Effects of chlorhexidine and sodium hypochlorite on the microhardness of root canal dentin

Objective. The purpose of this study was to evaluate the effects of endodontic irrigants on the microhardness of root canal dentin.Study design. Thirty extracted single-rooted human teeth were used. The crowns were sectioned at the cementoenamel junction. Each root was transversely sectioned into cervical, middle, and apical segments, resulting in 90 specimens. The 3 sections of each root were separately mounted in an individual silicon device with acrylic resin. The specimens were randomly divided into the following 3 groups (n = 30), according to the irrigant solution used: (1) group 1, control (saline solution); (2) group 2, 2% chlorhexidine gluconate solution; and (3) group 3, 1% sodium hypochlorite (NaOCl). After 15 minutes of irrigation, dentin microhardness was measured on each section at 500 mu m and 1000 mu m from the pulp-dentin interface with a Vickers diamond microhardness tester in Vickers hardness number (VHN).Results. Data obtained were analyzed using analysis of variance and the Tukey test (5%). Specimens irrigated with 2% chlorhexidine (group 2) or 1% NaOCl (group 3) presented lower values of dentin microhardness, with significant difference in relation to the control group (P < .05).Conclusion. It could be concluded that chlorhexidine and NaOCl solutions significantly reduced the microhardness of root canal dentin at 500 mu m and 1000 mu m from the pulp-dentin interface.

The adhesive system and root canal region do not influence the degree of conversion of dual resin cement

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

Scanning electron microscope evaluation of chlorhexidine gel and liquid associated with sodium hypochlorite cleaning on the root canal walls

Objective. The aim of this study was to evaluate, by scanning electronic microscopy (SEM), the cleaning of the root canal walls after instrumentation and irrigation with 2.5% sodium hypochlorite (NaOCl) associated with 2% chlorhexidine (CHX) gel or liquid, combined or not with 17% ethylenediamine tetra-acetic acid (EDTA).Study design. Sixty single-root human teeth were subjected to standardized root canal instrumentation with different irrigants (n = 10): G1) NaOCl + CHX liquid; G2) NaOCl + CHX liquid + EDTA + saline solution; G3) NaOCl + CHX gel; G4) NaOCl + CHX gel + EDTA + saline solution; G5) saline solution; G6) saline solution + EDTA. After instrumentation, the teeth were prepared for SEM analysis (x500 and x2,000) to evaluate the cleaning of the cervical, middle, and apical thirds. The area analyzed was quantified according to the percentage of open and closed tubules, and data were statistically analyzed by analysis of variance and Tukey tests (P = .05).Results. The number of open tubules was highest in G4 in all root thirds, showing statistically significant difference from G1, G2, and G5 (P < .05). G1 presented higher quantity of closed tubules significant than G2.Conclusion. Irrigation with NaOCl and CHX gel followed by EDTA and saline solution produced greater cleaning of the root canal walls. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:e82-e87)

Search for a Fermiophobic and Standard Model Higgs Boson in Diphoton Final States

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Developmental anatomy of Cyperus laxus (non-Nranz) and Fimbristylis dichotoma (Kranz) (Cyperaceae, Poales) and tissue continuity

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

Tempo de jejum na granja sobre o perfil hormonal e os parâmetros fisiológicos em suínos de abate pesados

