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PURPOSE: The composition and properties of resin-based composite materials could affect tooth wear and lead to clinical problems. Therefore, the study objective was to characterize human tooth wear behavior against a bulk-fill restorative (BF) compared to a conventional resin composite (RC) and a CAD/CAM resin nano ceramic (RN). METHODS: Square-shaped specimens of each material were prepared and sub-divided according to the number of testing cycles (n=8): 100,000, 250,000, and 500,000 cycles. An occlusal wear test was performed using a chewing machine with 49 N, 2 Hz, in 37°C distilled water. Human premolar cusps were used as antagonists. Micro-CT and laser scanner were used to scan antagonists and specimens, respectively. Wear volume was assessed using a software and the wear pattern was examined with SEM. Softening in solvent analysis was performed by measuring the materials' Knoop microhardness (KHN) before and after immersion in ethanol. Wear volume data were analyzed with two-way ANOVA and Student-Neuman-Keuls test (α=0.05). RESULTS: For tooth and specimen wear volume, there was statistical significance for material and number of cycles, but not for the interaction between factors. BF resulted in less tooth (p=0.008) and specimen (p=0.030) wear than RN and RC, which were similar (p⟩0.05). Volume loss increased from 100,000 to 500,000 cycles. BF showed the lowest microhardness (KHN1); and %ΔKHN similar to RC, but greater than RN. CONCLUSION: BF induced less volume loss to the tooth than RC and RN, while presenting greater wear resistance. The tooth wear pattern and damage progression were mild for all materials. CLINICAL SIGNIFICANCE: Resin composites show favorable wear behavior, leading to low volume loss and mild structural damage of the tooth. Regular bulk-fill resin composite stands out for its efficient restorative technique, low wear susceptibility and reduced capacity to wear down the tooth.

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STATEMENT OF PROBLEM: Additive (AM) and subtractive (SM) manufacturing have become popular for fabricating occlusal devices with materials of different chemical compositions. However, knowledge on the effect of material and antagonist type on the wear characteristics of occlusal devices fabricated by using different methods is limited. PURPOSE: The purpose of this in vitro study was to evaluate the effect of material and antagonist type on the wear of occlusal devices fabricated by using conventional manufacturing, AM, and SM. MATERIAL AND METHODS: Two-hundred and forty Ø10×2-mm disk-shaped specimens were fabricated by using heat-polymerized polymethylmethacrylate (control, CM), AM clear device resin fabricated in 3 different orientations (horizontal [AMH], diagonal [AMD], and vertical [AMV]), SM polymethylmethacrylate (SMP), and SM ceramic-reinforced polyetheretherketone (SMB) (n=40). Specimens were then divided into 4 groups based on the antagonists: steatite ceramic (SC); multilayered zirconia (ZR); lithium disilicate (EX); and zirconia-reinforced lithium silicate (ZLS) used for thermomechanical aging (n=10). After aging, the volume loss (mm3) and maximum wear depth (µm) were digitally evaluated. Data were analyzed with 2-way analysis of variance and Tukey honestly significant difference tests (α=.05). RESULTS: The interaction between the device material and the antagonist affected volume loss and maximum depth of wear (P<.001). AMH had volume loss and depth of wear that was either similar to or higher than those of other materials (P≤.044). When SC was used, CM had higher volume loss and depth of wear than AMV, and, when EX was used, AMD had higher volume loss and depth of wear than SMP (P≤.013). SC and ZR led to higher volume loss of CM and AMH than EX and led to the highest depth of wear for these materials, while ZR also led to the highest volume loss and depth of wear of AMD and AMV (P≤.019). EX led to the lowest volume loss and depth of wear of AMV and SMP and to the lowest depth of wear of AMH (P≤.021). Regardless of the antagonist, SMB had the lowest volume loss and depth of wear (P≤.005). CONCLUSIONS: AMH mostly had higher volume loss and depth of wear, while SMB had the lowest volume loss, and its depth of wear was not affected by the tested antagonists. ZR mostly led to higher volume loss and maximum depth of wear, while EX mostly led to lower volume loss and maximum depth of wear of the tested occlusal device materials.

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OBJECTIVE: The aim of the present study was to evaluate the influence of multidirectional brushing on the surface roughness, morphology, and bonding interface of resin-repaired CAD-CAM ceramic and composite restorations. MATERIALS AND METHODS: Twelve (N = 12) blocks (4 mm × 4 mm × 2 mm for parallel axis; 5 mm × 4 mm × 2 mm for perpendicular axis) of lithium disilicate glass-ceramic (IPS e.max CAD, Ivoclar AG) and CAD-CAM resin composite (Tetric CAD, Ivoclar AG) were obtained and repaired with direct resin composite (Clearfil AP-X, Kuraray). An abrasive slurry was prepared and the brushing was performed according to each restorative material and axis of brushing (n = 6; perpendicular to repair interface and parallel to repair interface) during 3,650 cycles (240 strokes per minute) to simulate 3 years of brushing. The surface roughness (Ra) and the profile variation for each material (restoration and direct repair resin composite) were measured at the baseline condition and after brushing, and the mean roughness and presence of steps at the repair interface were evaluated through factorial analysis of Variance (ANOVA). Scanning Electron Microscopy (SEM) images were taken to evaluate the surface topography of the repaired materials after brushing. RESULTS: The mean roughness of the repaired CAD-CAM restorations was affected by the brushing (P < .05), mainly when evaluating the repair material and the interface (P < .05), while the restorative CAD-CAM materials presented more stable values. The profile evaluation showed higher steps at the interface when repairing lithium disilicate than for CAD-CAM resin composite. CONCLUSION: Repaired CAD-CAM restorations were susceptible to wear after brushing simulation. The surface roughness of the direct resin composite was the most affected leading to step development at the interface, particularly in the repaired lithium disilicate samples. Cinical maintenance recalls and polishing protocols must be considered to enhance the longevity of such restorations.

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A impressão 3D surge como uma nova alternativa para confecção de próteses provisórias através do uso de resinas temporárias, visando otimizar e simplificar a técnica de confecção e sua aplicação. Este trabalho analisou o comportamento de uma resina provisória de impressão 3D sob simulação de desgaste frente a três diferentes antagonistas. Para isso, foram confeccionados 60 discos de resina provisória de impressão 3D (Resilab Temp) nas dimensões 12 x 2 mm. Os modelos 3D foram previamente desenhados no software Rhinoceros (Robert McNeel & Associates, Seattle, WA, EUA); versão 5, e processados no software de uma impressora 3D, produzidos utilizando impressora com processamento digital de luz (DLP). Metade das amostras recebeu uma camada de glaze na superfície da resina. Os espécimes foram submetidos à simulação de desgaste em cicladora mecânica com sliding (Byocicle V2, Biopdi, São Carlos, SP). Foram utilizados como antagonistas: esteatita, resina de impressão 3D e resina acrílica termicamente ativada, adaptados a mandris personalizados. O protocolo utilizado para a simulação do desgaste foi de 30 N ‭̸1,7 Hz ‭̸2x103 ciclos ‭̸37ºC, imersos em água. Realizou-se os testes de rugosidade, análise de superfície com microscopia eletrônica de varredura (MEV) e análise digital de varredura única de perda de volume de desgaste. O desgaste dos antagonistas foi avaliado através de estereomicroscópio óptico. A análise estatística foi realizada aplicando-se o teste de ANOVA 2 fatores para todos os grupos analisados. Na rugosidade, foram observadas diferenças estatisticamente significantes entre todos os grupos (p<0,05), exceto Rz do grupo com glaze, em que todas as variáveis foram iguais (p=0,377). Para perda de volume em desgaste, observou-se diferenças estatisticamente significantes entre os antagonistas (p=0,015) e para o tratamento com glaze (p=0,001). No desgaste dos antagonistas, observou-se diferenças estatisticamente significantes entre eles (p=0,001) e o tratamento com glaze (p=0,001). A resina em estudo apresenta resistência ao desgaste adequada para uso a curto prazo, sendo essa resistência influenciada pelo material antagonista. A aplicação da camada de glaze sobre a resina diminui a rugosidade superficial média do material e melhora a resistência ao desgaste (AU)

