Can different etching protocols change the properties of a hybrid ceramic?

The aim of this study was to evaluate the effects of different concentrations of hydrofluoric acid (HF) and etching times on the flexural strength, roughness, wettability, and type of failure of a hybrid ceramic (VITA ENAMIC). Blocks of the ceramic material were made according to the norms of International Organization for Standardization standard 6872:2015 and randomly divided into 7 groups (n = 13): control (no treatment); surface etching with 5% HF for 30 (HF5-30), 60 (HF5-60), or 90 (HF5-90) seconds; and surface etching with 10% HF for 30 (HF10-30), 60 (HF10-60), or 90 (HF10-90) seconds. The adhesive surface of 10 specimens in each group was cemented with dual-curing resin cement. The specimens were submitted to biaxial flexural tests and fractographic analysis. Surface analyses were carried out using 3 noncemented specimens from each group. The surface roughness was evaluated through optical profilometry and the surface wettability through goniometry (contact angle). The values obtained were analyzed by a Dunnett test followed by 2-way analysis of variance and Tukey test (α = 5%). The flexural test results indicated a statistically significant reduction in the resistance of the ceramic when conditioned with 10% acid (P < 0.01). Etching with HF, at any concentration used for any applied time, significantly modified the ceramic roughness of the experimental groups (P < 0.01). The wettability was also significantly altered in the HF5-90 group and in all HF10 groups (P < 0.01). The higher the concentration of the acid, the lower the wettability of the ceramic (P < 0.01). Based on these results, a 5% HF concentration is best indicated for the surface treatment of VITA ENAMIC.

Bond strength between a polymer-infiltrated ceramic network and a composite for repair: effect of several ceramic surface treatments.

The effects of several ceramic surface treatments on bond strength of a polymer-infiltrated ceramic network and resin composite as repair material were evaluated. CAD-CAM blocks of a polymer-infiltrated ceramic network (Vita Enamic) were sliced and subjected to aging process, followed by embedding in acrylic resin. The bonding/repair area was treated as follows (n = 30): C- without treatment; UA- universal adhesive application; FM- 10% hydrofluoric acid and silane application; OM-airborne-particle abrasion with aluminum oxide and silane application; RP- tribochemical silica coating; and CA- surface grinding and application of universal adhesive. Composite resin cylinders were made on the treated surface. Specimens from each group were assigned randomly to two subgroups (n = 15) considering storage condition: Baseline (shear tests after 48 hours) or Storage (tests after 6 months under distilled water). The treated surfaces were analyzed by goniometry, roughness, and SEM. Two-way ANOVA and 1-way ANOVA were applied to analyze the bond data and roughness / contact angle data, respectively, followed by Tukey's test (α = 5%). Surface treatments and storage conditions affected bond strengths (p < 0.01). Surface grinding (CA) followed by universal adhesive promoted the highest value of bond strength (14.5 ± 4.8 MPa for baseline, 8.5 ± 3.4 MPa for storage) and the roughest ceramic surface. Grinding with silicon carbide paper (simulating diamond bur) followed by the application of a universal adhesive system is the best option for repairing fractures of the polymer-infiltrated ceramic network.

Bond strength between a polymer-infiltrated ceramic network and a composite for repair: effect of several ceramic surface treatments

Abstract: The effects of several ceramic surface treatments on bond strength of a polymer-infiltrated ceramic network and resin composite as repair material were evaluated. CAD-CAM blocks of a polymer-infiltrated ceramic network (Vita Enamic) were sliced and subjected to aging process, followed by embedding in acrylic resin. The bonding/repair area was treated as follows (n = 30): C- without treatment; UA- universal adhesive application; FM- 10% hydrofluoric acid and silane application; OM-airborne-particle abrasion with aluminum oxide and silane application; RP- tribochemical silica coating; and CA- surface grinding and application of universal adhesive. Composite resin cylinders were made on the treated surface. Specimens from each group were assigned randomly to two subgroups (n = 15) considering storage condition: Baseline (shear tests after 48 hours) or Storage (tests after 6 months under distilled water). The treated surfaces were analyzed by goniometry, roughness, and SEM. Two-way ANOVA and 1-way ANOVA were applied to analyze the bond data and roughness / contact angle data, respectively, followed by Tukey's test (α = 5%). Surface treatments and storage conditions affected bond strengths (p < 0.01). Surface grinding (CA) followed by universal adhesive promoted the highest value of bond strength (14.5 ± 4.8 MPa for baseline, 8.5 ± 3.4 MPa for storage) and the roughest ceramic surface. Grinding with silicon carbide paper (simulating diamond bur) followed by the application of a universal adhesive system is the best option for repairing fractures of the polymer-infiltrated ceramic network.

