Reparo apical e periapical em dentes de cães pós tratamento endodôntico em função do curativo de demora e de um novo cimento obturador. Importância do curativo de demora e do cimento obturador na infiltração apical in vitro

Pós-graduação em Odontologia - FOAR

Revestimento de sementes de milho superdoce

Pós-graduação em Agronomia - FCAV

Resistência á fratura de diferentes selamentos de orifício de acesso ao parafuso de fiação e da porcela de cobertura de restaurações metalo-cerâmicas parafusadas implantossuportadas

Pós-graduação em Reabilitação Oral - FOAR

Reimplante dentário após o preenchimento do canal com pasta de β-glicerofosfato de cálcio ou pasta de hidróxido de cálcio + MTA estudo histomorfométrico em ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of calcium hydroxide addition on the physical and chemical properties of a calcium silicate-based sealer

Recently, various calcium silicate-based sealers have been introduced for use in root canal filling. The MTA Fillapex is one of these sealers, but some of its physicochemical properties are not in accordance with the ISO requirements. Objective: The aim of this study was to evaluate the flowability, pH level and calcium release of pure MTA Fillapex (MTAF) or containing 5% (MTAF5) or 10% (MTAF10) calcium hydroxide (CH), in weight, in comparison with AH Plus sealer. Material and Methods: The flowability test was performed according to the ISO 6876: 2001 requirements. For the pH level and calcium ion release analyses, the sealers were placed individually (n=10) in plastic tubes and immersed in deionized water. After 24 hours, 7 and 14 days, the water in which each specimen had been immersed was evaluated to determine the pH level changes and calcium released. Flowability, pH level and calcium release data were analyzed statistically by the ANOVA test (alpha=5%). Results: In relation to flowability: MTAF>AH Plus>MTAF5>MTAF10. In relation to the pH level, for 24 h: MTAF5=MTAF10=MTAF>AH Plus; for 7 and 14 days: MTAF5=MTAF10>MTAF>AH Plus. For the calcium release, for all periods: MTAF>MTAF5=MTAF10>AH Plus. Conclusions: The addition of 5% CH to the MTA Fillapex (in weight) is an alternative to reduce the high flowability presented by the sealer, without interfering in its alkalization potential.

Influência da reinstrumentação do degrau apical radicular após o posicionamento primário do cone principal de guta-percha noselamento apical

The aim of this study was to evaluate in vitro the apical leakage after the apical re-preparation and replacement of the principal gutta-percha point plus endodontic sealer (Sealer 26TM). Sixty extracted human canines were prepared by using a step back technique up to size 50 K type file apically. At each change of instrument the canals were irrigated with distilled water. After that step, the external surface roots were coated and subdivided into six groups with ten roots each: I – single gutta percha point technique; II – lateral condensation and III – hybrid technique. The IV, V and VI groups were similar to others groups but after to place the principal gutta percha point, it was removed, re-prepared up to size 60K file and in sequence replaced the principal gutta percha point and the root canal filling finished. The specimens were immersed in 2% Rhodamine BTM for 7 days at 37 oC. The apical leakage was measured by Image ToolsTM program. With Kruskal Wallis test statistical analysis showed that there was no significant difference between the techniques (p > 0.05).

Resolução por retratamento não cirúrgico de dente com lesão periapical: relato de caso clínico

The development and maintenance of periapical lesion occurs as a result of bacterial infection of the root canal system. Faced with the failure of endodontic treatment, retreatment is the first option with great potential for success, when performed with proper disinfection of the root canal system. Case report: Patient aged 39 years needing dental care show at clinical examination moderate gingival bleeding in the region of tooth 22 and the presence of radiographic periapical bone rarefaction due to unsatisfactory endodontic treatment. It was indicated the endodontic retreatment. We performed procedures to remove the filling material, root canal preparation using manual and mechanical techniques and completion with the use of root canal medication based on calcium hydroxide. After root canal filling, clinical and radiographic success were demonstrated for the case. Conclusion: We conclude that the non-surgical retreatment with disinfection and proper use of medication to the base of calcium hydroxide promoted success after outcome monitoring for 2 years and 8 months (AU)

Desenvolvimento, implantação e avaliação do desempenho de biorreator anaeróbico de leito fluidizado e leito fixo com filtros biológicos em materiais diversos