3D printing emerges as a new alternative for making provisional prostheses through the use of temporary resins, aiming to optimize and simplify the manufacturing technique and its application. This work analyzed the behavior of a provisional 3D printing resin under wear simulation against three different antagonists. For this, 60 discs of temporary 3D printing resin (Resilab Temp) in dimensions 12 x 2 mm were made. The 3D models were previously designed in Rhinoceros software (Robert McNeel & Associates, Seattle, WA, USA); version 5, and processed in the software of a 3D printer, produced using a printer with digital light processing (DLP). Half of the samples received a glaze layer on the resin surface. The specimens were submitted to wear simulation in a mechanical cycler with sliding (Byocicle V2, Biopdi, São Carlos, SP). The following antagonists were used: steatite, 3D printing resin and thermally activated acrylic resin, adapted to customized mandrels. The protocol used for the simulation of wear was 30 N ‭̸1.7 Hz ‭̸2x103 cycles ‭̸37ºC, immersed in water. Roughness tests, surface analysis with scanning electron microscopy (SEM) and single-scan digital analysis of wear volume loss were performed. The wear of the antagonists was evaluated using an optical stereomicroscope. Statistical analysis was performed by applying the 2-way ANOVA test for all analyzed groups. In terms of roughness, statistically significant differences were observed between all groups (p<0.05), except for the Rz group with glaze, in which all variables were equal (p=0.377). For volume loss in grinding, statistically significant differences were observed between antagonists (p=0.015) and for treatment with glaze (p=0.001). In the wear of the antagonists, statistically significant differences were observed between them (p=0.001) and the treatment with glaze (p=0.001). The resin under study has adequate wear resistance for short-term use, and this resistance is influenced by the antagonist material. The application of the glaze layer over the resin decreases the average surface roughness of the material and improves wear resistance. (AU)

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Este estudo propôs avaliar o efeito do envelhecimento hidrotérmico no padrão de desgaste, topografia superficial, microdureza, tenacidade à fratura e composição cristalina das zircônias 3Y-TZP, 5Y-PSZ e multicamadas. Para isso, foram utilizadas as zircônias 3Y-TZP - Zpex e 5Y-TZP - Zpex Smile (Tosoh Corporation) para confecção de discos (Ø= 12 mm e 1,2 mm de espessura) e a ZirCAD Prime (Ivoclar Vivadent) para confecção de blocos (14 x 14 x 1,5 mm). Os espécimes foram divididos em 6 grupos (n=18) entre os fatores "tipo de zircônia" (3Y-TZP, 5Y-TZP e multicamadas) e "envelhecimento hidrotérmico" (com e sem). Exceto para os grupos controle, as amostras passaram por envelhecimento em reator hidrotérmico (134◦C, 20 horas, 2,2 bar). As amostras (n=10) foram submetidas ao desgaste por deslizamento horizontal de 2 mm, com esferas de zircônia 3Y-TZP como antagonistas (150N, 4Hz, 600.000 ciclos). O volume do desgaste e os parâmetros de rugosidade foram quantificados em perfilômetro de contato. A altura do desgaste dos antagonistas foi determinada em estereomicroscópio óptico. Foram realizadas a análise de difração de raios-X, espectroscopia Raman e microscopia eletrônica de varredura para cada grupo experimental, bem como microdureza Vickers e tenacidade à fratura. Os dados de volume de desgaste, altura dos antagonistas e rugosidade foram analisados estatisticamente por meio do ANOVA on Ranks e teste de Dunn. Os dados de microdureza e tenacidade à fratura foram analisados estatisticamente por meio do ANOVA 2 fatores e Tukey 5%. Os dados das análises de difração de raios-X e microscopia eletrônica de varredura foram submetidos à análise qualitativa. Com os resultados obtidos, foi possível observar que o envelhecimento hidrotérmico afetou o desgaste apenas para as zircônias 3Y-TZP e multicamadas, tendo o grupo 3Y-TZP com envelhecimento o maior volume de desgaste, semelhante estatisticamente à zircônia multicamadas com envelhecimento. Para os parâmetros de rugosidade, o fator "envelhecimento" foi significativo apenas para o parâmetro Ra. O envelhecimento hidrotérmico afetou a dureza e tenacidade à fratura para a zircônia 3Y-TZP e para as diferentes camadas da zircônia multicamadas. As análises microestruturais indicaram que a fase monoclínica é mais sujeita ao desgaste e o envelhecimento hidrotérmico causou mudança de fase para 3Y-TZP. O MEV mostrou que o envelhecimento hidrotérmico causou arrancamento de grãos e desgaste em camadas para a zircônia 3Y-TZP e superfícies mais irregulares e rugosas para a zircônia 5Y-PSZ e multicamadas. Desse modo, podemos concluir que o envelhecimento hidrotérmico aumenta o desgaste para as zircônias 3Y-TZP e multicamadas e produz transformação de fase, sendo a camada monoclínica mais sujeita ao desgaste. Além disso, o envelhecimento hidrotérmico não alterou a incidência do desgaste para a zircônia 5Y-PSZ, mas produziu alterações superficiais vistas por micrografias (AU)

This study aimed to evaluate the effect of hydrothermal aging on the wear pattern, surface topography, microhardness, fracture toughness and crystalline composition of 3Y-TZP, 5YPSZ and multilayer zirconia. 3Y-TZP - Zpex and 5Y-TZP - Zpex Smile (Tosoh Corporation, Japão) were used to fabricate discs (Ø= 12 mm x 1,2 mm) and ZirCAD Prime (Ivoclar Vivadent, Liechtenstein) to fabricate blocks (14 mm x 14 mm x 1,5 mm). The specimens were divided into 6 groups (n=18) according to the following factors "type of zirconia" (3Y-TZP, 5Y-TZP e multilayers) and "hydrothermal aging" (with and without). Except for the control groups, the samples aged in hydrothermal reactor (134◦C, 20 horas, 2,2 bar). The samples were subjected to wear through cyclic load (150N, 4Hz, 600.000 cycles) with horizontal sliding of 2 mm (n=10) under distilled water, using 3Y-TZP zirconia spheres (Ø= 6mm) as antagonist. The wear volume and roughness parameters were quantified using a contact profilometer. The height of the wear of the antagonists was determined by stereomicroscope. X-rays diffraction analysis, Raman spectroscopy, and scanning electron microscopy were performed for each experimental group, along with fracture toughness and Vickers microhardness measurements. The data of the wear volume and roughness were analyzed statistically by ANOVA on Ranks and Dunn test. The microhardness and fracture toughness data were statistically analyzed by two-way ANOVA and Tukey test (α=0.05). The data of X-rays diffraction analysis and electronic microscope were subjected to the descriptive analysis. The results showed that hydrothermal aging affected the wear of only 3Y-TZP and multilayers zirconia. The 3Y-TZP group with aging had the highest wear volume; however, it was statistically similar to the wear observed in the multilayer zirconia with aging. Regarding the wear of the antagonist, there was no statistical difference between the groups. For the roughness parameters, the "aging" factor was significant only for the Ra parameter. The hydrothermal aging affected the hardness and fracture toughness for 3Y-TZP zirconia and the different layers of zirconia multilayers. The microstructure analyses indicated that the monoclinic phase is more susceptible to wear, and hydrothermal aging caused phase transformation on 3Y-TZP. The scanning electron microscope showed that hydrothermal aging caused grain detachment in 3Y-TZP, resulting in layered wear. For the 5Y-PSZ and multilayers zirconia, the aging caused more irregular and rougher surface. Thus, we can conclude that the hydrothermal aging increases wear in 3-TZP and multilayers zirconia, leading to a phase transformation and formation of a monoclinic layer that is more susceptible to wear. Furthermore, the hydrothermal aging did not alter the incidence of wear for 5Y-PSZ zirconia, but it caused surface alterations seen by micrograph. (AU)

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Com base no desenvolvimento da odontologia adesiva, restaurações minimamente invasivas em cerâmica são utilizadas como alternativas para restaurar um dente. As cerâmicas odontológicas são amplamente aplicadas na área odontológica principalmente devido à sua estética e resistência mecânica. Uma das propriedades da cerâmica a ser bem conhecida antes de seu uso, é a resistência ao desgaste que deve ser compatível com o comportamento de desgaste do antagonista para evitar desempenhos indesejados. Portanto, vários métodos têm sido realizados para avaliar o comportamento do desgaste dos materiais cerâmicos considerando diferentes condições presentes no complexo meio oral. Este estudo teve como objetivo compilar os métodos utilizados para investigar o desgaste das cerâmicas odontológicas e descrever os mecanismos de desgaste envolvidos nos mesmos. A obtenção e análise de dados também é abordada para discutir os resultados obtidos a partir de diferentes métodos, bem como a análise clínica do desgaste e perspectivas futuras sobre esse tema. Em conclusão, muitas metodologias estão disponíveis para medir o desgaste cerâmico. Portanto, os métodos devem ser selecionados com base na relevência clínica de cada estudo e devem seguir parâmetros previamente relatados para padronização, permitindo a comparação da literatura (AU)

