Effect of novel pre-sintered zirconia surface treatment on shear bond strength between zirconia and veneering porcelain compared to conventional surface treatments: an in-vitro study / Efeito de um novo tratamento de superfície de zircônia pré-sinterizada na resistência ao cisalhamento entre zircônia e porcelana em comparação com os tratamentos de superfície convencionais: estudo in vitro

Objective: to evaluate the effect of novel zirconia surface treatment method on shear bond strength between zirconia and veneering porcelain compared to air abrasion and CoJet surface treatment methods. Material and Methods: twenty-one zirconia ceramic discs were fabricated with diameter of 7mm and 3mm thickness and divided according to surface treatment into three subgroups, control group I: Air Abrasion (n=7), group II: CoJet (n=7) and group III: Z-etch (n=7). Porcelain was built over the zirconia specimens with a customized mold and fired in a ceramic furnace. All specimens were thermocycled (20000 cycles) between 5°C ­ 55 °C with a dwell time of 30 seconds in distilled water and shear bond strength of veneering porcelain to each zirconia specimen was tested using a universal testing machine. Results: numerical data were explored for normality by checking the distribution of data and using tests of normality (Kolmogorov-Smirnov and Shapiro-Wilk tests). One-way ANOVA test was used to compare between the groups. There was a statistically significant difference between the three groups (P-value = 0.002, Effect size = 0.503). Pair-wise comparisons between groups revealed that Z-etch showed the statistically significantly highest mean shear bond strength. Conclusion: zirconia coating using z-etch is showing promising results in promoting higher bond strength than conventional surface treatment methods as air abrasion and silica coating (AU)

Objetivo: avaliar o efeito do novo método de tratamento de superfície de zircônia na resistência ao cisalhamento entre a zircônia e a porcelana de cobertura em comparação com os métodos de abrasão a ar e jateamento com CoJet. Material e Métodos: vinte e um discos de zircônia foram confeccionados com diâmetro de 7mm e espessura de 3mm e divididos de acordo com o tratamento de superfície em três subgrupos, grupo controle I: Abrasão a ar (n=7), grupo II: CoJet (n=7) e grupo III: Z-etch (n=7). A porcelana foi aplicada sobre os espécimes de zircônia com um molde personalizado e sinterizada em forno de cerâmica. Todos os espécimes foram termociclados (20.000 ciclos) entre 5°C - 55°C com um tempo de permanência de 30 segundos em água destilada e a resistência ao cisalhamento da porcelana de cobertura foi testada através de uma máquina de ensaio universal. Resultados: os dados numéricos foram avaliados quanto à normalidade, verificando a distribuição dos dados e utilizando testes de normalidade (testes de Kolmogorov-Smirnov e Shapiro-Wilk). O teste ANOVA de um fator foi utilizado para comparar os grupos. Houve uma diferença estatisticamente significativa entre os três grupos (P-valor = 0,002, tamanho do efeito = 0,503). As comparações pareadas entre os grupos revelaram que o Z-etch apresentou a resistência de união ao cisalhamento estatisticamente significativamente mais alta. Conclusão: o revestimento de zircônia utilizando Z-etch mostrou resultados promissores para o aumento da resistência de união em comparação aos métodos convencionais de tratamento de superfície, como abrasão a ar e revestimento de sílica (AU)

Clinical Effectiveness of Composite Resin Bonded with Universal Adhesive for the Restoration of Non-Carious Cervical Lesions Using Air Abrasion: A Randomised Controlled Trial

ABSTRACT @#Restorative treatment is very challenging for non-carious cervical lesions (NCCLs) due to functional and structural complexities. The purpose of this randomised controlled trial (RCT) was to evaluate the clinical performance of nanocomposite restorations bonded using universal adhesive in self-etch mode with and without air abrasive surface treatment for NCCLs. A total of 70 NCCLs, from a group of consenting patients who fulfilled the inclusion criteria, were recruited for the study. The study was carried out following CONSORT guidelines. Block randomisation was done for equal allocation of lesions into; Group 1 (surface treatment with alumina air abrasion) and Group 2 (control group without mechanical surface treatment). The lesions were restored with nanocomposite using a universal bonding agent in self-etch mode. The clinical performance of the restorations was evaluated by two examiners using modified United States Public Health Service (USPHS) criteria at baseline, 3 months, 6 months and 12 months. A Chi-square test was performed for inter-group comparison. Cochran’s Q test and Dunn’s post hoc analysis were used for intra-group comparison. The inter-group comparison revealed no statistically significant difference between the experimental and control group for all the parameters assessed. With the intra-group analysis, it was found that there was a significant decrease in the performance of the restorations concerning marginal staining, marginal adaptation and surface texture during the evaluation period (p < 0.05). However, all of them demonstrated clinically acceptable performance. According to the results of this RCT, it was concluded that airborne particle abrasion of NCCLs did not improve the clinical performance of nanocomposite resin bonded using universal adhesive.

Surface treatment and adhesion approaches on polymer-infiltrated ceramic network: influence on the bond strength to resin cement

Aim: To evaluate the effect of different surface treatments and adhesive approaches on the microshear bond strength of resin cement to a polymer-infiltrated ceramic network (PICN). Methods: PICN blocks were randomly assigned into 9 groups (n=10): CTRL: no treatment; HF: 5% hydrofluoric acid etching; HF-S: HF + silane; HF-S-A: HF-S + adhesive (Adper Single Bond 2); HF-UA: HF + universal adhesive (Single Bond Universal); SB: sandblasting with 50 µm Al2O3 particles; SB-S: SB + silane; SB-S-A: SB-S + adhesive; SB-UA: SB + universal adhesive. Resin cement microcylinders (Ø = 0.96 mm; height = 1 mm) (RelyX Ultimate) were built upon the PICN surface after roughness and contact angle measurements. Next, microshear bonding tests (µSBS) were performed (0.5 mm/min) after water storage (37ºC, 90 days) and thermocycling (12,000 cycles; 5ºC-55ºC). Failure modes were observed under stereomicroscope. Bond strength data were analyzed by two-way ANOVA/Tukey's test and t-tests. Kruskal-Wallis/Dunn's tests were conducted for roughness and contact angle data (α = 0.05). Results: A rougher surface and lower contact angles were observed for Sandblasting. HF-S (18.54 ± 2.03 MPa), SB-S (19.00 ± 1.66 MPa) and SB-UA (18.07 ± 2.36 MPa) provided the highest bond strength values, followed by the other treated groups. The CTRL group resulted in lower bond strength (7.18 ± 2.34 MPa). Conclusion: Hydrofluoric acid etching followed by silane application and sandblasting followed by silane or universal adhesive are useful clinical steps to enhance bonding to PICN. Adhesive applications after HF etching have no advantages in bonding to PICN

