Planning and treatment in oral rehabilitation with implant-supported prostheses using cephalometric analysis / Planejamento e tratamento em reabilitação oral com próteses sobre implantes usando análise cefalométrica

There are growing prosthetic and esthetic demands for Oral Rehabilitations on osseointegratable implants, requiring precise prosthetic-surgical planning. In edentulous patients planning may be done using cephalometric analysis to determine the position of the teeth in the dental prosthesis, and consequently, those of the implants. In this clinical case, the planning and treatment of an oral implant-supported rehabilitation is described, using cephalometry to optimize prosthetic success and patient comfort. The patient presented complete mandibular and partial maxillary edentulism, with unsatisfactory esthetics and function of the anterior teeth, with accentuated vestibular inclination. In order to determine the correct position of maxillary teeth it was necessary to use a Steiner cephalometric tracing to position the maxillary central incisor in the diagnostic wax-up. Therefore, the maxillary anterior teeth were extracted, osseointegratable implants were placed (Neodent(r), Curitiba, Brazil), and an immediate temporary fixed denture was inserted. After 30 days, surgery was performed for the placement of 4 osseointegratable implants (Neodent(r), Curitiba, Brazil) in the inter-mentonian region, on which a complete, temporary, implant-supported denture was placed. After the period of osseointegration, the definitive implant-supported dental prosthesis were fabricated.

Reabilitações orais sobre implantes osteointegráveis enfrentam crescentes exigências protéticas e estéticas, necessitando de um planejamento protético-cirúrgico preciso. O planejamento em pacientes edêntulos pode ser realizado usando análise cefalométrica para determinar o posicionamento dos dentes na prótese e conseqüentemente dos implantes. Esse caso clínico descreve o planejamento e tratamento de uma reabilitação oral sobre implantes usando análise cefalométrica para otimizar o sucesso protético assim como o conforto do paciente. Paciente apresentando edentulismo total mandibular e parcial maxilar com elementos anteriores insatisfatórios estética e funcionalmente, com inclinação vestibular acentuada. Para a determinação do correto posicionamento dos elementos superiores foi necessário a utilização de traçado cefalométrico de Steiner para o posicionamento do incisivo central superior no enceramento diagnóstico. Dessa forma, foi realizado exodontia dos elementos anteriores superiores, instalação de implantes osteointegraveis (Neodent(r), Curitiba, Brasil) e instalação de prótese fixa provisória imediata. Após 30 dias, foi realizada cirurgia para instalação de 4 implantes osteointegráveis (Neodent(r), Curitiba, Brasil) na região intermentoniana, sobre os quais foi instalada uma prótese total implanto-suportada inferior provisória. Após período de osteointegração, as próteses sobre implantes definitivas foram confeccionadas.

Ictiofauna do estuário de São Caetano de Odivelas e Vigia (Pará, Estuário Amazônico) / Ichthyofauna of the estuary of São Caetano de Odivelas and Vigia (Pará, Amazon Estuary)

Fish diversity in the Amazon Basin is recognized as one of the highest in the world. However, information on the estuarine ichthyofauna of the region is still fragmented and based on localized inventories. This study reports on an inventory carried out in the estuaries of São Caetano de Odivelas and Vigia, State of Pará, a poorly known area within the Amazon Estuary. Two research cruises of four days long each were undertaken in 2003, one in June (austral winter) and other in December (summer), with use of gill nets, traps, cast net and hook-and-line. It was collected 1,689 individuals, including 58 species from 23 families, all of them previously recorded in the Amazon Estuary. Perciformes, Siluriformes and Clupeiformes were the most diverse taxa, comprising 73.8 percent of the species. From the 58 recorded species, 24 percent are pelagic, 50 percent are demersal and the remaining have pelagic-demersal habits. Coastal-marine species predominated in the region.