Based on the development of adhesive dentistry, minimally invasive restorations in ceramics are used as alternatives to restore a tooth. Dental ceramics are largely applied in the dentistry field mainly due to their esthetic and mechanical strength. One of the ceramic properties to be well known before its use is the wear resistance that should be compatible with the antagonist wear behavior to avoid unwanted performance. Therefore, several methods have been performed to assess the ceramic materials wear behavior considering different conditions present in the complex oral medium. This study aimed to compile the methods used to investigate dental ceramics wear and to describe the wear mechanisms involved on them. Obtaining and analyzing data is also addressed to discuss the results obtained from different methods, as well as the clinical analysis of wear and future perspectives on this topic. In conclusion, many methodologies are available to measure the ceramic wear. Therefore, the methods must be selected based on the clinical significance of each study and should follow previously reported parameters for standardization, allowing literature comparison. (AU)

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Objetive: To compare the clinical behavior of two types of Bulk Fill composite resins and a nanohybrid resin at 18 months in occlusal restorations. Material and Methods: Three occlusal restorations were performed in each one of the 55 participants. They were randomly distributed into three groups, TN: Tetric-N-Ceram Bulk-Fill, FK: Filtek Bulk-Fill, and Z350: Filtek Z350XT. Adhesive techniques and restorative procedures were performed according to the manufacturer's instructions for each restorative material used. In TN and FK an increment of 4mm was applied, and in Z350 increments of ≤2mm depth were applied. Two calibrated operators evaluated the restorations at baseline and at 18 months using the FDI World Dental Federations system (1: excellent, 2: good, 3: satisfactory, 4: unsatisfactory, 5: poor) for clinical marginal staining (MS) properties, fracture-retention (FR), superficial texture (ST), marginal integrity (MI), postoperative sensitivity (PS) and caries (C). Kruskal-Wallis and Wilcoxon were used to compare the 3 groups at 18 months (5% significance). Results: 38 patients with a total of 114 restorations were assessed, being evaluated with excellent clinical behavior; MI, 78.9% in Z350, 89.51% in TN and 81.6% in FK; ST 73.5% in Z350, 86.8% in TN, and 84.2% in FK; MS 84.2% in Z350, 84.2% in TN, and 91.2% in FK; PS 100% in Z350 and 97.3% in TN and FK; in C and FR, 100% in the 3 groups. There were no significant differences between the three groups (p>0.05). Conclusion: The three resins studied presented a good clinical performance at 18 months without showing significant differences in the clinical properties evaluated.

Objetivo: Comparar el comportamiento clínico a 18 meses en restauraciones oclusales entre dos tipos de resinas compuestas Bulk Fill y una resina nanohíbrida. Material y Métodos: En 55 participantes se realizaron 3 restauraciones oclusales en cada paciente, distribuidas aleatoriamente en 3 grupos, TN: Tetric-N-Ceram Bulk-Fill, FK: Filtek Bulk-Fill y Z350: Filtek Z350XT. Las técnicas adhesivas y procedimientos restauradores fueron realizados según las instrucciones de los fabricantes de cada material restaurador utilizado. En TN y FK se aplicó un incremento de 4mm y en Z350 se aplicó incrementos ≤ 2 mm de profundidad. Dos operadores calibrados evaluaron las restauraciones al baseline y a los 18 meses mediante el sistema FDI World Dental Federations (1: excelente, 2: aceptable, 3: suficiente, 4: insatisfactorio, 5: inaceptable) en las propiedades clínicas de tinción marginal (TM), fractura-retención (FR), textura superficial (TS), integridad marginal (IM), sensibilidad postoperatoria (SP) y caries (C). Se utilizó Kruskal-Wallis y Wilcoxon para la comparación de los 3 grupos a 18 meses (significancia de 5%). Resultados: Se controlaron 38 pacientes con un total de 114 restauraciones, siendo evaluados con comportamiento clínico excelente; IM, 78.9% en Z350, 89.51% en TN y 81.6% en FK; TS 73.5%, en Z350, 86.8% en TN y 84.2% en FK; TM, 84.2% en Z350, 84.2% en TN y 91.2% en FK; SP 100% en Z350 y 97,3% en TN y FK; en C y FR 100% en los 3 grupos. No hubo diferencias significativas entre los 3 grupos (p>0,05). Conclusión: Las 3 resinas estudiadas presentaron un buen desempeño clínico a 18 meses sin mostrar diferencias significativas en las propiedades clínicas evaluadas.

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Introduction: The lack of knowledge about denture hygiene can negatively affect their maintenance. On the other hand, good oral hygiene can reduce the chances of plaque accumulation. Objetive: To determine if there is a relationship between knowledge of hygiene and denture maintenance. Material and Methods: A questionnaire was applied to 67 patients who wore partial and/or total removable prostheses daily to evaluate their knowledge of denture hygiene. For the evaluation of denture maintenance, clinical inspection of the removable prosthesis was carried out using the Vigild criterion to observe the amount of plaque that was adhered to it. Data were statistically processed with Spearman's correlation test to determine the relationship between hygiene knowledge and denture maintenance. Results: The patients presented a medium (37.3%) and low (56.7%) denture hygiene knowledge; and fair (68.7%) and poor (11.9%) maintenance of their prosthesis. There is a statistically significant relationship between hygiene knowledge and denture maintenance (p<0.001). Conclusion: There is little knowledge of denture hygiene. This level of knowledge has a statistically significant relationship with the maintenance of the prostheses.

Introducción: El desconocimiento sobre la higiene de prótesis, de los pacientes portadores de estas, puede afectar negativamente en el mantenimiento protésico, una correcta higiene puede disminuir las probabilidades de acúmulo de placa. Objetivo: Determinar si existe relación entre el conocimiento de higiene y el mantenimiento protésico. Material y Métodos: Para la evaluación del conocimiento en higiene protésica se aplicó un cuestionario a 67 pacientes que utilizaban diariamente prótesis removibles parciales y/o totales; y para la valoración del mantenimiento protésico se realizó la inspección clínica de la prótesis removible mediante el criterio de Vigild, observando la cantidad de placa que se encontraba adherida. Se procesaron los datos estadísticamente con la prueba de correlación de Spearman para determinar la relación entre el conocimiento de higiene y el mantenimiento protésico. Resultados: Los pacientes presentaron un conocimiento de higiene protésica medio (37,3%) y bajo (56,7%); y un mantenimiento de la prótesis de forma regular (68,7%) y malo (11,9%). Existiendo relación estadísticamente significativa entre el conocimiento de higiene y el mantenimiento protésico (p<0, 0 01). Conclusión: Existe un bajo conocimiento de higiene protésica, teniendo este nivel de conocimiento una relación estadísticamente significativa con el mantenimiento que evidenciaban las prótesis.

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Este estudo avaliou influência de diferentes métodos de acabamento de superfície na probabilidade de sobrevivência de restaurações de zircônia translúcida e o potencial de desgaste ao antagonista. Foram utilizados 220 preparos confeccionados em resina epóxi (Nema G10) que receberam restaurações do tipo "table top" de zircônia e dissilicato de lítio (1.0 mm de espessura), 100 em YZ HT, 100 em KATANA UTML e 20 em IPS e.max CAD. Cada grupo de zircônia foi dividido em cinco subgrupos de acordo com o acabamento de superfície: Polimento - borrachas diamantadas com 2 granulações; Glaze - camada de glaze; Polimento e Glaze - polimento e glaze associados; Infiltração com sílica; Infiltração com vidro. As restaurações de dissilicato de lítio receberam uma camada de glaze. Os espécimes foram submetidos à fadiga deslizante em uma máquina de ensaio com carga de 200 N, a uma frequência de 4 Hz, totalizando 1.250.000 ciclos. A cada 416.666 ciclos a máquina foi interrompida e as restaurações foram avaliadas quanto à presença de falhas em estereomicroscópio. O antagonista foi analisado quanto aos parâmetros de desgaste. Foram realizadas análises de rugosidade, microestruturais e fractográfica. Kaplan ­ Meier, Mantel ­ Cox (log-rank) e ANOVA compararam os dados. Não foram observadas diferenças para profundidade de desgaste entre os grupos de zircônia, porém os acabamentos glaze e infiltração de vidro promoveram maior volume de desgaste do que a infiltração de sílica e polimento e glaze. Ambas zircônias promoveram maior profundidade e volume de desgaste ao antagonista do que o dissilicato de lítio. Foi observada diferença na rugosidade entre o tipo de zircônia e os acabamentos de superfície, enquanto que o dissilicato de lítio apresentou rugosidade semelhante as zircônias com glaze. Micrografias (MEV) demonstraram a remoção dos acabamentos de superfície após a fadiga deslizante para todos os grupos. A análise fractográfica demonstrou que as fraturas tiveram início na área de contato oclusal e a análise de cross-section demonstrou que Katana e e.max CAD apresentaram mais defeitos na superfície após a fadiga do que a Vita. A zircônia Vita apresentou maior probabilidade de sobrevivência comparado a Katana e ao dissilicato de lítio. Restaurações de zircônia com os acabamentos polimento+glaze e infiltração de sílica promoveram menor volume de desgaste ao antagonista comparadas as restaurações de zircônia com glaze ou infiltradas com vidro, enquanto o polimento apresentou o mesmo potencial abrasivo de todos os acabamentos. Além disso, a vitrocerâmica apresentou menor potencial de desgaste do antagonista do que ambas as zircônias.