Contaminación de la dentina con diferentes técnicas de secado / Contamination of dentin with different drying techniques

El secado es uno de los factores clave para lograr una adhesión micromecánica exitosa en la dentina con los sistemas adhesivos de grabado independiente. El objetivo de este trabajo fue comparar los residuos remanentes luego de cuatro procedimientos diferentes de secado en preparaciones ex vivo en dentina. Se utilizaron cinco terceros molares ex-vivo, en cada uno de los cuales se realizó una preparación dentinaria en piso y paredes con al menos un socavado. Las unidades experimentales fueron almacenadas en solución fisiológica durante 7 días. Las distintas técnicas de secado (G1- G8) se aplicaron, luego de que las preparaciones fueron tratadas con gel de ácido fosfórico al 37% (Blue Gel etch Megadental) durante 15s y lavadas con jeringa y agua a presión durante 15s (Técnica de Grabado Ácido o TGA), de la siguiente manera: algodón común (Condesa) (G1), papel tisú (Achiss) cortado a mano (G2) y con tijera (G3), esponja (Sharpys) (G4), papel tisú (Simplicity) cortado a mano (G5)(AU)

Estimation of the autoclave and different surface treatments on microleakage between soft liner and heat-cured acrylic / Estimativa da autoclavagem e diferentes tratamentos de superfície na microinfiltração entre o soft liner e o acrílico termopolimerizável

Objective: The present study was oriented to estimate the effect of different surface treatments on the microleakage between the soft liner and acrylic with and without the use of autoclave as disinfection method. Material and Methods: Sixty samples were split into two groups: the autoclaved groups and non-autoclaved groups. Each one subdivided into three groups: first one without any treatments as a control group; in the second group surface of the samples were treated with CO2 laser (10.6 nm wavelength for 15 seconds), and in the third group the surface was treated with sandblasting (250 µm Al2O3). All the samples exposed to thermocycling, then the microleakage test was evaluated by gauging dye penetration depth between the soft liner and acrylic disc using a digital microscope. Data analyzed statistically by One-way ANOVA and Tukey's post-hoc tests. In addition, t-test was used for comparison between two groups (P-value ≤ 0.05). Results: The maximum mean values for the microleakage were observed in the untreated group (control) followed by the group treated by CO2 laser and the lowest mean value of microleakage was related to the third group for both non-autoclaved and autoclaved groups with significant differences among them. In addition, depending on the use of autoclave, there was non-significant in all studied groups. Conclusions: There was a decrease in the microleakage when the surface treated with CO2laser and sandblast. The use of autoclave did not badly change the microleakage between the soft liner and denture base. (AU)

Objetivo: O presente estudo teve como objetivo estimar o efeito de diferentes tratamentos de superfície na microinfiltração entre o soft liner e o acrílico usando ou não a autoclve como método de desinfecção. Material e Métodos: Sessenta amostras foram divididas em dois grupos: grupo com uso da autoclave e grupo sem uso da autoclave. Cada um subdivide em três grupos: o primeiro sem nenhum tratamento como grupo controle; no segundo grupo, a superfície das amostras foi tratada com laser de CO2 (comprimento de onda de 10,6 nm por 15 segundos) e, no terceiro grupo, a superfície foi tratada com jateamento (250 µm Al2O3). Todas as amostras foram expostas à termociclagem, em seguida o teste de microinfiltração foi realizado medindo-se a profundidade de penetração do corante entre o soft liner e o disco de acrílico em microscópio digital. Os dados foram analisados estatisticamente por One-way ANOVA e testes post-hoc de Tukey. Além disso, o teste t foi usado para comparação entre dois grupos (P-valor ≤ 0,05). Resultados: Os valores médios máximos de microinfiltração foram observados no grupo não tratado (controle) seguido pelo grupo tratado com laser de CO2 e o valor médio mínimo de microinfiltração foi relacionado ao terceiro grupo para ambos os grupos não autoclavado e autoclavado com diferenças significativas entre eles. Além disso, dependendo do uso de autoclave, não houve significância em todos os grupos estudados. Conclusão: Houve diminuição da microinfiltração quando a superfície foi tratada com laser de CO2e jateamento. O uso de autoclave não alterou a microinfiltração entre o soft liner e a base da prótese (AU)

Retention strength of ball-attachment titanium post for removable partial denture or overdenture

Aim: To evaluate the retention of an endodontic titanium postwith a spherical head for removable partial denture or overdentureattachment according to surface treatment type. Methods: Sixtyhealthy single-rooted teeth, sectioned at the enamel/cementumjunction, were treated endodontically and steadily fixed in theembedding acrylic resin. The titanium posts were subdivided intofour groups: control, no surface treatment (Ctrl); posts with macroretentivegrooves (MR); air abrasion of the post surface (AB); andposts with macro-retentive grooves and air abrasion of the postsurface (MR+AB). The posts were luted in the root canal usingself-adhesive dual resin cement. Pull-out testing was performedusing a universal testing machine until complete detachment wasachieved. After pull-out testing, the metallic posts were examinedunder an optical microscope and the failures were classifiedbased on the cement distribution pattern on the extracted posts:0, no cement left on the post (cement/post failure); 1, postsurface partially covered by adhered cement (post/cement anddentin/cement mixed failure); 2, post surface completely coveredby cement (dentin/cement failure). The retention data wereanalyzed by one-way ANOVA, Bonferroni­Dunn test (p<0.05)and Weibull analysis. Results: AB showed the highest retentionvalue (485.37±68.36), followed by MR+AB (355.80±118.47), MR(224.63±42.54) and Ctrl (113.12 ± 51.32). AB and MR showedthe highest Weibull moduli. Conclusions: The data indicatedthat air abrasion alone could significantly increase the retentionof titanium posts/attachments for use with overdentures orremovable partial denture

Influence of alumina air-abrasion for highly translucent partially stabilized zirconia on flexural strength, surface properties, and bond strength of resin cement

