Aspectos relacionados a procedimentos restauradores em odontopediatria

O objetivo deste texto foi realizar uma revisão crítica de trabalhos realizados após o doutoramento do autor, de parte de uma linha de pesquisa focalizada na dentística em odontopediatria. Desta forma, foram revisados artigos referentes a alguns procedimentos realizados na prática da odontologia restauradora, envolvendo estudos de microinfiltração, onde foi avaliada a influência de técnicas e materiais restauradores sobre este fenômeno. Outros trabalhos revisados relacionaram-se ao uso do microscópio eletrônico de varredura. Neste caso, foram descritos estudos que avaliaram aspectos micromorfológicos das estruturas dentárias (esmalte e dentina) de dentes permanentes, mas principalmente decíduos. Foram observados os efeitos de diferentes tratamentos realizados sobre as estruturas dentárias, como a ação de agentes condicionadores e métodos de desgaste das estruturas dentárias (laser, abrasão a ar, instrumentos cortantes rotatórios e ponta CVD). Também foram apresentados os trabalhos que avaliaram a interface adesiva, após diferentes tratamentos da dentina. Finalmente foram realizados comentários sobre os trabalhos revisados e apresentadas as tendências futuras desta linha de pesquisa.

Avaliação in vitro da adaptação cervical de coroas totais metálicas, variando os preparos dos términos cervicais, aliviando ou não as superfícies internas das coroas e empregando diferentes cimentos definitivos

Este trabalho avaliou a qualidade das adaptações cervicais de coroas totais metálicas, tendo como fonte de variação: a) o término do ombro cervical do preparo - biselado, inclinado em 1350; reto em 900, chanfro e gume de faca; b) o alívio ou não das superfícies internas das coroas; e, c) os tipos de agente de cimentação permanente, cimentos - fosfato de zinco Harvard; ionômero de vidro Ketac-Cem, policarboxilato de zinco Durelon e resinoso Panavia Ex. Inicialmente, foram confeccionados corpos-de-prova em modelos-padrão de aço inoxidável usinado, de acordo com o tipo de preparo dos términos cervicais experimentais. As cápsulas metálicas de aço inoxidável preparadas, tendo ou não alívio da superfície interna de 30 micrometros até a distância de 0,5 mm do limite do término cervical, justapunham-se precisamente e formavam um conjunto com adaptação e assentamento exatos. Estas foram cimentadas nos corpos-de-prova com os diferentes agentes cimentantes, os quais foram manipulados de acordo com as instruções dos fabricantes. Desenvolveram-se metodologias de reaproveitamento dos corpos-de-prova, estabilidade das cápsulas impedindo seu deslocamento durante a tomada das medidas e mensuração precisa. Concluiu-se que: a) as melhores médias de adaptações cervicais, semelhantes entre si, foram obtidas em modelos-padrão com ombros: lâmina de faca, ombro inclinado em 1350 e chanfro; b) as piores médias de adaptações cervicais, semelhantes entre si, foram obtidas em modelos-padrão com ombros reto em 900 e degrau em 900 com bisel de 450; c) houve melhora significativa na adaptação quando cápsulas metálicas foram cimentadas com alívio de sua superfície interna; d) os cimentos...(Resumo completo, clicar acesso eletrônico abaixo)

Avaliação do tempo e da concentração do condicionamento com ácido fluorídrico sobre a resistência de união entre cerâmica e cimento resinoso

The aim of this study was to verify through microtensile test the influence of time and concentration of surface conditioning with hydrofluoric acid and its interference in the adhesion of dual resin cement to porcelain.We used 32 bodies of glass-ceramic lithium disilicate system IPS e.max Press LT with dimensions of 6mm thick, 8 mm in length and 8 mm in length, which will be molded to obtain composite resin blocks corresponding to blocks ceramics. Ceramic and resin blocks were divided into 16 groups (n = 4) and numbered according to the concentration of hydrofluoric acid (2.5%, 5%, 7.5% and 10%) and conditioning time (20 seconds, 40 seconds, 1 minute and 2 minutes). The blocks were cleaned in ultrasonic apparatus with distilled water and dried with compressed air, subjected to acid etching and air-jet washed with water, dried with compressed air and received application of silane agent Monobond-S, followed by adhesive Excite ( Ivoclar Vivaden). Each ceramic block was bonded to the corresponding block of resin through the resin cement Multilink Automix. The specimens were cut to obtain nine micro samples for each set of ceramic-resin with 1 mm X 1 mm X 12 mm in length, which were submitted to microtensile test. The results were analyzed with descriptive statistics and analysis of variance with significance level of 5%, revealing that there were statistically significant (p = 0.000001 <0.05). From the Tukey test can be concluded that etching with hydrofluoric acid and 2.5% for 120 seconds gave the best bond strength, however, no statistical difference between the conditioning with the same acid in the concentration of 5.0% for 20 to 40 seconds

Fácies, diagênese e arquitetura estratigráfica de reservatórios deltaico-lacustres da fase rifte (formação pendência), campo Serraria da Bacia Potiguar

