de 6% e 12% mostraram resistência de união mais estável do que 0% de MDP. Para o sistema ternário, todas as formulações (0%, 6% e 12% em massa de MDP) mostraram resistência de união estável em função do tempo. Conclusão: Para o sistema binário, as concentrações de 6 e 12% em massa de MDP foram capazes de manter a resistência de união em função do tempo, enquanto que para o sistema ternário, a estabilidade de união foi obtida independentemente da concentração de MDP. Pode-se concluir que, para a formulação dos adesivos utilizados neste estudo, independente do sistema fotoiniciador, a concentração de 12% MDP apresentou valores de resistência de união mais estáveis após 12 meses de armazenamento em água (AU)


Objective: The aim was to evaluate the bond strength of six experimental adhesives containing binary or ternary photoinitiator systems, associated with three different MDP concentrations (0-12wt%) after 12 months of storage in distilled water. Material and Methods: Experimental adhesives were prepared with: bis-GMA, UDMA, bis-EMA, TEGDMA, HEMA, BHT, and ethanol, containing binary (CQ/amine) or ternary (CQ/amine/DPIHFP (diphenyliodonium hexafluorophosphate) ­ 0.5wt%) photoinitiator systems. It was added to this composition 0wt%, 6wt%, or 12wt% of MDP. The adhesive systems were applied following the etch-and-rinse protocol. Transparent cylindrical molds were placed on the hybridized dentin, filled with composite resin and light-cured. The specimens were stored in distilled water at 37oC for 24h or 12 months and submitted to a microshear bond strength test (n=6). Data were analyzed by three-way ANOVA and Tukey's test (α=5%). Results: For the binary system, after 12 months of storage, all bond strength values were similar. Regarding bond strength degradation over time, 6wt% and 12wt% MDP formulations showed more stable bond strength than 0wt% MDP. For the ternary system, all formulations (0wt%, 6wt% and 12wt%) showed stable bond strength over time. Conclusion: For the binary photoinitiator system, the 6wt% and 12wt% MDP concentrations were able to keep bond strength stable over time, while for the ternary system, bond strength stability was achieved regardless the MDP concentration. (AU)


Subject(s)
Dental Cements , Photoinitiators, Dental
8.
Braz. j. oral sci ; 20: e210445, jan.-dez. 2021. ilus
Article in English | LILACS, BBO | ID: biblio-1253016

ABSTRACT

Aim. To evaluate the bond durability of two universal adhesives; mild and ultra-mild in both etch-and-rinse and self-etch modes after simulated in-vitro degradation by long-term water storage or thermocycling. Methods. A total of 144 specimens were used in this study; 120 specimens (prepared from 30 teeth) for microshear bond strength testing and fracture mode assessment, and 24 specimens for scanning electron microscopic evaluation (prepared from 24 teeth). Specimens were prepared from 54 recently extracted caries free third molars and randomly divided into 12 groups, according to the adhesive treatment (All Bond or Scotchbond Universal), etching mode (etch-andrinse or self-etch) and aging method (thermocycling or water storage). Each tooth was sectioned mesio-distally into two halves exposing free dentin surface for bonding where dentin substrate 1 mm below the dentino-enamel junction was used. After adhesive application and composite build up, specimens were tested in shear mode after storing in distilled water at 37˚C for 24 hours or 1 year, or after being thermocycled between 5 and 55 °C for 10,000 cycles (n=10). Microshear bond strength (µSBS) was tested using a universal testing machine. Adhesive-dentin interface was examined using scanning electron microscope (SEM) (n=2). Data were analyzed using 3 way AN0VA and pairwise comparisons was performed using Bonferroni correction at significance level of α ≤0.05. Results. Statistical analysis revealed non-significant difference for etching mode in both adhesives (p=0.596). After aging, the bond strength was only reduced in Scotchbond Universal after one year of water storage in both modes (p<0.001). SEM evaluation revealed intact hybrid layer and longer resin tags for etch-and-rinse mode than selfetch mode of both adhesives. Conclusion. The bond strength of universal adhesives is not affected by the etching mode, however its durability was shown to be material dependent


Subject(s)
Dental Bonding , Dental Cements , Dentin
9.
Rev. cuba. estomatol ; 58(2): e3283, 2021. tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1289402

ABSTRACT

Introducción: Las restauraciones indirectas de resina son ampliamente empleadas para realizar tratamientos estéticos en dientes posteriores. Recientemente se ha propuesto el uso de resinas precalentadas como agentes de unión. Objetivo: Evaluar la resistencia a la tracción de restauraciones indirectas cementadas con una resina precalentada comparándola con un cemento de resina autoadhesivo y un cemento resinoso. Métodos: Las preparaciones dentarias se realizaron en 45 premolares con piedras diamantadas calibradas. Las muestras se dividieron aleatoriamente en tres conjuntos (n = 15) según los grupos experimentales: grupo 1 (resina precalentada), grupo 2 (resina autoadhesiva) y grupo 3 (cemento de resinoso adhesivo). Las muestras fueron incluidas en acrílico autopolimerizable. Se realizaron restauraciones indirectas para cada muestra, las superficies internas fueron microarenadas y se aplicó silano antes de la cementación con los agentes de unión. La resistencia a la tracción se realizó utilizando una máquina universal de ensayos con una velocidad de cruceta de 5 mm/min. El análisis estadístico se llevó a cabo con ANOVA de un factor y la prueba post hoc de Tukey. Se adoptó un nivel de significancia de p < 0,05. Resultados: La resina Filtek Z250 XT precalentada a 60 °C durante 15 minutos tuvo una fuerza de resistencia a la tracción de 5,775 MPa, similar a RelyX Ultimate con 5,442 MPa (p > 0,05), ambos grupos poseen una fuerza de resistencia a la tracción significativamente mayor que RelyX U200 (3,430 MPa). Conclusiones: La resina precalentada (Filtek, Z250 XT) y el cemento resinoso (RelyX Ultimate) muestran las mismas propiedades de resistencia a la tracción cuando se usan como agentes adhesivos en restauraciones indirectas de resina(AU)


