ABSTRACT
Objetivo: o objetivo do presente estudo foi avaliar in vitro a microin ltraçaÌo coronaÌria em cavidades complexas seladas com materiais restauradores temporaÌrios (MRT). MeÌtodos: as cavidades foram preparadas em 60 preÌ-molares superiores extraiÌdos de humanos, e os espeÌcimes foram divididos em treÌs grupos, de acordo com o MRT utilizado: G1 = IRM; G2 = Coltosol; G3 = Fill Magic Tempo. TreÌs dentes serviram como controle negativo e naÌo tiveram cavidades preparadas. Antes do selamento das cavidades com o MRT, uma esponja de colaÌgeno foi deixada dentro da caÌmara pulpar, para avaliaçaÌo binaÌria da penetraçaÌo do corante. Dez dentes de cada grupo naÌo foram submetidos aÌ açaÌo de termociclagem e força mecaÌnica oclusal, enquanto outros dez foram submetidos a essas açoÌes. A amostra foi imersa em corante Rodamina B a 0,5% a 37°C, por 7 dias. Resultados: todos os dentes examinados (100%), exceto os controles negativos, apresentaram in ltraçaÌo pelo corante. Todos os dentes selados com Coltosol (100%) fraturaram apoÌs ensaio mecaÌnico, enquanto aqueles com IRM e Fill Magic Tempo mantiveram-se intactos macroscopicamente. A açaÌo ou naÌo das intempeÌries teÌrmicas e mecaÌnicas naÌo interferiu na penetraçaÌo do corante nas amostras no presente estudo. ConclusaÌo: nenhum dos materiais testados impediu a in ltraçaÌo do corante. No entanto, o Coltosol naÌo deve ser indicado para utilizaçaÌo em cavidades complexas onde haÌ incideÌncia de forças mastigatoÌrias, devido ao seu alto iÌndice de fratura.
Subject(s)
Humans , Coloring Agents , Dental Leakage/diagnosis , Dental Materials/therapeutic use , Mechanical Phenomena/drug effectsABSTRACT
The objective of this study was to consider the effects of boron [B] and calcium [Ca] supplementation on mechanical properties of bone tissues and mineral content of selected bones in rats. Adult male Sprague Dawley rats underwent three different treatments with boron and calcium in their drinking water, while being fed ad libitum for 4weeks. Rats were placed into three treatment groups: group1 were given 2 mg B/d; group 2, 300 mg Ca/d, and group 3, a combination of 2 mg B + 300 mg Ca/d. After the experimental period body weights were recorded and bone mechanical properties were determined on the tibiae, femurs, and fifth lumbar vertebral bones and the mineral contents of these bones was calculated as the ash percentage. Bone mechanical properties were observed to be better after boron supplementation. The hardness of the lumbar vertebral bones tended to increase in all groups. The group receiving Boron supplementation demonstrated maximal hardness in all bones while calcium supplementation had the least effect; however, in the case of lumbar vertebral bones, this negative effect was corrected in the presence of boron,. Highest mean energy to maximal load was shown with boron supplementation, demonstrating significant differences with Ca group; in comparison with the controls, least difference in mean energy to maximal load, was seen in the Calcium group. There were no significant differences in energy and deformation with ultimate load among the four groups. There were no significant differences in ash weights among the four groups. Boron supplementation increased the bone mechanical properties in rats and its efficiency tended to be higher in lumbar vertebral bones