Biologic width and its importance in periodontal and restorative dentistry

An adequate understanding of the relationship between periodontal tissues and restorative dentistry is paramount to ensure adequate form, function, esthetics and comfort of the dentition. While most clinicians are aware of this important relationship, uncertainty remains regarding specific concepts such as biologic width, its maintenance and applications of crown lengthening in cases of biologic width violation. Relevant publications regarding biologic width, its violation and management were identified up to August 2011 using manual and electronic database search in Medline, Embase, Directory of Open Access Journals and Google Scholar. This review discusses the concept of biologic width around tooth and its relationship to periodontal health and restorative dentistry

Aspectos cinemáticos e neuromusculares relacionados com o desempenho da saída do bloco na natação

O objetivo deste estudo foi relacionar o desempenho (distância e tempo de voo) na saída de bloco com variáveis cinemáticas e neuromusculares. Participaram 10 nadadores do sexo masculino (26,4 ± 6,6 anos, 76,4 ± 6,6 kg, 1,81 ± 0,07 m de estatura). Utilizou-se uma câmera filmadora (30 Hz) para a aquisição das variáveis cinemáticas, sendo analisadas: distância de voo, tempo de voo, altura máxima do quadril, ângulos de saída de bloco e entrada na água. Para a obtenção da potência muscular foi utilizado o "Squat Jump" realizado sobre uma plataforma de força. Foram obtidas as seguintes variáveis: altura do salto, potência e pico de velocidade. Utilizou-se estatística descritiva e correlação de Pearson para relacionar as variáveis neuromusculares e cinemáticas com o desempenho na saída de bloco, utilizando nível de significância de 5%. Encontrou-se correlação significativa do ângulo de saída com a distância (r = -0,59) e com o tempo de voo (r = 0,88), além da altura máxima com o tempo de voo (r = 0,59). Não foi observada correlação significativa da distância e do tempo de voo com as variáveis neuromusculares (p > 0,05). Com base nos resultados pode-se concluir que o desempenho na saída de bloco da natação foi relacionado com o ângulo de saída de bloco e com a altura máxima do quadril na fase aérea. A potência muscular não interferiu no desempenho nos nadadores investigados.The aim of this study was to investigate the association between the performance of the start off the swimming block with kinematical and neuromuscular parameters (flight distance and flight time). Ten male swimmers (26.4 ± 6.6 years, 76.4 ± 6.6 kg, 1.81 ± 0.07 m) participated in the study. A video camera (30 Hz) was used to obtain the kinematic variables: flight distance, flight time, maximum height, start angle and entry angle. Muscle power was assessed via the performance of a Squat Jump on a force plate. Jump height, power and peak of velocity were analyzed. Pearson correlation was used to correlate kinematic and neuromuscular variables with starting performance. The level of significance was set at 5%. A significant correlation between the starting angle and both the flight distance (r = -0.59) and the flight time (r = 0.88) were found; also, a positive correlation was found between maximum height and flight time (r = 0.59). No significant correlation between swimming start performance and neuromuscular parameters (p>0.05) were found. We can conclude that performance in the swimming start was related with the start angle and maximum height. Muscle power did not affect swimming start performance in this study