Internal connection implants presented the most favorable biomechanical situation, whereas the least favorable situation was the biomechanical behavior of external connection implants. Parafunctional loading increased the magnitude of stress by 3 to 4 times.

It was concluded that the patients presented high level of satisfaction and quality of life for the most of the items evaluated as well as the groups showed similar results.

The aim of this study was to assess, by the three-dimensional finite element method, the influence of crown-to-implant ratio and parafunctional occlusal loading on stress distribution in single external hexagon implant-supported prosthesis. Computer-aided design software was used to confection three models. Each model was composed of a block bone and an external hexagon implant (5x10.0 mm) with screw-retained implant prostheses, varying the height crown: 10, 12.5 and 15 mm. Finite element analysis software was used to generate the finite element mesh and to establish the loading and boundary conditions. Normal (200 N axial and 100 N oblique load) and parafunctional forces (1,000 N axial and 500 N oblique load) were applied. The results were visualized by von Mises and maximum principal stress. In comparison with the normal occlusal force, the parafunctional occlusal force induced an increase in stress concentration and magnitude on implant (platform and first threads) and screw (neck). The cortical bone showed the highest tensile stress under parafunctional force (oblique load). The stress concentration increased as the crown height increased. It was concluded that: increasing the C/I increased stress concentration in both implant components and cortical bone; parafunctional loading increased between 4-5 times the value of stresses in bone tissue compared with functional loading; the type of loading variation factor is more influential than the crown-to-implant factor.

ObjectiveThe aim of this study was to gather information and discuss the predictability of implant-supported prostheses in patients with bruxism by performing a literature review. Methods In order to select the studies included in this review, a detailed search was performed in PubMed and Conclusion Although there is still no general consensus on this matter, most of the literature review articles do provide clinical guidelines that contribute to implant supported prostheses longevity and stability in patients with bruxism.Indexing terms: Bruxism. Dental implantation. Dental prosthesis. RESUMO ObjetivoRealizar uma revisão sistemática, a fim de reunir informações e discutir a previsibilidade de próteses sobre implantes em pacientes com bruxismo.Métodos Para a identificação dos estudos dessa revisão, foi realizada uma estratégia de busca detalhada e avançada nos bancos de dados PubMed e Medline. Foram utilizados como descritores: bruxismo, implantes dentários, prótese implantossuportada e falha da restauração dentárial; bruxism, dental implants, implant-supported prosthesis e dental restoration failure. Os critérios de inclusão foram: artigos clínicos, estudos controlados aleatórios, estudos in vitro, revisões de literatura e revisões sistemáticas com e sem meta-análise dos últimos 20 anos que abordassem o tema proposto. Os critérios de exclusão foram: artigos sem resumo, estudos em animais, artigos cujo idioma não fosse o inglês e artigos de periódicos que não pertencessem à área odontológica. ResultadosDe um total de 54 artigos, após uma análise segundo o critério de inclusão e exclusão, foram selecionados 28 artigos. É sabido que a quantidade de artigos científicos que avaliaram, seja através de estudos retrospectivos, prospectivos ou experimentais, o impacto biológico e biomecânico do bruxismo em próteses sobre implantes é pequena e pouco tem contribuído para melhor exemplificação e discernimento dos limites protéticos de segurança para o especialista sob um ponto de vista clínico. ConclusãoPortanto, ainda não há um consenso geral acerca desse assunto, porém, a maioria dos artigos de revisão de literatura fornecem guias de orientação clínica, os quais auxiliam na longevidade e estabilidade de próteses sobre implantes em pacientes com bruxismo.Termos de indexação: Bruxismo. Implantação dentária. Prótese dentária. failure. Items that were included are: case reports, randomized controlled trials, in vitro studies, literature and systematic reviews, with or without meta-analysis, of the last 20 years that addressed the theme. Articles without abstracts, animal studies, articles in languages other than English and articles from journals unrelated to the dental field were excluded. After analysis according to inclusion and exclusion criteria, 28 articles were selected from a total of 54. The obtained data were then analysed, crossreferenced and debated in order to reach conclusions. Relation between bruxism and dental implants