Effect of the nanofilm-coated zirconia ceramic on resin cement bond strength.

Background. New surface treatments have been proposed to expand the clinical indications of zirconia prostheses. This study aimed to evaluate the effect of silica and fluorine nanofilms on zirconia ceramic on the resin cement bond strength. Methods. Zirconia blocks and discs underwent different surface treatments: untreated zirconia (CON), sandblasted, silica-coated alumina particles (30 µm) (SC), silica nanofilm (SN), and fluorine nanofilm (FN). Nanofilm deposition was performed through plasma enhanced chemical vapor deposition (PECVD). Zirconia surfaces were characterized on disks by morphology (atomic force microscopy, AFM), chemical analysis (x-ray photoelectron spectroscopy, XPS), and contact angle analysis. A silane coupling agent was applied on each treated surface, and a cylinder of resin cement was built up. Half of the specimens in each group were submitted to 6000 thermal cycles (TC). Bond strength was analyzed using the shear test, and the fractographic analysis was performed with stereomicroscopy and SEM/EDS. Statistical analysis was performed through one-way ANOVA and Tukey test in the non-aged and aged specimens. Results. Nanofilms modified the zirconia surface, which became more hydrophilic and chemically reactive. Chemical bonding between Si-O was found in SN, and FN promoted a fluorination process on the ceramic surface, converting zirconia into zirconium oxyfluoride. Specimens of the SN (TC) group failed on pre-testing. FN (TC) bond strength (3.8 MPa) was lower than SC (TC) and CON (TC) after shearing. Adhesive failure predominated in the experimental groups. Silica nanofilm failure occurred after aging. Conclusion. Silica and fluorine nanofilms deposited by PECVD did not promote effective bonding between zirconia and resin cement.

Dislodgement Resistance of Zirconia Copings Cemented onto Zirconia and Titanium Abutments.

PURPOSE: To determine the effect of the cement type and abutment material on the tensile strength required to dislodge zirconia copings. MATERIALS AND METHODS: Two experimental groups of abutments were prepared: (1) titanium abutments (n = 30) and (2) zirconia abutments (n = 30). Sixty zirconia copings (custom designed) were fabricated using 3-dimensional computer-assisted design to have a 6-mm projection above the abutment to accommodate a hole, through which a wire was inserted to attach the zirconia coping to a universal testing machine. Each abutment was placed onto an implant analog embedded in acrylic resin blocks to fit onto the universal testing machine. The zirconia copings were cemented onto the abutments with a provisional luting agent, zinc phosphate (ZP) cement, and adhesive resin cement, and after 5500 thermocycles, a tensile force was applied at a crosshead speed of 0.5 mm/min. The removal force was recorded for each specimen. Two-way analysis of variance (ANOVA) and 1-way ANOVA were used for the statistical analysis (P < 0.05). RESULTS: The mean forces necessary to remove the zirconia copings from titanium abutments were 6.52, 83.09, and 251.18 N for temporary cement, ZP cement, and resin cement, respectively. For zirconia abutments, the required forces were 17.82, 116.41, and 248.72 N. CONCLUSIONS: The abutment material had no effect on retention, but the cement type affected the retention of the zirconia copings.

Evaluation of Surface Roughness of Monolithic Zirconia after Using Different Polishing Kits

Objective: To evaluate the effect of different kits to polish monolithic zirconia on its surface roughness. Material and Methods: Five samples were fabricated using zirconia blocks. Each sintered block was divided into four areas of equal size and each area was subjected to a specific surface treatment according to the four groups of the study: GC: no surface treatment, GG: unidirectional grinding with high speed tapered bur under refrigeration, GP1: wear similar to GG followed by polishing with zirconia polishing kit Kenda at the same wear direction, and GP2: wear similar to GG followed by polishing with zirconia polishing kit Diacera at the same wear direction. Qualitative and quantitative analyses of ceramic topography and roughness were performed using a digital optical profilometer, and Roughness measurements were performed using two parameters (Ra and Rz: arithmetical mean of the absolute values of the surface departures and of the five highest peaks and valleys, respectively). Scanning electron micrographs of each ceramic surface were obtained to illustrate sample roughness. The means of each group were analyzed by 1-way ANOVA followed by Tukey's test. Results: Morphological analysis showed that polishing kits provided the same pattern of a smooth surface. To statistical analysis, this study showed that different polishing kits influenced zirconia roughness for both Ra and Rz after surface wear (p < 0.05) with both situations improved the surface roughness observed immediately after zirconia sintering. Conclusion: According to the results, both polish kits resulted in a surface texture within acceptable clinical parameters.