This study aimed to develop, implement and evaluate the performance of a new type of bioreactor for anaerobic treatment of wastewater using different filling materials like trickling filters post-reactor. This bioreactor has mixed characteristics of the UASB reactors and horizontal flow from the point of view of removal of BOD (Biochemical Oxygen Demand) ssed (settled solids), TS (Total Solids), SS (Suspended Solid), SD (Dissolved Solids) and turbidity. The experimental model consists of a bioreactor with a volume of 12 m³, 2/3 filled by fluidized bed and 1/3 for fixed. The fluidized bed is made of polystyrene plates used as a system percolation and compartmentalized trickling filters, where each compartment was filled with a support medium with different characteristics (gravel number 4, plastic rings of polystyrene, PET and HDPE) . In addition, the output of a filter system was installed three entries filled with activated carbon. The bioreactor was installed in private residence in the city of Igarapava-SP (20° 02'40.18"S and 47° 45'01.36" W). The system was highly efficient as the removal of organic contaminant load 92% on average reducing the BOD, a significant result when compared to other anaerobic systems. For the other parameters, the mean reduction was 96% for turbidity, 99% ssed, 67.5% ST, 57% SD and 88% of SS. As for its operation the system was capable of operating in continuous flow without the need for maintenance during the entire period of evaluation and without energy, as it operates taking advantage of the natural slope of the terrain where it is installed. The environmental impacts were minimized due to the preservation of local vegetation allowing the ecosystem to remain unchanged beyond the prototype was completely sealed preventing exhalation of odors and therefore not causing inconvenience to neighboring populations. Given these facts it was concluded that the prototype is shown to be highly feasible deployed as a new alternative for treatment of sewage in rural and urban settings (individual homes, condos, farms, ranches, etc.) Due to ease of design and operability, and sustainability at all stages of execution.

Biological compatibility of some types of endodontic calcium hydroxide and glass ionomer cements

The purpose of this work was to evaluate the biological compatibility of the Sealapex, Apexit, Sealer 26 and Ketac Endo endodontic cements. Polyethylene tubes containing these cements were implanted in the subcutaneous tissue of 40 (forty) rats. The animals were sacrificed after 14 and 90 days. A descriptive analysis of the reactions found in the connective tissue by contact with the cements was performed. The magnitude of inflammatory infiltrate, the presence and predominance of cell types and their distribution as to the filling material and reparative phenomena, such as fibroblastic and angioblastic proliferation and formation of fibrous capsules, were subjectively measured. After 90 days, all cements presented statistically significant reduction of the inflammatory reaction, presence of a fibrous tissue capsule in contact with the opening of the tubes containing the filling materials, and reduction of fibroblastic proliferation. Angioblastic proliferation decreased only for the Sealer 26 and Ketac Endo groups. All cements tested were either partially or totally phagocyted, and the mildest inflammatory response was found for the Sealer 26 group at both evaluation periods.

Avaliação clínica e radiográfica de pacientes submetidos ao levantamento da membrana do seio maxilar

Implant dentistry is a dental specialty which presents great predictability in the rehabilitation at posterior, partially edentulous maxillary areas. Early tooth loss results in significant jaw remodeling. The maxillary sinus lifting followed by implant placement is a predictable technique initially described in 1980. Since then, several different techniques have been investigated varying filling materials and the management of complications in order to provide effective guidance in the rehabilitation of these patients. The current study evaluated ten patients who underwent sinus lifting before implant placement and crown installation. First, a retrospective analysis of the medical records was conducted to obtain information about possible postoperative complications. Clinical and radiographic analyses were performed at baseline and 180 days after surgeries. The sinus lifting with immediate implant placement provided satisfactory outcomes and can be considered a safe procedure. Treatment predictability was demonstrated in 90% of patients and for 86.96% of implants placed. It is important to highlight knowledge of anatomical structures at this area, the use of delicate surgical techniques, and strict patient follow-up.

