Mechanical and microstructural properties of fixation systems used in oral and maxillofacial surgery.

OBJECTIVES: This paper aims to evaluate in vitro the mechanical and microstructural properties of internal fixation systems used in oral and maxillofacial surgeries. MATERIALS AND METHODS: Four brands of internal fixation systems (screws and 4-hole straight plates) were selected and assigned to four groups: G1 Leibinger®, G2 Tóride®, G3 Engimplan®, and G4 Medartis®. The systems were submitted to Vickers hardness testing, metallographic and interstitial elements chemical composition analyses. Data were submitted to ANOVA and Tukey's test for statistical analysis. RESULTS: Plates in groups 1, 2, and 3 showed similar microstructure and mechanical properties, different from those in G4 revealing larger grains. In all groups, the screws showed similar microstructure, with uniform arrangement and size of grains; the screws showed higher hardness values than those observed for the plates. CONCLUSIONS: The results indicate that all materials tested are adequate for use in oral maxillofacial surgeries.

Analysis of residual stress and hardness in regions of pre-manufactured and manual bends in fixation plates for maxillary advancement.

The aim of this study was to analyze, through Vickers hardness test and photoelasticity analysis, pre-bent areas, manually bent areas, and areas without bends of 10-mm advancement pre-bent titanium plates (Leibinger system). The work was divided into three groups: group I-region without bend, group II-region of 90° manual bend, and group III-region of 90° pre-fabricated bends. All the materials were evaluated through hardness analysis by the Vickers hardness test, stress analysis by residual images obtained in a polariscope, and photoelastic analysis by reflection during the manual bending. The data obtained from the hardness tests were statistically analyzed using ANOVA and Tukey's tests at a significance level of 5 %. The pre-bent plate (group III) showed hardness means statistically significantly higher (P < 0.05) than those of the other groups (I-region without bends, II-90° manually bent region). Through the study of photoelastic reflection, it was possible to identify that the stress gradually increased, reaching a pink color (1.81 δ / λ), as the bending was performed. A general analysis of the results showed that the bent plate region of pre-bent titanium presented the best results.

Avaliação dos Níveis de Gravidade dos AcidentesAutomobilísticos no Estado do Piauí / Evaluation of Gravity Levels of Traffic Accidents in the State of Piauí

Identificar os principais tipos de acidentes de trânsitono estado do Piauí, bem como caracterizar o nível degravidade destes acidentes, durante o ano de 2005. Materiale Métodos: Para realização desta pesquisa, foi feita umaabordagem quantitativa, a partir da leitura de dados einformações disponíveis, classificando-os e analizando-osatravés de métodos estatísticos. Realizou-se um levantamentodos acidentes de trânsito no estado do Piauí, no qual foi listadoa existência ou não de feridos e/ou mortes, bem como o númerode feridos envolvidos em cada acidente. Realizou-seacompanhamento das vítimas não fatais até 30 dias após adata do acidente, para inclusão do óbito. Para a coleta dosdados, quanto aos pacientes internados, fez-se a análise doprontuário médico de pacientes que deram entrada no HospitalGetúlio Vargas (HGV), local de referência em Teresina noatendimento de vítimas de acidentes de trânsito. Paracondutores de veículos envolvidos em acidentes que nãogeraram prontuário hospitalar, a fonte foi o banco de dados daPolícia Rodoviária Federal, do Batalhão de Policiamento deTrânsito – BPTRAN-PI e da Superintendência Municipal deTransportes - Strans. Resultados: Constatou-se que o númerode vítimas não-fatais (3.021) superou em muito o número dasvítimas-fatais (400) durante o ano de 2005. O tipo de acidentede trânsito que mais causou vítimas foi a modalidade “colisão”,com 73% do total de acidentes de trânsito. Discussão: Asmaiores vítimas em acidentes de trânsito no ano de 2005foram os motociclistas, com 132 mortes, sendo 32,92% dototal de fatalidades...

The objective of this work is to identify the main kind of trafficaccidents in the State of Piauí, as well as define the seriousnessof these accidents in the year of 2005. In this research, weapplied a quantitative analysis to the available data, whichwere classified and analyzed through statistical methods. Aneeds assessment was performed in Piauí; a list of the existinginjuries and/or death was obtained, as well as the number ofpeople involved in each accident. A 30-day follow-up for nonfatalvictims was performed after the date of the accident, toregister any case of later death. In order to collect the data, inrelation to the patients that were hospitalized, we performedan analysis of the medical records of patients who were inGetúlio Vargas Hospital (HGV), the reference hospital inreceiving victims of traffic accident in Teresina. In the case ofdrivers who were involved in traffic accidents without victims,who did not have to go to the hospital, the database from theFederal Traffic Police and the Traffic Police (BPTRAN-PI) andthe City Transportation Authority (Strans) were used as themain sources. The results showed that, in 2005, the number ofnon-fatal victims (3,021) was larger than the fatal ones (400).The kind of accident that resulted in a bigger number of victimswas “collision” (73% of the total traffic accidents). The maintraffic accident victims were motorcycle drivers (132 deathsrepresenting 32.92% of total deaths)...