Aprendizagem por projeto e inovação tecnológica: união por competências / Project-based learning and technological innovation: integration by skills

Metodologias ativas de ensino focadas em promover a integração dos agentes envolvidos podem fazer a diferença no processo de ensinoaprendizagem. Na Aprendizagem Baseada em Projeto (ABP), os estudantes mobilizam capacidades cognitivas e comportamentais, apresentando melhor evolução que os obtidos pela via tradicional de ensino onde há apenas transmissão de conhecimento. Este artigo vem relatar a experiência da Universidade Potiguar no uso desta metodologia, bem como os resultados apresentados em projetos de inovação tecnológica desenvolvidos ao longo de três anos (AU).

Active teaching methodologies with focus to promote the integration of stakeholders can make a difference in teaching-learning process. In the Project Based Learning (PBL), students mobilize cognitive and behavioral skills, presenting better evolution than obtain using traditional way of teach that only transfer knowledgement. This article report the Potiguar University background in the use of PBL as well as the results presented as technological innovation projects developed over three years (AU).

The Effect of Water or Wax-based Binders on the Chemical and Morphological Characteristics of the Margin Ceramic-Framework Interface.

This study evaluated the effect of binder choice in mixing ceramic powder on the chemical and morphological features between the margin ceramic-framework interfaces. Titanium and zirconia frameworks (15 x 5 x 0.5 mm3) were veneered with margin ceramics prepared with two different binders, namely a) water/conventional or b) wax-based. For each zirconia framework material, four different margin ceramics were used: a- Creation Zi (Creation Willi Geller International); b- GC Initial Zr (GC America); Triceram (Dentaurum); and d- IPS emax (voclar Vivadent). For the titanium framework, three different margin ceramics were used: a- Creation Ti (Creation Willi Geller International); b- Triceram (Dentaurum); and c- VITA Titaniumkeramik (Vita Zahnfabrik). The chemical composition of the framework-margin ceramic interface was analyzed using Energy Dispersive X-ray Spectroscopy (EDS) and porosity level was quantified within the margin ceramic using an image program (ImageJ) from four random areas (100 x 100 pixels) on each SEM image. EDS analysis showed the presence of Carbon at the margin ceramic-framework interface in the groups where wax-based binder technique was used with the concentration being the highest for the IPS emax ZirCAD group. While IPS system (IPS ZirCAD and IPS Emax) presented higher porosity concentration using wax binder, in the other groups wax-based binder reduced the porosity of margin ceramic, except for Titanium - Triceram combination.

Síndrome da Combinação: considerações clínicas e relato de caso / The Combination Syndrome: clinical consideration and case report

Pacientes usuários de prótese total superior e prótese parcial removível inferior (Classe I de Kennedy) podem apresentar a Síndrome da Combinação ou Síndrome de Kelly. Esta síndrome caracteriza-se principalmente pela perda acentuada de suporte ósseo na região anterior da maxila, aumento das tuberosidades, hiperplasia papilar da mucosa do palato duro, extrusão dos dentes naturais anteriores inferiores e perda óssea da região posterior do arco inferior sob a base da PPR. Algumas dessas alterações merecem uma abordagem especial, pois os esforços para prevenir sua ocorrência vão nortear o planejamento reabilitador para esses casos. Este trabalho tem como objetivo demonstrar as características clínicas presentes da síndrome da combinação e apresentar uma forma de tratamento, por intermédio de um caso clínico, devolvendo ao paciente uma reabilitação protética adequada e qualidade de vida ao mesmo...

Patients with maxillary complete dentures and mandibular removable partial denture (Kennedy Class I) may present the Combination Syndrome. This syndrome is characterized mainly by severe loss of supporting bone in the anterior maxilla, increased tuberosities, papillary hyperplasia of the hard palate mucosa, extrusion of anterior lower natural teeth, and bone loss in the posterior region of the mandibular arch in the base of the RPD. Some of these changes ask for special consideration because efforts to prevent its occurrence will orient the rehabilitation planning for these cases. This paper aims to demonstrate the clinical features present in the combination syndrome and present through a case report a treatment that provide proper prosthetic rehabilitation and improve patientÆs quality of life...

Efeitos adversos em usuárias de implante contraceptivo / Adverse effects on contraceptive implant users

A gravidez indesejada continua a ser um grave problema de saúde pública em todo o mundo. Uma das explicações para a manutenção de altas taxas de gestações não planejadas relaciona-se com os efeitos adversos provocados por grande parte dos métodos contraceptivos disponíveis que levam as usuárias a descontinuar seu uso. Nos últimos anos, tem se visto um aumento nas opções de contracepção para garantir métodos mais eficazes, com maiores taxas de continuação e níveis elevados de satisfação da paciente. Entre os métodos contraceptivos de longa ação e com rápida reversibilidade, o implante é considerado um dos mais eficazes e mais seguros. Dentre os efeitos adversos relacionados com esse tipo de contracepção, estão incluídos: alterações no padrão do sangramento, cefaleia, aumento do peso, acne, mastalgia, labilidade emocional e dor abdominal. Portanto, no presente estudo, fez-se uma atualização sobre os possíveis efeitos colaterais desse contraceptivo, visando a um melhor aconselhamento pelos profissionais de saúde antes da inserção desse método, a fim de garantir melhor adesão a ele. Estudos demonstram que um aconselhamento claro antes de iniciar um método de longa duração como o implante subdérmico é imprescindível para melhorar a satisfação e a adesão ao método contraceptivo.

