Avaliação funcional do desenho de três brocas de preparo para colocação do implante dentário / Functional evaluation of three different drill designs for dental implant osteotomy: an in vitro study

Objetivos: avaliar o desempenho de furação de brocas. Material e métodos: três sistemas de implantes brasileiros foram testados: A (FGM, Joinville); B (Neodent, Curitiba); e C (SIN, São Paulo). A força de furação foi mantida constante e igual a 35 N. A rotação das brocas foi de 800 rpm e os corpos-de-prova foram mantidos em temperatura de 36°C ± 2°C, sendo a água destilada como fluido refrigerante. Dados sobre a temperatura e torque de furação foram adquiridos, e o desgaste das brocas foi avaliado por MEV. Os testes Anova e Tukey (α=5%) foram utilizados na análise estatística. Resultados: as brocas são eficazes, não ultrapassando a temperatura de limite biológico (47°C). Conclusão: de acordo com os ensaios realizados, a broca do grupo A reúne características que a habilitam como broca de perfuração única no preparo do leito do implante dentário. A análise em MEV mostrou que os grupos A e B mantiveram os gumes de corte bem defi nidos e sem desgaste aparente.

Objectives: to evaluate the osteotomy performance of implant drills. Material and methods: three different Brazilian dental implant systems were tested: A (FGM, Joinville), B (Neodent, Curitiba), and C (SIN, São Paulo). Drilling force was kept at 35 N. Drill rotation was set at 800 RPM and samples were kept at 36 ± 2°C under water coolant. Data regarding temperature and torque were acquired and drill wear evaluated under SEM. The Anova and Tukey tests (α=5%) were applied for statistical analyses. Results: all drills were effi cient and remained below the biologic limit level (47°C). Conclusion: according to the tests, drills of the A group had characteristics for a single osteotomy at the bone bed for implant placement. The SEM analysis demonstrated that groups A and B still had sharp, well-defi ned cutting edges with no visible wear.

Is optimal cutting temperature compound essential embedding solution treatment to cryo-sectioning of brain tissue?

We tested a set of conditions for obtaining optimal tissue quality in preparation for histology in samples of mouse brain. C57BL/6J mice were sacrificed and perfused with 4% paraformaldehyde, after which the brains were removed and dehydrated in 30% sucrose solution. The brains were then divided into four groups according to freezing temperature and usage of optimal cutting temperature (OCT) compound. Next, we stained the sectioned brain tissues with Harris hematoxylin and eosin Y and immunohistochemistry was performed for doublecortin. The best quality tissue was obtained at -25℃ and by not embedding with the OCT compound. When frozen at -25℃, the embedded tissue was significantly damaged by crystals, while at -80℃ there were no meaningful differences between qualities of embedded- and non-embedded tissues. Overall, we identified a set of conditions to obtain quality frozen brain sections. Our developed protocol will help resolve matters associated with damage caused to sectioned brain tissue by crystal formation during freezing.