O objetivo deste estudo foi avaliar o tempo de jejum na granja e a posição dos animais na carroceria do caminhão durante o transporte ao abatedouro sobre o status hormonal e fisiológico de suínos de abate pesados visando obter melhorias no manejo pré-abate e reduzir perdas na qualidade de carne. Foram utilizadas 64 fêmeas com peso médio de 133+11kg, oriundas de duas granjas de terminação. Os tempos de jejum avaliados foram nove, 12, 15 e 18h, enquanto que as posições consideradas na carroceria foram box (frente, meio e atrás), piso (inferior e superior) e lado (lateral direita e esquerda). Ao abate, foram medidos os níveis de glicose, lactato e CPK no sangue. A concentração de cortisol na saliva (CCS) foi medida nas granjas (24 horas antes e após embarque) e no abatedouro (logo após o descarregamento e antes do abate). A freqüência cardíaca foi monitorada durante todo o manejo pré-abate. Foi observado o efeito da interação entre TJG e o local de avaliação sobre a CCS e a freqüência cardíaca. A CCS e a freqüência cardíaca aumentaram significativamente da granja ao desembarque no abatedouro em relação ao descanso pré-abate no abatedouro foi observada uma redução (P<0,05) nos valores. A CCS variou em função do TJG e o local de avaliação da seguinte maneira: suínos com 18 horas de jejum apresentaram menor (P<0,05) variação na CCS durante o transcorrer das diferentes etapas do manejo pré-abate do que suínos com TJG menores e, entre estes, os animais com TJG de nove horas apresentaram a maior (P<0,05) variação. Antes do abate, os suínos com TJG de nove horas apresentaram o maior valor (P<0,05) de CCS quando comparados aos outros TJG. Conclui-se que o TJG promove mudanças (P<0,05) nos valores do cortisol na saliva e na freqüência cardíaca no manejo pré-abate, mas não afetam (P>0,05) os níveis de glicose, lactato e CPK no abate dos suínos.

NATRIURESIS, NOT SEIZURES, INDUCED BY CHOLINERGIC STIMULATION OF THE LOCUS-CERULEUS IS AFFECTED BY FOREBRAIN LESIONS AND WATER-DEPRIVATION

Two groups of rats with electrolytic lesions of the medial and upper septal area (MUL) or, alternatively, of the anteroventral portion of the third ventricle (AV3V) and a third group of sham-operated rats were water loaded and received three carbachol injections into the locus coeruleus according to the following schedule: 1) prelesion, 2) on the second postlesion day and 3) on the seventh postlesion day. Both MUL and AV3V lesions inhibited the carbachol-induced natriuresis on the second postlesion day. Recovery was almost complete after MUL but not after AV3V lesion on the seventh day. Water deprivation also reduced the carbachol-induced natriuresis but passive hydration of AV3V animals did not avoid the impairment induced by the lesion. Transient seizure phenomena such as clonic convulsions, salivation and analgesia subsequent to carbachol injection were not altered by the lesions.

Morphometry and histochemistry of the semitendinosus muscle of tufted capuchin monkeys (Cebus apella Linnaeus, 1758)

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

In vitro evaluation of root canal preparation using oscillatory and rotary systems in flattened root canals

Objective: the aim of this study was to evaluate the biomechanical preparation of flattened root canals using the following systems: Endo-Eze AET stainless steel oscillatory instruments (Ultradent) and RaCe rotary NiTi instruments (FKG Dentaire). Materials and Methods: Twenty extracted human mandibular incisors were randomly assigned to two groups: Group I Instrumentation with oscillatory Endo-Eze AET files (oscillatory technique); Group 2 - Instrumentation with rotary NiTi RaCe files (rotary technique). The teeth were decoronated, had their apices and coronal openings sealed with sticky wax and were embedded in crystal-clear orthophtalic polyester resin. The roots were sectioned transversally with diamond discs at 10 mm (middle third) and 5 mm (apical third) from the apex and the segments were reassembled for instrumentation. The sections were photographed before and after root canal instrumentation and evaluated with respect to whether the original root canal shape was modified by instrumentation. To evaluate the differences in the root canal shape before and after biomechanical preparation, scores were given regarding the instruments touch on the intracanal walls. Results: In middle third of the root canals instrumented with the rotary system, there was a change in the original canal anatomy (p < 0.05), with formation of a protuberance in the mesiodistal direction. This protuberance did not occur when the oscillatory instrumentation was used. The oscillatory system had better results in the middle and apical thirds as evaluated by Dunn's multiple-comparison test (p > 0.05). Conclusion: Under the tested conditions, Endo-Eze oscillatory system yielded the instrumentation of all flattened oot canal walls, maintaining the canal original shape throughout the biomechanical preparation, and was more effective than RaCe rotary system.