Unwanted pregnancy remains a serious public health problem worldwide. An explanation for keeping high rates of unplanned pregnancies is related to the adverse effects caused by most of the available contraceptive methods that lead users to discontinue its use. In recent years, it has been seen an increase in contraceptive options to ensure the most effective methods with higher continuation rates and high levels of patient satisfaction. Among the long-acting contraceptive methods with rapid reversibility, the implant is considered one of the most effective and safest ways. Among the adverse effects associated with the drug are included: changes in the pattern of bleeding, headache, weight gain, acne, breast pain, emotional lability and abdominal pain. Therefore, in our study it was made an update review on possible side effects of contraception, seeking a better counseling by health professionals before insertion in order to ensure better adherence to the method. Studies show that clear advice before starting long duration method as subdermal implant is essential to improve the satisfaction and adherence to contraception.

Evaluation of spatial and functional roughness parameters on air-abraded zirconia as a function of particle type and deposition pressure.

PURPOSE: This study evaluated the spatial and functional roughness parameters on air-abraded zirconia as a function of particle type and deposition pressure. MATERIALS AND METHODS: Polished zirconia blocks (Cercon, Degussa/Dentsply) (N=30) with dimensions of 5 × 4 × 4 mm3 were air abraded according to 2 factors: a) particle type - 30-µm silica-coated alumina (CoJet) or alumina particles (45 µm); b) deposition pressure (1.5, 2.5 and 4.5 bar). Roughness parameters (Sdr, Vi, Sci and Svi) were measured in an optical profilometer (Wyko NT 1100) at the center of the air-abraded area (301.3 × 229.2 µm). Two measurements were made for each parameter from each surface. The means of each group were analyzed by 2-way ANOVA followed by Tukey's adjustment test and Student's t-test (alpha = 0.05). RESULTS: Both the particle type (p < 0.05) and deposition pressure (p < 0.05) significantly affected the roughness parameters. Interaction terms were significant except for Sci and Svi. With the increase in pressure from 1.5 to 4.5 bar, Sdr (CoJet 1.5: 15.7 ± 0.2; CoJet 4.5: 26.6 ± 0.2; alumina 1.5: 14.7 ± 0.2; alumina 4.5: 24.4 ± 0.2) and Vi (CoJet 1.5: 0.66 ± 0.01; CoJet 4.5: 1.37 ± 0.07; alumina 1.5: 0.62 ± 0.02; alumina 4.5: 1.19 ± 0.02) parameters showed a significant increase with both alumina and CoJet particles. Mean Sci values (CoJet 1.5: 1.62 ± 0.01, CoJet 4.5: 1.49 ± 0.02; alumina 1.5: 1.6 ± 0.03; alumina 4.5: 1.42 ± 0.04) and SVi (CoJet 1.5: 0.98 ± 0.01, CoJet 4.5: 0.112 ± 0.01; alumina 1.5: 0.98 ± 0.01, alumina 4.5: 0.12 ± 0.01) decreased significantly (p < 0.05) with the increase in pressure from 1.5 to 4.5 bar. The pressure increase from 2.5 to 4.5 bar did not cause any significant difference (p > 0.05) in these parameters for either particle type. CONCLUSION: Considering roughness parameters for micromechanical retention and parameters for adsorption mechanisms of adhesion, zirconia surfaces presented better morphological features when air abraded with silica-coated alumina than alumina particles at pressures higher than 1.5 bar. Particle deposition at 2.5 bar may be preferable to 4.5 bar pressure for avoiding possible deposition-related damage on zirconia, as there were no significant differences for the functional parameters.

Degree of chronic orofacial pain associated to the practice of musical instruments in orchestra's participants.

OBJECTIVE: The practice of playing musical instruments can affect structures of the head, neck, mouth, and the masticatory system. The aim of this study was to obtain information regarding the prevalence of orofacial pain in musicians according to the type of instrument they play, by applying a specific questionnaire. MATERIALS AND METHODS: One hundred and seventeen musicians of Sao Paulo state's orchestras participated in this study. They answered an anamnesis questionnaire with 20 questions regarding their personal data, type of instrument played, hours of daily practice, and presence or absence of orofacial pain according to the Chronic Pain Grade Classification (CPGC). Musicians were divided into two groups in accordance with the risk of affecting TMJ: RG (risk group, including violin, viola, vocalist, trombone, tuba, clarinet and saxophone); CG (control group, other instruments). They received an informative brochure about the subject. Data obtained from the questionnaire were submitted to descriptive statistics, Pearson's correlation analysis and Z-test for difference between two proportions. RESULTS: The participants were from 15 to 62 years old. Pain degree showed positive correlation for reported symptoms (P = 0.002) and hour/day practice (P = 0.030). Regarding the prevalence of pain degree, data were, for RG: Grade 0 (54.5%), Grade 1 (30.3%), and Grade ≥2 (15.1%). For CG, Grade 0 (84.4%), Grade 1 (8.9%), and Grade ≥2 (6.6%). Z-test showed positive difference between groups (P = 0.0001). CONCLUSION: It was concluded that the musicians of risk group presented higher prevalence of orofacial pain than control (non-risk) group.

