Molars Fracture Resistance with Class II Cavities Restored with Different Resin - Based Materials / Resistência à Fratura de Molares com Cavidades Classe II Restauradas com Diferentes Materiais à Base de Resina

The teeth weakening due to the preparation of class II mesio-occluso-distal cavities is a challenge for the clinician. The objective of this study was to evaluate the molars fracture resistance with class II mesio-occluso distal cavities restored with different restorative techniques and materials. Forty extracted molars were divided into 5 groups: Group 1 ­ intact healthy teeth (positive control); Group 2 ­ unrestored teeth with mesio-occluso distal class II cavities (negative control); Groups 3 to 5 ­ restored teeth with standardized dimensions. In groups 3 to 5, the cavities were restored with flow resin only, flow resin coated with a nano-hybrid resin, and nano-hybrid resin only, respectively. All specimens were tested for resistance to fracture using an axial compressive load, a metallic sphere measuring 8 mm in diameter on a universal testing machine EMIC DL-2000. A 10 kN load cell operated at a speed of 5 mm/min until the tooth fracture. Data were subjected to analysis of variance and Tukey's tests (α = 0.05). Group 3 showed higher fracture strength (2243.1 ± 473.7N) when compared to groups 2, 4 and 5. This difference was statistically significant (p<0.05). The fracture strength of teeth restored with flow mesio occluso-distal restorations was similar to that of intact natural teeth. (AU)

O enfraquecimento dos dentes devido às preparações de cavidades mesio-ocluso-distal é um desafio para o clínico. O objetivo deste estudo foi avaliar a resistência à fratura de molares com cavidades mesio-ocluso-distais classe II restauradas com diferentes técnicas e materiais restauradores. Quarenta molares extraídos foram divididos em 5 grupos: Grupo 1 ­ dentes saudáveis intactos (controle positivo); Grupo 2 ­ dentes não restaurados com cavidades mesio-occluso-distais classe II (controle negativo); Grupos 3 a 5 ­ dentes restaurados com dimensões padronizadas. Nos grupos 3 a 5, as cavidades foram restauradas apenas com resina flow, resina flow recoberta com uma resina nanohíbrida e somente resina nano-híbrida, respectivamente. Todas as amostras foram testadas quanto à resistência à fratura usando uma carga compressiva axial, usando uma esfera metálica medindo 8 mm de diâmetro em uma máquina de teste universal EMIC DL-2000. Uma célula de carga de 10 kN operava a uma velocidade de 5 mm/min até a fratura do dente. Os dados foram submetidos à análise de variância e testes de Tukey (α = 0,05). O grupo 3 apresentou maior resistência à fratura (2243,1 ± 473,7N) quando comparado aos grupos 2, 4 e 5. Essa diferença foi estatisticamente significante (p <0,05). A resistência à fratura dos dentes restaurados com resina flow foi semelhante à dos dentes naturais intactos. (AU)

Factors associated with depression, anxiety and stress among dentists during the COVID-19 pandemic

Abstract The objective of this work was to evaluate the relationship between factors associated with the COVID-19 pandemic and depression, anxiety, and stress (DAS) in dentists. Factors associated with the COVID-19 pandemic were evaluated using a questionnaire and scores of the Depression, Anxiety, and Stress Scales-21 were measured. The differences between the DAS scores based on the factors associated with the COVID-19 pandemic were tested through the successive application of multivariate analysis of variance (MANOVA, α = 0.05). After a sample size calculation, 998 participants with a mean age of 39.39 (± 11.69) years were included. The effect size indicated that changes in sleep quality (η2 = 0.161), eating habits (η2 = 0.057), and physical health (η2 = 0.051) were the ones that most negatively affected DAS scores. The highest DAS scores were observed in professionals who lived with someone at high-risk for COVID-19 (p < 0.001) and in those who did not engage in leisure activities during the pandemic (p < 0.001). Dentists who worked on the frontline against COVID-19 had higher scores of anxiety and stress (p = 0.029). The highest scores for anxiety, depression, and/or stress were seen in dentists living with someone at high-risk for COVID-19, who acts on the frontline, who does not practice in leisure activities during the pandemic, who completely changed eating habits, quality of sleep and physical health during the pandemic. In general, DAS levels of dentists were associated with factors related to the COVID-19 pandemic.