Postsurgical stability of oropharyngeal airway changes following counter-clockwise maxillo-mandibular advancement surgery

Purpose: This study evaluated oropharyngeal airway changes and stability following surgical counter-clockwise rotation and advancement of the maxillo-mandibular complex.Methods and Patients: Fifty-six adults (48 females, 8 males), between 15 and 51 years of age, were treated with Le Fort I osteotomies and bilateral mandibular ramus sagittal split osteotomies to advance the maxillo-mandibular complex with a counter-clockwise rotation. The average postsurgical follow-up was 34 months. Each patient's lateral cephalograms were traced, digitized twice, and averaged to estimate Surgical changes (T2-T1) and Postsurgical changes (T3-T2).Results: During surgery, the occlusal plane angle decreased significantly (8.6 +/- 5.8 degrees) and the maxillo-mandibular complex advanced and rotated counter-clock-wise. The maxilla moved forward (2.4 +/- 2.7 mm) at ANS and the mandible was advanced 13.1 +/- 5.1 min at menton, 10 +/- 4.4 mm at point B, and 6.9 +/- 3.7 mm at lower incisor edge. Postsurgical hard tissue changes were not statistically significant. While the upper oropharyngeal airway decreased significantly (4.2 +/- 3.4 min) immediately after surgery, the narrowest retropalatal, lowest retropalatal airway, and the narrowest retroglossal airway measurements increased 2.9 +/- 2.7, 3.7 +/- 3.2, and 4.4 +/- 4.4 mm, respectively. Over the average 34 months Postsurgical period, upper retropalatal airway increased 3.9 +/- 3.7 mm, while narrowest retropalatal, lowest retropalatal airway, and narrowest retroglossal airway remained stable. Head posture showed flexure immediately after Surgery (4.8 +/- 5.9 degrees) and extension postsurgically (1.6 +/- 5.6 degrees).Conclusion: Maxillo-mandibular advancement with counter-clockwise rotation produces immediate increases in middle and lower oropharyngeal airway dimensions, which were constrained by changes in head posture but remain stable over the postsurgical period. The upper oropharyngeal airway space increased only on the longest follow-up. (C) 2006 American Association of Oral and Maxillofacial Surgeons.

Topographical, diametral, and quantitative analysis of dentin tubules in the root canals of human and bovine teeth

The aim of this study was to evaluate the number and the diameter of dentin tubules in root canals, in the cervical, middle, and apical thirds, of human and bovine teeth. Twenty-four single-rooted, human premolars were divided into four groups (n = 6): GH1, 10 to 15 years; GH2, 16 to 30 years; GH3, 31 to 45 years; and GH4, 46 to 80 years; and 24 bovine incisors were divided into four groups (n = 6): GB1, central; GB2, lateral first; GB3, lateral second; and GB4, lateral third. The crowns were removed from the specimens, which were then debrided, sectioned longitudinally in the vestibular-lingual direction, and submitted to ultrasonic cleaning. Scanning electron microscopic evaluations were made with 1,000x and 5,000x magnification. According to the root thirds, statistically significant differences were found both for the number and the diameter of dentin tubules, with the cervical third presenting the highest mean values for both specimen types. As regards the number of dentin tubules, it was observed that the bovine specimens presented a significantly higher mean value than the human specimens; this difference was not observed when the diameters of the two types were compared.

The Serido Group of NE Brazil, a late Neoproterozoic pre- to syn-collisional basin in West Gondwana: insights from SHRIMP U-Pb detrital zircon ages and Sm-Nd crustal residence (T-DM) ages