A diversidade de peixes da Bacia Amazônica é reconhecida como uma das mais altas do mundo. No entanto, o conhecimento acerca da ictiofauna do estuário do Rio Amazonas é fragmentado e baseado em levantamentos localizados. O presente trabalho apresenta um inventário da ictiofauna dos estuários de São Caetano de Odivelas e Vigia, Pará, numa área ainda pouco conhecida do estuário Amazônico. Foram efetuadas duas campanhas de coleta em 2003, com duração de quatro dias cada, uma em junho (inverno) e outra em dezembro (verão), com uso de diferentes artes de pesca (redes de emalhar, currais, tarrafas e linha). Foram coletados 1.689 indivíduos pertencentes a 58 espécies distribuídas em 23 famílias, todas com ocorrência anteriormente registrada no estuário amazônico. As ordens Perciformes, Siluriformes e Clupeiformes foram os grupos mais diversificados, abrangendo 73,8 por cento das espécies. Das 58 espécies registradas, 24 por cento são pelágicas, 50 por cento são demersais e as demais têm hábitos pelágico-demersais. Espécies de hábitos costeiro-marinho predominaram na região.

A rationale method for evaluating unscrewing torque values of prosthetic screws in dental implants

OBJECTIVES: Previous studies that evaluated the torque needed for removing dental implant screws have not considered the manner of transfer of the occlusal loads in clinical settings. Instead, the torque used for removal was applied directly to the screw, and most of them omitted the possibility that the hexagon could limit the action of the occlusal load in the loosening of the screws. The present study proposes a method for evaluating the screw removal torque in an anti-rotational device independent way, creating an unscrewing load transfer to the entire assembly, not only to the screw. MATERIAL AND METHODS: Twenty hexagonal abutments without the hexagon in their bases were fixed with a screw to 20 dental implants. They were divided into two groups: Group 1 used titanium screws and Group 2 used titanium screws covered with a solid lubricant. A torque of 32 Ncm was applied to the screw and then a custom-made wrench was used for rotating the abutment counterclockwise, to loosen the screw. A digital torque meter recorded the torque required to loosen the abutment. RESULTS: There was a significant difference between the means of Group 1 (38.62±6.43 Ncm) and Group 2 (48.47±5.04 Ncm), with p=0.001. CONCLUSION: This methodology was effective in comparing unscrewing torque values of the implant-abutment junction even with a limited sample size. It confirmed a previously shown significant difference between two types of screws.

The need for complete dentures in Brazil: an epidemiological approach for the next 10 years

The only two censuses on oral health (Levantamento Epidemiológico em Saúde Bucal em 1986 e Projeto em Saúde Bucal de 2003) show a tendency in the reduction of edentulous patients in Brazil. The aim of this article was to estimate the variation in rates of the need for dentures in Brazil in 2010 and 2020. The projection was obtained from a linear variation carried out between the 1986 and 2003 censuses. A formula was used to calculate the result, which showed a strong trend in the decline of the number of edentulous patients until 2020. After the result analyses, it was found that by 2020 the need for complete denture for people between 15 and 74 years old will be none. Unfortunately, the only two censuses on oral health do not give us sufficient data to show a reliable projection of edentulous patients in Brazil

Influence of application site of provisional cement on the marginal adaptation of provisional crowns

Introduction: Marginal discrepancies may lead to cement washout and marginal leakage, damaging periodontal and pulp tissues or causing premature loss of the restoration. Purpose: This study evaluated the influence of application site of provisional cement on the marginal adaptation of provisional crowns. Material and Methods: Four different application sites of provisional cement (Temp Bond NE, Kerr Corporation) were used for cementation of provisional crowns on phantom teeth prepared for full crown restorations, performing 4 experimental groups (n=10): cement applied to all internal surfaces of the crown (CAO); cement applied to all internal surfaces of the crown, except for the occlusal surface (CA); cement applied to the cervical crown margin (CM); and cement applied to the cervical tooth margin (TM). A comparison microscope (Mitutoyo America Corporation) was used to measure the distances between the internal tangents of two circular marks, one made on the provisional crown and one made apical to the tooth preparation margin, in areas corresponding to buccal, lingual, mesial and distal surfaces. Marginal adaptation was determined before and after cementation, with 0.0001-mm accuracy. Data were analyzed statistically by ANOVA and Tukey’s test at 5% significance level. Results: Mean values of marginal opening obtained for each group were: CAO: 145 µm; CA: 67 µm; CM: 46 µm; TM: 34 µm. CA, CM and TM presented significantly lower marginal openings than CAO (p<0.05). Conclusion: complete filling of the crown with provisional cement, including the occlusal surface, provided grater marginal discrepancies when compared to the other methods evaluated.