Abstract Objective This study aims to evaluate the influence of different air-abrasion pressures and subsequent heat treatment on the flexural strength, surface roughness, and crystallographic phases of highly translucent partially stabilized zirconia (Y-PSZ), and on the tensile bond strength of resin cement to Y-PSZ. Methodology Fully sintered zirconia specimens were ground with SiC paper (control) and/or air-abraded with 50 µm particles of alumina at 0.1, 0.15, 0.2, or 0.3 MPa or left as-sintered. After air-abrasion at 0.2 MPa (0.2AB), additional specimens were then heated to 1500°C, and held for one hour at this temperature (0.2AB+HT1h). Flexural strength and surface roughness were evaluated. Crystalline phase identification was also carried out using X-ray diffraction. Bonded zirconia specimens with self-adhesive resin cement were stored in distilled water at 37°C for 24 h, either with or without aging (thermal cycling 4-60°C/20000). Results were analyzed statistically by ANOVA and Tukey-Kramer tests. Results The flexural strength decreased with the increase in air-abrasion pressure, while in contrast, the surface roughness increased. The lowest flexural strength and the highest roughness value were found for the 0.2AB and 0.3AB groups, respectively. All groups contained cubic-, tetragonal ( t )-, and rhombohedral ( r )-ZrO2 phases with the exception of the as-sintered group. Upon increasing the air-abrasion pressure, the relative amount of the r -ZrO2 phase increased, with a significant amount of r -ZrO2 phase being detected for the 0.2AB and 0.3AB groups. The 0.2AB+HT1h group exhibited a similar flexural strength and t -ZrO2 phase content as the as-sintered group. However, the 0.2AB group showed a significantly higher tensile bond strength (p<0.05) than the 0.2AB+HT1h group before and after aging. Conclusion Micromechanical retention by alumina air-abrasion at 0.2 MPa, in combination with chemical bonding of a resin to highly translucent Y-PSZ using a MDP-containing resin cement may enable durable bonding.

Avaliação da resistência de união de uma cerâmica de óxido de zircônia submetida a tratamentos de superfície por abrasão / Evaluation of the bond strength of a ceramics of zirconia oxide subjected to surface treatments by abrasion

Resumo Introdução A cimentação adesiva, com cerâmicas puras, é um passo relevante no estabelecimento da longevidade de trabalhos protéticos, sendo estes os melhores materiais utilizados para a reposição de dentes perdidos, de forma a reabilitar o sorriso. O sistema cerâmico de zircônia não se beneficia do tratamento com ácidos e necessita de diferentes métodos para tratar sua superfície, visando à efetividade na união adesiva. Objetivo Avaliar os resultados de diferentes técnicas de jateamento e aplicação de agente de união desenvolvidas para metais e cerâmica de zircônia (Ceramill ZI®), por meio de ensaio de tração, em dois diferentes tratamentos de superfície. Material e método Foram preparadas 20 amostras de Ceramill Zi® (n = 20), em forma de cilindro, e unidas entre si por meio do cimento resinoso (Multilink®), formando 10 espécimes (n = 10). Formaram-se sete grupos experimentais com os mesmos 10 espécimes e estes receberam dois tratamentos de superfície diferentes: abrasão e aplicação de agentes silânicos de união. Resultado A análise estatística mostrou diferenças significativas na resistência à fratura dos espécimes silicatizados com Rocatec®. Os valores de resistência de união à tração, mensurados em MPa, dos grupos 1 a 7, foram, respectivamente: 2,27; 4,48; 8,06; 8,32; 9,15; 10,56 e 10,70. As médias entre os grupos se apresentam estatisticamente significantes, exceto entre os grupos 3 e 4 e entre 6 e 7. Conclusão Os resultados mostraram que o tratamento da superfície cerâmica baseado no método de silicatização promoveu melhor união nos ensaios com Ceramill ZI® e cimentados com Multilink®.

Abstract Introduction Adhesive cementation, with pure ceramics, is a relevant step in establishing the longevity of prosthetic works. Being these, the best materials used for the replacement of lost teeth, in order to rehabilitate the smile. The ceramic zirconia system does not benefit from the treatment and planning needs for its surface, effectively in adhesive therapy. Objective Evaluate the results of different blasting techniques and application of bonding agent for metals and ceramics (Ceramill ZI®) by means of a tensile test in two different surface treatments. Material and method Twenty samples of Ceramill Zi® (n = 20), cylindrical and joined with resin cooling (Multilink®), were prepared, forming 10 specimens (n ​​= 10). The first 10 ingredients were formed by 7 experimental groups and they received 2 surface problems: abrasion and application of silane bonding agents. Result The research resulted in fracture resistance of Rocatec® silica specimens. The values ​​of tensile strength, measured in MPa, of groups 1 to 7, were: 2.27; 4.48; 8.06; 8.32; 9.15; 10.56 and 10.70. We observe how to enter the groups are statistically significant, except between groups 3 and 4 and between 6 and 7. Conclusion The results of the ceramic surface treatment were based on no silicate method, promoting the union of results with Ceramill ZI® and cemented with Multilink®.

Effect of aluminum oxide sandblasting, plasma application and their combination on the bond strength of resin cement to zirconia ceramics / Efeito do jateamento de óxido de alumínio, aplicação de plasma e sua combinação na resistência de união do cimento resinoso à zircônia

Objective: to evaluate the effect of aluminum oxide sandblasting (AOS), argon plasma application (APL) and their combination (AOS+APL) on the shear bond strength (SBS) of dual-cure resin cement (Panavia F 2.0, Kuraray Noritake) to two zirconia-based ceramics (Lava, 3M ESPE and Katana, Kuraray Noritake). Material and Methods: One hundred twenty zirconia plates (13 mm in length X 5 mm in width X 1 mm in thickness) were prepared and treated according to the following treatments: 1- AOS, 2- APL,3- AOS+APL and 4- no treatment (control). After treatments, resin cement cylinders (1.4 mm in diameter x 1 mm in height) bonded to zirconia surface were obtained by filling up the silicon matrix. The shear bond test was performed following storage of the samples for 24 hours and one year. Bond strength values were recorded in MPa and the data were analyzed by three-way ANOVA and Tukey post-hoc test (preset alpha of 0.05). Results: In general, AOS and AOS +APL showed the higher SBS. After one-year storage, SBS of the resin cement to the Katana zirconia did not reduce, regardless of the zirconia surface treatment. Conclusion: AOS alone was able to increase the SBS of the resin cement to both zirconia ceramics compared to control and SBS remained stable after one year depending on type of zirconia ceramic. (AU)

