This retrospective study evaluated the clinical outcome of 139 teeth restored with carbon fiber posts after 3 years of placement, considering the amount of remaining dentin as the main variable. Eighty-one patients received the fiber posts within a period of 16 months and were recalled after 3 years. The tooth type, amount of remaining dentin, and prosthetic crown material were evaluated. No loss of post or core retention was detected after 3 years of follow up. During the observed time, root or post fracture and secondary caries were not recorded. Only one failure concerning endodontic treatment was detected. The amount of remaining dentin was not an important characteristic in the restorative failure of endodontically treated teeth restored with carbon fiber posts within 3 years.

The prevention of dental enamel wear has particular relevance for preventive and restorative purposes in dentistry. The wear damage can increase due to salivary disorders and/or parafunction (bruxism); antagonists incisal surfaces become flat and coincident. This study aims to investigate the wear behavior and the related mechanisms in sliding pairs of conformal incisal enamel, with similar values of hardness and fracture toughness, with different applied normal loads and lubricated conditions. Bovine incisors, under pin on flat configuration, were tested in two lubrication condition (dry or with natural saliva) and two applied normal loads (8 and 16 N). The worn surfaces were investigated by 3D profilometry and SEM. The analysis of worn surfaces indicated mechanisms of brittle fracture, but with different severities. Under a normal load of 16 N and dry condition, wear is controlled by a brittle process: microcracking with flake-like wear particles, which results in high friction coefficient (> 0.85), wear rate and wear volume. On the other hand, under a normal load of 8 N and natural saliva, wear took place in the interprismatic region, with consequent exposure of prisms and fracture in localized regions. In this case, the friction coefficient was 16% lower and the wear volume was one order of magnitude lower. Under 8 N and natural saliva, the wear was greater than in the dry condition, probably due to tribochemical reactions.

Agradecer tem a ver com viver uma experiência boa, alegre. Um esforço contra tudo que pode nos entristecer; resistência. Parece que, numa caminhada como esta, somos orientados pela insistência. Tudo que somos é oriundo de um esforço para continuar a ser e, ainda, esta força é o que nos move para nos tornarmos cada vez melhores. E, assim, vivemos dificuldades diárias, alegrias e tristezas, em busca de uma maior potência para nós mesmos, em busca de aperfeiçoamento, o que nos estimula a continuar lutando. Lutas que sempre travaremos. Isto é o que vale a pena. É o que torna a vida feliz. Porque a dificuldade é parte do caminho, e, lutar contra ela, também. Por tudo, agradeço: à minha família, Maria, Alfredo, Rodrigo e Pedro, que, conviveu com minha ausência, ao mesmo tempo que sempre apoiou incondicionalmente e respeitou minhas decisões. O amor, o companheirismo, uma palavra de carinho e, até mesmo, o silêncio num abraço são bens inestimáveis;