This study evaluated the surface finishes influence on the survival probability of translucent zirconia restorations and also the wear potential against steatite antagonist. 220 epoxy resin (Nema G10) preparations received zirconia and lithium disilicate table top restorations (1.0 mm thickness), 100 milled in YZ HT, 100 in KATANA UTML and 20 in IPS e.max CAD. Each zirconia group was divided into five subgroups according to the surface finish: Polishing (P) 2 granulations diamond rubbers; Glaze (G) glaze layer; Polishing and Glaze (PG) polishing and glaze associated; Silica infiltration (IS); Glass infiltration (IV). The lithium disilicate restorations received a glaze layer (EG). The specimens were submitted to sliding fatigue test in a mechanical machine against steatite sphere. The parameters were: 200 N loads, 4 Hz of frequency, totaling 1,250,000 cycles. Every 416,666 cycles the restorations were evaluated in stereomicroscope for failures presence (cracks, fractures or detachment of the restorations). Roughness, microstructural, fractographic and wear analysis were performed. Kaplan­Meier, Mantel­Cox (log-rank) and ANOVA compared the data. The failure survival was different among the groups. No difference was observed for wear depth among zirconia groups, whereas glaze and glass infiltration promoted greater volume loss than silica infiltration and polishing plus glaze. Both zirconia promoted greater volume loss and wear depth to the antagonist than lithium disilicate. Difference was observed for roughness among the zirconia and surface finishes, while lithium disilicate presented similar roughness compared to both glazed zirconia. Micrographs (SEM) showed the surface finishes removal after sliding fatigue for all groups. Fractographic analysis showed occlusal contact area as fractures origin and the cross-section analysis showed that Katana and e.max CAD presented more surface defects after fatigue than Vita. The Vita restorations presented higher survival probability compared to Katana and lithium disilicate restorations. Zirconia polished+glaze and silica infiltration promoted less antagonist volume loss compared to glazed or glass infiltrated, while polishing had the same wear potential as all finishes. In addition, the glass-ceramic presented less potential to wear the antagonist than both zirconia.

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Este trabalho teve como objetivo investigar a rugosidade, o desgaste e o brilho superficial de uma resina composta nanoparticulada (Filtek Z350 XT - 3M ESPE), com diferentes sistemas de polimento a seco e lubrificado antes e após envelhecimento artificial. Foram confeccionados 100 espécimes de resina composta em forma de disco, divididos em: grupo controle (sem polimento) e em três sistemas de polimento (pontas de diamante de etapa única Dimanto - VOCO, discos de lixa Sof-Lex Pop-On - 3M ESPE - e escova de polimento com carbeto de silício nas cerdas Astrobrush - IVOCLAR VIVADENT). Os sistemas polidores foram empregados sem lubrificação, com água e com vaselina. Após a fase de envelhecimento por escovação, foi realizado o repolimento das amostras, exceto no grupo controle. Ao final de cada tempo do estudo (inicial, polimento, envelhecimento e repolimento), os grupos foram submetidos as leituras de rugosidade, desgaste e brilho, verificando assim a efetividade de cada sistema de polimento. Os dados referentes a cada avaliação quantitativa foram submetidos à análise estatística de variância de medidas repetidas. As comparações múltiplas foram realizadas por teste Pos-hoc de Tukey. Diferenças significantes foram determinadas por p < 0,05. Para as análises de brilho e rugosidade póspolimento o Dimanto não foi influenciado pelo uso ou não de lubrificantes. O Sof-Lex Pop-On obteve melhor desempenho sem utilização de lubrificante, enquanto a escova Astrobrush apresentou maiores valores de brilho e menor rugosidade quando lubrificada por água ou vaselina. Em relação ao desgaste superficial, o Dimanto foi melhor, quando associado a vaselina. O Sof-Lex PopOn apresentou menor desgaste, quando utilizado com água. A escova Astrobrush obteve o pior resultado quando lubrificada com vaselina. Portanto, o brilho, a rugosidade e o desgaste superficial dependem do polidor e da combinação com ou sem lubrificação(AU)

The aim of this study was to investigate the roughness, wear and surface gloss of a nanoparticulated resin composite (Filtek Z350 XT - 3M ESPE), with dry and lubricated polishing systems before and after artificial aging. One hundred resin composite specimens were fabricated in cylindrical shape, which was further divided into: control group (no polishing) and three polishing systems (One step diamond tips Dimanto -VOCO, Sof-Lex Pop-On -3M ESPE, and a silicon carbide polishing brush - Astrobrush -IVOCLAR VIVADENT). Polishing systems was used dry, with water or petroleum jelly. After aging by simulated tooth brushing, the samples' repolishing was carried out, except in the control group. After each study period (initial, polishing, aging and repolishing), the groups were subjected to roughness, wear and gloss, thus verifying the effectiveness of each polishing system. The data for each quantitative evaluation was submitted to repeated-measures analysis of variance. Multiple comparisons were performed by Tukey post-hoc test. Significant differences were determined by p <0.05. For post-polishing gloss and roughness analyzes, Dimanto was not influenced by the use or not of lubricants. Sof-Lex Pop-On achieved better performance without using lubricant, while the Astrobrush brush showed higher values of gloss and less roughness when lubricated by water or petroleum jelly. Regarding surface wear, Dimanto was better when associated with petroleum jelly. Sof-Lex Pop-On showed less wear when used with water. The Astrobrush brush obtained the worst result when lubricated with petroleum jelly. The brightness, roughness and surface wear depend on the polisher and the combination with or without lubrication(AU).

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ABSTRACT: The objective of the study was to evaluate marginal adaptation of Class II mesial-occlusal-distal (MOD) restorations before and after thermo-mechanical loading and volumetric shrinkage of the bulk-fill vs conventional composite resin. For marginal adaptation assessment, 24 Class II MOD cavities with cervical margins extending 1.0 mm below (distal) and 1.0 mm beyond (mesial) the cement-enamel junction were prepared in extracted human molars. The teeth were filled as follows: Group A - bulk-fill with SureFil SDR flow (first increment, 4 mm; second increment, 2 mm); Group B - bulk-fill with SureFil SDR flow as a base (first increment, 4 mm) and covered with the conventional nanohybrid composite Esthet-X HD (second increment, 2 mm); and Group C - incrementally filled with Esthet-X HD. Marginal adaptation was evaluated by scanning electron microscopy before and after thermomechanical loading (240,000 loading cycles and simultaneous 600 thermal cycles). To evaluate volumetric polymerization shrinkage, a semi-spherical mold was filled with the tested composites and placed in an AccuVol device after light curing. Both before and after loading, marginal adaptation in cervical dentin was superior (p < 0.05) for Groups A and B compared with Group C. In cervical enamel, Group B showed better marginal adaptation than Group C, and Group A presented intermediary results, between Groups B and C. Furthermore, bulk-fill flow resulted in greater shrinkage than Esthet-X HD. A significant improvement of marginal adaptation was observed when bulkfill flow was used instead of conventional composite resin both before and after thermomechanical loading. However, the bulk-fill flow presented higher volumetric polymerization shrinkage than the conventional composite.