Introduction: Indirect resin restorations are widely used in the esthetic treatment of posterior teeth. Preheated resins have been recently proposed as luting agents. Objective: Evaluate the tensile bond strength of indirect restorations cemented with a preheated resin versus a self-adhesive resin cement and a resinous cement. Methods: Tooth preparation was conducted of 45 premolars using calibrated diamond-coated stones. The samples were randomly divided into three sets (n = 15) according to the following experimental groups: Group 1 (preheated resin), Group 2 (self-adhesive resin) and Group 3 (adhesive resinous cement), and soaked in self-polimerizable acrylic. Indirect restorations were performed for each sample. The inner surfaces were microsanded, and silane was applied before cementation with the luting agents. Tensile bond strength was verified with a universal testing machine at a crosshead speed of 5 mm/min. Statistical analysis was based on one-factor ANOVA and Tukey's post hoc test. A significance level of p < 0.05 was established. Results: The Filtek Z250 XT resin preheated at 60°C for 15 minutes displayed a tensile bond strength of 5.775 MPa, similar to RelyX Ultimate with 5.442 MPa (p > 0.05). Both groups displayed a significantly greater tensile bond strength than RelyX U200 (3.430 MPa). Conclusions: The preheated resin (Filtek Z250 XT) and the resinous cement (RelyX Ultimate) exhibit the same tensile bond strength properties when used as luting agents in indirect resin restorations(AU)


Subject(s)
Humans , Adhesives , Resin Cements/therapeutic use , Dental Cements/therapeutic use , Data Interpretation, Statistical , Esthetics, Dental
10.
Braz. dent. j ; 32(3): 21-31, May-June 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1345507

ABSTRACT

Abstract This study assessed the fracture resistance of simulated immature teeth reinforced with calcium aluminate cement (CAC) or mineral trioxide aggregate (MTA) containing calcium carbonate nanoparticles (nano-CaCO3). The microstructural arrangement of the cements and their chemical constitution were also evaluated. Forty-eight canines simulating immature teeth were distributed into 6 groups (n=8): Negative control - no apical plug or root canal filling; CAC - apical plug with CAC; CAC/nano-CaCO3 - apical plug with CAC+5% nano-CaCO3; MTA - apical plug with MTA; MTA/nano-CaCO3 - apical plug with MTA+5% nano-CaCO3; and Positive control - root canal filling with MTA. The fracture resistance was evaluated in a universal testing machine. Samples of the cements were analyzed under Scanning Electron Microscope (SEM) to determine their microstructural arrangement. Chemical analysis of the cements was performed by Energy Dispersive X-ray Spectroscopy (EDS). The fracture resistance of CAC/nano-CaCO3 was significantly higher than the negative control (p<0.05). There was no significant difference among the other groups (p>0.05). Both cements had a more regular microstructure with the addition of nano-CaCO3. MTA samples had more calcium available in soluble forms than CAC. The addition of nano-CaCO3 to CAC increased the fracture resistance of teeth in comparison with the non-reinforced teeth. The microstructure of both cements containing nano-CaCO3 was similar, with a more homogeneous distribution of lamellar- and prismatic-shaped crystals. MTA had more calcium available in soluble forms than CAC.


Resumo Este estudo avaliou a resistência à fratura de dentes imaturos simulados reforçados com cimento de aluminato de cálcio (CAC) ou trióxido agregado mineral (MTA) contendo nanopartículas de carbonato de cálcio (nano-CaCO3). O arranjo microestrutural dos cimentos e sua constituição química também foram avaliados. Quarenta e oito caninos simulando dentes imaturos foram distribuídos em 6 grupos (n=8): Controle negativo - sem plug apical ou obturação do canal radicular; CAC - plug apical com CAC; CAC/nano-CaCO3 - plug apical com CAC + 5% nano-CaCO3; MTA - plug apical com MTA; MTA/nano-CaCO3 - plug apical com MTA + 5% nano-CaCO3; e Controle positivo - obturação dos canais radiculares com MTA. A resistência à fratura foi avaliada em máquina universal de ensaios. Amostras dos cimentos foram analisadas em Microscópio Eletrônico de Varredura (MEV) para determinar seu arranjo microestrutural. A análise química dos cimentos foi realizada por Espectroscopia de Energia Dispersiva de Raio-X (EDS). A resistência à fratura de CAC/nano-CaCO3 foi significativamente maior do que o controle negativo (p<0,05). Não houve diferença significativa entre os outros grupos (p>0,05). Ambos os cimentos apresentaram microestrutura mais regular com a adição de nano-CaCO3. As amostras de MTA apresentaram mais cálcio disponível em formas solúveis do que CAC. A adição de nano-CaCO3 ao CAC aumentou a resistência à fratura dos dentes em comparação aos dentes não reforçados. A microestrutura de ambos os cimentos contendo nano-CaCO3 foi semelhante, com uma distribuição mais homogênea de cristais de formato lamelar e prismático. MTA apresentou mais cálcio disponível nas formas solúveis do que CAC.