Heat treatment following surface silanization in rebonded tribochemical silica-coated ceramic brackets: shear bond strength analysis.

OBJECTIVE: This study aimed to evaluate the effects of heat treatment on the tribochemical silica coating and silane surface conditioning and the bond strength of rebonded alumina monocrystalline brackets. MATERIAL AND METHODS: Sixty alumina monocrystalline brackets were randomly divided according to adhesive base surface treatments (n=20): Gc, no treatment (control); Gt, tribochemical silica coating + silane application; Gh, as per Gt + post-heat treatment (air flux at 100ºC for 60 s). Brackets were bonded to the enamel premolars surface with a light-polymerized resin and stored in distilled water at 37ºC for 100 days. Additionally, half the specimens of each group were thermocycled (6,000 cycles between 5-55ºC) (TC). The specimens were submitted to the shear bond strength (SBS) test using a universal testing machine (1 mm/min). Failure mode was assessed using optical and scanning electron microscopy (SEM), together with the surface roughness (Ra) of the resin cement in the bracket using interference microscopy (IM). 2-way ANOVA and the Tukey test were used to compare the data (p>0.05). RESULTS: The strategies used to treat the bracket surface had an effect on the SBS results (p=0.0), but thermocycling did not (p=0.6974). Considering the SBS results (MPa), Gh-TC and Gc showed the highest values (27.59±6.4 and 27.18±2.9) and Gt-TC showed the lowest (8.45±6.7). For the Ra parameter, ANOVA revealed that the aging method had an effect (p=0.0157) but the surface treatments did not (p=0.458). For the thermocycled and non-thermocycled groups, Ra (µm) was 0.69±0.16 and 1.12±0.52, respectively. The most frequent failure mode exhibited was mixed failure involving the enamel-resin-bracket interfaces. CONCLUSION: Regardless of the aging method, Gh promoted similar SBS results to Gc, suggesting that rebonded ceramic brackets are a more effective strategy.

Heat treatment following surface silanization in rebonded tribochemical silica-coated ceramic brackets: shear bond strength analysis

OBJECTIVE: This study aimed to evaluate the effects of heat treatment on the tribochemical silica coating and silane surface conditioning and the bond strength of rebonded alumina monocrystalline brackets. MATERIAL AND METHODS: Sixty alumina monocrystalline brackets were randomly divided according to adhesive base surface treatments (n=20): Gc, no treatment (control); Gt, tribochemical silica coating + silane application; Gh, as per Gt + post-heat treatment (air flux at 100ºC for 60 s). Brackets were bonded to the enamel premolars surface with a light-polymerized resin and stored in distilled water at 37ºC for 100 days. Additionally, half the specimens of each group were thermocycled (6,000 cycles between 5-55ºC) (TC). The specimens were submitted to the shear bond strength (SBS) test using a universal testing machine (1 mm/min). Failure mode was assessed using optical and scanning electron microscopy (SEM), together with the surface roughness (Ra) of the resin cement in the bracket using interference microscopy (IM). 2-way ANOVA and the Tukey test were used to compare the data (p>0.05). RESULTS: The strategies used to treat the bracket surface had an effect on the SBS results (p=0.0), but thermocycling did not (p=0.6974). Considering the SBS results (MPa), Gh-TC and Gc showed the highest values (27.59±6.4 and 27.18±2.9) and Gt-TC showed the lowest (8.45±6.7). For the Ra parameter, ANOVA revealed that the aging method had an effect (p=0.0157) but the surface treatments did not (p=0.458). For the thermocycled and non-thermocycled groups, Ra (µm) was 0.69±0.16 and 1.12±0.52, respectively. The most frequent failure mode exhibited was mixed failure involving the enamel-resin-bracket interfaces. CONCLUSION: Regardless of the aging method, Gh promoted similar SBS results to Gc, suggesting that rebonded ceramic brackets are ...

Effect of diamond-like carbon thin film coated acrylic resin on candida albicans biofilm formation.