Objetivo: avaliar o efeito do jateamento de óxido de alumínio (AOS), aplicação de plasma de argônio (APL) e sua combinação (AOS + APL) na resistência ao cisalhamento (SBS) do cimento resinoso dual (Panavia F 2.0, Kuraray Noritake) a duas cerâmicas à base de zircônia (Lava, 3M ESPE e Katana, Kuraray Noritake). Material e Métodos: Cento e vinte placas de zircônia (13 mm de comprimento X 5 mm de largura X 1 mm de espessura) foram preparadas e tratadas de acordo com os seguintes tratamentos: 1- AOS, 2- APL, 3- AOS + APL e 4 - sem tratamento (controle). Após realizados os tratamentos, com a utilização de uma matriz de silicone (1,4 mm de diâmetro x 1 mm de altura) foram confeccionados cílindros de cimento resinoso na superfície da zircônia. O teste de cisalhamento foi realizado após o armazenamento das amostras por 24 horas e um ano. Os valores de resistência de união foram registrados em MPa e os dados foram analisados por ANOVA de três fatores e teste post-hoc de Tukey (alfa de 0,05). Resultados: Em geral, AOS e AOS + APL apresentaram a maior SBS. Após um ano de armazenamento, o SBS do cimento resinoso para a zircônia Katana não reduziu, independentemente do tratamento da superfície da zircônia. Conclusão: AOS isoladamente foi capaz de aumentar a SBS do cimento resinoso para ambas as zircônias em comparação com o controle e a SBS permaneceu estável após um ano, dependendo do tipo de zircônia. (AU)

A new approach for Y-TZP surface treatment: evaluations of roughness and bond strength to resin cemen

Abstract Objective This study aims to evaluate the effect of sonochemical treatment on the surface of yttria-stabilized tetragonal zirconia (Y-TZP) before and after the final sintering. Material and Methods Twenty-eight Y-TZP discs were divided into four groups (n=7), according to surface treatment: PRE: pre-sintering sonication with 30% nominal power for 15 min; POS: post-sintering sonication with 30% nominal power for 15 min; JAT: air abrasion with 50-μm alumina particles; and CON: control group with no treatment. The POS and JAT groups were sintered before sonication and the PRE group after sonication. Surface roughness was analyzed using confocal microscopy, after which resin cement cylinders were placed on the surface of the Y-TZP discs and subjected to mechanical microshear bond strength test until fracture. Surface roughness and microshear bond strength values underwent ANOVA and the Tukey tests. Results The surface roughness values for the PRE group (299.91 nm) and the POS group (291.23 nm) were not significantly different (p≥0.05), statistically, and the surface roughness value of the JAT group (925.21 nm) was higher than those of PRE and POS (p=0.007) groups. The mechanical microshear bond strength test showed that there was no statistically significant difference between the groups (p=0.08). Conclusions Therefore, the results showed that sonochemical treatment modifies the Y-TZP surface and is similar to the well-established sandblasting surface treatment regarding the strength of the bond with the resin cement.

Bond and topography evaluation of a Y-TZP ceramic with a superficial low-fusing porcelain glass layer after different hydrofluoric acid etching protocols / Avaliação da adesão e topografia de uma zircônia Y-TZP com uma camada de glaze após diferentes protocolos de condicionamento com ácido fluorídrico

Introduction: Despite being one of the most studied ceramics today, zirconia still does not have a well-defined adhesion protocol. Objective: Evaluate the influence of different etching times and hydrofluoric acid (HF) concentrations on the zirconia surface and bond strength between a vitrified Y-TZP ceramic and a resin cement. Materials and method: The zirconia surface treatments were: sandblasting with silica-coated alumina (Co); glaze application + 5% HF etching for 5s (G5-5s), 10s (G5-10s) or 20s (G5-20s); glaze application + 10% HF etching for 5s (G10-5s), 10 (G10-10s) or 20s (G10-20s) . Then, cement cylinders (3.3 × 3.3 mm) were built up for shear bond test on all specimens. The specimens were subjected to 6000 thermal cycling before the test. Fractures were analyzed by stereomicroscope. Data were statistically analyzed by Kruskal-Wallis and Dunn statistical tests (5%). Extra samples of each group were made to obtain profilometry and scanning electron microscopy (SEM). Result: Zirconia-cement bond strength was affected by the ceramic surface treatments (p = 0.001). G10-5s (2.71 MPa) recorded the highest bond strength values, followed by the Co (2.05 MPa) while G5 groups had the lowest bond value. Adhesive failure of the samples predominated. The image analysis revealed G5 groups seem to have a lower roughness when compared to groups treated by 10% HF. The creation of pores in the low-fusing porcelain glass layer surface occurred only when 10% HF was used. Conclusion: The low-fusing porcelain glass layer application was able to overcome the sandblasting and obtain a greater adhesive bond to the resinous cement, however, only when 10% HF was used for an interval of 5 seconds.

Introdução: Apesar de ser uma das cerâmicas mais estudadas atualmente, a zircônia ainda não possui um protocolo bem definido para uma cimentação adesiva. Objetivo: Avaliar a influência de diferentes tempos de condicionamento e concentrações do ácido fluorídrico (AF) na superfície da zirconia e na resistência de união entre uma cerâmica Y-TZP vitrificada e um cimento resinoso. Material e método: Os tratamentos de superfície foram: jateamento com óxido de alumínio revestido com sílica (Co); aplicação de glaze + condicionamento com AF 5% por 5s (G5-5s), 10s (G5-10s) ou 20s (G5-20s); aplicação de glaze + condicionamento com AF 10% por 5s (G10-5s), 10 (G10-10s) ou 20s (G10-20s). Em seguida, cilindros de cimento (3,3 × 3,3mm) para teste de cisalhamento foram feitos em todos os espécimes. Os espécimes foram submetidos a 6000 ciclos térmicos antes do teste de adesão. As fraturas foram analisadas por estereomicroscópio. Os dados foram analisados ​​estatisticamente por Kruskal-Wallis e Dunn (5%). Amostras extra de cada grupo foram feitas para realização de perfilometria e microscopia eletrônica de varredura (MEV). Resultado: A resistência de união zircônia-cimento foi afetada pelos tratamentos de superfície (p = 0,001). Os grupos G10-5s (2,71 MPa) registraram os maiores valores de resistência de união, seguidos pelos Co (2,05 MPa), enquanto os grupos G5 apresentaram o menor valor de união. Falhas adesivas foram predominantes. As análises por imagem revelaram que os grupos G5 parecem ser menos rugosos quando comparados aos grupos tratados com AF 10%. A criação de poros na superfície vítrea (glaze) ocorreu apenas quando foi utilizado AF 10%. Conclusão: A aplicação de camada de vidro de porcelana de baixa fusão foi capaz de superar o jateamento e obter uma maior adesão adesiva ao cimento resinoso, no entanto, somente quando foi utilizado 10% de HF por um intervalo de 5 segundos.