Evaluation of physical-mechanical properties of self-adhesive versus conventional resin cements

Aim: The purpose of this study was to compare the microhardness, diametral tensile strength, compressive strength and the rheological properties of self-adhesive versus conventional resin cements. Methods: Specimens of a conventional (RelyX ARC) and 3 self-adhesive (RelyX U200, Maxcem Elite, Bifix SE) types of resin cements were prepared. The Knoop test was used to assess the microhardness, using a Microhardness Tester FM 700. For the diametral tensile strength test, a tensile strength was applied at a speed of 0.6 mm/minute. A universal testing machine was used for the analysis of compressive strength and a thermo-controlled oscillating rheometer was used for the Rheology test. One-way ANOVA and Tukey's test (α=0.05) were used for data analysis. Results:According to microhardness analysis, all the cements were statistically similar (p>0.05), except for Maxcem that presented lower hardness compared with the other cements in relation to the top surface (p<0.05). In the diametral tensile strength test, Relyx U200 and RelyX ARC cements were statistically similar (p>0.05), presented higher value when compared to the Maxcem and Bifix cements (p<0.05). The compressive strength of RelyX ARC and Maxcem Elite cements was statistically higher than RelyX U200 and Bifix cements (p<0.05). Regarding the rheology test, Maxcem Elite and RelyX ARC cements showed a high modulus of elasticity. Conclusions: The self-adhesive cements presented poorer mechanical properties than conventional resin cement. Chemical structure and types of monomers employed interfere directly in the mechanical properties of resin cements

Multidisciplinary aesthetic rehabilitation: case report

Objective: This work aims to report a clinical case that performed the aesthetic rehabilitation of a patient through the integration of different dental specialties (Orthodontics, Periodontics and Dentistry). Case Report: An 18-year-old female patient received compensatory orthodontic treatment for correction of class II malocclusion, overbite and overjet, and interproximal diastema. After orthodontictreatment, a gingivoplasty was performed to remove excess gingival tissue and increase the crown of the teeth, and a frenectomy for the anomalous labial frenulum removal. After periodontal treatment the in-office bleaching was conducted, and the diastema was closed with microhybrid composite resins. Conclusion: It was concluded that multiprofessional planning made possible the aesthetic / functional rehabilitation of the patient.

Objetivo: Este trabalho visa relatar um caso clínico que realizou a reabilitação estética de um paciente por meio da integração de diferentes especialidades odontológicas (Ortodontia, Periodontia e Dentística). Relato do Caso: Paciente do sexo feminino, com 18 anos, recebeu tratamento ortodôntico compensatório para correção de má-oclusão classe II, overbite e overjet acentuados, e diastemas interproximais. Após tratamento ortodôntico, foi realizada uma gengivoplastia para a remoção do excesso de tecido gengival e aumento da coroa dos dentes, e uma frenectomia para a remoção do freio labial anômalo. Após o tratamento periodontal, foi realizado um clareamento dentário de consultório, e o fechamento dos diastemas anterosuperiores e o recontorno da cosméticados dentes com resinas compostas microhíbridas. Conclusão: Concluiu-se que o planejamento integrado multiprofissional possibilitou o êxito da reabilitação estética/funcional do paciente.

Randomized clinical trial of the effect of NovaMin and CPP-ACPF in combination with dental bleaching