PURPOSE: The purpose of this study was to evaluate the effect of diamond-like carbon thin films doped and undoped with silver nanoparticles coating poly(methyl methacrylate) (PMMA) on Candida albicans biofilm formation. The control of biofilm formation is important to prevent oral diseases in denture users. MATERIALS AND METHODS: Forty-five PMMA disks were obtained, finished, cleaned in an ultrasonic bath, and divided into three groups: Gc, no surface coating (control group); Gdlc, coated with diamond-like carbon film; and Gag, coated with diamond-like carbon film doped with silver nanoparticles. The films were deposited using a reactive magnetron sputtering system (physical vapor deposition process). The specimens were characterized by optical profilometry, atomic force microscopy, and Rutherford backscattering spectroscopy analyses that determined differences in chemical composition and morphological structure. Following sterilization of the specimens by γ-ray irradiation, C. albicans (ATCC 18804) biofilms were formed by immersion in 2 ml of Sabouraud dextrose broth inoculated with a standardized fungal suspension. After 24 hours, the number of colony forming units (cfu) per specimen was counted. Data concerning biofilm formation were analyzed using ANOVA and the Tukey test (p < 0.05). RESULTS: C. albicans biofilm formation was significantly influenced by the films (p < 0.00001), reducing the number of cfu, while not affecting the roughness parameters (p > 0.05). The Tukey test showed no significant difference between Gdlc and Gag. Films deposited were extremely thin (∼50 nm). The silver particles presented a diameter between 60 and 120 nm and regular distribution throughout the film surface (to Gag). CONCLUSION: Diamond-like carbon films, doped or undoped with silver nanoparticles, coating the base of PMMA-based dentures could be an alternative procedure for preventing candidosis in denture users.

Effect of multiple firing and silica deposition on the zirconia-porcelain interfacial bond strength.

OBJECTIVES: To test the hypothesis that multiple firing and silica deposition on the zirconia surface influence the bond strength to porcelain. MATERIALS AND METHODS: Specimens were cut from yttria-stabilized zirconia blocks and sintered. Half of the specimens (group S) were silica coated (physical vapor deposition (PVD)) via reactive magnetron sputtering before porcelain veneering. The remaining specimens (group N) had no treatment before veneering. The contact angle before and after silica deposition was measured. Porcelain was applied on all specimens and submitted to two (N2 and S2) or three firing cycles (N3 and S3). The resulting porcelain-zirconia blocks were sectioned to obtain bar-shaped specimens with 1mm(2) of cross-sectional area. Specimens were attached to a universal testing machine and tested in tension until fracture. Fractured surfaces were examined using optical microscopy. Data were statistically analyzed using two-way ANOVA, Tukey's test (α=0.05) and Weibull analysis. RESULTS: Specimens submitted to three firing cycles (N3 and S3) showed higher mean bond strength values than specimens fired twice (N2 and S2). Mean contact angle was lower for specimens with silica layer, but it had no effect on bond strength. Most fractures initiated at porcelain-zirconia interface and propagated through the porcelain. SIGNIFICANCE: The molecular deposition of silica on the zirconia surface had no influence on bond strength to porcelain, while the number of porcelain firing cycles significantly affected the bond strength of the ceramic system, partially accepting the study hypothesis. Yet, the Weibull modulus values of S groups were significantly greater than the m values of N groups.

Métodos de caracterização de materiais para pesquisa em odontologia / Materials characterization methods in dentistry research

Esta revisão tem por finalidade esclarecer alguns pontos relevantes a respeito de algumas técnicas utilizadas em odontologia para caracterização dos materiais. Após um levantamento bibliográfico de 2006/2011 na base de dados PubMed, a microscopia eletrônica de varredura e a espectroscopia no infravermelho por transfor mada de Fourier foram as técnicas mais utilizadas para cada método de caracterização (microscopia e espectroscopia). Porém, outras técnicas têm sido utilizadas na caracterização dos materiais na pesquisa em odontologia.

Surface characterization of feldspathic ceramic using ATR FT-IR and ellipsometry after various silanization protocols.

OBJECTIVES: This study characterized the feldspathic ceramic surfaces after various silanization protocols. METHODS: Ceramic bars (2 mm × 4 mm × 10 mm) (N = 18) of feldpathic ceramic (VM7, VITA Zahnfabrik) were manufactured and finished. Before silane application, the specimens were ultrasonically cleaned in distilled water for 10 min. The ceramic specimens were randomly divided into nine groups (N = 2 per group) and were treated with different silane protocols. MPS silane (ESPE-Sil, 3M ESPE) was applied to all specimens and left to react at 20°C for 2 min (G20). After drying, the specimens were subjected to heat treatment in an oven at 38°C (G38), 79°C (G79) or 100°C (G100) for 1 min. Half of the specimens of each group were rinsed with water at 80°C for 15s (G20B, G38B, G79B, G100B). The control group (GC) received no silane. Attenuated total reflection infrared Fourier transform analysis (ATR FT-IR) was performed using a spectrometer. Thickness of silane layer was measured using a spectroscopic ellipsometer working in the λ = 632.8 nm (He-Ne laser) at 70° incidence angle. Surface roughness was evaluated using an optical profilometer. Specimens were further analyzed under the Scanning Electron Microscopy (SEM) to observe the topographic patterns. RESULTS: ATR FT-IR analysis showed changes in Si-O peaks with enlarged bands around 940 cm(-1). Ellipsometry measurements showed that all post-heat treatment actions reduced the silane film thickness (30.8-33.5 nm) compared to G20 (40 nm). The groups submitted to rinsing in hot water (B groups) showed thinner silane films (9.8-14.4 nm) than those of their corresponding groups (without washing) (30.8-40 nm). Profilometer analysis showed that heat treatments (Ra ≈ 0.10-0.19 µm; Rq ≈ 0.15-0.26 µm) provided a smoother surface than the control group (Ra ≈ 0.48 µm; Rq ≈ 0.65 µm). Similar patterns were also observed in SEM images. SIGNIFICANCE: Heat treatment after MPS silane application improved the silane layer network. Rinsing with boiling water eliminated the outmost unreacted regions of the silane yielding to thinner film thicknesses.