Effect of several repair techniques on the bond strength between composite resin and degraded Y-TZP ceramic / Efeito de várias técnicas de reparo na resistência de união entre resina composta e zircônia degradada

Objective: To evaluate the bond strength of different repair treatments for composite resin to aged Y-TZP ceramics. Material and Methods: Zirconia blocks were cut into smaller specimens, sintered according to manufacturer's recommendations (final dimensions of 4×4×3 mm), and randomly allocated into nine groups (n=15) according to the surface treatment and presence/ absence of aging of the substrate (subjected to lowtemperature degradation - LTD), as follows: without LTD (Control: without treatment; TBS: tribochemical silica coating + silane + adhesive); with LTD (Control-LTD: without treatment; TBS-LTD: TBS with hydrothermal degradation; MoS-LTD: Monobond S + adhesive; MoPLTD: Monobond Plus + adhesive; MZP-LTD: Metal/ Zirconia Primer + adhesive; USB-LTD: Single Bond Universal; AP-LTD: Alloy primer + adhesive). LTD was simulated in an autoclave (134 °C, 2 bar, 5 h). The ceramic blocks were embedded in PVC cylinders with a self-curing acrylic resin; each surface treatment protocol was performed; a composite resin cylinder ( : 3.25 mm and height: 3 mm) was then build-up using split metallic matrices. All the specimens were aged (thermocycling + storage in water for 90 days) and subjected to the shear bond strength test using a universal testing machine (1 mm/min). The failure mode was classified into four types: adhesive, composite resin cohesive fracture, ceramic cohesive fracture, and mixed. The bond strength values were subjected to Mann­Whitney test. Results: Only air-abraded samples (TBS and TBS­LTD) survived thermocycling. More than 80% of the samples of the other groups presented pre-test failures. TBS groups presented higher values of bond strength (3.94) compared to TBSLTD (0.96). The predominant type of failure for the surviving samples were adhesive. Conclusion: Air particle abrasion is mandatory to improve the bond strength of the Y-TZP substrate; an aged substrate presents an even more unfavorable scenario for adhesion. (AU)

Objetivo: Avaliar a resistência de união ao cisalhamento gerada por diferentes técnicas de reparo em resina composta aderida em zircônia envelhecida (sujeita a degradação a baixa temperatura - LTD). Material e Métodos: blocos de zircônia foram seccionados em espécimes, sinterizados de acordo com o fabricante (dimensões finais de 4x4x3 mm), e aleatorizados em nove grupos (n=15) de acordo com o tratamento de superfície e presença/ausência de envelhecimento do substrato (LTD), conforme: sem LTD (Control: sem tratamento; TBS: tribosilicatização + silano + adesivo); com LTD (Control-LTD: Monobond S + adesivo; MoP-LTD: Monobond plus + adesivo; MZPLTD: Meta/Zirconia primer + adesivo). LTD foi simulada em autoclave (134 °C, 2 bar, 5 h). Os blocos de cerâmica foram embutidos em cilindros de PVC com resina acrílica autopolimerizável; cada tratamento de superfície foi realizado; um cilindro de resina composta ( : 3,25 mm 3 mm de altura) foi confeccionado usando matrizes metálicas bipartidas. Todos os espécimes foram envelhecidos (termociclagem + armazenagem em água por 90 dias) e sujeitos ao teste de cisalhamento usando um equipamento de teste universal (1 mm/ min). O modo de falha foi classificado em quatro grupos: adesivo, fratura coesiva em resina composta, fratura coesiva da cerâmica, e mista. Os valores de adesão foram sujeitos ao teste de Mann-Whitney. Resultados: somente as amostras jateadas (TBS e TBSLTD) sobreviveram a termociclagem. Mais que 80% dos espécimes dos outros grupos apresentaram falhas préteste. Os grupos TBS apresentaram os maiores valores de resistência ao cisalhamento (3,94) comparado com TBS-LTD (0,96). Os tipos predominantes de falha para os espécimes sobreviventes foi adesiva. Conclusão: o jateamento é recomendável para aumentar a resistência adesiva à zircônia; um substrato envelhecido apresenta um cenário mais desfavorável de adesão. (AU)

Resistência de união de tratamentos de superfície realizados anteriormente à realização de restaurações em resina composta / Bonding strength of surface treatments performed prior to composite resin restorations

As lesões cervicais não cariosas (LCNCs) são definidas pela perda de estrutura dental na junção cemento/esmalte que envolve três mecanismos de estresse mecânico (tensão), atrito (fricção) e erosão (degradação química).. Existem tratamentos preventivos e dessensibilizantes para o principal sintoma das LCNCs, a hipersensibilidade dentinária cervical (HDC), porém, em casos que há perda de estrutura dental maior que 1mm é necessário realizar uma intervenção restauradora. Dessa forma, o objetivo deste estudo foi avaliar a resistência de união da dentina erodida e abrasionada modificada com diferentes pré-tratamentos e posteriormente restauradas com resina composta, através do teste de microtração. Para tanto, foram selecionados 40 molares humanos íntegros, que tiveram as porções oclusais seccionadas até exposição da dentina. Os espécimes passaram por desafio erosivo e abrasivo em uma ciclagem de 5 dias. Após os desafios, os espécimes receberam os tratamentos de superfície (n=10): G1: controle sem tratamento; G2: tratamento de superfície com ponta diamantada; G3: jateamento com óxido de alumínio, G4: ciclagem com enxaguatório fluoretado Elmex Erosion. Feito isso os espécimes foram restaurados, seccionados em palitos e submetidos ao teste de microtração em uma máquina universal de ensaios a 0,5mm/min. Para a analise estatística, foi utilizado o teste paramétrico de análise de variância (ANOVA) um fator e o teste auxiliar de Tukey. Foi observado que não houve diferença entre os tratamentos com ponta diamantada, óxido de alumínio e enxaguatório fluoretado. O único grupo a se diferenciar dos demais foi o grupo controle que apresentou valores de resistência de união inferiores. Dentro das limitações de um trabalho in vitro, conclui-se que os tratamentos de superfície estudados são procedimentos indicados para melhorar a adesão dental frente à necessidade de restaurar uma LCNC.

