Espelho sem reflexos: conflitos e vulnerabilidades socioambientais em uma região produtora de cana-de-açúcar / Mirror without reflections: social and environmental conflicts and vulnerabilities in a sugarcane producing region

Resumo O objetivo deste estudo é analisar os impactos socioambientais e sanitários decorrentes do monocultivo da cana-de-açúcar em um município da Zona da Mata pernambucana. Foi realizado um mapeamento coletivo, com uso da cartografia social. Os problemas investigados foram representados graficamente em mapas, cujas versões finais foram elaboradas pelo Software ArcGIS 10.2. O estudo foi realizado no distrito de Tejucupapo, situado em Goiana, selecionado por sua proximidade dos canaviais. No ambiente observou-se aumento do desmatamento, degradação do mangue, assoreamento dos rios, diminuição do pescado e contaminação das águas e de outras culturas por agrotóxicos e esgoto. Para a saúde, foram apontados problemas respiratórios pela queima da cana, intoxicações por agrotóxicos e precariedade da rede assistencial. Na dimensão sociocultural foram identificados conflitos relacionados ao uso e à ocupação das terras, com perda, expropriação e destruição de objetos e símbolos históricos da comunidade, tendo como reflexos a perda da identidade cultural. Os problemas relacionados ao cultivo da cana afetam severamente a saúde e destroem o território tanto em seus aspectos ambientais como na própria construção identitária da comunidade, ameaçando os modos de vida tradicionais.

Abstract This study aims to analyze the socio-environmental and health effects of sugarcane crops in a county in the Zona da Mata of the state of Pernambuco, Brazil. A collective mapping was carried out with use of social cartography. The issues investigated were plotted on maps, whose final versions were elaborated by means of the ArcGIS 10.2 software. The study was carried out in the district of Tejucupapo, located in the municipality of Goiana, selected due to its proximity to the sugarcane fields. In the environment there was an increase in deforestation, mangrove degradation, silting of rivers, reduction of fish and contamination of water and other crops by pesticides and sewage. For health, respiratory problems were pointed out by sugarcane burning, pesticide poisoning and the precariousness of the governmental health care. In the socio-cultural dimension, conflicts related to land use and occupation were identified, with loss, expropriation and destruction of historical objects and symbols of the community, reflecting the loss of cultural identity. The problems related to sugarcane production severely affect human health and destroy the territory both in its environmental aspects and the very identity construction of the community, threatening traditional livelihoods.

Periodontal ligament influence on the stress distribution in a removable partial denture supported by implant: a finite element analysis

OBJECTIVES: The non-homogenous aspect of periodontal ligament (PDL) has been examined using finite element analysis (FEA) to better simulate PDL behavior. The aim of this study was to assess, by 2-D FEA, the influence of non-homogenous PDL on the stress distribution when the free-end saddle removable partial denture (RPD) is partially supported by an osseointegrated implant. MATERIAL AND METHODS: Six finite element (FE) models of a partially edentulous mandible were created to represent two types of PDL (non-homogenous and homogenous) and two types of RPD (conventional RPD, supported by tooth and fibromucosa; and modified RPD, supported by tooth and implant [10.00x3.75 mm]). Two additional Fe models without RPD were used as control models. The non-homogenous PDL was modeled using beam elements to simulate the crest, horizontal, oblique and apical fibers. The load (50 N) was applied in each cusp simultaneously. Regarding boundary conditions the border of alveolar ridge was fixed along the x axis. The FE software (Ansys 10.0) was used to compute the stress fields, and the von Mises stress criterion (svM) was applied to analyze the results. RESULTS: The peak of svM in non-homogenous PDL was higher than that for the homogenous condition. The benefits of implants were enhanced for the non-homogenous PDL condition, with drastic svM reduction on the posterior half of the alveolar ridge. The implant did not reduce the stress on the support tooth for both PDL conditions. Conclusion: The PDL modeled in the non-homogeneous form increased the benefits of the osseointegrated implant in comparison with the homogeneous condition. Using the non-homogenous PDL, the presence of osseointegrated implant did not reduce the stress on the supporting tooth.

Influencia del nivel de inserción ósea del diente soporte en el desplazamiento de PPR de extremidad libre mandibular asociada al implante oseointegrado / Influence bone attachment level tooth displacement support free end PPR associated mandibular implant osseointegrated

La rehabilitación con prótesis parcial removible de extremidad libre (PPREL) inferior es compleja y el uso de implantes han mejorado el funcionamiento de este tipo de aparato. El nivel de inserción ósea alrededor del último diente soporte es factor agravante, ya que puede comprometer la longevidad del tratamiento. Así, el objetivo de este estudio fue evaluar la tendencia al desplazamiento de una PPREL asociada al implante oseointegrado, con diferentes niveles de inserción ósea y diferentes conexiones entre la PPR y el diente soporte, a través del método del elementos finitos. Fueron confeccionados 8 modelos: MA - PPREL, apoyo incisal, inserción integra; MB - PPREL, placa distal, inserción integra; MC - PPREL, apoyo incisal, inserción integra, con implante y sistema ERA; MD - PPREL, placa distal, inserción integra, con implante y sistema ERA; ME - PPREL, apoyo incisal, pérdida ósea; MF - PPREL, placa distal, pérdida ósea; MG - PPREL, apoyo incisal, pérdida ósea, con implante y sistema ERA; MH - PPREL, placa distal, pérdida ósea, con implante y sistema ERA. Fueron aplicadas fuerzas verticales de 50 N en cada cúspide. Fueron obtenidos mapas de desplazamiento que mostraron que el implante favorece esta asociación y la pérdida ósea perjudica el pronóstico de la prótesis. Se concluyó que: la introducción del implante con sistema ERA disminuyó la tendencia al desplazamiento del diente y estructuras subyacentes; la introducción de la placa distal disminuyó la tendencia a desplazamiento del diente soporte; la disminución del periodonto de sustentación no influenció significativamente la tendencia al desplazamiento en los modelos con placa distal, pero influenció en los modelos con apoyo distal