Abstract Objective This randomized, controlled, double-blind clinical study evaluated the effect of calcium sodium phosphosilicate (NovaMin) and casein phosphopeptide-amorphous calcium phosphate with fluoride (CPP-ACPF) on the prevention of post-operative sensitivity and on the effects of clinical bleaching treatment. Material and Methods Sixty volunteers were selected according to inclusion and exclusion criteria and were randomly assigned into three groups (n=20): CG (control group) patients, who were treated with 35% hydrogen peroxide; NOVAG (NovaMin group) patients, who were treated with 35% hydrogen peroxide followed by the application of NovaMin; and CPPG (CPP group) patients, who were treated with 35% hydrogen peroxide followed by the application of CPP-ACPF. Both bioactive agents were applied for five minutes. An evaporative stimulus associated with a modified visual scale was used to analyze sensitivity 24 hours after each bleaching session. The color evaluation was performed on the maxillary central incisors using a spectrophotometer. Associations between the intervention group, bleaching session, and reported sensitivity were tested using Chi-square partitioning. Results Color change values (ΔE) were analyzed using analysis of variance (ANOVA). The significance level used for both tests was 5%. In the intragroup assessment, the Friedman test showed that only the CPP-ACPF group showed no statistically significant difference (p<0.05) between baseline and first bleaching session. In the intergroup assessment, the Kruskal-Wallis test showed that the CPPG had less postoperative sensitivity after the first session, when compared to the other groups (p<0.05). Color change analysis (ΔE) showed a significant difference between the means obtained in the different bleaching sessions in all groups (p<0.05). Conclusions This study showed that the combination of CPP-ACPF with 35% hydrogen peroxide significantly reduced post-operative sensitivity in the first session, compared with the other evaluated treatments. The association of CPP-ACPF and NovaMin did not affect the color change induced by tooth bleaching.

Compressive strength of esthetic restorative materials polymerized with quartz-tungsten-halogen light and blue LED

This study compared the compressive strength of a composite resin and compomer photoactivated with a conventional quartz-tungsten halogen-light (XL 3000, 3M/SPE) and a blue light-emitting diode (LED) (SmartLite PS; Dentsply/De Trey). Forty disc-shaped specimens were prepared using a split polytetrafluoroethylene matrix (4.0 mm diameter x 8.0 mm hight) in which the materials were inserted incrementally. The curing time of each increment was of 40 s with the QTH and 10 s with the LED. The specimens were randomly assigned to 4 groups (n=10), according to the light source and the restorative material. After storage in distilled water at 37oC ± 2oC for 24 h, the specimens was tested in compressive strength in a universal testing machine with load cell of 500 kgf running at a crosshead speed of 0.5 mm/min. Data (in MPa) were analyzed statistically by ANOVA and Student-Newman-Keuls test (p<0.05). For the composite resin, light curing with the QTH source did not produce statistically significant difference (p>0.05) in the compressive strength when compared to light curing with the LED source. However, light curing of the compomer with the QTH source resulted in significantly higher compressive strength than the use of the LED unit (p>0.05). The composite resin presented significantly higher (p>0.05) compressive strength than the compomer, regardless of the light source. In conclusion, the compressive strength of the tested materials photoactivated with a QTH and a LED light source was influenced by the energy density employed and the chemical composition of the esthetic restorative materials.

Este estudo comparou a resistência à compressão de uma resina composta e de um compômero, fotoativados com luz halógena convencional de quarto-tungstênio (QTH) (XL 300, 3M/SPE) e LED azul (SmartLite PS; Dentsply/De Trey). Foram confeccionados 40 espécimes em forma de disco usando uma matriz bipartida de politetrafluoretileno (4,0 mm de diâmetro x 8,0 mm de altura) em que o material foi inserido incrementalmente. O tempo de polimerização de cada incremento foi de 40 s para a luz halógena convencional e de 10 s para o LED. Os espécimes foram aleatoriamente alocados em 4 grupos (n=10), de acordo com a fonte de luz e com o material restaurador. Depois de armazenadas em água destilada a 37°C ± 2°C por 24 h, a resistência à compressão dos espécimes foi testada em uma máquina universal de ensaios com célula de carga de 500 kgf a uma velocidade de carregamento de 0,5 mm/min. Os dados (em MPa) foram analisados estatisticamente por ANOVA e teste de Student-Newman-Keuls (p<0,05). Para a resina composta, a fotopolimerização com luz halógena não produziu diferença estatisticamente significante (p>0,05) em sua resistência à compressão quando comparada à fotopolimerização com LED. Contudo, a fotopolimerização do compômero com a luz halógena resultou em uma resistência à compressão significativamente maior que a feita o LED (p>0,05). A resina composta apresentou resistência à compressão significativamente maior que a do compômero, independente da fonte de luz. Concluiu-se que a resistência à compressão dos materiais fotopolimerizados com luz halógena e LED foi influenciada pela densidade de energia empregada e pela composição química dos materiais restauradores estéticos.