Dentin pretreatment and adhesive temperature as affecting factors on bond strength of a universal adhesive system

Abstract Objectives: To evaluate the effects of dentin pretreatment and temperature on the bond strength of a universal adhesive system to dentin. Material and Methods: Ninety-six extracted non-carious human third molars were randomly divided into 12 groups (n=8) according to Scotchbond Universal Adhesive (SbU) applied in self-etch (SE) and etch-and-rinse (ER) mode, adhesive temperature (20°C or 37°C) and sodium bicarbonate or aluminum oxide air abrasion. After composite build up, bonded sticks with cross-sectional area of 1 mm2 were obtained to evaluate the microtensile bond strength (μTBS). The specimens were tested at a crosshead speed of 0.5 mm/min on a testing machine until failure. Fractured specimens were analyzed under stereomicroscope to determine the failure patterns in adhesive, cohesive (dentin or resin) and mixed fractures. The microtensile bond strength data was analyzed using two-way ANOVA and Tukey's test (α=5%). Results: Interaction between treatment and temperature was statistically significant for SbU applied in self-etch technique. Both dentin treatments showed higher bond strength for ER mode, regardless of adhesive temperature. When compared to control group, sodium bicarbonate increased bond strength of SbU in SE technique. Adhesive temperature did not significantly affect the μTBS of tested groups. Predominantly, adhesive failure was observed for all groups. Conclusions: Dentin surface treatment with sodium bicarbonate air abrasion improves bond strength of SbU, irrespective of adhesive application mode, which makes this approach an alternative to increase adhesive performance of Scotchbond Universal Adhesive to dentin.

Análise comparativa da resistência de união de um cimento convencional e um cimento autoadesivo após diferentes tratamentos na superfície de pinos de fibra de vidro / Bond strength comparative analysis of a conventional cement with a self-adhesive cement after different treatments on the fiberglass post surface

Introdução: Os pinos de fibra de vidro são uma alternativa aos núcleos metálicos e apresentam vantagens, tais como: estética, módulo de elasticidade semelhante à dentina e cimentação imediata após o término do tratamento endodôntico. Ainda, apresentam a capacidade de aderir ao cimento resinoso e este, à dentina, por meio de técnicas adesivas. Objetivo: Comparar a adesão de um cimento resinoso convencional e um autoadesivo a pinos de fibra de vidro, e os efeitos de diferentes tratamentos de superfície na resistência adesiva dos pinos. Material e método: Trinta pinos foram divididos em três grupos: Controle: sem tratamento na superfície; Jateamento: jateamento com óxido de alumínio por 30 segundos, e Peróxido: imersão em peróxido de hidrogênio 24% por um minuto. Em seguida, corpos de prova foram obtidos a partir de cilindros de cimento resinoso contendo o pino de fibra posicionado no centro de seu longo eixo. Em cada grupo, cinco pinos foram associados ao adesivo Âmbar + cimento convencional AllCem Core e os outros cinco pinos, ao cimento autoadesivo RelyX U200. O conjunto pino/cimento foi segmentado e avaliado em relação à resistência de união (RU) por push-out. Os dados foram analisados estatisticamente pelos testes de ANOVA e Tukey (p< 0,05). Resultado: Os cimentos avaliados exibiram valores de RU semelhantes. Em relação aos tratamentos de superfície, os maiores valores de RU foram encontrados no grupo Jateamento. Conclusão: O cimento convencional, AllCem Core, e o cimento autoadesivo, RelyX U200, mostraram valores de resistência de união semelhantes. Ainda, o jateamento com óxido de alumínio favoreceu a adesão dos pinos aos cimentos.

Introduction: The fiberglass posts are an alternative to the metal cast, presenting some advantages, such as aesthetics, tensile modulus similar to dentin and can be placed in a single session, immediately after the endodontic treatment. It also has the ability to adhere to the resin cement and the last to dentin by means of bonding techniques. Objective: To compare the adhesion of a conventional resin cement with a self-adhesive to fiberglass posts, and the effects of different surface treatments on adhesion of posts. Material and method: Thirty fiber posts were divided into 3 groups: control: untreated surface; Blasting: blasting with aluminum oxide for 30 seconds and peroxide: immersion in 24% hydrogen peroxide for 1 minute. Then, the samples were obtained from resin cement cylinders containing the fiber post positioned in the center of its long axis. In each group 5 posts were associated with the adhesive Ambar+conventional cement Allcem Core and the other 5 posts with the self-adhesive cement RelyX U200. The post/cement sample was segment in discs and evaluated for bond strength (BS) by push-out test. Data were analyzed statistically by ANOVA and Tukey tests (p< 0.05). Result: The cements evaluated exhibited similar BS values. Regarding surface treatments, the highest BS values were found in blasting group. Conclusion: Conventional cement, Allcem Core, and self-adhesive, RelyX U200, showed similar bond strength values. Also, blasting with aluminum oxide favored the adhesion of posts to cements.