A comparative study between crack analysis and a mechanical test for assessing the polymerization stress of restorative composites

Objectives. To verify the hypothesis that crack analysis and a mechanical test would rank a series of composites in a similar order with respect to polymerization stress. Also, both tests would show similar relationships between stress and composite elastic modulus and/or shrinkage. Methods. Soda-lime glass discs (2-mm thick) with a central perforation (3.5-mm diameter) received four Vickers indentations 500 mu m from the cavity margin. The indent cracks were measured (500x) prior and 10 min after the cavity was restored with one of six materials (Kalore/KL, Gradia/GR, Ice/IC, Wave/WV, Majesty Flow/MF, and Majesty Posterior/MP). Stresses at the indent site were calculated based on glass fracture toughness and increase in crack length. Stress at the bonded interface was calculated using the equation for an internally pressurized cylinder. The mechanical test used a universal testing machine and glass rods (5-mm diameter) as substrate. An extensometer monitored specimen height (2 mm). Nominal stress was calculated dividing the maximum shrinkage force by the specimen cross-sectional area. Composite elastic modulus was determined by nanoindentation and post-gel shrinkage was measured using strain gages. Data were subjected to one-way ANOVA/Tukey or Kruskal-Wallis/Mann-Whitney tests (alpha: 5%). Results. Both tests grouped the composites in three statistical subsets, with small differences in overlapping between the intermediate subset (MF, WV) and the highest (MP, IC) or the lowest stress materials (KL, GR). Higher stresses were developed by composites with high modulus and/or high shrinkage. Significance. Crack analysis demonstrated to be as effective as the mechanical test to rank composites regarding polymerization stress. (c) 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Antimicrobial Photodynamic Therapy for the Treatment of Teeth with Apical Periodontitis: A Histopathological Evaluation

Introduction: This study evaluated the in vivo response of apical and periapical tissues of dogs' teeth with apical periodontitis after one-session endodontic treatment with and without antimicrobial photodynamic therapy (aPDT). Methods: Sixty root canals with experimentally induced apical periodontitis were instrumented and assigned to 4 groups receiving aPDT and root canal filling (RCF) or not: group aPDT+/RCF- (n = 20): aPDT (photosensitizer phenothiazine chloride at 10 mg/mL for 3 minutes and diode laser [2 = 660 nm, 60 mW/cm(2)] for 1 minute) and RCF in the same session; group aPDT+/RCF (n = 10); group aPDT /RCF+ (n = 20), and group aPDT /RCF (n = 10). Teeth were restored, and the animals were killed after 90 days. Sections from the maxillas and mandibles were stained with hematoxylin-eosin and Mallory trichrome and examined under light microscopy. Descriptive (ie, newly formed apical mineralized tissue, periapical inflammatory infiltrate, apical periodontal ligament thickness, and mineralized tissue resorption) and quantitative (ie, periapical lesion size and number of inflammatory cells) microscopic analysis was performed. Quantitative data were analyzed by the Kruskal-Wallis and Dunn tests (alpha =.05). Results: In the aPDT-treated groups, the periapical region was moderately/severely enlarged with no inflammatory cells, moderate neoangiogenesis and fibrogenesis, and the smallest periapical lesions. Conclusions: Although apical closure by mineralized tissue deposition was not achieved, the absence of inflammatory cells, moderate neoangiogenesis, and fibrogenesis in the periapical region in the groups treated with aPDT indicate that this can be a promising adjunct therapy to cleaning and shaping procedures in teeth with apical periodontitis undergoing one-session endodontic treatment. (J Endod 2012;38:360-366)

Healing of a tooth with an overinstrumented apex, extensive transportation and periapical lesion using a 5 mm calcium hydroxide apical plug: an 8-year follow-up report

Besides the risk of filling material extrusion throughout the apex, a satisfactory apical seal can be difficult to achieve in canals with open apices or iatrogenic enlargements of the apical constriction. These situations pose a challenge to root canal filling. This paper describes the root canal filling of a maxillary right canine with an overinstrumented apex, complete loss of the apical stop, extensive canal transportation and apical periodontitis. A 5 mm calcium hydroxide apical plug was placed before root canal filling. The plug was made by soaking paper points with saline, dipping the points in calcium hydroxide powder and then applying it to the apex several times, until a consistent apical plug was obtained. The canal was then irrigated with saline in order to remove any residual calcium hydroxide from the root canal walls, dried with paper points and obturated with an inverted #80 gutta-percha cone and zinc oxide-eugenol based sealer by the lateral condensation technique. An 8-year radiographic follow-up showed formation of mineralized tissue sealing the apical foramen, apical remodeling and no signs of apical periodontitis.