Subject(s)
Humans , Root Canal Filling Materials , Tooth Fractures , Oxides , Root Canal Obturation , Silicates , Calcium Compounds , Aluminum Compounds , Tooth Apex , Dental Cements , Drug Combinations
11.
Rev. Ciênc. Plur ; 7(2): 61-73, maio 2021. tab
Article in Portuguese | LILACS, BBO | ID: biblio-1282737

ABSTRACT

Introdução:Os sistemas adesivos possibilitama execução de restaurações estéticas e minimamente invasivas, sendo, portanto,objeto de pesquisas para contornar os problemas que se apresentam no procedimento restaurador.Objetivo:Avaliar in vitroa resistência de união de um sistema adesivo autocondicionante, e deste modificado com soluções extrativas de semente de uva.Metodologia:Duas soluções extrativas foram preparadas comextrato de semente de uva em pó dissolvido em acetona e etanol. A partir delas e de umadesivo,seis sistemas adesivos autocondicionantes experimentais foram preparados, diferindo quanto aosolvente utilizado eàsproporções entre adesivo puro e solução extrativa(7,5%, 15% e 30%). Setenta incisivos bovinos hígidos tiveram as raízes removidas com disco de carborundum e as faces vestibulares desgastadas comlixas d'água de granulação 120, 240, 600 e 1200 sob refrigeração até expor a dentina superficial. Os dentes foram distribuídos aleatoriamenteem sete grupos distintos: Controle; A7,5; A15; A30; E7,5; E15; e E30, contendo 10 elementos cada. A aplicação dos adesivos foi executada de acordo com as recomendações do fabricante do adesivo controle. A restauração foi realizada com uma matriz de silicone com dimensões 2mm de altura e 4mm de diâmetro e inserido o material restaurador em incremento único e fotopolimerizado por 40s. Após três meses armazenados em água destilada, os espécimes foram submetidos ao teste de resistência de união. Foi empregado ométodo estatísticoTeste Paramétrico Anova 1 Fator e pós-teste de Tamhane (p<0,05). Resultados:Os grupos A7,5, E7,5 e E30 não apresentaram diferença em relação ao grupo Controle; A15 e A30 mostraram desempenho estatisticamente semelhante entre si; e E15 não apresentou diferença estatística em relação aos outros adesivos.Conclusões:A adição de proantocianidina teve efeitos diferentes,dependendodos solventes e das concentrações utilizadas, mas sem alterar significativamente o desempenho do adesivo (AU).


Introduction:Adhesive systems make it possible to perform aestheticand minimally invasive restorations, being the subject of research to circumvent the problems that arise in the restorative procedure.Objective:Evaluate in vitrothe bond strength of a self-etching adhesive system,and modified with extractive grape seed solutions. Methodology:Two extractive solutions were prepared with powdered grape seed extract dissolved in acetone and ethanol. From them and an adhesive, six experimental self-etching adhesive systems were prepared, differing in terms of the solvent used and the proportions between pure adhesive and extractive solution(7.5%, 15% and 30%). Seventy healthy bovine incisors had their roots removed with carborundum disc and the vestibular faces were worn with sandpaper with granulation water 120, 240, 600 and 1200 under refrigeration until the superficial dentin was exposed. The teeth were randomly assigned to seven different groups: Control; A7.5; A15; A30; E7.5; E15; and E30, containing 10 elements each. The application of the adhesives was carried out according to the recommendations of the manufacturer of the control adhesive. The restoration was performed with a silicone matrix with dimensions 2mm high and 4mm indiameter and the restorative material was inserted in a single increment and light cured for 40s. After three months stored in distilled water, the specimens were submitted to the bond strength test. The statistical method Parametric Test Anova 1 Factor and Tamhane post-test (p<0.05) were used. Results:Groups A7.5, E7.5 and E30 showed no difference in relation to the Control group; A15 and A30 showed a statistically similar performance; and E15 showed no statistical difference in relation to the other adhesives. Conclusions:The addition of proanthocyanidin had different effects, depending on the solvents and concentrations used, but without significantly altering the performance ofthe adhesive (AU).


