Caracterização de superfície, adesiva e mecânica de uma zircônia parcialmente estabilizada por ítria em função da partícula ou do momento do jateamento

Pós-graduação em Reabilitação Oral - FOAR

Estrutura do esmalte humano e sua interface com sistemas adesivos

Esta tese sistematiza uma série de estudos dedicados à compreensão da interface do esmalte e sistemas adesivos. Para tanto, a estrutura da camada aprismática do esmalte em alta resolução pela microscopia eletrônica de varredura foi avaliada quanto a sua continuidade, espessura, distribuição nas faces coronárias e em fossas e fissuras, predominantemente em dentes decíduos não erupcionados. Foi também analisado pela microscopia eletrônica de varredura os efeitos do condicionamento de diferentes tipos de ácido e, em especial, do ácido fosfórico em diferentes concentrações, metodologias e tempos de aplicação. Estes trabalhos permitiram visualizar as principais ações ácidas desmineralizantes e os tipos de retenções no centro ou periferias dos prismas ou em ambas as regiões, bem como a profundidade e forma dos “tags” resinosos com carga e sem carga na intimidade do esmalte. No caso particular da aplicação dos selantes em fossas e fissuras foi também avaliada comparativamente a eficácia das técnicas invasivas ou não invasivas. Os últimos experimentos foram dedicados ao estudo da microinfiltração de diferentes sistemas adesivos e da resistência destes sistemas adesivos na estrutura do esmalte. Novos estudos merecem dar continuidade à linha de pesquisa de sempre priorizando o propósito de vincular os procedimentos aplicados com uma consistente e indispensável fundamentação de pesquisa básica no interesse da clínica odontopediátrica.

Histometric analysis and topographic characterization of cp Ti implants with surfaces modified by laser with and without silica deposition

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of surface treatment on the bond strength between yttria partially stabilized zirconia ceramics and resin cement

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of Decomposition Procedure to Determine Ba, Co, Cr, Cu, Ni, Mn, V, and Zn Total Content in Soil Samples

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Resistência de união de cimentos resinosos em superfície de cerâmica de Y-TZP após aplicação de filme vitrocerâmico

Pós-graduação em Odontologia Restauradora - ICT

Efeito de protocolos de cimentação na carga de fratura para uma cerâmica de dissilicato de lítio

Pós-graduação em Odontologia Restauradora - ICT

Caracterização de uma cerâmica 3Y-TZP e avaliação do efeito de tratamentos de superfície na adesão da cerâmica ao glaze ou cimento resinoso

Pós-graduação em Odontologia Restauradora - ICT

Efeito do tratamento térmico em cerâmica feldspáticas silanizada na adesão do cimento resinoso

Pós-graduação em Odontologia Restauradora - ICT

Effect of time between adhesive application and photoactivation on adhesion and collagen exposure

Fundacao de Amparo a Pesquisa do Estado de sao Paulo (FAPESP)

Variáveis que afetam o procedimento de colagem direta ortodôntica: braquetes e materiais adesivos

Following the introduction of the acid-etching technique in enamel surface, direct attachment of orthodontic appliances on the surface of the tooth and/or restorations became a routine procedure in the assembly of the fixed devices. The attainment of a success result is related to the criterion attention to the details and the steps of the bonding technique, as well as, to the knowledge of the characteristics of the adhesive materials and orthodontic brackets. This paper presents some aspects of various types of brackets and adhesives materials.

Immediate human pulp response to ethanol-wet bonding technique

To evaluate the short-term response of human pulps to ethanol-wet bonding technique. Methods Deep class V cavities were prepared on 17 sound premolars and divided into three groups. After acid-etching, the cavities from groups 1 (G1) and 2 (G2) were filled with 100% ethanol or distilled water, respectively, for 60 s before the application of Single Bond 2. In group 3 (G3, control), the cavity floor was lined with calcium hydroxide before etching and bonding. All cavities were restored with resin composite. Two teeth were used as intact control. The teeth were extracted 48 h after the clinical procedures. From each tooth serial sections were obtained and stained with haematoxylin and eosin (H/E) and Masson's trichrome. Bacteria microleakage was assessed using Brown & Brenn. All sections were blindly evaluated for five histological features. Results Mean remaining dentine thickness was 463 ± 65 μm (G1); 425 ± 184 μm (G2); and 348 ± 194 μm (G3). Similar pulp reactions followed ethanol- or water-wet bonding techniques. Slight inflammatory responses and disruption of the odontoblast layer related to the cavity floor were seen in all groups. Stained bacteria were not detected in any cavities. Normal pulp tissue was observed in G3 except for one case. Conclusions After 48 h, ethanol-wet bonding does not increase pulpal damage compared to water-wet bonding technique. Clinical significance Ethanol-wet bonding may increase resin-dentine bond durability. This study reported the in vivo response of human pulp tissue when 100% ethanol was applied previously to an etch-and-rinse simplified adhesive system.