Avaliação da efetividade da fotoativação de dois materiais resinosos com diferentes fontes de luz, por meio da microdureza Knoop, resistência à compressão, resistência flexural e caracterização dos materiais / Evaluation of the effect of the light source on the photo polymerization of two resin material by the Knoop microhardness, compressive strength, flexural strength and material characterization

O objetivo deste trabalho foi avaliar o efeito de um diodo emissor de luz (LED) Smart Lite PS (Dentsply) e da lâmpada halógena convencional Curing Light XL 3000 (3M) na efetividade de polimerização do compômero Dyract Ap (Dentsply) e da resina composta TPH Spectrum (Dentsply) por meio de testes de microdureza Knoop, resistência à compressão e resistência flexural e caracterização dos materiais. Foram confeccionadas 100 amostras e divididas em 12 grupos de acordo com o teste aplicado, a luz de polimerização e o material utilizado. A lâmpada halógena convencional selecionada, Curing Light XL 3000 (3M), tinha intensidade de 470mW/cm2 e comprimento de onda entre 400 e 510nm; o LED Smart Lite PS (Dentsply) tinha intensidade de 950mW/cm2 e comprimento de onda entre 450 e 490nm. O tempo de fotopolimerização para cada incremento com 2mm de espessura foi de 40 s. para a lâmpada halógena convencional e 10 s. para o LED. Para os testes de microdureza Knoop foram confeccionadas 20 amostras numa matriz cilíndrica com 8,0mm de diâmetro e 2,0mm de altura. As leituras da microdureza foram realizadas nas superfícies superiores e inferiores das amostras utilizando um microdurômetro Micromet 2003, com uma carga de 50 gf por 15 s. Para o teste de resistência à compressão foram confeccionadas 40 amostras numa matriz cilíndrica com 4,0mm de diâmetro e 8,0mm de altura. A resistência foi medida na máquina de teste universal de ensaios Emic DL 10.000 com uma célula de carga 500Kgf e velocidade de carregamento de 0,5 mm/min. Para o teste de resistência flexural foram construídas 40 amostras numa matriz em forma de caixa com 25,0mm de comprimento, 2,0mm de altura e 2,0mm de largura. A resistência foi medida na máquina de teste universal de ensaios Emic DL 10.000 com uma célula de carga 50Kgf e velocidade de carregamento de 0,5 mm/min...

The goal of this work was to evaluate the effects of the blue light emitting diodes (LEDs) Smart Lite PS (Dentsply) and the conventional halogen lamp Curing Light XL 3000 (3M) on the polymerization effectiveness of the Dyract Ap compomer (Dentsply) and the TPH Spectrum composite resin (Dentsply) by the Knoop microhardness, compressive strength, flexural strength and material characterization tests. A hundred samples were prepared and divided into 12 groups according to the test applied, the polymerization light and the material. The conventional halogen lamp light had power of 470mW/cm² and wavelength between 400 and 510nm; the LED light had power of 950mW/cm² and wavelength between 450 and 490nm. The polymerization time for each material 2mm buildup was 40 seconds for the conventional halogen lamp and 10 seconds for LED. For the Knoop microhardness tests the 20 samples were cylinder shaped, 8mm diameter and 2mm height. The hardness was read in the upper and lower side of the samples by a micrometer (Micromet 2003), with 50 gf for 15 seconds. For the compressive strength test the 40 samples were cylinder shaped, 4mm diameter and 8mm height. The strength was measured in an universal testing machine Emic DL 10.000 with 500Kgf and cross-head speed of 0,5 mm/min. For the flexural strength test the 40 samples were box shaped, 25mm length, 2mm width and 2mm height. The strength was measured in an universal testing machine Emic DL 10.000 machine with 50Kgf and cross-head speed of 0,5 mm/min...

