Reabilitação com implantes dentários em doentes periodontais

Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas MonizOs implantes dentários são considerados, atualmente, uma alternativa de reabilitação oral em pacientes desdentados, devido à estética, funcionalidade e à efetividade que proporcionam. Apesar das diversas vantagens e das elevadas taxas de sobrevivência, têm sido relatadas complicações e casos de insucesso. A periodontite é uma doença inflamatória oportunista do periodonto e é amplamente considerada como uma das doenças mais comuns em todo o mundo, sendo uma das principais causas de perda de peças dentárias. Tendo em conta que a reabilitação com implantes é uma opção terapêutica muito utilizada em pacientes edêntulos por doença periodontal, torna-se pertinente avaliar os fatores que condicionam o prognóstico da mesma. Os estudos analisados concluem que a reabilitação com implantes dentários é uma opção de tratamento viável para os doentes periodontais, contudo, há evidência de que os pacientes com história de doença periodontal podem apresentar um risco superior no que diz respeito à falha dos implantes e a complicações futuras, incluindo periimplantite e uma maior perda de osso de suporte, em comparação com pacientes peridontalmente saudáveis. Deste modo, a reabilitação com implantes dentários em pacientes periodontais não está contraindicada, desde que esta seja precedida por uma avaliação periodontal completa e estabilização da doença. Para uma maior longevidade e sucesso do tratamento, é igualmente importante que o paciente compareça regularmente às consultas de manutenção.Dental implants are currently reputed as an oral rehabilitation alternative in edentulous patients due to their aesthetics, functionality and effectiveness. Despite the many advantages of this type of rehabilitation and the high survival rates, complications and cases of failure have been reported. Periodontitis is an opportunistic inflammatory disease of the periodontium and is broadly considered one of the most common diseases worldwide, being one of the main causes of tooth loss. Taking into account that implant rehabilitation is a widely adopted option by edentulous patients due to periodontal disease, it is relevant to evaluate the factors that might limit the use of this therapeutic option. The studies that have been analyzed establish that dental implant rehabilitation is a viable treatment option for periodontal patients, however there are evidences that patients with a history of periodontal disease may present a higher risk of implant failure and future complications, including peri-implantitis and a bigger support bone loss, compared with periodontally healthy patients. Thus, rehabilitation with dental implants in periodontal patients is not contraindicated, provided that it is preceded by a complete periodontal evaluation and stabilization of the disease. For a bigger longevity and success of the treatment, it is equally important that the patient attends regularly to the maintenance appointments

User- and process-driven dynamic voltage and frequency scaling

We describe and evaluate two new, independently-applicable power reduction techniques for power management on processors that support dynamic voltage and frequency scaling (DVFS): user-driven frequency scaling (UDFS) and process-driven voltage scaling (PDVS). In PDVS, a CPU-customized profile is derived offline that encodes the minimum voltage needed to achieve stability at each combination of CPU frequency and temperature. On a typical processor, PDVS reduces the voltage below the worst-case minimum operating voltages given in datasheets. UDFS, on the other hand, dynamically adapts CPU frequency to the individual user and the workload through direct user feedback. Our UDFS algorithms dramatically reduce typical operating frequencies and voltages while maintaining performance at a satisfactory level for each user. We evaluate our techniques independently and together through user studies conducted on a Pentium M laptop running Windows applications. We measure the overall system power and temperature reduction achieved by our methods. Combining PDVS and the best UDFS scheme reduces measured system power by 49.9% (27.8% PDVS, 22.1% UDFS), averaged across all our users and applications, compared to Windows XP DVFS. The average temperature of the CPU is decreased by 13.2°C. User trace-driven simulation to evaluate the CPU only indicates average CPU dynamic power savings of 57.3% (32.4% PDVS, 24.9% UDFS), with a maximum reduction of 83.4%. In a multitasking environment, the same UDFS+PDVS technique reduces the CPU dynamic power by 75.7% on average. © 2009 IEEE.link_to_subscribed_fulltex

Power reduction through measurement and modeling of users and CPUs: Summary

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User-driven frequency scaling

We propose and evaluate User-Driven Frequency Scaling (UDFS) for improved power management on processors that support Dynamic Voltage and Frequency Scaling (DVFS), e.g, those used in current laptop and desktop computers. UDFS dynamically adapts CPU frequency to the individual user and the workload through a simple user feedback mechanism, unlike currently-used DVFS methods which rely only on CPU utilization. Our UDFS algorithms dramatically reduce typical operating frequencies while maintaining performance at satisfactory levels for each user. We evaluated our techniques through user studies conducted on a Pentium M laptop running Windows applications. The UDFS scheme reduces measured system power by 22.1%, averaged across all our users and applications, compared to the Windows XP DVFS scheme.link_to_subscribed_fulltex

Power reduction through measurement and modeling of users and CPUs: Summary

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