Introducción: Sistemas adhesivos permiten realizar restauraciones estéticas y mínimamente invasivas, siendo objeto de investigación para sortear problemas que surgen en elprocedimiento restaurador. Objetivo: Evaluar in vitrola fuerza de unión de un sistema adhesivoautograbante y modificado con soluciones extractivas de semilla de uva. Metodología: Se prepararon dos soluciones extractivas con extracto de semilla de uva en polvo disuelto en acetona y etanol. A partir de ellos y de un adhesivo, se prepararon seis sistemas experimentales de adhesivos autograbantes, que se diferencian en cuanto al solvente utilizado y las proporciones entre adhesivo puro y solución extractiva (7,5%, 15% y 30%). Setenta incisivos bovinos sanos fueron removidos con un disco de carborundo y las caras vestibulares fueron usadas com lija de agua de granulación 120, 240, 600 y 1200 bajo refrigeración hasta que la dentina superficial quedo expuesta. Los dientes se asignaron aleatoriamente a siete grupos diferentes: Control; A7,5; A15; A30; E7,5; E15; y E30, que contiene 10 elementos cada uno. La aplicación de los adhesivos se realizó siguiendo las recomendaciones del fabricante del adhesivo de control. La restauración se realizó con matriz de silicona con 2mm de altura y 4mm de diámetro y el material restaurador se insertó en un solo incremento y se fotopolimerizó durante 40s. Tres meses después, almacenados em agua destilada, las muestras se sometieron a la prueba de resistencia de la unión. Se utilizó el método estadístico Prueba Paramétrica Factor Anova 1 y post-prueba de Tamhane (p<0,05). Resultados: Los grupos A7,5, E7,5 y E30 no mostraron diferencias em relación con el grupo Control; A15 y A30 mostraron un desempeño estadísticamente similar; y E15 no mostró diferencia estadística en relación con los otros adhesivos. Conclusiones: La adición de proantocianidina tuvo diferentes efectos, dependiendo de los disolventes y concentraciones utilizadas, pero sin alterar significativamente el rendimiento del adhesivo (AU).


Subject(s)
Animals , Cattle , Dental Polishing/instrumentation , Proanthocyanidins , Materials Science , Flexural Strength , Solvents , In Vitro Techniques/methods , Brazil , Intervention Studies , Analysis of Variance , Dental Cements/chemistry , Grape Seed Extract
12.
Odontol. Clín.-Cient ; 20(2): 18-24, abr.-maio 2021. ilus, tab
Article in Portuguese | LILACS, BBO | ID: biblio-1369090

ABSTRACT

A escolha errada do sistema cimentante pode levar ao fracasso clínico na cimentação de coroas e próteses parciais fixas. Este trabalho teve como objetivo estudar "in vitro" a espessura de película de seis cimentos odontológicos para fixação de peças protéticas, de três grupos distintos, sendo eles: dois cimentos de fosfato de zinco, dois cimentos de ionômero de vidro convencional e dois cimentos resinosos. Foi realizado a manipulação dos cimentos de acordo com as instruções dos fabricantes e após, interposto 1g de material entre duas placas de vidro polidas e sobre as mesmas um peso de 3 Kg, durante 10 minutos. Estas placas foram medidas com um paquímetro digital antes e após a presa dos materiais. Foi realizada a análise estatística com o teste T Student e com o Teste de Variância ANOVA e foi observado uma menor espessura de película de um cimento de ionômero de vidro perante os outros cimentos testados, com diferenças estatísticas ao nível de 5%. Os autores concluíram que o cimento de ionômero de vidro obteve a menor espessura de película, sendo apropriado para cimentação de coroas e pontes fixas... (AU)


The incorrect choice of the cementing system may lead to clinical failure in the cementation of fixed partial crowns and prostheses. The aim of this study was to study the film thickness of six dental cements for the fixation of prosthetic pieces from three different groups of cement: two zinc phosphate cements, two conventional glass ionomer cement and two resin cements. Handling of the cements was carried out according to the manufacturers' instructions and after 1g of material was placed between two polished glass plates and a weight of 3 kg was placed thereon for 10 minutes. These plates were measured with a digital caliper before and after the prey of the materials. Statistical analysis was performed with the Student T test and the ANOVA Variance Test, and a lower film thickness of a glass ionomer cement was observed compared to the other cements tested, with statistical differences at the level of 5%. The authors concluded that glass ionomer cement had the lowest film thickness and was suitable for cementation of fixed crowns and bridges... (AU)


Subject(s)
Dental Prosthesis , Physical Phenomena , Dental Cements , Prostheses and Implants , Resin Cements , Glass Ionomer Cements
13.
Dent. press endod ; 11(1): 35-39, Jan-Apr2021. Tab
Article in English | LILACS | ID: biblio-1348160

ABSTRACT

Introdução: O tratamento endodôntico busca sanificar o sistema de canais radiculares para permitir adequada obturação tridimensional. Para tanto, necessita-se de materiais plásticos, como a guta-percha, associados a cimentos endodônticos com adequadas características físico-químicas. Métodos: Comparação das propriedades físico-químicas tempo de endurecimento e escoamento dos cimentos endodônticos AH Plus e Sealer Plus, de acordo com a especificação 57 da American National Standard Institute/American Dental Association para materiais obturadores. Resultados: O tempo de endurecimento do AH Plus foi de 1178 minutos e do Sealer Plus foi de 422 minutos. O escoamento do APlus foi de 3259 milímetros e do Sealer Plus, 3150 milímetros. Conclusões: O tempo de endurecimento do AH Plus foi maior quando comparado ao do cimento Sealer Plus, e não houve diferença estatística no escoamento entre os cimentos estudados (AU).


Introduction: Endodontic treatment seeks to sanitize the root canal system to allow adequate three-dimensional filling, for which plastic materials such as guttapercha are required, associated with endodontic cements with adequate physico-chemical characteristics. Methods: Comparison of the physico-chemical properties hardening and flow time of the AH Plus and Sealer Plus endodontic sealers according to the American Dental Association / American Dental Association Specification 57 for sealing materials. Results: The hardening time of the AH Plus was 1178 minutes and the Sealer Plus was 422 minutes. The AH Plus flow was 3259 millimeters and the Sealer Plus was 3150 millimeters. Conclusions: The AH Plus hardening time was higher when compared to the Sealer Plus cement and there was no statistical difference in the flow between the cements studied (AU).


