ABSTRACT
AIM: To evaluate the influence of varying the water/powder ratio on the compressive strength of type IV mineral and synthetic casts. METHODS: Four commercial brands of type IV mineral and synthetic casts were evaluated: Durone, Herostone, Fuji Rock, and Elite Rock. Ninety-six test samples were prepared from a silicone matrix, according to ADA's standard no. 25. The samples were prepared according to the manufacturer's recommendations with a normal water/powder ratio (n = 12) and with 20% extra water (n = 12), forming the control (A) and experimental (B) subgroups, respectively. Compressive strength tests were performed using a universal testing machine EMIC (DL 2000) with a load cell of 2,000 kgf/cm2. The obtained data were analyzed statistically using two-way ANOVA and Tukey's test (α=5%). RESULTS: The synthetic Elite Rock cast was statistically different from the one obtained when the portion of water indicated by the manufacturer was used; no significant differences were found in the remaining casts when the proportion of water was increased by 20%. CONCLUSIONS: the groups of synthetic and mineral casts differed and the water increase (20%) did not cause significant difference on the compressive strength of the materials...
Subject(s)
Humans , Calcium Sulfate , Dental MaterialsABSTRACT
Este trabalho teve por objetivo avaliar o conhecimento de ortodontistas quanto aos principais aspectos legais relacionados ao exercício da Ortodontia que podem ser utilizados como importantes instrumentos de defesa em caso de ação ética e/ou judicial. Neste estudo transversal e descritivo, dos 46 cirurgiões dentistas inscritos no Conselho Regional de Odontologia do Piauí como especialistas em Ortodontia ou Ortodontia e Ortopedia Facial, 25 (54,3%) concordaram em participar da pesquisa. Um questionário fechado abordando os aspectos éticos e legais da Ortodontia foi respondido e os dados analisados no programa Excel. Os resultados mostraram que os profissionais avaliados estão sujeitos a problemas judiciais futuros. Foi observado o desconhecimento de termos tais como obrigação de meios, obrigação de resultados e inversão do ônus da prova. Houve grande divergência entre os profissionais em relação ao tempo de arquivamento da documentação ortodôntica. Apesar de todos os especialistas terem cursado disciplina de ética e legislação, há a necessidade de aprofundarem seus conhecimentos em relação ao tema para uma prática clínica mais segura.
This study aimed to evaluate the knowledge of orthodontists about the main legal issues related to the practice of orthodontics that can be used as important instruments of defense on cases of lawsuit. At this crosssectional and descriptive study, from the 46 dentists enrolled in the Regional Council of Dentistry of Piauí as specialists in Orthodontics or Facial Orthopedics and Orthodontics, 25 (54,3%) have agreed to join the research. A closed questionnaire addressing the ethical and legal aspects of orthodontics was filled and the data analyzed using Microsoft Excel. The results showed that the studied population is a possible target for future law suits. It was observed a lack of knowledge regarding some important terms, such as: obligation of means, obligation of results and reversal of the burden of proof. There was great disagreement among professionals regarding the time of storage of orthodontic documentation. Even after all the experts reported to have attended the discipline of legal ethics, it is necessary to reinforce their knowledge about this subject for a safer clinical practice.