Avaliação in vitro da influência do selante de superfície na prevenção ao manchamento em resina composta fotopolimerizável / Assessment in vitro of the surface-penetrating sealant influence in the rpevention of the staining of light-cured composite resin

Introdução - Este trabalho teve o objetivo de avaliar in vitro, a influência de um selante de superfície (Vigodent) na prevenção do manchamento de uma resina composta microhíbrida fotopolimerizável (Fili Magic/Vigodent) quando em contato com substâncias corantes como o café e o vinho. Métodos - Foram confeccionados 30 corpos de prova de resina composta fotopolimerizável Fili Magie na cor A2, que foram divididos em dois grupos, constituídos de 15 corpos de prova: grupo 1 - recebeu tratamento superficial com lixas d'água de granulação 600 e 1200; e grupo 2 - recebeu aplicação do selante de superfície após o tratamento com as lixas d'água. Os corpos de prova foram imersos em água destilada à temperatura de 37C. Diariamente, cinco corpos de prova de cada grupo foram imersos em café, cinco em vinho e cinco permaneceram em água destilada, durante 4 horas. As avaliações da cor foram feitas após 2, 4, 7 e 15 dias, através de colorimetria tristí- mulo Hunter L a b. Resultados - Os resultados evidenciaram que o selante de superfície não preveniu o manchamento da resina composta. Conclusões - Os corpos de prova com selante de superfície apresentaram maior intensidade de manchamento quando imersos em café do que quando imersos no vinho e os sem selante apresentaram maior intensidade de manchamento quando imersos em vinho do que no café. C) manchamento, tanto pelo café como pelo vinho, aumentou progressivamente em função do tempo de imersão nas soluções corantes.(au)

Faceta laminada indireta em resina composta de laboratório - relato de caso clínico / Indirect laminate veneers with laboratory composite resin system - a clinical case report

Este trabalho tem o objetivo de realatar um caso clínico de reabilitação estética de um paciente utilizando resina composta de laboratório (Artglass/Heraeus/Kulzer)

Shear bond strength of an adhesive system in human, bovine and swinish teeth

The purpose of this work was to compare the shear bond strength of an adhesive system in human enamel and dentin, as well as in bovine and swinish, after 24 hours and 7 days storage at 37oC water and 100% of relative humidity. Sixty human upper premolars, sixty bovine upper incisors and thirty swinish molars were used. Rigth after the extractions the tooth were cleaned and stored in 0,09% physiologic solution with 0,05% thymol, at 4o C until they were used. The teeth were divided into 12 groups made by 15 specimens, according to the kind of tooth, the surface to be tested and storage period. The surfaces to be tested were planed by using 180 followed by 400 and 600 wet sandpaper and received Prisma Universal Bond 3 adhesive system according to the manufacturer. A polyethylene cilinder 3 mm in diameter was fixed over these surfaces to limit the area and matrix which was filled with Prisma AP.H/Compules resin. Using an Kratus testing machine the bond strength in MPa were: enamel 24 hours 37.6 ± 7.81(H); 30.77 ± 5.68(B); 25.54 ± 6.72(S); enamel 7 days 36.17 ± 4.83(H); 36.94 ± 6.72(B); 23.33 ± 25.54 ± 6.72(S); enamel 7 days 36.17 ± 4.83(H); 36.94 ± 6.72(B); 23.33 ± 7.72(S); dentin 24 hours 8.49 ± 2.25 (H); 6.04 ± 2.51(B); 7.99 ± 3.03(S); dentin 7 days 9.37 ± 4.21(H); 7.83 ± 3.15(B); 8.45 ± 4.33(S). Analysis of the values by to Tukey-Kramer test (P<0.05) revealed: bond strength in enamel were significantly higher when compared to dentin; bond strength in human enamel did not present significant statistical differences relating to bovine enamel, however both registered significant differences relating to swinish enamel; bond strength obtained in human dentine, bovine and swinish did not present any significant difference among themselves; bond strength obtained after periods storage of 24 hours and 7 days did not present significant statistical differences