Of the four lacustrine deltaic models, which were found in the Pendência formation, two are represented in the Serraria field. Respectively the deltaic models 1 and 3 shows the reservoir zones A and B. The Zone A is divided into six sub-areas. Each is representing a smaller cycle of development of sigmoidal lobes of deltaic front. Zone B produces in reservoirs of Model 3, or so called Full delta. The Zone B is formed by overlapping the deltaic plain system over the deltaic/prodeltaic front (model 1). This work uses the method of zooming with the aim to contextualize the geometric aspects of the sand bodies, highlighting the analysis of facies and diagenesis with help of pictures and testimonies of thin sections. The sigmoidal lobes of Zone A are fine to very fine sandstones, well sorted, with a arcosian composition.;practically with a weak compaction and cementation of a kind of film of clay (if very fine) and overgrowth feldspar (fine texture). This silicate phases are succeeded by cementation of poiquilotópica calcite, and after this a stage of dissolution, containing only regular permoporosity for this reservoir. Zone B has a combination of two types of deltaic plain reservoir. One is the rarest of distributary channel and the other the most common of lobes of crevasse. In the channel coarse to medium-grained and poor to moderate sorted sandstones are formed (tuning up), and with a lytic arcosiana nature. Rarely there are cements, including growth of feldspar and rhombohedral dolomite, which prevent a high permoporosity of the reservoir. In the crevasse lobes, the sandstones are laminated, fine and well sorted, arkosic, rarely with overgrowth feldspar and calcite poiquilotópica, and with a good intergranular permoporosity

Avaliação mecânica da colagem estrutural entre compósitos poliméricos e materiais metálicos utilizados em dutos petroquímicos

The development of technology for structural composites has as one of its ends form a set of materials that combine high values of mechanical strength and stiffness and low density. Today, companies like Embraer and PETROBRAS and research institutions like NASA, working with these materials with recognized advantages in terms of weight gain, increased performance and low corrosion. We have developed a systematic study to determine the bond strength between composite carbon fiber / epoxy and fiberglass / epoxy laminate both bonded to a carbon steel which are widely used in the petrochemical industry and repair. For morphological evaluation and bonding between materials of different natures, ultrasound analysis, optical microscopy and stereoscopy were performed. To simulate actual conditions, the composites were subjected to conditioning by using heat shock temperatures from -50 to 80 ° C for 1000 cycles for composite carbon fiber / epoxy composites and 2000 cycles for fiberglass / epoxy . The use of composites studied here proved to be efficient to perform repairs in metallic pipes with application petrochemical, as when exposed to sudden changes of temperature (-50 ° to 80 ° C) cycling at 1000 to 2000 times, its mechanical properties (shear and tensile) practically do not change

Efeito do tratamento da superfície dental com os lasers Nd:YAG e Er: Yag na adesão da resina composta à dentina recém clareada

To evaluate the effect of surface treatment with Er:YAG and Nd:YAG laser on resin composite bond strength to recently bleached dentin. Material and Methods: In this study 120 bovine incisors were used and distributed into two groups: Group C: without bleaching treatment; Group B: with bleaching treatment (35% hydrogen peroxide). Each group was divided into three subgroups: Subgroup N: without laser treatment; Subgroup Nd: irradiation with Nd:YAG laser; Subgroup Er: irradiation with Er:YAG laser. Next, the adhesive system (Adper Single Bond 2) was applied and composite buildups were constructed with Z350 composite. The teeth were sectioned to obtain dentin-resin sticks (1x1mm) and analyzed by microtensile bond testing. The data were statistically analyzed by the ANOVA and Tukey tests. Results: The results showed that the bond strength values in the bleached control group (16.17 MPa) presented no significant difference in comparison with the group bleached and irradiated with Er:YAG laser (14.69 MPa). The non bleached control group (26.79 MPa) presented significant difference in bond strength when compared with the non bleached group irradiated with Er:YAG laser (22.82 MPa) and with the group treated by bleaching and irradiation with Nd:YAG laser (28,792 MPa). The group without bleaching treatment and irradiated with Nd:YAG (36.1 MPa) presented a significant increase in bond strength in comparison with the other groups. Conclusion: The use of Nd:YAG laser on bleached specimens was able of completely reversing the immediate effects of bleaching, obtaining bond strength values similar to those of the control group

Estudo clínico longitudinal de dentes restaurados com sistemas cerâmicos livres de metal: estudo prospectivo sobre a hipersensibilidade dental pós-operatória

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 da limpeza pós-condicionamento e do tratamento térmico do silano na resistência de união de um cimento resinoso à cerâmica

Pós-graduação em Odontologia - FOA

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

Coquinas eoaptianas do sudoeste da Bacia de Campos: fácies deposicionais, eventos diagenéticos e fatores controladores da qualdade do reservatório

Pós-graduação em Geologia Regional - IGCE

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

Pós-graduação em Odontologia Restauradora - ICT

Influência da superfície dentinária bovina na resistência de união de sistemas adesivos

Pós-graduação em Odontologia Restauradora - ICT

Efeito do tipo de adesivo e do seu mecanismo de ativação, assim como da viscosidade da resina composta, na resistência de união à dentina antes e após envelhecimento artificial

Pós-graduação em Odontologia Restauradora - ICT

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.