RESUMEN: El objetivo de este trabajo consistió en evaluar la adaptación marginal de las restauraciones mesiales-oclusales-distales (MOD) de Clase II antes y después de la carga termo-mecánica y la contracción volumétrica de la carga compuesta de resina "bulk-fill" en comparación con resina convencional. Para la evaluación de adaptación, se prepararon 24 cavidades MOD de Clase II en molares humanos extraídos, los que se restauraron de la siguiente manera: Grupo A: restaurado con resina fluida Bulk-Fill SureFilSDR (primer incremento, 4 mm; segundo incremento, 2 mm); Grupo B: restaurado con resina fluida Bulk-Fill SureFil SDR (primer incremento, 4 mm) y cubierto con resina compuesta nanohíbrida Esthet-X HD (segundo incremento, 2 mm); y Grupo C - rellenado incrementalmente con Esthet-X HD. La adaptación marginal se evaluó mediante microscopía electrónica de barrido antes y después de la carga termomecánica (240.000 ciclos de carga y 600 ciclos térmicos simultáneos). Para evaluar la contracción volumétrica de la polimerización, se llenó un molde semiesférico con los compuestos probados y se colocó en un dispositivo AccuVol después del fotopolimerización. Tanto antes como después de la carga, la adaptación marginal en la dentina cervical fue superior (p <0,05) para los grupos A y B en comparación con el grupo C. En el esmalte cervical, el grupo B mostró una mejor adaptación marginal que el grupo C, y el grupo A presentó resultados intermedios, entre Grupos B y C. Se observó una mejora significativa de la adaptación marginal al utilizar la resina fluida Bulk-Fill en lugar de resina compuesta convencional tanto antes como después de la carga termomecánica. Sin embargo, la resina fluida 'Bulk-Fill' presentó una mayor contracción volumétrica de polimerización que el compuesto convencional.

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O presente estudo teve por objetivo avaliar o comportamento da camada de caracterização sobre zircônia de alta translucidez (YZHT, Vita YZ HT), cerâmica feldspática (FD/VMII, Vita Mark II) e silicato de lítio reforçado por zircônia (ZLS, Vita Suprinity) frente à simulação de desgaste fisiológico variando os antagonistas em YZHT, esteatita e cerâmica híbrida com polímero (Vita Enamic). Foram obtidos 120 discos (ø 12 mm, 1,2 mm de espessura) cerâmicos, sendo 30 de YZHT e FD, e 60 de ZLS, através de corte de blocos para CAD/CAM. As amostras de YZHT foram sinterizadas, e na sequência os grupos YZHT e FD receberam a camada de caracterização. A caracterização das amostras de ZLS foi realizada no mesmo ato da cristalização (ZLS1, etapa única) ou em queima posterior a cristalização (ZLS2, duas etapas). A caracterização foi realizada de acordo com as recomendações do fabricante e todas as amostras receberam aplicação de glaze e consequente queima. Os espécimes foram divididos em subgrupos (n=10) de acordo com os antagonistas: esteatita, cerâmica híbrida ou zircônia; em seguida, foram submetidos à simulação do desgaste fisiológico. Os parâmetros de rugosidade média (Ra) e largura média dos elementos do perfil de rugosidade (Rsm) foram analisados em diferentes momentos da simulação de desgaste fisiológico desde o início até o final da ciclagem. Após os 15.000 ciclos foram calculados a perda de massa dos discos cerâmicos e dos pistões antagonistas. Os resultados foram analisados estatisticamente por Anova 2 fatores e Tukey (p<0,05). Antes do desgaste, as cerâmicas não apresentaram diferenças para os parâmetros de rugosidade, Ra (p=0,3348), Rz (p=0,5590) e Rsm (p=0,5330). Os antagonistas não apresentaram diferenças para os parâmetros, Ra (p=0,0541) e Rsm (p=0,0613), enquanto que o parâmetro Rz (p=0,000) apresentou diferença, já que a esteatita (18,98 ± 2,98 µm) apresentou uma maior rugosidade média quando analisada a altura máxima do perfil quando comparado com os antagonistas em enamic (12,35 ± 0,91 µm) e zircônia (11,47 ± 0,89 µm). Após o desgaste, as cerâmicas continuaram sem apresentar diferenças estatísticas para os parâmetros de rugosidade, Ra (p=0,488), Rz (p=0,681) e Rsm (p=0,256). Os antagonistas não apresentaram diferença para o parâmetro Ra (p=0,124), porém, apresentaram diferença para o parâmetro Rz (p=0,000), já que a esteatita (57,98 ± 4,11 µm) apresentou uma maior média para tal parâmetro quando comparado com os antagonistas em enamic (44,86 ± 2,34 µm) e zircônia (37,81 ± 1,40 µm); e para o parâmetro Rsm (p=0,000), já que as médias da esteatita (502,72 ± 72,20 µm), enamic (385,67 ± 24,84 µm) e zircônia (268,94 ± 27,99 µm) apresentaram diferenças entre si. O tipo de cerâmica (p<0,0001) influenciou a perda de massa das amostras e a interação entre cerâmica e antagonista (p=0,0098), com isso influenciou a perda de massa dos pistões antagonistas. O grupo ZLS 2 apresentou a maior perda de massa entre os grupos testados. Todos os antagonistas testados apresentaram perda de massa semelhante contra o FD, enquanto a esteatita apresentou maior perda de massa quando testadas com amostras YHZT, ZLS 1 e ZLS 2. Todas as cerâmicas apresentaram rugosidade semelhante antes e após a simulação de desgaste. As amostras de cerâmicas apresentaram uma perda de massa semelhante. No entanto, a queima adicional da caracterização da cerâmica de silicato de lítio reforçado por zircônia favoreceu uma maior perda de massa, sem que houvesse alteração de sua resistência(AU)

The present study aimed to evaluate the behavior of the characterization layer on high translucency zirconia (YZHT, Vita YZ HT), feldspar ceramic (FD / VMII, Vita Mark II) and zirconia reinforced lithium silicate (ZLS, Vita Suprinity) compared to the simulation of physiological wear, varying the antagonists in YZHT, steatite and hybrid ceramic with polymer (Vita Enamic). 120 ceramic discs (ø 12 mm, 1.2 mm thick) were obtained, 30 from YZHT and FD, and 60 from ZLS, by cutting blocks for CAD / CAM. The YZHT samples were sintered, and in the sequence the groups YZHT and FD received the characterization layer. The characterization of the ZLS samples was carried out in the same act of crystallization (ZLS1, single step) or in burning after crystallization (ZLS2, two steps). The characterization was carried out according to the manufacturer's recommendations and all samples received application of glaze and consequent burning. The specimens were divided into subgroups (n = 10) according to the antagonists: steatite, hybrid ceramic or zirconia; then, they were submitted to the simulation of physiological wear. The parameters of average roughness (Ra) and average width of the elements of the roughness profile (Rsm) were analyzed at different moments of the simulation of physiological wear from the beginning to the end of the cycle. After 15,000 cycles, the mass loss of the ceramic discs and antagonistic pistons was calculated. The results were analyzed statistically by Anova 2 factors and Tukey (p <0.05). Before wear, the ceramics showed no differences for the roughness parameters, Ra (p = 0.3348), Rz (p = 0.5590) and Rsm (p = 0.5330). The antagonists showed no differences for the parameters, Ra (p = 0.0541) and Rsm (p = 0.0613), while the parameter Rz (p = 0.000) showed a difference, since steatite (18.98 ± 2) , 98 µm) presented a higher average roughness when the maximum profile height was analyzed when compared with the antagonists in enamic (12.35 ± 0.91 µm) and zirconia (11.47 ± 0.89 µm). After wear, the ceramics continued to show no statistical differences for the roughness parameters, Ra (p = 0.488), Rz (p = 0.681) and Rsm (p = 0.256). The antagonists showed no difference for the Ra parameter (p = 0.124), however, they showed a difference for the Rz parameter (p = 0.000), since steatite (57.98 ± 4.11 µm) showed a higher average for such parameter when compared with antagonists in enamic (44.86 ± 2.34 µm) and zirconia (37.81 ± 1.40 µm); and for the parameter Rsm (p = 0.000), since the averages of steatite (502.72 ± 72.20 µm), enamic (385.67 ± 24.84 µm) and zirconia (268.94 ± 27.99 µm ) showed differences between them. The type of ceramic (p <0.0001) influenced the loss of mass of the samples and the interaction between ceramic and antagonist (p = 0.0098), thereby influencing the loss of mass of the antagonist pistons. The ZLS 2 group showed the greatest loss of mass among the tested groups. All tested antagonists showed similar mass loss against FD, while steatite showed greater mass loss when tested with YHZT, ZLS 1 and ZLS 2 samples. All ceramics showed similar roughness before and after wear simulation. The ceramic samples showed a similar mass loss. However, the additional burning of the characterization of the zirconia-reinforced lithium silicate ceramic favored a greater loss of mass, without altering its strength(AU)

