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Niterói, Brazil

Li G.-H.,Fuzhou Dongfang Hospital | Niu L.-N.,PLA Fourth Military Medical University | Zhang W.,Huazhong University of Science and Technology | Olsen M.,North Shore Endodontics | And 5 more authors.
Acta Biomaterialia | Year: 2014

New obturation biomaterials have been introduced over the past decade to improve the seal of the root canal system. However, it is not clear whether they have really produced a three-dimensional impervious seal that is important for reducing diseases associated with root canal treatment. A review of the literature was performed to identify models that have been employed for evaluating the seal of the root canal system. In vitro and in vivo models are not totally adept at quantifying the seal of root canals obturated with classic materials. Thus, one has to resort to clinical outcomes to examine whether there are real benefits associated with the use of recently introduced materials for obturating root canals. However, there is no simple answer because endodontic treatment outcomes are influenced by a host of other predictors that are more likely to take precedence over the influence of obturation materials. From the perspective of clinical performance, classic root filling materials have stood the test of time. Because many of the recently introduced materials are so new, there is not enough evidence yet to support their ability to improve clinical performance. This emphasizes the need to translate anecdotal information into clinically relevant research data on new biomaterials. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Source


Jimbo R.,Malmo University | Tovar N.,New York University | Anchieta R.B.,New York University | MacHado L.S.,New York University | And 3 more authors.
International Journal of Oral and Maxillofacial Surgery | Year: 2014

This study investigated the effect of undersized preparations with two different implant macrogeometries. There were four experimental groups: group 1, conical implant with an undersized osteotomy of 3.2mm; group 2, conical implant with an undersized osteotomy of 3.5mm; group 3, cylindrical implant with an undersized osteotomy of 3.2mm; group 4, cylindrical implant with an undersized osteotomy of 3.5mm. Implants were placed in one side of the sheep mandible (n =6). After 3 weeks, the same procedure was conducted on the other side; 3 weeks later, euthanasia was performed. All implants were 4mm×10mm. Insertion torque was recorded for all implants during implantation. Retrieved samples were subjected to histological sectioning and histomorphometry. Implants of groups 1 and 2 presented significantly higher insertion torque than those of groups 3 and 4 (P <0.001). No differences in bone-to-implant contact or bone area fraction occupied were observed between the groups at 3 weeks (P >0.24, and P >0.25, respectively), whereas significant differences were observed at 6 weeks between groups 1 and 2, and between groups 3 and 4 (P <0.01). Undersized drilling affected the biological establishment of bone formation around both dental implant macrogeometries. © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Source


Lamas C.D.C.,Instituto Nacional Of Cardiologia | Ramos R.G.,Instituto Nacional Of Cardiologia | Lopes G.Q.,UNIGRANRIO | Santos M.S.,Instituto Nacional Of Cardiologia | And 3 more authors.
International Journal of Infectious Diseases | Year: 2013

PCR was used to detect Coxiella burnetii and Bartonella spp in heart valves obtained during the period 1998-2009 from patients operated on for blood culture-negative endocarditis in a cardiac surgery hospital in Brazil. Of the 51 valves tested, 10 were PCR-positive; two were positive for Bartonella and one for C. burnetii. © 2012 International Society for Infectious Diseases. Source


Jimbo R.,Malmo University | Tovar N.,New York University | Marin C.,UNIGRANRIO | Teixeira H.S.,New York University | And 5 more authors.
International Journal of Oral and Maxillofacial Surgery | Year: 2014

Information concerning the effects of the implant cutting flute design on initial stability and its influence on osseointegration in vivo is limited. This study evaluated the early effects of implants with a specific cutting flute design placed in the sheep mandible. Forty-eight dental implants with two different macro-geometries (24 with a specific cutting flute design - Blossom group; 24 with a self-tapping design - DT group) were inserted into the mandibular bodies of six sheep; the maximum insertion torque was recorded. Samples were retrieved and processed for histomorphometric analysis after 3 and 6 weeks. The mean insertion torque was lower for Blossom implants (P < 0.001). No differences in histomorphometric results were observed between the groups. At 3 weeks, P = 0.58 for bone-to-implant contact (BIC) and P = 0.52 for bone area fraction occupied (BAFO); at 6 weeks, P = 0.55 for BIC and P = 0.45 for BAFO. While no histomorphometric differences were observed, ground sections showed different healing patterns between the implants, with better peri-implant bone organization around those with the specific cutting flute design (Blossom group). Implants with the modified cutting flute design had a significantly reduced insertion torque compared to the DT implants with a traditional cutting thread, and resulted in a different healing pattern. © 2014 International Association of Oral and Maxillofacial Surgeons. Source


Menezes B.C.,Petrobras | Menezes B.C.,Federal University of Rio de Janeiro | Moro L.F.L.,Petrobras | Lin W.O.,UNIGRANRIO | And 2 more authors.
Industrial and Engineering Chemistry Research | Year: 2014

The oil industry in Brazil has accounted for US$300 billion in investments over the past 10 years, and further expansions are planned to supply the needs of the future fuel market in terms of both quantity and quality. In this paper we analyze the Brazilian fuel production and market scenarios considering the country's planned investments to prevent a fuel deficit of around 30% in 2020. A nonlinear programming model is proposed to predict the national overall capacity for different oil-refinery units considering four future market scenarios. Single-period operational planning cases for the present and intermediate scenarios and those considered in 2020 are proposed by changing demands, costumer preference, and planned investments to calculate fuel production and import figures for the current and future production and market scenarios in the country. The results indicate a different processing outline in the national overall unit capacity planning. © 2014 American Chemical Society. Source

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