Extensometria – cargas axiais e não axiais sobre coroa unitária implantossuportada / Strain gauge analysis – axial and non-axial loads on the single-tooth implant-supported crown

Este estudo avaliou, in vitro, por meio da extensometria, as diferentes deformações ao redor de um implante de hexágono externo após a aplicação de carga em três pontos distintos sobre coroas unitárias, fixado em um bloco de poliuretano. Quatro extensômetros foram colados, diametralmente opostos e tangentes ao implante, na superfície do bloco para quantificar a microdeformação peri-implantar no momento da aplicação da carga. Um pilar protético esteticone foi conectado ao implante com torque de 20 Ncm. Sobre o pilar foi parafusado, a cada sessão de teste, um padrão fundido em liga de Co-Cr (n = 10) com torque de 10 Ncm, que recebeu o carregamento. A carga de 30 kg foi aplicada sobre três pontos predeterminados e os dados de microdeformação registrados com auxílio de um condicionador de sinais elétricos e do software Strain-Smart. Os resultados obtidos foram submetidos à análise estatística utilizando a Análise de Variância (Anova) e o teste de comparação múltipla de Tukey (5%). Os valores médios da microdeformação para as cargas foram: ponto A = 307,6 ponto B = 302,3 e ponto C = 669,5. Pôde-se concluir que os fatores de deslocamento centrífugo do ponto de aplicação de carga interferem significativamente na microdeformação gerada ao redor do implante.

This in vitro study evaluated microstrain levels around a single-tooth, external hexagon dental implant crown. An Estheticone abutment was connected to the implant with 20 Ncm torque, and a single crown cast in Co-Cr alloy (n=10) delivered with 10Ncm. Four strain gauges were bonded, diametrically opposed and tangential to the implant, on the surface of the polyurethane block. After, a 30Kg-load was applied at three different points (A, B, and C). Microstrain (µε) values were recorded with the aid of an electric signal conditioner and the Strain-Smart software. Statistical analyses were performed with Anova and multiple comparison Tukey´s test (5% significance level). Mean deformation values were: point A = 307.6 µε, point B = 302.3 µε, and point C = 669.5 µε. It was concluded that centrifugal displacement of the loading application point interferes significantly with microstrain levels around the dental implant.

Influence of silane heat treatment on bond strength of resin cement to a feldspathic ceramic.

This study evaluated the influence of heat treatment (HT) of the silane on the microtensile bond strength of resin cement to a feldspathic ceramic. Ceramic (VITA VM7) and composite blocks (N=32) were divided into four groups (n=6 for bond test, n=2 for SEM) at random and subject to following sequence of conditioning: G1: HF 9.6%+Silane+Panavia F2.0, G2: HF 9.6%+Silane+HT+Panavia F2.0, G3: Silane+HT+Panavia F2.0, and G4: Silane+Panavia F2.0. HT was performed in an oven (100°C, 2 minutes). G1 (17.6±2.3 MPa) and G2 (19±3.2 MPa) showed significantly higher mean bond strength than those of G3 (9.1±2.8 MPa) and G4 (10.9±1.8 MPa). SEM analysis showed exclusively mixed failures. Silane HT did not increase the bond strength.

Filmes de SiOx crescidos em substrato de Zircônia tetragonal policristalina estabilizada por ítria: influência na durabilidade da adesão a cimentos resinosos / SiOx films growth on Y-TZP: influence on adhesion to resin cements