Subject(s)
Humans , Root Canal Obturation , Dental Cements , Gutta-Percha , Chemical Phenomena , Dental Pulp Cavity
14.
Rev. cient. odontol ; 9(1): e43, ene.-mar. 2021. ilus, tab
Article in Spanish | LILACS, LIPECS | ID: biblio-1254247

ABSTRACT

Objetivo: El propósito del presente estudio fue evaluar comparativamente las características de porosidad entre el cemento Portland, MTA Angelus® y Biodentine Septodont®, observados con un microscopio electrónico de barrido. Materiales y métodos: Se prepararon los cementos según las indicaciones del fabricante y se empaquetaron en tubos cilíndricos de polietileno con un diámetro interno de 10 mm y una altura de 5 mm. Se analizó la porosidad de las muestras mediante el microscopio electrónico de barrido. El análisis estadístico se realizó utilizando la prueba Kruskal-Wallis. El nivel de significancia se estableció en 0,05 Resultados: Se observó la descripción de la media de los valores del diámetro de los poros, y el tamaño mayor correspondió al cemento Portland (11,07). Existen diferencias significativas entre las medias del diámetro de los poros con un p = 0,05. Se identificó que el MTA Angelus® tiene la mayor cantidad de poros, le sigue el Biodentine Septodont® y, por último, el Portland. Se comparó la cantidad de poros entre los tres cementos y no se encontraron diferencias significativas, con un p = 0,09. Conclusión: Los análisis realizados en los cementos endodónticos dieron como resultado que el cemento Portland tiene mayor diámetro de poro a diferencia de los otros dos, lo cual implica que tanto el Biodentine Septodont® como el MTA Angelus® tienen mejores propiedades de resistencia y permeabilidad para evitar la microfiltración, y por tanto son mejores para la solución de casos clínicos. (AU)


Objective: The purpose of this study was to compare the porosity characteristics of Portland cement, mineral trioxide aggregate (MTA) Angelus® and Biodentine Septodont® by scanning electron microscopy. Materials and Methods: Cements were prepared according to the manufacturer's instructions and packed in cylindrical polyethylene tubes with an internal diameter of 10 mm and a height of 5 mm. The porosity of the samples was analyzed using scanning electron microscopy. Statistical analyses were performed using the Kruskall Wallis test. The level of significance was established at 0.05. Results: The largest size mean diameter valus was found with Portland cement (11.07). There were significant differences between the mean pore diameters (p = 0.05). MTA Angelus® had the largest number of pores, followed by Biodentine Septodont®, and finally, Portland. There were no significant differences in the pores of the three cements (p = 0.09). Conclusion: The results of this comparative analysis of endodontic cements showed that Portland cement has a larger pore diameter than MTA Angelus® and Biodentine Septodont®, demonstrating that these latter two cements present better resistance and permeability properties, and thereby prevent microleakage. (AU)


Subject(s)
Microscopy, Electron , Porosity , Dental Cements , Epidemiology, Descriptive , Cross-Sectional Studies
15.
Braz. dent. j ; 32(1): 53-58, Jan.-Feb. 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1180728

ABSTRACT

Abstract The endodontic revascularization may be an alternative treatment for necrotic immature teeth, however, several treatment steps may cause tooth discoloration. This study evaluated the use of three calcium silicate-based cements with different radiopacifying agents on the color alteration (∆E) of extracted premolars after simulation of revascularization. Forty single rooted extracted premolars were shaped with #1-6 gates Glidden drills, rinsed with sodium hypochlorite, and filled with fresh human blood. Three calcium silicate-based cements with different radiopacifying agents (bismuth oxide - CSBi, calcium tungstate - CSW, and zirconium oxide - CSZr) were applied over the blood clot (n=10). The control group received the application of a temporary zinc oxide-based cement (TFZn) (n=10). ∆E was measured with a spectrophotometer, using the L*a*b* color system of the International Commission on Illumination (CIELab), in different times: prior to the preparation of the access cavity (t0); right after treatment (t1); and after one (t2), two (t3), three (t4) and four (t5) months. The tooth site for color evaluation was standardized by silicon matrix, the color reading was performed 3 times per tooth, and the teeth were stored in 37º water between evaluations. ∆E, whiteness (WID index) and yellowness (b*) were evaluated. Data were subjected to one-way ANOVA and repeated measures ANOVA, followed by Tukey's post hoc test (α=0.05). All groups were similar in ∆E1 (t0-t1). The ∆E was the lowest and constant in the control group. In all evaluation times, CSBi presented the highest ∆E (p<0.01). CSW and CSZr were similar in all evaluated times and presented intermediate ∆E values. WID index from CSBi and CSW presented more distancing from 'white' reference. CSBi presented the greatest decrease in yellowness (b* value). The cement containing bismuth oxide presented the highest color alteration values. All tested calcium silicate-based cements presented clinically perceptible discoloration. Calcium tungstate and zirconium oxide may be used as alternative radiopacifiers to decrease tooth discoloration after endodontic tooth revascularization.