Influência da clorexidina na capacidade de umectabilidade da dentina hígida e afetada por cárie por um sistema adesivo

To evaluate the effect of chlorhexidine (CHX) on the wettability of sound and caries affected dentin by a simplified adhesive system. Material and Methods: Flat coronal dentin surfaces were produced on 60 sound molars, 30 of which were artificially decayed. The teeth were divided randomly into 3 groups (n = 10) with smear layer (SL), without SL impregnated with water and without SL impregnated with chlorhexidine. The SL removal was performed by phosphoric acid etching for 15 s. 20 uL of distilled water or 2% chlorhexidine digluconate were applied on the demineralized dentin for 60 s. Then, a drop of Single Bond 2 was deposited on each surface. Contact angles between dentin surface and adhesive was measured by means of a goniometer and data were submitted to ANOVA and Tukey tests (α = 0.05). Results: Higher contact angles were obtained on sound versus caries affected dentin (p <0.05), regardeless of the surface treatment. For both substrates, contact angles statistically higher were obtained for dentin covered with SL (P <0.05). The SL removal resulted in significant reduction of the angles (P <0.05) and no difference was found among angles produced on demineralized dentin impregnated with water or chlorhexidine (p> 0.05). Conclusion: Caries affected dentin wettability was higher than sound dentin and that characteristic was not influenced by chlorhexidine application.

Bone apposition and surface treatment in dental implants: histomorphometric pilot evaluation in rabbits

The surface of dental implants is an important factor for osseointegration process and different methods of surface treatment have been described. Objective: To investigate the bone apposition in implant surface treated with sandblasting and acid-etching. Material and methods: Ten rabbits were selected and received one implant treated with method I in the left tibia and one implant treated with method II in the right tibia. Then, twenty implants were divided in two groups, according to methods of sandblasting and acid-etching (method I and method II). After 7, 14, 30, 45 and 60 days, tibias were retrieved and submitted to histotechnical procedures. The percentages of bone–implant contact (BIC) and bone area between threads (BABT) were determined throughout histomorphometric analysis and bone apposition was detected in implants of both groups. Results: In BABT measurements, an increase was observed after 45 and 60 days in the method II, compared to method I and no differences were found after 7, 14 and 30 days. In BIC measurements, an increase was detected with method II at 45 days when compared to method I. No differences between groups in BIC values were observed after 7, 14, 30 and 60 days. Conclusion: Our data demonstrated that implants treated with the method II presented increase in the contact between bone and implant after 45 days compared to method I. Moreover, with concern to bone area between threads, it was observed an increased in the method II after 45 and 60 days. However, both groups can be successfully used as a therapeutic strategy to rehabilitation of edentulous patients. Then, further experiments are needed to evaluate, in depth, the putative differential role of each surface treatment.

Efeito de um gel de peróxido de carbamida a 10% sobre a resistência de união de restaurações adesivas à dentina

The present study aimed to analyze the effects of tooth bleaching with 10% carbamide peroxide (CP) gel on the bond strength of resin composite restorations to dentin. Material and Methods: Twenty cavities were prepared on the buccal surface of bovine teeth. After acid etching and application of bonding agent on dentin and enamel, the cavities were restored with composite resin. The specimens were divided into groups according to treatment on the surface of enamel / restoration: G1 - control (no treatment) and G2 (10% PC gel application for 8h/day during 14 days). After this period, the teeth were cut to produce beams with 0.81 mm2 cross-sectional area, which were subjected to microtensile test. The fractures were examined with a stereomicroscope and classified as cohesive in resin or dentin, adhesive, or mixed. Results: The statistical analysis (ANOVA / χ2) revealed that the factor treatment interfered with the bond strength, which was significantly higher for specimens of G2 (p <0.05). Adhesive fractures occurred in most of specimens of both groups with values ranging from 48.3% to 75%. Mixed fractures were the second more frequent in G1 and cohesive resin failure in G2. Conclusion: It was concluded that tooth bleaching with 10% of PC increased the bond strength of adhesive restorations to dentin.