Este estudo comparou o efeito de filmes à base de Si depositados pela técnica reactive magnetron sputtering com o uso do jateamento de partículas de alumina e a aplicação de primer na adesão de cimentos resinoso a superfície de zircônia. Blocos de zirconia (N=300) (4,5¡¿4,5)mm foram sinterizados e regularizados com lixas de SiC (1200), sonicamente limpos com água destilada por 10 min e randomicamente divididos em 30 grupos (n=10) de acordo com 3 parâmetros: 1- cimento resinoso (Panavia/Kuraray; Multilink/Ivoclar; RelyX U100/3M); 2- tratamento de superfície (sem tratamento controle, Metal/Zirconia Primer, jateamento com partículas +Metal/Zirconia Primer, Filme A + Monobond S; Filme B + MonobondS); 3- termociclagem (TC). Parâmetros de rugosidade da superfície (Ra, Rz, Sdr) foram avaliados por Microscopia de Interferência e Microscopia Eletrônica de Varredura (MEV). Cilindros de cimento resinoso foram construídos (¨ª: 2,4 mm; altura: 2 mm) sobre asuperfície de zirconia. O ensaio de resistência adesiva ao cisalhamento foi realizado no momento inicial (24 h) e após a termociclagem (5o-55 oC, 6.000 ciclos) utilizando máquina de ensaio universal (1 mm/min). As superfícies fraturadas foram analisadas por microscopia ótica (30¡¿) e MEV (100¡¿ e 2000¡¿) para categorizar o modo de falha. Adicionais blocos de zirconia (15¡¿15)mm confeccionados para análises por Espectroscopia por Retroespalhamento de Rutheford (RBS), e Trabalho de Adesão (WA) após os tratamentos de superfície. Os dados foram estatisticamente analisados por Anova 3-fatores e teste Tukey (5%). Fotomicrografias revelaram microdefeitos nos filmes. Os resultados de Wa mostraram que os filmes melhoraram a molhabilidade da superfície. As análises por RBS mostraram que a concentração elementar dos filmes variou de acordo com os parâmetros de deposição utilizados nessa pesquisa. O tratamento por jateamento de partículas produzio os maiores valores para os diferentes parâmetros de rugosidade diferentes...

This study compared the effectjavascript:void(Set_Locked(0,'GRAVA REGISTRO/COMPLEMENTO.x')) of si-based nanofilm deposition usingreactive magnetron sputtering to application of air-abrasion (aluminaparticles) and zirconia primers on the adhesion of resin cements to zirconia. Zirconia (Nblocks=300) (4.5 mm ¡¿ 3.5 mm ¡¿ 4.5 mm) were sintered, ground finished to 1200 SiC paper and cleaned ultrasonically in distilled water for 10 min. The blocks were randomlydivided into 30 groups (n=10) according to 3 testing parameters: 1-Resin Cements (Panavia/Kuraray; Multilink/Ivoclar; RelyX U100/3M); 2- Surface conditioning (no conditioning-control, Metal/Zirconia Primer, air-abrasion + Metal/Zirconia Primer, Sibased film A + Monobond S; Si-based film B + Monobond S); 3- Aging (with and without). Surface roughness parameters (Ra, Rz, Sdr) before and after surface conditioning were evaluated using interference microscopy (IM). Rutheford Backscattering Spectroscopy (RBS), Scanning Electron Microscopy (SEM), and Work of Adhesion(WA) analyses were performed after surface treatments. Resin cementswere incrementally built up (¨ª: 2.4 mm; height: 4 mm) on the zirconia surfaces. Bonded specimens were then thermocycled (5o-55oC, 6,000 cycles). Shear bond strength (SBS) was performed using the Universal Testing Machine (1 mm/min). After fracture, the surfaces were analyzed using an optical microscopy (30 ¡¿), SEM (100 ¡¿ and 2000 ¡¿) to categorize the failure modes. The data were statistically evaluated using 3-way ANOVA and Tukey's test (5%). Scanning Electron Microscopy showed micro defects on Si-based nanofilms surface. The result to Wa showed that surface coated with Si-based nanofilms improved wetability when compared to the other surface treatments. RBS analysis showed that was produced films with different chemical elemental concentration. While air-abraded zirconia surfaces presented the highest roughness parameters (Ra: 0.57 nm ¡¾ 0.1, Rz: 6.2 ¥ìm ¡¾ 0.2, Sdr: 80.4% ¡¾ 4.9), non-conditioned....

Efeito da desinfecção associada à escovação na rugosidade superficial de resina acrílica termopolimerizável / Effect of disinfection associated to brushing on surface roughness of heat-polymerized acrylic resin

