Critérios para a boa performance clínica em casos de união entre dente e implante / Criteria for good clinical performance in cases of tooth-implant restorations: a literature review

Apesar das altas taxas de sucesso com implantes osseointegráveis, situações anatômicas e clínicas específicas de cada paciente podem limitar o uso de um número adequado de implantes. Nestes casos, alternativas como a união entre dente suporte e implante vêm sendo discutidas há algum tempo, mas algumas controvérsias ainda permanecem, sendo a diferença de resiliência do ligamento periodontal e a rigidez da interface osso-implante as maiores delas. Esta revisão da literatura teve como objetivo analisar quais os critérios biomecânicos exigidos para esta modalidade de tratamento, as diferentes conexões propostas, suas vantagens e complicações a médio e longo prazo. Com base nos resultados de estudos anteriores, considera-se preferível – sempre que possível – a não união de dentes a implantes. Porém, em casos específicos onde o uso de cantiléver e próteses parciais removíveis sejam inevitáveis, as vantagens da junção devem ser consideradas com parcimônia. Até o presente momento, entende-se que o número de retentores esplintados não interfere na estabilidade da junção. O que parece ter interferência positiva é a escolha de implantes hexágono externo, ajuste oclusal específico (protegendo o implante de forças horizontais e verticais excessivas), prótese com união rígida e de característica reversível; nestes casos, as taxas de insucesso são muito próximas aos casos reabilitados em próteses fixas sem configuração mista. Concluiu-se que, depois de ponderadas as vantagens e desvantagens para cada caso, não se pode contraindicar tal técnica, pois ela demonstra ser uma alternativa reabilitadora estável, confortável e estética.

Despite its high success rates, patient´s specific anatomic and clinical situations may limit the use of an adequate number of implants. For these cases, alternatives such as tooth-implant restorations have been discussed for some time, but controversies still remain, being the difference between the resilience of periodontal ligament and bone-implant interface one of them. this literature review analyzed the biomechanical criteria for this treatment modality, different connections, as well as short- and middle-term complications for tooth-implant restorations. According to the available evidence, it is recommended not to join teeth to implants. However, for some cases where cantilever and removable partial prostheses seems mandatory, tooth-to implant possibilities must be considered. In the light of current evidence, the number of splinted units does not interfere with the overall biomechanics. Factors such as the use of external hex implants, careful occlusal adjustment (to protect against horizontal and excessive vertical forces), rigid and reversible splinting were considered positive; failure rates are close to cases with fixed partial prostheses solely on teeth or implants. It can be concluded that this technique cannot be contraindicated because it constitutes a viable, comfortable, and esthetic alternative.

Microbial quality of water in rural communities of Trinidad

A cross-sectional study was conducted in four rural communities of northeastern Trinidad to determine the microbial quality of water supply to households and that quality's relationship to source and storage device. Of the 167 household water samples tested, total coliforms were detected in 132 of the samples (79.0 por cent), fecal coliforms in 102 (61.1 por cent), and E. coli in 111 (66.5 por cent). There were significant differences among the towns in the proportion of the samples contaminated with coliforms (P < 0.001) and E. coli (P < 0.001). Of 253 strains of E. coli studied, 4 (1.6 por cent) were mucoid, 9 (3.6 por cent) were hemolytic, and 37 (14.6 por cent) were nonsorbitol fermenters. Of 69 isolates of E. coli tested, 10 (14.5 por cent) were verocytotoxigenic. Twenty-eight (14.0 por cent) of 200 E. coli isolates tested belonged to enteropathogenic serogroups. Standpipe, the most common water source, was utilized by 57 (34.1 por cent) of the 167 households. Treated water (pipeborne in homes, tandpipes, or truckborne) was supplied to 119 households (71.3 por cent), while 48 households (28.7 por cent) used water from untreated sources (rain, river/stream, or well) as their primary water supply. The type of household storage device was associated with coliform contamination. Water stored in drums, barrels, or buckets was more likely to harbor fecal coliforms (74.2 por cent of samples) htan was water stored in tanks (53.3 por cent of samples), even after controlling for water source (P = 0.04). Compared with water from other sources, water piped into homes was significantly less likely to be contaminated with total coliforms (56.9 por cent) versus 88.8 por cent, P<0.001) and fecal coliforms (41.2 por cent versus 69.8 por cent, P<0.01), even when the type of storage device was taken into account. However, fecal contamination was not associated with whether the water came from a treated or untreated source. We concluded that the drinking water in rural communities in Trinidad was grossly unfit for human consumption, due both to contamination of vaious water sources and during household water storage