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Este estudo avaliou a resistência ao desgaste fisiológico da camada de caracterização aplicada sobre cerâmica híbrida com diferentes tratamentos de superfície, em função do antagonista. Foram confeccionados 160 discos (12 mm de diâmetro, 1,2 mm de espessura) de cerâmica híbrida com polímero (Vita Enamic, Vita Zhanfabrick, Bad Säckingen, Alemanha) e foram polidos com lixas de carbeto de silício até # 1200 e divididas aleatoriamente em grupos experimentais (n = 10), de acordo com o tratamento da superfície da cerâmica previamente à caracterização e a finalização da cerâmica com camada de glaze ou não (P: amostras polidas sem caracterização; PG: amostras polidas, finalização com glaze; C: pigmentação convencional; CG: pigmentação convencional, finalização com glaze; J: jateamento; JG: jateamento, finalização com glaze; S: uso de silano autocondicionante; SG: uso de silano autocondicionante, finalização com glaze). Metade dos espécimes foram submetidos à simulação do desgaste fisiológico com aplicadores de esteatita, enquanto para a outra metade com aplicadores de cerâmica híbrida. Com auxílio de perfilômetro de contato foram analisados parâmetros de rugosidade. A rugosidade média Ra e espaçamento RSm foram analisados pela estatística ANOVA 3 fatores (tratamento de superfície x presença de glaze x antagonista), seguido por teste de Tukey com a=5%. Houve influência da interação dos 3 fatores na rugosidade média (Ra) da cerâmica PIC (p=0,000) e na interação 2 fatores (tratamento de superfície x presença glaze) na rugosidade de espaçamento RSm da cerâmica PIC (p=0,011). A cerâmica híbrida necessita de um tratamento de superfície para que seja realizada a caracterização extrínseca. A aplicação do glaze após a caracterização reduz a rugosidade superficial e o potencial de desgaste do antagonista(AU)

This study evaluated the resistance to physiological wear of the characterization layer applied over hybrid ceramic with different surface treatments, with different antagonists. One hundred and sixty discs were confectioned (12 mm of diameter, 1.2 mm of thickness) of hybrid ceramic with polymer (Vita Enamic, Vita Zhanfabrick, Bad Säckingen, Germany) and were polished with silicon carbide paper # 1200 and randomly divided into experimental groups (n = 10), according to the surface treatment previously to the characterization and finishing of the ceramic either with a glaze layer or not (P: samples polished without characterization; PG: polished samples with glaze finishing; C: conventional pigmentation; CG: conventional pigmentation finishing with glaze; J: sandblasting; JG: sandblasting, finishing with glaze; S: use of self-etching silane; SG: use of self-etching silane, finishing with glaze). Half of the specimens were submitted to simulation of physiological wear with steatite applicators, meanwhile for the other half, applicators of hybrid ceramic were used. With the aid of a contact perfilometer, roughness parameters were analyzed. The mean roughness Ra and spacing roughness RSm were statistically analyzed by 3-way ANOVA (surface treatment x glaze presence x antagonist), followed by Tukey (a= 5%). There was influence of interaction of the three factors in mean roughness (Ra) of hybrid ceramic (p=0.000) and in the interaction of two factors (surface treatment x glaze presence) in the spacing roughness RSm of the hybrid ceramic (p=0.011). Hybrid ceramic require a surface treatment for extrinsic characterization. Glaze application after characterization decreases surface roughness and wear potential of the antagonist(AU)

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O objetivo do estudo foi avaliar o comportamento mecânico de materiais restauradores utilizados na reabilitação da guia canino. O estudo foi dividido em uma etapa in sílico e outra in vitro. Dez modelos 3D de dentes caninos hígidos foram obtidos por engenharia reversa e utilizados como Grupo Controle (n = 10) para o teste in sílico por meio da análise por elementos finitos (FEA). Um desgaste incisal de 2 mm foi simulado em cada amostra 3D e reabilitado com restauração incisal direta de resina composta (Grupo IRC, n = 10) e indireta de cerâmica (Grupo IC, n = 10). Os mesmos modelos também receberam, além do desgaste incisal, um preparo vestibular para faceta laminada, restaurados com os mesmos materiais, compondo os Grupos FRC (faceta de resina composta, n = 10) e FC (faceta cerâmica, n = 10). Os modelos foram exportados para um software de engenharia assistida por computador (CAE) e as geometrias foram transformadas em malhas de elementos tetraédricos, consideradas sólidas, isotrópicas, homogêneas e lineares. Uma carga de 100 N foi aplicada simulando a desoclusão pelo canino para análise mecânica estrutural dinâmica. A deformação total foi mensurada e a tensão máxima principal foi usada como critério de falha. Com base nos resultados da avaliação in sílico, dois tipos de restauração foram selecionados para a fase in vitro, onde realizou-se um ensaio mecânico de fadiga para análise do desgaste. Trinta dentes caninos hígidos foram distribuídos em três grupos: Controle (n = 10), IRC (n = 10) e FC (n = 10). As amostras foram submetidas ao ensaio de fadiga em cicladora mecânica com deslizamento de 2 mm por 240.000 ciclos, carga de 49 N e 4 Hz de frequência, imersas em água em temperatura ambiente. A cada 60.000 ciclos as amostras foram moldadas e seus modelos escaneados para avaliação da quantidade de desgaste através da técnica de correlação por imagem digital, quantificando a perda de estrutura a cada intervalo. As técnicas restauradoras com resina composta sofreram maior deformação total, tendo a cerâmica um comportamento semelhante ao dente hígido. A probabilidade de falha no movimento de desoclusão foi menor na cerâmica. Para o desgaste, não houve diferença significante entre grupos experimentais até 180.000 ciclos. Aos 240.000 ciclos, a resina composta apresentou maior desgaste que a cerâmica (p = 0,02). Todos os grupos provocaram desgaste em seus antagonistas, mas não houve diferença significante entre eles (p < 0,05). Dentro das limitações deste estudo, pode-se concluir que os laminados cerâmicos apresentaram menor desgaste, deformação e probabilidade de falha na restauração da guia canino. Ainda, a anatomia do dente e o tipo de restauração influenciaram o comportamento dos materiais(AU)

The purpose of this study was to evaluate the mechanical behavior of materials restorative used in rehabilitation of canine guide. The study was divided in two parts in silico and in vitro test. Ten 3D models of sound canine teeth were obtained by reverse engineering technique and used as Control Group (n = 10) to in silico test by finite elements analysis (FEA). A 2 mm wear were simulated in each 3D sample and restored according to restorative material; Group IRC (Incisal Composite Resin, n=10) and Group IC (Incisal Ceramic, n = 10). Laminate preparations were modeled and restored with the same materials, Group FRC (Laminate Composite Resin, n=10) and Group FC (Laminate Ceramic, n = 10). All models were exported to Computer Aided Engineering (CAE) software, the geometries were meshed with tetrahydric elements and all contacts were considered perfectly bonded. The load simulated the canine guide (100 N) and the assembly was constrained at the bottom surface to run a structural mechanic dynamic analysis. The Total Deformation was measured and Maximum Principal Stress was used as failure criteria. Thirty sound canine tooth were divided in three groups to in vitro test; Control (n = 10), IRC (n = 10) and FC (n = 10). The samples were subjected to the fatigue test in a wear machine for 240.000 cycles, load of 49 N, frequency of 4 Hz, sliding distance of 2 mm in water at room temperature. The samples were molded every 60.000 cycles and their models scanned to evaluate wear by digital image correlation. Composite resin groups showed higher total deformation and ceramic groups had a more similar behavior to the control group. The probability of failure was lower for the ceramic in the canine guidance. For wear, there was no significant difference between groups up to 180.000 cycles. After 240.000 cycles, the wear was greater in the IRC group (p = 0,02). The wear of the antagonists was not statistically different between groups. Within the limitations of this study, it can be concluded that the ceramic laminates showed less wear, deformation and probability of failure in restoring of the canine guide. In addition, anatomy of the tooth and type of restoration influenced the behavior of the materials(AU)

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Objective: to evaluate the clinical performance of the dual shade layering and polychromatic resin composite layering techniques using a randomized controlled trail. Material and Methods: 42 participants (84 restorations) of class IV or class III through and through within a pair of anterior contra-lateral teeth were randomly allocated into two groups according to technique of composite restoration placement: control "polychromatic layering" and intervention "dual-shade layering". Follow-up was done at 1 month (baseline) and 1 year. Restorations were evaluated using Visual Analog Scale (VAS), restoration color shade match using Vita Easyshade V ®, and blinded assessor using FDI criteria for assessment of dental restorations measuring (aesthetic properties). Chi-square test was used to compare between restorations of both techniques. Results: There was no statistically significant difference between restorations of both techniques for patient satisfaction outcome, restorations color match outcome, and for all tested FDI outcomes except surface luster with 100% success. Conclusion: Bothdual-shade layering and polychromatic natural layering techniques, exhibited acceptable clinical and esthetic performance (AU)