The rehabilitation with mandibular distal extension removable partial dentures (DERPD) is complex and the use of implants has been improving the functioning of this approach. The insertion bony level around of the last support tooth is an aggravating factor, since it can harm the longevity of the treatment. Thus, the aim of this research was to evaluate the displacement tendency of a mandibular DERPD associated to an implant, with different insertion bony levels and different connections between the RPD and the support tooth, by finite element analysis. Eight models were made: MA - DERPD, incisal rest, no bony loss; MB - DERPD, distal plate, no bony loss; MC - DERPD, incisal rest, no bony loss, with implant and ERA system; MD - DERPD, distal plate, no bony loss, with implant and ERA system; ME - DERPD, incisal rest, bony loss; MF - DERPD, distal plate, bony loss; MG - DERPD, incisal rest, bony loss, with implant and ERA system; MH - DERPD, distal plate, bony loss, with implant and ERA system. Loads of 50 N in each peak were applied. Displacement maps were obtained and showed that implant favors this association and the bony loss harms the prognostic of the prosthesis. It is concluded that: the introduction of the implant with ERA system reduced the displacement tendency of the tooth and supporting structures; introduction of distal plate reduced the movement tendency of the support tooth; the decrease of the periodontal support didn't influence significantly the displacement tendency of the models with distal plate distal, but it influenced the models with distal incisal rest

Avaliação da distribuição de tensões em casos de prótese parcial removível de classe 1 mandibular convencional e associada a implante osseointegrado pelo método dos elementos finitos / Evaluation of the distribution of tensions in cases of inferior removable partial denture class 1 conventional and associated with osseointegrated implant by the finite element analysis

A associação das próteses parciais removíveis (PPRs) e implantes osseointegrados tem sido relatada na literatura, mas ainda não existem relatos sobre a melhor forma de conexão com o último dente suporte nos casos de extremidade livre. Assim, o objetivo deste trabalho foi estudar, através do MEF bidimensional, o comportamento das estruturas de suporte de uma PPR convencional e associada a implante osseointegrado, agindo apenas como suporte, variando-se os sistemas de conexão com o último dente suporte entre apoio distal e placa distal. Foram confeccionados 4 modelos hemi-mandibulares, com presença apenas do dente 33, sendo: Mod A, PPR convencional e apoio distal; Mod B, PPR convencional e placa distal; Mod C, PPR associada a implante de 3,75 x 10,0 mm e apoio distal; Mod D, PPR associada a implante de 3,75 x 10,0 mm e placa distal. O programa de elementos finitos utilizados foi o ANSYS 9.0 com carregamento de 50N em cada ponta de cúspide, estritamente vertical. Os resultados foram obtidos através de mapas de deslocamento e tensão de Von Mises. Os resultados mostraram alívo do ligamento periodontal e dente suporte quando da presença da placa distal, tanto nos mapas de deslocamento quanto nos mapas de tensão. Por esta metodologia foi possível concluir que: 1. A placa distal diminuiu a tendência de movimento do dente suporte, tanto dos modelos com PPR convencional, quanto nos associados a implante; 2. Os modelos que incorporaram a placa distal melhoraram a distribuição interna de tensões de von Mises, principalmente pelo alívio do dente suporte.

The association of the removable partial dentures (RPDs) and osseointegrated implants it has been mentioned in the literature, but reports don’t still exist on the best connection form with the last support tooth in the cases of distal extension. Like this, the objective of this work was to study, through the bidimensional FEA, the behavior of the support structures of a conventional RPD and associated with implants, just acting as support, by variation in the connection systems with the last support tooth between distal incisal rest or and distal plate. 4 hemi-mandibular models were made, with presence just of the tooth 33: Model A: conventional RPD and distal incisal rest; Model B: conventional RPD and distal plate; Model C: RPD associated with implant (3,75 x 10,0 mm) and distal incisal rest; Model D: RPD associated with implant (3,75 x 10,0 mm) and distal plate. The finite element program used was ANSYS 9.0 with loading of 50N in each cusp tip, strictly vertical. The results were obtained through displacement maps and tension maps. The results showed decrease of the ligament and support tooth tension when distal plate were present, as in the displacement maps or in the tension maps. For this methodology it was possible conclude: 1. The distal plate reduced the tendency of movement of the support tooth in all models; 2. the models that incorporated the distal plate improved the internal distribution of von Mises tensions, mainly for the relief of the support tooth.