Resumo A revascularização endodôntica pode ser um tratamento alternativo para dentes imaturos necrosados, porém, várias etapas do tratamento podem causar alteração de cor dental. Este estudo avaliou o uso de três cimentos a base de silicato de cálcio com diferentes agentes radiopacificadores na alteração de cor (∆E) de pré-molares extraídos após a simulação de revascularização. Quarenta pré-molares unirradiculares extraídos foram conformados com brocas gates glidden #1-6, irrigados com hipoclorito de sódio, e preenchidos com sangue humano fresco. Três cimentos a base de silicato de cálcio com diferentes agentes radiopacificadores (óxido de bismuto - CSBi, tungstato de cálcio - CSW, e óxido de zircônio - CSZr) foram aplicados sobre o coágulo sanguíneo (n=10). O grupo controle recebeu a aplicação de um cimento temporário a base de óxido de zinco (TFZn) (n=10). ∆E foi medida com um espectrofotômetro, utilizando o sistema de cor L*a*b* da International Commission on Illumination (CIELab), em tempos diferentes: previamente ao preparo da cavidade de acesso (t0); logo após o tratamento (t1); e após um (t2), dois (t3), três (t4) e quatro (t5) meses. O local do dente para a avaliação de cor foi padronizado por uma matriz de silicone, a leitura da cor foi realizada 3 vezes por dente, e os dentes foram armazenados em água a 37ºC entre as avaliações. ∆E, 'clareamento' (índice WID) e tom amarelado (b*) foram avaliados. Os dados foram submetidos ao teste de ANOVA um fator e teste ANOVA de medidas repetidas, seguidos pelo teste post hoc de Tukey (α=0,05). Todos os grupos foram semelhantes em ∆E1 (t0-t1). A ∆E foi menor e constante no grupo controle. Em todos os tempos de avaliação, CSBi apresentou os maiores valores de ∆E (p<0.01). CSW e CSZr foram semelhantes em todos os tempos avaliados e apresentaram valores intermediários de ∆E. O índice WID de CSBi e CSW se distanciaram mais da referência 'branco'. CSBi apresentou maior diminuição no tom amarelado (valor de b*) os outros grupos. O cimento contendo óxido de bismuto apresentou os maiores valores de alteração de cor. Todos os cimentos testados apresentaram alteração de cor clinicamente perceptível. O tungstato de cálcio e óxido de zircônio podem ser usados como radiopacificares alternativos para a diminuição da alteração de cor dental após o processo de revascularização endodontica.


Subject(s)
Humans , Root Canal Filling Materials , Tooth Discoloration , Oxides , Silicates , Calcium Compounds , Aluminum Compounds , Dental Cements , Drug Combinations
16.
Braz. dent. j ; 32(1): 85-90, Jan.-Feb. 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1180721

ABSTRACT

Abstract This study evaluated the chemical composition and microhardness of human enamel treated with an Enamel Matrix Derivative (EMD) solution, and the bond strength between composite resin and this enamel. Thirty human enamel samples were randomly divided into three groups: Untouched Enamel (UE), Demineralized Enamel (DE) and Demineralized Enamel Treated with EMD (ET). DE and ET groups were subjected to acid challenge and ET treated with EMD (EMD was directly applied over conditioned enamel and left for 15 min). Samples from each group (n=4) had chemical composition assessed through to attenuated total reflectance Fourier transform infrared (ATR-FTIR). Knoop microhardness of enamel samples from each group (n=10) was measured. For the microshear bond strength, the samples were etched for 30 s, and the adhesive was applied and cured for 10 s. Two matrixes were placed on the samples, filled with Filtek Z350 XT composite and cured for 20 s, each. The matrix was removed, and the microshear bond strength of each group (n=10) was tested. Data were subjected to Kruskal-Wallis test (for microhardness), to analysis of variance and to Tukey's test (for microshear bond strength); (α=0.05). FTIR results have shown phosphate (hydroxyapatite indicator) in 900-1200 cm-1 bands in the UE and ET groups, which were different from the DE group. Microhardness and microshear analyses recorded higher statistical values for the UE and ET groups than for DE. EMD application to demineralized enamel seems to have remineralized the enamel; thus, the microhardness and bond strength was similar between UE and ET groups.


Resumo Este estudo avaliou a composição química e microdureza do esmalte humano tratado com solução de Derivados da Matriz do Esmalte (EMD) e a resistência de união entre compósito e este esmalte. Trinta amostras de esmalte humano foram aleatoriamente divididas em três grupos: Esmalte Intocado (UE), Esmalte Desmineralizado (DE) e Esmalte Desmineralizado Tratado com EMD (ET). Os grupos DE e ET foram submetidos a desafio ácido e ET tratado com EMD (O EMD foi aplicado diretamente sobre esmalte condicionado e deixado por 15 minutos). Amostras de cada grupo (n = 4) tiveram composição química avaliada através de espectroscopia no infravermelho por transformada de Fourier com reflectância total atenuada (FTIR-ATR). A microdureza Knoop das amostras de esmalte de cada grupo (n=10) foi mensurada. Para a resistência ao microcisalhamento, as amostras foram condicionadas por 30 s, o adesivo aplicado e foto-ativado por 10 s. Duas matrizes plásticas (1 mm de comprimento) foram posicionadas sobre as amostras, preenchidas com compósito Filtek Z350 XT e foto-atiavadas por 20 s cada. As matrizes foram removidas e a resistência ao microcisalhamento de cada grupo (n=10) foi testada. Os dados foram submetidos ao teste de Kruskal-Wallis (para análise da microdureza), à análise de variância e ao teste de Tukey (para análise da resistência ao microcisalhamento); (α=0.05). Os resultados do FT-IR mostraram fosfato (indicador de hidroxiapatita) na banda entre 900-1200 cm-1 nos grupos UE e ET, diferentemente do grupo DE. Análises de microdureza e microcisalhamento demonstraram resultados estatisticamente superiores para os grupos UE e ET quando comparados ao DE. A aplicação de EMD ao esmalte desmineralizado parece ter remineralizado o esmalte; assim, a microdureza e a resistência de união foram semelhantes entre os grupos UE e ET.