The Serido Group is a deformed and metamorphosed metasedimentary sequence that overlies early Paleoproterozoic to Archean basement of the Rio Grande do Norte domain in the Borborema Province of NE Brazil. The age of the Serido Group has been disputed over the past two decades, with preferred sedimentation ages being either Paleoproterozoic or Neoproterozoic. Most samples of the Serido Formation, the upper part of the Serido Group, have Sm-Nd T-DM ages between 1200 and 1600 Ma. Most samples of the Jucurutu Formation, the lower part of the Serido Group, have T-DM ages ranging from 1500 to 1600 Ma; some basal units have T-DM ages as old as 2600 Ma, reflecting proximal basement. Thus, based on Sm-Nd data, most, if not all, of the Serido Group was deposited after 1600 Ma and upper parts must be younger than 1200 Ma.Cathodoluminescence photos of detrital zircons show very small to no overgrowths produced during ca. 600 Ma Brasiliano deformation and metamorphism, so that SHRIMP and isotope dilution U-Pb ages must represent crystallization ages of the detrital zircons. Zircons from meta-arkose near the base of the Jucurutu Formation yield two groups of ages: ca. 2200 Ma and ca. 1800 Ma. In contrast, zircons from a metasedimentary gneiss higher in the Jucurutu Formation yield much younger ages, with clusters at ca. 1000 Ma and ca. 650 Ma. Zircons from metasedimentary and metatuffaceous units in the Serido Formation also yield ages primarily between 1000 and 650 Ma, with clusters at 950-1000, 800, 750, and 650 Ma. Thus, most, if not all, of the Serido Group must be younger than 650 Ma. Because these units were deformed and metamorphosed in the ca. 600 Ma Brasiliano fold belt during assembly of West Gondwana, deposition probably occurred ca. 610-650 Ma, soon after crystallization of the youngest population of zircons and before or during the onset of Brasiliano deformation.The Serido Group was deposited upon Paleoproterozoic basement in a basin receiving detritus from a variety of sources. The Jucurutu Formation includes some basal volcanic rocks and initially received detritus from proximal 2.2-2.0 Ga (Transamazonian) to late Paleoproterozoic (1.8-1.7 Ga) basement. Provenance for the upper Jucurutu Formation and all of the Serido Formation was dominated by more distal and younger sources ranging in age from 1000 to 650 Ma. We suggest that the Serido basin may have developed as the result of late Neoproterozoic extension of a pre-existing continental basement, with formation of small marine basins that were largely floored by cratonic basement (subjacent oceanic crust has not yet been found). Immature sediment was initially derived from surrounding land; as the basin evolved much of the detritus probably came from highlands to the south (present coordinates). Alternatively, if the Patos shear zone is a major terrane boundary, the basin may have formed as an early collisional foredeep associated with south-dipping subduction. In any case, within 30 million years the region was compressed, deformed, and metamorphosed during final assembly of West Gondwana and formation of the Brasiliano-Pan African fold belts. (C) 2003 Elsevier B.V. All rights reserved.

Repair characteristics of horizontal root fracture: a case report

Radicular fractures in permanent teeth are uncommon injuries among dental traumas, comprising 0.5-7% of the cases. Fracture occurs most often in the middle-third of the root and rarely at the apical-third. The present paper reports a clinical case of a horizontal radicular fracture located between the middle- and apical-third of a upper left-central incisor followed-up for over 3 years. The tooth was extracted owing to periodontal reasons. Histomorphologically, it showed pulp-vitality preservation and root healing by hard-tissue deposition.

Flammability limits: A review with emphasis on ethanol for aeronautical applications and description of the experimental procedure

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

Effect of juvenility on cutting propagation of red pitaya

Introduction. Pitaya (Hylocereus undatus) is an exotic fruit species little known in Brazil and which needs basic studies about plant nutrition, propagation and physiology. Emphasizing the co-existence of juvenile and adult stages in the pitaya canopy, the plant is generally propagated by cuttings. Materials and methods. A completely randomized design with four treatments and five replications was adopted. Each treatment was represented by the part of the canopy from which the cutting was taken ( upper, middle and lower cutting and cuttings from young plants). The following variables were registered: % cuttings with roots, % of live cuttings, root density, root diameter, root area, root length and root dry mass. Results were submitted to variance analyses, Tukey's test at 0.01 probability error and simple correlation analysis. Results and discussion. The results indicated that the position from which the cutting is taken had a quantitative effect on rooting formation of pitaya cuttings. Juvenile cuttings presented 35% more cuttings with roots than adult cuttings. Root density, root area, root length and root dry mass depended on juvenility, the highest results being registered for juvenile cuttings, independently of the variable. Conclusion. Juvenile and adult stages co-exist in the pitaya canopy. Juvenility is an important rooting factor for red pitaya cuttings.