Objetivo: Avaliar o comportamento de desgaste do esmalte humano e lascamento de zircônia de cobrimento e monolítica para restaurações posteriores de cobertura total. Material e métodos: Trinta e quatro restaurações de zircônia de cobertura total (dezessete em cada grupo) foram fabricadas. Os pacientes foram divididos em dois grupos de acordo com o tipo de zircônia utilizada; grupo 1 (grupo comparador) coroas com zircônia de cobrimento e grupo 2 (grupo de intervenção) coroas únicas de zircônia monolítica. Todas as coroas foram fabricadas e polidas em laboratório. Para medidas de desgaste de dentes opostos, foi utilizado um perfilômetro 3D sem contato, onde réplicas de resina epóxi foram construídas para o arco oposto imediatamente após a cimentação das coroas, três, seis e doze meses. O lascamento da restauração foi medido usando critérios modificados dos Serviços de Saúde Pública dos Estados Unidos (USPHS). Resultados: Todas as restaurações foram relatadas como alfa sem lascamento. Não houve diferença estatisticamente significativa entre (Grupo 1) e (Grupo 2) para o teste de desgaste. Conclusão: As restaurações monolíticas e de cobrimento revelaram propriedades mecânicas satisfatórias sem lascamento após um ano de uso clínico. O desgaste do esmalte oposto foi clinicamente aceitável para ambos os materiais (AU)

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INTRODUCTION: Polymer-based composite materials have been proposed as an alternative for single unit restorations, due to their resilient and shock absorbing behavior, in contrast to the brittleness of ceramic materials that could result in failure by fracture. OBJECTIVE: To evaluate the fatigue strength and damage modes of monolithic posterior resin nanoceramic and lithium disilicate glass ceramic crowns. METHODOLOGY: Twenty-six resin nanoceramic (RNC) and lithium disilicate glass ceramic (LD) 2 mm monolithic crowns (n=13) were cemented on composite resin replicas of a prepared tooth and subjected to cyclic load with lithium disilicate indenters for 2 million cycles. Specimens and indenters were inspected every 500,000 cycles and suspended when presenting fractures or debonding. Surviving specimens were embedded in epoxy resin, polished and subsurface damage was analyzed. Specimens presenting fractures or severe subsurface damage were considered as failures. Survival data was subjected to Fisher's exact test; damage modes were subjected to Mann-Whitney test (p<0.05). RESULTS: There were no debonding, cohesive or catastrophic failures. Considering subsurface damage, 53.8% of RNC and 46.2% of LD crowns survived the fatigue test, presenting no statistical difference. Chief damage modes were radial cracks for RNC and inner cone cracks for LD, presenting no statistical difference. CONCLUSIONS: The results suggest that if debonding issues can be resolved, resin nanoceramic figures can be an alternative to posterior crowns. Although distinct, damage modes revealed potential to cause bulk fracture in both glass ceramic and resin nanoceramic crowns.

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Los padrones estéticos impuestos por la sociedad y medios de comunicación hoy en día son muy altos, y la expectativa de nuestros pacientes por los procedimientos odontológicos realizados principalmente en el sector anterior no es menor. La evolución de los sistemas de resinas compuestas, así como de los sistemas de acabado y pulido posibilitan hoy en día obtener superficies de alta calidad en las restauraciones, lo que se traduce en buenas propiedades ópticas, mejor estética, buena función, mayor duración de las restauraciones y disminución de la placa dental, maximizando así la salud bucal de los pacientes. La efectividad de un buen procedimiento de acabado y pulido en una restauración dental de cualquier tipo es un objetivo muy importante de ser alcanzado.

The today aesthetic standards imposed by society and the media are very high, and the expectation of our patients for dental procedures mainly in the anterior sector is not minor. The evolution of resin composite systems as well as the finishing and polishing systems now a days enable to obtain high quality surfaces areas in restorations, which translates into good optical properties, better aesthetics, good function, longer duration of restorations and the decrease in dental plaque, thus maximizing the oral health of patients. The effectiveness of a good finishing and polishing procedure in any kind dental restoration is a very important goal to be achieved.

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No ambiente bucal, as restaurações de resina composta estão sujeitas a ações físicas, provenientes do desgaste e carga oclusal, e químicas, pelo contato com a saliva e os alimentos. Os efeitos desses processos físico-químicos estão diretamente relacionados com a característica da composição do material restaurador resinoso. Ensaios laboratoriais são especialmente importantes para avaliar a resistência física e estabilidade química dos materiais restauradores. O objetivo do estudo foi realizar a caracterização in vitro de uma resina composta bulk fill contendo partículas pré-reagidas de ionômero de vidro (S-PRG) (Beautifil-Bulk, Shofu Inc). As variáveis dependentes foram resistência à flexão (FS), absorção de água (WS) e solubilidade (SL), grau de conversão (DC), liberação de monômeros em água destilada e morfologia superficial em microscopia eletrônica de varredura (MEV), após incubação da resina composta em água destilada. As variáveis independentes foram a cor da resina composta, em cinco níveis, e o tempo de armazenamento dos corpos-de-prova, em seis níveis. Os ensaios de FS, WS e SL foram realizados de acordo com a metodologia preconizada pela ISO 4049(2009). Os corpos-de-prova para os ensaios de liberação de monômeros e análise de superfície em MEV foram confeccionados com as dimensões de 15 mm de diâmetro por 1 mm de espessura , usando resina da cor A3. O grau de conversão foi determinado em corpos-de-prova cilíndricos (1 x 1 mm) com resina da cor A3. Para confecção de todos os corpos-de-prova foi utilizado o fotopolimerizador LED RadiiCal (SDI Inc., Victoria, Austrália; 1200 mW/cm2). Após os períodos de incubação das amostras em água destilada (10 min, 24 h, 7 dias, 30 dias, 3 e 6 meses), foram realizadas análises em cromatografia líquida de alta eficiência (HPLC) para identificação e quantificação de monômeros liberados, usando padrões de Bis-GMA e TEGDMA. Para análise de superfície, os corpos-de-prova incubados em água destilada (7 dias, 30 dias, 3 e 6 meses) receberam pulverização de 4 nm de carbono e foram avaliados em MEV (FEI - Quanta 200, FEG). Os resultados foram expressos em média e desvio padrão. Foram realizados testes de normalidade (Kolmogorov-Smirnov e Shapiro-Wilk) e de homocedasticidade (Levene). Análise de Variância (ANOVA) e teste de comparações múltiplas, e teste de Kruskal-Wallis verificaram as diferenças entre os níveis dos fatores em estudo. Foi adotado o nível de significância de 5%. Não houve diferença significativa entre as cores para as variáveis FS, WS e SL (p>0,05). A média (dp) do DC foi 59,37(14,49)%. TEGDMA foi identificado em todos os tempos avaliados com maiores concentrações aos 30 dias e 3 meses de armazenamento. Bis-GMA não foi detectado em nenhuma das soluções. As imagens em MEV mostraram alterações morfológicas sugestivas de rugosidade da superfície aos 6 meses de armazenamento. A resina composta Giomer Beautifil-Bulk atingiu os requisitos da norma ISO 4049(2009) para FS, WS e SL e apresentou um DC aceitável. Não houve liberação de Bis-GMA e o TEGDMA foi detectado durante todo o período de 6 meses de avaliação.