Caracterização microestrutural de um esmalte dentário submetido à radiação ionizante e ensaio de desgaste antagonizados por uma cerâmica híbrida / Microstructural characterization of a gamma irradiated dental enamel and wear performance antagonized by a hybrid ceramic

A radioterapia de cabeça e pescoço pode alterar e causar danos à estrutura dentária. Anteriormente a radioterapia, estes pacientes devem passar por consultas e tratamento odontológico orais, sugerindo a cerâmica híbrida como escolha para reabilitações orais, uma vez que esta cerâmica apresenta a característica de menor desgaste do dente. O presente estudo objetivou avaliar o efeito de diferentes doses de radiação ionizante sobre: o comportamento mecânico e estrutural da cerâmica híbrida; as propriedades mecânicas e químicas do esmalte dentário; o desempenho do esmalte dentário irradiado e dois materiais antagonistas distintos (Enamic e Esteatita). Para isto, discos de Enamic e os fragmentos dentais foram submetidos às doses diárias de 2 Gy; totalizando as doses: 0, 20, 40 e 70 Gy (esmalte e Enamic), e, 50 Gy e 60 Gy (esmalte). Após a radiação, as cerâmicas foram analisadas mecanicamente pelos testes de: dureza e flexão biaxial, e, quimicamente pelo FT-IR. Enquanto, os fragmentos de dentes (n = 60) foram observados: a degradação estrutural por FT-IR e DR-X (n=5), a nanodureza e módulo elástico (n = 10), teste de riscamento (n = 3) e desgaste antagonizados por Enamic e Esteatita (n = 10). Os dados foram submetidos aos testes ANOVA (1 e 2 fatores) e Tukey. Mediante os resultados observados, conclui-se que a radiação ionizante não alterou as propriedades da cerâmica híbrida e as propriedades cristalinas do esmalte dentário, porém, alterou a dureza, o módulo elástico, a resistência ao riscamento, a composição química (degradação do colágeno) e desgaste do esmalte dentário(AU)

The head and neck radiotherapy treatment can change and damage the dental structure. Before the radiotherapy treatment, the patients should have a dental consultation and to submit to dentistry treatments, suggesting the hybrid ceramics material are suggested as the choice to oral rehabilitations, for this material shows the characteristic of less damage of the tooth. This study aimed to evaluate the effects of different doses of gamma irradiation on: mechanical and structural behavior of hybrid ceramics; mechanical and chemical properties of dental enamel; the wear performance of irradiated dental enamel and two distinct antagonist materials (Enamic and Steatite). For that, Enamic discs (ISO 6872) and dental fragments were submitted to daily irradiation doses of 2 Gy; about the doses adding up to: 0, 20, 40 and 70 Gy (enamel and Enamic), and, 50 Gy and 60 Gy (enamel only). Then Following that procedure, ceramics were analyzed for: hardness (n = 4), biaxial flexural (n = 10) and chemically by FT-IR (n = 2). While In the meantime, 60 fragments of third molars were observed about: structural degradation by FT-IR and DR-X (n = 5), nano hardness and elastic modulus (n = 10), scratch test (n = 3), chewing simulator test antagonized by: Enamic and steatite (n = 10). The data were submitted to ANOVA- 1Way, and ANOVA-Two Way and Tukey's Test. It is This study concluded that: gamma irradiation did not affect the properties of the hybrid ceramics and the crystalline properties of the dental enamel; however, composition and mechanical properties were affected, such as: hardness, elastic modulus, scratch resistance, chemical composition (collagen degradation) and tooth enamel wear(AU)

Protocolo totalmente cerâmico: uma opção para desafios estéticos / Full-ceramic, complete, fixed implant-supported prosthesis: an option for esthetic challenges

A indicação do uso de sistemas totalmente cerâmicos (infraestrutura em zircônia) para a confecção de próteses implantossuportadas ainda causa questionamentos ao profissional quanto à durabilidade e recomendação desta solução protética. No entanto, o estabelecimento das vantagens da escolha do uso de infraestruturas em zircônia para a confecção de próteses totais fixas com implantes tem sido notável. Logo, este trabalho apresenta um relato clínico planejado e executado sob os parâmetros de planejamento reverso e funcional que norteiam a Implantologia. Cabe ressaltar que o objetivo de todo tratamento odontológico é a satisfação do paciente e a obtenção de estética, com base em evidências científicas.

The indication of full ceramic systems (zirconia infraestructure) to fabricate implant-supported prostheses still causes some professional concerns regarding their durability and recommendation of a prosthetic solution. Nevertheless, the advantages of zirconia infra-estructures for total fixed prostheses over dental implants has been recognized. Thus, this paper presents a clinical report planned and executed under the reverse functional treatment planning at the implant dentistry field. It is important to highlight that the aim of all dental treatment is patient satisfaction and esthetics, based on scientific evidences.