Effects of air abrasion with alumina or glass beads on surface characteristics of CAD/CAM composite materials and the bond strength of resin cements

ABSTRACT Objective The study aimed to evaluate effects of air abrasion with alumina or glass beads on bond strengths of resin cements to CAD/CAM composite materials. Material and Methods CAD/CAM composite block materials [Cerasmart (CS) and Block HC (BHC)] were pretreated as follows: (a) no treatment (None), (b) application of a ceramic primer (CP), (c) alumina-blasting at 0.2 MPa (AB), (d) AB followed by CP (AB+CP), and (e) glass-beads blasting at 0.4 MPa (GBB) followed by CP (GBB+CP). The composite specimens were bonded to resin composite disks using resin cements [G-CEM Cerasmart (GCCS) and ResiCem (RC)]. The bond strengths after 24 h (TC 0) and after thermal cycling (TC 10,000 at 4–60°C) were measured by shear tests. Three-way ANOVA and the Tukey compromise post hoc tests were used to analyze statistically significant differences between groups (α=0.05). Results For both CAD/CAM composite materials, the None group exhibited a significant decrease in bond strength after TC 10,000 (p<0.05). AB showed significantly higher bond strength after TC 10,000 than the None group, while CP did not (p<0.05). GBB exhibited smaller surface defects than did AB; however, their surface roughnesses were not significantly different (p>0.05). The AB+CP group showed a significantly higher bond strength after TC 10,000 than did the AB group for RC (p<0.05), but not for GCCS. The GBB+CP group showed the highest bond strength for both thermal cyclings (p<0.05). Conclusions Air abrasion with glass beads was more effective in increasing bond durability between the resin cements and CAD/CAM composite materials than was using an alumina powder and a CP.

Biological characterization of implant surfaces - in vitro study / Caracterização biológica de superfície de titânio - estudo in vitro

Objective: Evaluate the biological performance of titanium alloys grade IV under different surface treatments: sandblasting and double etching (Experimental surface 1; Exp1, NEODENT); surface with wettability increase (Experimental surface 2; Exp2, NEODENT) on response of preliminary differentiation and cell maturation. Material and method: Immortalized osteoblast cells were plated on Exp1 and Exp2 titanium discs. The polystyrene plate surface without disc was used as control group (C). Cell viability was assessed by measuring mitochondrial activity (MTT) at 4 and 24 h (n = 5), cell attachment was performed using trypan blue exclusion within 4 hours (n = 5), serum total protein and alkaline phosphatase normalization was performed at 4, 7 and 14 days (n = 5). Data were analyzed using one-way ANOVA and Tukey test. Result: The values of cell viability were: 4h: C - 0.32±0.01A; Exp1 - 0.34±0.08A; Exp2 - 0.29±0.03A. 24h: C - 0.43±0.02A; Exp1 - ; 0.39±0.01A; Exp2 - 0.37±0.03A. The cell adhesion counting was: C -85±10A; Exp1- 35±5B; Exp2& - 20±2B. The amounts of serum total protein were 4d: C - 40±2B; Exp1 - 120±10A; Exp2 -130±20A. 7d: C 38±2B; Exp1 - 75±4A; Exp2 -70±6A. 14 d: C - 100±3A; Exp1 - 130±5A; Exp2 - 137±9A. The values of alkaline phosphatase normalization were: 4d: C - 2.0±0.1C; Exp1 - 5.1±0.8B; Exp2 - 9.8±2.0A<. 7d: C -1.0±0.01C; Exp1 - 5.3±0.5A; Exp2 - 3.0±0.3B. 14 d: C - 4.1±0.3A; Exp1 - 4.4±0.8A; Exp2 - 2.2±0.2B. ...

Objetivo: Avaliar o desempenho biológico de ligas de titânio grau IV submetidos a diferentes tratamentos de superfície - jateamento e duplo ataque ácido (Superfície experimental 1; Exp1, NEODENT) e superfície com aumento na molhabilidade (Superfície experimental 2; Exp2, NEODENT) em resposta preliminar de diferenciação e maturação celular. Material e método: Foram plaqueados osteoblastos imortalizados sobre discos de titânio de Exp1 e Exp2 e como controle o poço da placa de cultura sem disco (C). Empregou-se ensaios de viabilidade celular (MTT) em 4 e 24 horas (n = 5), adesão celular em 4 horas (n = 5), dosagem de proteínas totais e fosfatase alcalina normalizada em 4, 7 e 14 dias (n = 5). Os dados foram analisados por ANOVA em fator único seguido de teste de Tukey. Resultado: Os valores de viabilidade celular foram: 4h: C - 0,32±0,01A; Exp1 - 0,34±0,08A; Exp2 - 0,29±0,03A. 24h: C - 0,43±0,02A; Exp1 - 0,39±0,01A; Exp2 - 0,37±0,03A. A contagem de adesão celular foi: C - 85±10A; Exp1 - 35±5B; Exp2 - 20±2B. Os valores de proteínas totais foram: 4d: C - 40±2B; Exp1 - 120±10A; Exp2 - 130±20A. 7d: C - 38±2B; Exp1 - 75±4A; Exp2 - 70±6A. 14 d: C - 100±3A; Exp1 - 130±5A; Exp2 - 137±9A. Os valores de fosfatase alcalina normalizada foram: 4d: C - 2,0±0,1C; Exp1 - 5,1±0,8B; Exp2 - 9,8±2,0A, 7d: C - 1,0±0,01C; Exp1 - 5,3±0,5A; Exp2 - 3,0±0,3B, 14 d: C - 4,1±0,3A; Exp1 - 4,4±0,8A; Exp2 - 2,2±0,2B. Letras diferentes representam ...

Effect of Different Surface Treatments for Ceramic Bracket Base on Bond Strength of Rebonded Brackets

The aim of this study was to evaluate the shear bond strength of rebonded ceramic brackets after subjecting the bracket base to different treatments. Seventy-five premolars were selected and randomly distributed into five groups (n=15), according to the type of the bracket surface treatment: I, no treatment, first bonding (control); II, sandblasting with aluminum oxide; III, sandblasting + silane; IV, silica coating + silane; and V, silicatization performed in a laboratory (Rocatec system). The brackets were fixed on an enamel surface with Transbond XT resin without acid etching. The brackets were then removed and their bases were subjected to different treatments. Thereafter, the brackets were fixed again to the enamel surface and the specimens were subjected to shear bond strength (SBS) test. The adhesive remnant index (ARI) was then evaluated for each specimen. Data were subjected to ANOVA and Tukey's tests (α=0.05). A statistically significant difference was observed only between Rocatec and the other groups; the Rocatec group showed the lowest SBS values. The highest SBS values were observed for group 1, without any significant difference from the values for groups II, III and IV. Most groups had a higher percentage of failures at the enamel-resin interface (score 1). It was concluded that the surface treatments of rebonded ceramic brackets were effective, with SBS values similar to that of the control group, except Rocatec group.