O objetivo desse estudo é avaliar o efeito da desinfecção associada à escovação na rugosidade (Ra e Rz) superficial de resina acrílica termopolimerizável. Cinquenta cilindros de resina acrílica (Lucitone 550 Dentsply) de dimensões 0,5 mm x 0,5 mm foram confeccionados, utilizando-se o ciclo térmico curto de polimerização (73°C por 90 min, seguidos por imersão em água a 94°C durante 30 min), de acordo com as instruções do fabricante. Os espécimes termopolimerizados foram imersos em água destilada a 37 ±1°C por 48 horas e divididos em 5 grupos (n=10) de acordo com o método de desinfecção: GrControle- sem desinfecção e sem escovação; Gr1-água destilada seguido de escovação; Gr2- hipoclorito de Sódio 1% seguido de escovação; Gr3- gluconato de clorexidina 2% seguido de escovação, e G4- perborato de sódio a 3,78% seguido de escovação. Os grupos foram imersos por 5 min nas soluções correspondentes antes do ciclo de escovação (10.000 ciclos). Foram analisados em rugosímetro de contato os valores para Ra e Rz. Os resultados foram analisados estatisticamente pelo método ANOVA e as médias comparadas pelo teste de Tukey (α=0,05). As médias obtidas para o Ra e Rz respectivamente foram: Gr controle 0,16 (0,03) e 0,77 (0,21); Gr1 0,3 (0,13) e 1,25 (0,62); Gr2 0,24(0,09) e 1,02 (0,4); Gr3 0,34 (0,14) e 1,45(0,55); Gr4 0,38(0,14) e 1,7(0,65). O teste ANOVA revelou que a rugosidade para os dois parâmetros foi significativamente afetada pela abrasão provocada pela escovação com dentifrício (PRa=0,0009; PRz=0,0021). Pode-se concluir que a escovação associada à desinfecção com hipoclorito de sódio produziu menor efeito sobre a rugosidade da superfície da resina acrílica que os demais desinfetantes testados.

The aim of this study was to evaluate the effect of disinfection associated to brushing the superficial crease (Ra and Rz) of heat-polymerized acrylic resin. Fifty cylinders of 0.5mm x o.5mm acrylic resin (Lucitone 550 Dentsply) were produced by using the short thermal cycle of polymerization (73ºC for 90 minutes and then immersion on water at the temperature of 94ºC for 30 minutes), according to the manufacturer’s instructions. The thermo-polymerized samples were immersed in distilled water at the temperature of 37ºC (plus or minus 1ºC) for 48 hours and divided into 5 groups (n=10) according to the disinfection method, that is: GrControl – no chemical disinfection nor brushing; Gr1 – distilled water and brushing; Gr2 – sodium hypoclorite 1% and brushing; Gr3 – chlorexidine gluconate 2% and brushing and G4 – sodium perborate 3,78% and brushing. The groups were immersed for 5 minutes before brushing cycle (10.000 cycles) and the values for Ra and Rz were analyzed with crease contact measuring instrument(contact profilometer). Results were statistically analyzed by the ANOVA method. The arithmetic means were compared by the Tukey test (ά=0.05). RESULTS: The arithmetic means obtained for Ra and Rz were : GrControl 0.16(0.03) and 0.77 (0.21); Gr1 0.3(0.13) and 1.25(0.62); Gr2 0.24(0.09) and 1.02(0.4); Gr3 0.34(0.14) and 1.45(0.55); Gr4 0.38(0.14) and 1.7(0.65) . The ANOVA test revealed that the roughness for the two parameters was significantly affected by brushing with toothpaste (PRa =0.0009; PRz=0.0021) .Tooth brushing together with sodium hypoclorite results in a lessened effect over the surface crease of the acrylic resin than other tested disinfectants

Pilar de zircônia em implante unitário imediato anterior / Zirconia abutment for single-tooth immediate implant restoration: a case report

Com a crescente busca pela estética, uma integração final invisível entre tecido, implante e coroa tem sido um dos principais desafios da Implantodontia atual. Uma alternativa recente é a utilização do pilar protético de zircônia, que permite ao cirurgião-dentista realizar reabilitações protéticas totalmente cerâmicas, pilar protético e coroa, combinando fatores como resistência, excelente estética e satisfação do paciente. Este artigo relata um caso clínico na região anterossuperior, envolvendo o dente 22, no qual uma fratura radicular inviabilizou a manutenção do dente na arcada dentária. O tratamento reabilitador consistiu na realização da cirurgia de extração do dente 22 e de colocação de implante imediato, seguido de instalação de coroa provisória imediata na região. Em seguida, o tratamento protético foi realizado por meio da confecção de coroa unitária implantossuportada sobre pilar de zircônia, utilizando-se o sistema In-ceram Alumina. Clinicamente, observou-se que o uso do pilar de zircônia associado a coroa também livre de metal permitiu ao cirurgião-dentista alcançar o resultado estético e funcional desejado, com perfeita integração entre tecido gengival e coroa, além de adequada performance mecânica. Além disso, pode-se constatar que em condições clínicas favoráveis a instalação de implante imediato, seguida de instalação de coroa provisória imediata, representa uma opção de tratamento viável.

With the increasing quest for aesthetics, a perfect integration between tissue, dental implant, and restorations have been the challenge of current Implant Dentistry. An alternative is the use of high-strength ceramic abutments, such as zirconia, which combines factors such as resistance and aesthetics. This article reports a clinical case in where an anterior tooth loss was reestablished with an immediate implant, followed by immediate temporary implant-supported zirconia abutment, using the In-Ceram alumina system. The authors observed that treatment with zirconia abutment provided the desired functional and aesthetic outcomes.