Efeito da radiação ionizante, simulando radioterapia, nas propriedades de cerâmicas Y-TZP e cimentos resinosos / Effect of ionizing radiation, simulating radiotherapy, on properties of Y-TZP ceramics and resin cements

Os objetivos deste estudo foram avaliar o efeito de diferentes tipos de lavagens e exposição à radiação ionizante (raios gama), utilizada em tratamentos oncológicos, na resistência à flexão de 4 pontos, transformação de fase cristalina e alteração de cor da cerâmica policristalina de Y-TZP; e verificar a influência da radiação gama na resistência à miniflexão de cimentos resinosos cimentados com Y-TZP. Foram confeccionadas 114 barras de zircônia estabilizada parcialmente por ítria - Cercon®Zirconia (DENTSPLY Ceramco, EUA) e InCeram 2000 YZ cubes (Vita Zahnfabrik, Alemanha) segundo a norma ISO 6872 (21 mm de comprimento x 4,5mm de largura x 1,2mm de espessura) e 96 barras para mini-flexão de RelyX U200 (3M, Alemanha) e RelyX ARC (3M, Alemanha), divididos de acordo com a cerâmica de proteção. Metade das amostras de Y-TZP e 64 amostras dos cimentos foram irradiadas com gama 60Co, em etapa única de 70 Gy. Foi realizado o teste de resistência à flexão em máquina de ensaio universal (1 mm/min, 1000kg) e para o teste de mini-flexão (0,5 mm/min e 50 kg) e para alteração de cor das Y-TZP foi utilizado o sistema CieLab com o uso do Easyshade Compact® (Vita Zahnfabrik, Alemanha). Os dados de resistência (MPa) e os dados da cor foram submetidos a à análise de variância e ao teste de Tukey, ambos com α=0,05. Parte das amostras de Y-TZP (n=3) foram submetidas à difração de raio-X (DRX) para quantificação das fases cristalinas e à microscopia eletrônica de varredura (MEV) para análise da topografia superficial, enquanto uma amostra de cada grupo de cimentos foi submetido à análise de infravermelho (FTIR). A cerâmica (p=0,00), o tipo de lavagem (p=0,02) e a radiação (p=0,01) mostraram-se significantes, assim como as interações. Para resistência à flexão de 4 pontos, observou o maior valor para a YZ com lavagem em álcool isopropílico com exposição à radiação ionizante (1200,7 ± 166,2 MPa). Para coloração, os parâmetros: cerâmica (p = 0,00) e lavagem (p = 0,00) influenciaram ...

The aim of this study were to evaluate the effect of different types of washes and exposure to ionizing radiation (gamma rays), used in cancer treatments, the flexural strength of 4 points, crystalline phase transformation and color change of the polycrystalline ceramic Y- TZP; and the influence of gamma radiation on resistance to bending mini-resin cements protected with Y-TZP. 114 bars stabilized zirconia were made partially yttria - Cercon®Zirconia (DENTSPLY Ceramco, USA) and InCeram in 2000 YZ cubes (Vita Zahnfabrik, Germany) according to ISO 6872 (21 mm long x 4.5 mm wide x 1 2 mm thick) and 96 bars to mini-bending U200 RelyX (3M, Germany) and RelyX ARC (3M, Germany), divided according to the protective ceramic. Half of the samples Y-TZP and 64 samples of the cements were irradiated with 60Co gamma, in a single step of 70 Gy. Was held the flexural strength test in a universal testing machine (1 mm / min 1000 kg) and the mini-bending test (0,5 mm / min and 50 kg) and color change of the Y-TZP was used CIELAB system using the Compact® Easyshade (Vita Zahnfabrik, Germany). The strength data (MPa) and color data were submitted to the ANOVA and Tukey's test, both with α = 0.05. Part of the Y-TZP samples (n = 3) underwent-ray diffraction (XRD) for quantification of crystalline phases and scanning electron microscopy (SEM) to analysis of surface topography, while a sample from each group cement was subjected to infrared analysis (FTIR). The ceramic (p = 0.00), the type of wash (p = 0.02) and radiation (p = 0.01) and showed significant up, as well as interactions. For flexural strength of 4 points observed the largest value for the YZ washing with isopropyl alcohol and exposure to ionizing radiation (1200.7 ± 166.2 MPa). For staining, the ceramic parameters (p = 0.00) and wash (p = 0.00), as well as ceramics and washing interaction (p = 0.00) significantly influenced ΔE, ΔL, Δa and Δb. For staining the largest value is YZ washing with water the ΔE (12, 88 ± 0,90)..