Subject(s)
Humans , Dental Bonding , Materials Testing , Composite Resins , Resin Cements , Dental Cements , Dental Enamel , Shear Strength , Hardness
17.
J. oral res. (Impresa) ; 10(1): 1-8, feb. 24, 2021. ilus, tab
Article in English | LILACS | ID: biblio-1282719

ABSTRACT

Purpose: This study was designed to evaluate the diagnostic value of digital Bitewing (BW) radiographs with and without horizontal tube shift in detecting Residual excess cement (REC) on the proximal and non-proximal surfaces of implant restorations. Material and Methods: Eight mandibular models were fabricated with two implants placed on each side in the premolar and first molar positions. Excess cement was applied to either proximal or non-proximal surfaces of the restorations intentionally during the process of crown cementation. BW radiographs with and without applying horizontal tube shift were acquired. Three maxillofacial radiologists were asked to determine the presence and location of REC in the radiographs. Sensitivity and specificity of the radiographic technique were assessed according to the restoration surface that contained REC. Results: Sensitivity of BW radiographs was 100% for the detection of REC on the proximal surfaces and 41-18, 80% on the non-proximal surfaces. Specificity of the technique was 85.71%-100% for the proximal surfaces and 75-94. 12% for the non-proximal areas. Specificity of the radiographic method was generally greater than its sensitivity for the non-proximal surfaces while in the proximal areas, the two variables had quite similar values. Conclusion: Digital BW radiography is generally more useful for detection of REC on the proximal surfaces. Higher specificity of this technique for the bucco-lingual surfaces suggests more reliability of the negative diagnoses in the non-proximal areas.


Objetivo: Evaluar el valor diagnóstico de las radiografías digitales bitewing (BW), con y sin desplazamiento horizontal del tubo, para detectar el exceso de cemento residual (ECR) en las superficies proximales y no proximales de las restauraciones con implantes. Material y Métodos: Se fabricaron ocho modelos mandibulares con dos implantes colocados a cada lado en las posiciones premolar y primer molar. El exceso de cemento se aplicó intencionalmente en las superficies proximales o no proximales de las restauraciones durante el proceso de cementación de la corona. Se adquirieron radiografías BW con y sin aplicación de desplazamiento horizontal del tubo. Se pidió a tres radiólogos maxilofaciales que determinaran la presencia y ubicación de ECR en las radiografías. La sensibilidad y la especificidad de la técnica radiográfica se evaluaron según la superficie de restauración que contenía ECR. Resultados: La sensibilidad de las radiografías de BW fue del 100% para la detección de ECR en las superficies proximales y del 41,18-80% en las superficies no proximales. La especificidad de la técnica fue 85-71, 100% para las superficies proximales y 75-94, 12% para las áreas no proximales. La especificidad del método radiográfico fue generalmente mayor que su sensibilidad para las superficies no proximales, mientras que en las áreas proximales, las dos variables tuvieron valores bastante similares. Conclusión: La radiografía digital BW es generalmente más útil para la detección de ECR en las superficies proximales. La mayor especificidad de esta técnica para las superficies buco-linguales sugiere una mayor confiabilidad de los diagnósticos negativos en las áreas no proximales.


Subject(s)
Humans , Radiographic Image Enhancement/methods , Radiography, Bitewing/methods , Dental Cements , In Vitro Techniques , Dental Implants , Crowns
18.
Article in English | WPRIM | ID: wpr-887758

ABSTRACT

OBJECTIVES@#This work aimed to evaluate the ability of two kinds of antioxidants, namely, grape-seed extract and sodium ascorbate, in restoring bond strength at the resin-enamel interface after bleaching.@*METHODS@#Ten groups of samples with 15 teeth per group were prepared for shear-bond-strength test at the resin-enamel interface after bleaching. The groups were as follows: control; no antioxidant; 2.5%, 5%, 10%, or 15% grape-seed extract; and 2.5%, 5%, 10%, or 15% sodium ascorbate. The peak values of shear bond strength when resin was debonded from teeth and the failure modes under a microscope were recorded. Ten other groups of teeth with two teeth per group were prepared and treated in a similar approach before resin bonding. The samples were cut vertically to the bonding interface. The structures of the bonding interface were compared by scanning electron microscopy.@*RESULTS@#No statistically significant difference in shear bond strength was found among the no-antioxidant, 2.5% grape-seed extract, and 2.5%, 5%, or 10% sodium ascorbate groups (@*CONCLUSIONS@#Immediately after bleaching, the bond strength of dental enamel significantly decreased. Bond strength can be restored by 5% grape-seed extract or 15% sodium ascorbate in 5 min.