O objetivo do estudo foi avaliar o efeito de tratamentos da base de bráquetes cerâmicos monocristalinos na resistência de união ao esmalte após recolagem. Setenta e cinco pré-molares foram selecionados e aleatoriamente distribuídos em 5 grupos (n=15) de acordo com o tratamento da base do bráquete: I - sem tratamento, primeira colagem (controle), II - jateamento com óxido de alumínio, III - jateamento seguido da aplicação de silano, IV - jateamento com partículas de dióxido de sílica (silicatização) seguido de silano, V - silicatização realizada em laboratório (Sistema Rocatec). Os bráquetes foram colados no esmalte com Transbond XT sem condicionamento ácido. Em seguida, os bráquetes foram removidos e suas bases foram submetidas aos diferentes tratamentos. Os bráquetes foram recolados, armazenados por 24 h e submetidos ao ensaio mecânico de cisalhamento com velocidade de 0,5 mm/min. Após, o índice de remanescente adesivo (IRA) foi avaliado em cada espécime. Os dados foram submetidos à análise de variância e teste de Tukey (α=0,05). Pode-se observar que houve diferença significativa apenas entre o sistema Rocatec e os demais grupos, o qual apresentou os menores valores de resistência. Os maiores valores de resistência foram observados para o grupo I (controle), sem diferença significativa dos grupos II, III e IV. A maioria dos grupos apresentou maior porcentagem de falhas na interface esmalte/resina (escore 1). Pode-se concluir que os tratamentos da base do bráquete cerâmico foram efetivos, apresentando valores similares ao grupo controle, exceto para o grupo em que foi usado Rocatec.

Effect of Using Nano and Micro Airborne Abrasive Particles on Bond Strength of Implant Abutment to Prosthesis

Connecting prostheses to the implant abutments has become a concern and achieving a satisfactory retention has been focused in cement-retention prostheses recently. Sandblasting is a method to make a roughened surface for providing more retention. The aim of this study was to compare effects of nano and micro airborne abrasive particles (ABAP) in roughening surface of implant abutments and further retention of cemented copings. Thirty Xive abutments and analogues (4.5 D GH1) were mounted vertically in self-cured acrylic blocks. Full metal Ni-Cr copings with a loop on the top were fabricated with appropriate marginal adaptation for each abutment. All samples were divided into 3 groups: first group (MPS) was sandblasted with 50 µm Al2O3 micro ABAP, second group (NSP) was sandblasted with 80 nm Al2O3 nano ABAP, and the third group (C) was assumed as control. The samples were cemented with provisional cement (Temp Bond) and tensile bond strength of cemented copings was evaluated by a universal testing machine after thermic cycling. The t test for independent samples was used for statistical analysis by SPSS software (version 15) at the significant level of 0.05. Final result showed significant difference among all groups (p<0.001) and MPS manifested the highest mean retention (207.88±45.61 N) with significant difference among other groups (p<0.001). The control group showed the lowest bond strength as predicted (48.95±10.44 N). Using nano or micro ABAP is an efficient way for increasing bond strengths significantly, but it seems that micro ABAP was more effective.

A conexão das próteses nos pilares dos implantes dentários é um fator de preocupação e a obtenção de uma retenção satisfatória tem sido objeto de estudos recentes em próteses com retenção cementária. O jateamento é um método de obter uma superfície áspera para aumentar a retenção. O objetivo do presente estudo foi comparar os efeitos de jateamento com nano- e micropartículas abrasivas para tornar áspera a superfície dos pilares de implantes e a consequente aumentar a retenção dos copings cimentados. Trinta pilares Xive com seus análogos (4.5 D GH1) foram montados na posição vertical em blocos de acrílico auto-polimerizados. Copings metálicos de Ni-Cr com uma alça no topo foram feitos com adaptação marginal apropriada para cada pilar. Todas as amostras foram divididas em três grupos: o 1° grupo (MPS) foi jateado com micropartículas de Al2O3 com 50 µm de tamanho médio; o 2° grupo (NPS) foi jateado com nanopartículas de Al2O3 com 80 nm de tamanho médio; e o 3° grupo (C) foi considerado controle. As amostras foram cimentadas com cimento provisório (Temp Bond) e a resistência à tração dos copings cimentados foi avaliada em máquina universal de ensaios após processo de termociclagem. O teste t para amostras independentes foi usado para fins de análise estatística empregando-se o software SPSS v. 15, com nível de significância de 0,05. Os resultados demonstraram diferença significante entre todos os grupos (p<0,001) e o grupo MPS mostrou o maior valor médio de resistência de união (207,88±45,61 N) com diferenças significantes em relação aos outros grupos (p<0,001). Conforme previsto, o grupo controle obteve o menor valor de resistência (48,95±10,44 N). O jateamento com micro ou nano partículas mostrou-se um modo eficaz de aumentar significativamente a resistência de união, mas aparentemente as micropartículas são mais eficazes.

Clinical observation of glycine powder air-polishing during periodontal maintenance phase / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical effect of the 65 µm glycine powder air-polishing (GPAP) and ultrasonic scaling during periodontal maintenance phase.</p><p><b>METHODS</b>Twenty-three patients at the age of 28-72 (8 males and 15 females) who were systematically healthy were involved in this study. According to splitting-mouth design, one side of a mouth was randomly assigned to the experiment group with 65 µm GPAP therapy, while the other side was the control group with ultrasonic scaling therapy. The clinical parameters including probing depth (PD), bleeding index (BI), gingival recession (Rec), plaque index (PLI), staining index (SI) were recorded. The patients' perception of treatment was assessed by visual analogue scale (VAS). The treatment time was recorded and compared between the two groups.</p><p><b>RESULTS</b>Both of the two methods had good clinical effects. PD, BI and PLI of the two groups 12 weeks after treatment were better than those at baseline (P < 0.01). There was no significant deference between the two methods at baseline and at the 12 weeks after treatment. The VAS value of experiment group was better than that of control group (1.7 ± 1.3 vs. 3.3 ± 1.8, P < 0.01). The treatment time of experiment group was also shorter than that of control group [(192.7 ± 82.7) s vs. (345.4 ± 116.9) s, P < 0.01].</p><p><b>CONCLUSIONS</b>The results indicate that 65 µm GPAP may be as effective as the ultrasonic scaling during periodontal maintenance phase. 65 µm GPAP had the advantage of more comfort and less time consuming.</p>