In the oral environment, composite resin restorations are subject to physical actions, from occlusal wear and tear, and chemical actions, through contact with saliva and food. The effects of these physicochemical processes are directly related to the composition characteristic of resin restorative material. Laboratory assays are especially important for assessing the physical strength and chemical stability of restorative materials. The objective of the study was to perform in vitro characterization of a bulk fill composite containing glass ionomer pre-reacted particles (S-PRG) (Beautifil-Bulk, Shofu Inc). The dependent variables were flexural strength (FS), water sorption (WS) and solubility (SL), degree of conversion (DC), elution of monomers in distilled water and surface morphology in scanning electron microscopy (SEM). The independent variables were the shades of the composite resin, in five levels, and the storage time of the specimens, in six levels. The FS, WS and SL assays were performed according to the methodology recommended by ISO 4049:2009. For monomer elution assay and surface analysis in SEM specimens were made with 15 mm diameter and 1 mm thickness, using A3 shade resin. The degree of conversion was determined in cylindrical specimens measuring 1 x 1 mm with A3 shade resin. For the preparation of all the specimens, the Radii-Cal LED light curing unit (SDI Inc., Victoria, Australia, 1200 mW / cm2) was used. After the incubation periods of the samples in distilled water (10 min, 24 h, 7 days, 30 days, 3 and 6 months), analyzes were performed in high performance liquid chromatography (HPLC) for the identification and quantification of elution monomers using Bis-GMA and TEGDMA standards. For surface analysis, specimens incubated in distilled water (7 days, 30 days, 3 and 6 months) were sprayed with 4 nm of carbon and were evaluated in SEM (FEI-Quanta 200, FEG). The results were expressed as mean and standard deviation. Normality tests (Kolmogorov-Smirnov and Shapiro-Wilk) and homoscedasticity test (Levene) were performed. Analysis of Variance (ANOVA) and multiple comparison test, and Kruskal-Wallis test verified the differences between the levels of the factors under study. The significance level of 5% was set. There was no significant difference among the resin shades for FS, WS and SL (p> 0.05). The mean (SD) of DC was 59.37 (14.49)%. TEGDMA was identified at all time points with the highest concentrations at 30 days and 3 months of storage. Bis-GMA was not detected in any of the solutions. SEM images showed morphological changes suggestive of surface roughness at 6 months of storage. The composite resin Giomer Beautifil-Bulk reached the requirements of ISO 4049:2009 for FS, WS and SL and presented acceptable DC. There was no release of Bis-GMA and TEGDMA was detected throughout the 6-month evaluation period.

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A recessão gengival está frequentemente associada à lesão cervical não-cariosa. Quando as duas lesões estão associadas, dão origem a uma lesão combinada (LC) que tem um prognóstico de tratamento diferente de quando as duas lesões se apresentam sozinhas. A literatura apresenta alguns estudos que avaliaram uma abordagem multidisciplinar para otimizar o tratamento dessa LC. No entanto, as abordagens propostas possuem limitações de técnicas e materiais, sem um protocolo clínico ideal estabelecido. Dessa forma, o objetivo do presente estudo foi avaliar um novo protocolo multidisciplinar, com duas resinas compostas e dois sistemas adesivos distintos através de estudo clínico randomizado. Foram selecionadas 80 lesões combinadas, alocadas aleatoriamente em um dos seguintes grupos: AC+NP (n=20) - restauração parcial da lesão cervical com resina nanoparticulada e sistema adesivo de condicionamento total em 2 passos e cirurgia para recobrimento radicular, AU+NP (n=20) - restauração parcial da lesão cervical com resina nanoparticulada e sistema adesivo autocondicionante e cirurgia para recobrimento radicular, AC+MH (n=20) - restauração parcial da lesão cervical com resina microhíbrida e sistema adesivo de condicionamento total em 2 passos e cirurgia para recobrimento radicular, AU+MH (n=20) - restauração parcial da lesão cervical com resina microhíbrida e sistema adesivo autocondicionante e cirurgia para recobrimento radicular. Foram realizadas avaliações das restaurações pelo método USPHS após 1 semana, 6 meses e 12 meses. A análise de sobrevivência das restaurações foi realizada através do teste de Kaplan-Meier. Os protocolos restauradores foram comparados para cada parâmetro pelo teste exato de Fisher, considerando tipo de adesivo e tipo de resina empregados. Teste de Qui-Quadrado foi utilizado para comparação das taxas após 6 e 12 meses entre os grupos testados. A avaliação da normalidade foi realizada pelo teste de Shapiro-Wilks. As medidas clínicas de RGR, PS, NIC, ETQ, ATQ, Hipersensibilidade Dentinária e Estética (VAS) foram comparadas tanto intra como intergrupo por teste de variância de medidas repetidas ANOVA de dois fatores e Tukey com teste post-hoc. IP, IS foram avaliados pelo teste de Qui-Quadrado. Os parâmetros de DC, Porcentagem de recobrimento e RecRed foram analisados pelo ANOVA 1 fator. Pôde-se observar uma taxa de sucesso geral cumulativo do tratamento de 98,7% aos 6 primeiros meses e 92,4% aos 12 meses de acompanhamento, sem diferença estatisticamente significativa entre os tempos e grupos avaliados. Todos os grupos apresentaram melhora estética e redução de hipersensibilidade significativa em relação ao baseline (p<0,001) após 6 meses. Houve redução significativa da recessão gengival relativa (p<0,05) após 12 meses de acompanhamento. Dentro dos limites do presente estudo, pode-se concluir que os materiais utilizados apresentaram desempenho clínico similares, sendo que as diferentes combinações de materiais restauradores adesivos estudados associados às técnicas cirúrgicas utilizadas podem ser empregadas no tratamento das lesões cervicais não-cariosas associadas a recessão gengival(AU)

Non-carious cervical lesion is frequently associated with gingival recession, resulting in a combined lesion (CL) that has a different treatment prognosis when the two lesions appear alone. The literature presents few studies that evaluate a multidisciplinary approach to optimize the treatment of this CL. The previously proposed approaches and materials have limitations and an optimal clinical protocol has not been established yet. Thus, the aim of this study was to evaluate a novel multidisciplinary protocol with two resin composites and two different adhesive systems by a randomized clinical. Eighty combined lesions were randomly assigned to one of the following groups: NP + TE (n = 20) - partial restoration of cervical lesions with nanofilled composite and total-etch adhesive system and periodontal surgery for root coverage, NP + UA (n =20) - partial restoration of cervical lesions with nanofilled composite and self-etching adhesive system and periodontal surgery for root coverage, MH + TE (n = 20) - partial restoration of cervical lesions with microhybrid composite and total-etch adhesive system and periodontal surgery for root coverage, MH + UA (n = 20) - partial restoration of cervical lesions with microhybrid composite and selfetching adhesive system and periodontal surgery for root coverage. Restorations were assessed using the USPHS criteria after one week, six months and twelve months. Survival rate was assessed by Kaplan-Meier test. Restorative protocols were compared for each parameter by Fisher's exact test, considering type of adhesive and type of composite used. Chi-square test was used to compare the rates at 6 and 12 months between the groups tested. Normality evaluation was assessed by Shapiro-Wilks test. Clinical measures of RGR, PS, NIC, KTW, KTH, Hipersensitivity and Esthetics (VAS) were compared both intra and inter-group by analysis of variance of repeated measures Two-Way ANOVA and Tukey posthoc test. IP, IS were evaluated by Chi-square test. CD parameter, Coverage percentage and RecRed were evaluated by One-Way ANOVA. It was observed a successful cumulative rate of 98.7 % at 6 months and 92.4 % at 12 months with no significant difference between groups. When compared to baseline, all groups presented significant improvement in esthetics and reduction of hipersensitivity at 6 months (p<0.001). Significant reduction of gingival recession was recorded after 12 months (p<0.05). It can be concluded that there is no difference between the tested materials, and different combinations of adhesive restorative materials associated with periodontal surgical techniques can be used to treat non-carious cervical lesions associated with gingival recession(AU)

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Abstract Polymer-based composite materials have been proposed as an alternative for single unit restorations, due to their resilient and shock absorbing behavior, in contrast to the brittleness of ceramic materials that could result in failure by fracture. Objective: To evaluate the fatigue strength and damage modes of monolithic posterior resin nanoceramic and lithium disilicate glass ceramic crowns. Methodology: Twenty-six resin nanoceramic (RNC) and lithium disilicate glass ceramic (LD) 2 mm monolithic crowns (n=13) were cemented on composite resin replicas of a prepared tooth and subjected to cyclic load with lithium disilicate indenters for 2 million cycles. Specimens and indenters were inspected every 500,000 cycles and suspended when presenting fractures or debonding. Surviving specimens were embedded in epoxy resin, polished and subsurface damage was analyzed. Specimens presenting fractures or severe subsurface damage were considered as failures. Survival data was subjected to Fisher's exact test; damage modes were subjected to Mann-Whitney test (p<0.05). Results: There were no debonding, cohesive or catastrophic failures. Considering subsurface damage, 53.8% of RNC and 46.2% of LD crowns survived the fatigue test, presenting no statistical difference. Chief damage modes were radial cracks for RNC and inner cone cracks for LD, presenting no statistical difference. Conclusions: The results suggest that if debonding issues can be resolved, resin nanoceramic figures can be an alternative to posterior crowns. Although distinct, damage modes revealed potential to cause bulk fracture in both glass ceramic and resin nanoceramic crowns.

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