Subject(s)
Antioxidants , Composite Resins , Dental Bonding , Dental Cements , Dental Enamel , Humans , Shear Strength , Tooth Bleaching
19.
Dental press j. orthod. (Impr.) ; 26(3): e2119177, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1286215

ABSTRACT

ABSTRACT Objective: This study aims to determine shear debonding strength of metal and ceramic brackets, and the degree of enamel crack healing. Material and Methods: Extracted human maxillary premolars were flattened on the buccal surface, and randomly separated into five groups (n = 15). In control groups (groups 1 and 2), metal and ceramic brackets were bonded on flat polished enamel, while in experimental groups (groups 3 and 4), metal and ceramic brackets were bonded on the surface with boundary where corner cracks were created. Additionally, fifteen specimens (group 5) were also prepared for an indentation procedure with no bracket installation. The degree of crack healing was measured. All brackets were detached with a universal testing machine, and the adhesive remnant index (ARI) was also identified. Healing degree and apparent fracture toughness were then calculated. Results: Between groups with similar bracket types, there was no statistically significant difference in debonding strength. Regarding bracket types, ceramic brackets provided significantly higher debonding strength than metal brackets. There was a significant difference in ARI scores between metal and ceramic brackets. The corner cracks showed signs of healing in both horizontal and vertical directions. No statistically significant difference in the healing rates among the groups was found and the apparent fracture toughness increased from the initial to the final measurement. Conclusions: Within the limitations of this study, even though ceramic brackets required significantly higher debonding force compared to metal brackets, debonding stress was limited to the bonding site and did not affect the surrounding cracks on enamel.


RESUMO Objetivo: O presente estudo teve como objetivo determinar a resistência ao cisalhamento de braquetes metálicos e cerâmicos, e o grau de reparo de fraturas no esmalte. Métodos: Pré-molares superiores, extraídos de humanos, foram aplainados na face vestibular e aleatoriamente divididos em cinco grupos (n = 15). Nos grupos controle (Grupos 1 e 2), os braquetes metálicos e cerâmicos foram colados em esmalte liso e polido; enquanto nos grupos experimentais (Grupos 3 e 4), os braquetes metálicos e cerâmicos foram colados em superfície delimitada, em cujos cantos foram criadas fissuras. Adicionalmente, foram também preparados 15 espécimes (Grupo 5) para um teste com indentação, sem a instalação de braquetes. O grau de reparo das fraturas foi avaliado. Todos os braquetes foram descolados usando uma máquina universal de testes, e o índice de adesivo remanescente (ARI) também foi avaliado. O grau de reparo e a tenacidade à fratura aparente foram então calculados. Resultados: Entre os grupos com o mesmo tipo de braquetes, não houve diferença estatisticamente significativa na força de descolagem. Com relação aos tipos de braquetes, os cerâmicos apresentaram uma força de descolagem significativamente maior do que os metálicos. Houve uma diferença significativa nos escores ARI entre os braquetes metálicos e os cerâmicos. As fraturas de canto mostraram sinais de reparo nos sentidos horizontal e vertical. Não foi detectada diferença estatisticamente significativa no grau de reparo entre os grupos, e a tenacidade à fratura aparente aumentou da mensuração inicial para a final. Conclusão: Considerando-se as limitações desse estudo, apesar de os braquetes cerâmicos necessitarem de força de descolagem significativamente maior do que os braquetes metálicos, a tensão de descolagem foi limitada ao sítio de colagem, não afetando as fraturas de esmalte ao redor.


Subject(s)
Humans , Dental Bonding , Orthodontic Brackets , Surface Properties , Materials Testing , Ceramics , Dental Debonding , Dental Cements , Dental Enamel , Shear Strength , Dental Stress Analysis
20.
J. appl. oral sci ; 29: e20201031, 2021. tab, graf
Article in English | LILACS | ID: biblio-1250189

ABSTRACT

Abstract Fixed orthodontic appliances may lead to biofilm accumulation around them that may increase caries risk. This study aimed to evaluate the influence of quaternary ammonium methacrylates (QAMs) on the physicochemical properties, cytotoxicity, and antibacterial activity of adhesive resins for orthodontic purposes. Methodology: A base resin was prepared with a comonomer blend and photoinitiator/co-initiator system. Two different QAMs were added to the base adhesive: dimethylaminododecyl methacrylate at 5 wt.% (DMADDM) or dimethylaminohexadecyl methacrylate (DMAHDM) at 10 wt.%. The base adhesive, without QAMs, (GC) and the commercial Transbond™ XT Primer 3M (GT) were used as control. The resins were tested immediately and after six months of aging in the water regarding the antibacterial activity and shear bond strength (SBS). The antibacterial activity was tested against Streptococcus mutans via metabolic activity assay (MTT test). The groups were also tested for the degree of conversion (DC) and cytotoxicity against keratinocytes. Results: The resins containing QAM showed antibacterial activity compared to the commercial material by immediately reducing the metabolic activity by about 60%. However, the antibacterial activity decreased after aging (p<0.05). None of the groups presented any differences for SBS (p>0.05) and DC (p>0.05). The incorporation of DMADDM and DMAHDM significantly reduced the keratinocyte viability compared to the GT and GC groups (p<0.05). Conclusion: Both adhesives with QAMs showed a significant reduction in bacterial metabolic activity, but this effect decreased after water aging. Lower cell viability was observed for the group with the longer alkyl chain-QAM, without significant differences for the bonding ability and degree of conversion. The addition of QAMs in adhesives may affect the keratinocytes viability, and the aging effects maybe decrease the bacterial activity of QAM-doped materials.


Subject(s)
Orthodontic Brackets , Streptococcus mutans , Materials Testing , Biofilms , Resin Cements , Dental Cements , Methacrylates , Anti-Bacterial Agents
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