Integrated analisis of building and users: a way to reduce energy consuption

In many countries buildings are responsible for a substantial part of the energy consumption, nd it varies according to their energetic and environmental performances. The potential for major reductions in buildings consumption have bee well documented in Brazil. Opportunities have been identified throughout the life cycle of the buildings, due of projects in diverse locations without the proper adjustments. This article offers a reflection about project processes and how its understanding can be conducted in an integrated way, favoring the use of natural resources and lowering energy consumption. It concludes by indicating that the longest phase in the life cycle of a building is also the phase responsible for its largest energy consumption, not only because of its duration but also for the interaction with the end user. Therefore, in order to harvest the energy cost reduction potential from future buildings designers need a holistic view of the surrounding, end users, materials and methodologies.

Synthesis and characterization of metal-chalcogenide MQ 2-Nanoparticles (M = Mo, W, Zr; Q = S, O)

Here, we present the adaptation and optimization of (i) the solvothermal and (ii) the metal-organic chemical vapor deposition (MOCVD) approach as simple methods for the high-yield synthesis of MQ2 (M=Mo, W, Zr; Q = O, S) nanoparticles. Extensive characterization was carried out using X-ray diffraction (XRD), scanning and transmission electron micros¬copy (SEM/TEM) combined with energy dispersive X-ray analysis (EDXA), Raman spectroscopy, thermal analyses (DTA/TG), small angle X-ray scattering (SAXS) and BET measurements. After a general introduction to the state of the art, a simple route to nanostructured MoS2 based on the decomposition of the cluster-based precursor (NH4)2Mo3S13∙xH2O under solvothermal conditions (toluene, 653 K) is presented. Solvothermal decomposition results in nanostructured material that is distinct from the material obtained by decomposition of the same precursor in sealed quartz tubes at the same temperature. When carried out in the presence of the surfactant cetyltrimethyl¬ammonium bromide (CTAB), the decomposition product exhibits highly disordered MoS2 lamellae with high surface areas. The synthesis of WS2 onion-like nanoparticles by means of a single-step MOCVD process is discussed. Furthermore, the results of the successful transfer of the two-step MO¬CVD based synthesis of MoQ2 nanoparticles (Q = S, Se), comprising the formation of amorphous precursor particles and followed by the formation of fullerene-like particles in a subsequent annealing step to the W-S system, are presented. Based on a study of the temperature dependence of the reactions a set of conditions for the formation of onion-like structures in a one-step reaction could be derived. The MOCVD approach allows a selective synthesis of open and filled fullerene-like chalcogenide nanoparticles. An in situ heating stage transmission electron microscopy (TEM) study was employed to comparatively investigate the growth mechanism of MoS2 and WS2 nanoparticles obtained from MOCVD upon annealing. Round, mainly amorphous particles in the pristine sample trans¬form to hollow onion-like particles upon annealing. A significant difference between both compounds could be demonstrated in their crystallization conduct. Finally, the results of the in situ hea¬ting experiments are compared to those obtained from an ex situ annealing process under Ar. Eventually, a low temperature synthesis of monodisperse ZrO2 nanoparticles with diameters of ~ 8 nm is introduced. Whereas the solvent could be omitted, the synthesis in an autoclave is crucial for gaining nano-sized (n) ZrO2 by thermal decomposition of Zr(C2O4)2. The n-ZrO2 particles exhibits high specific surface areas (up to 385 m2/g) which make them promising candidates as catalysts and catalyst supports. Co-existence of m- and t-ZrO2 nano-particles of 6-9 nm in diameter, i.e. above the critical particle size of 6 nm, demonstrates that the particle size is not the only factor for stabilization of the t-ZrO2 modification at room temperature. In conclusion, synthesis within an autoclave (with and without solvent) and the MOCVD process could be successfully adapted to the synthesis of MoS2, WS2 and ZrO2 nanoparticles. A comparative in situ heating stage TEM study elucidated the growth mechanism of MoS2 and WS2 fullerene-like particles. As the general processes are similar, a transfer of this synthesis approach to other layered transition metal chalcogenide systems is to be expected. Application of the obtained nanomaterials as lubricants (MoS2, WS2) or as dental filling materials (ZrO2) is currently under investigation.