RESUMO
The aim of this in vitro study was to evaluate marginal leakage in class V restorations in primary teeth restored with amalgam, using three different techniques. Thirty maxillary anterior primary teeth, clinically sound and naturally exfoliated, were used. In group 1 (n = 10), two thin layers of a copal varnish (Cavitine) were applied. In group 2 (n = 10), Scotchbond Multi-Purpose Plus, a dual adhesive system, was used according to manufacturer instructions. In group 3 (n = 10), One-Step adhesive system in combination with a low-viscosity resin (Resinomer) were used according to manufacturer instructions. All samples were restored with a high-copper dental amalgam alloy (GS 80, SDI). After restoration, the samples were stored in normal saline at 37 degrees C for 72 h. The specimens were polished, thermocycled (500 cycles, 5 degrees and 55 degrees C, 30-s dwell time) and impermeabilized with fingernail polish to within 1.0 mm of the restoration margins. The teeth were then placed in 0.5% methylene blue for 4 h. Finally, the samples were sectioned and evaluated for marginal leakage. The Kruskal-Wallis test showed that the filled adhesive resin (group 3) had the least microleakage. There was no significant difference between groups 1 and 2.
Assuntos
Amálgama Dentário , Colagem Dentária/métodos , Infiltração Dentária/prevenção & controle , Restauração Dentária Permanente/métodos , Dente Decíduo , Resinas Compostas , Forramento da Cavidade Dentária , Materiais Dentários , Adesivos Dentinários , Humanos , Incisivo , Maxila , Metacrilatos , Cimentos de Resina , Resinas Vegetais , Estatísticas não ParamétricasRESUMO
PURPOSE: To evaluate with the scanning electron microscope (SEM) the effects of a pulsed Nd: YAG laser on the occlusal surface of human premolars in vitro. MATERIALS AND METHODS: Twenty normal premolars extracted for orthodontic reasons were used and separated in two groups. Group 1 received the irradiation at 2.0 watts, repetition rate of 20 Hz and 124.3 J/cm2 of energy density during 3 minutes, on the occlusal fissure. Group 2 received the laser irradiation in only half of the fissure. RESULTS: The SEM analysis revealed that in the case of shallow fissures the sealing was total but in narrow and deep fissure the sealing was partial or was in complete.
Assuntos
Esmalte Dentário/efeitos da radiação , Fissuras Dentárias/radioterapia , Lasers , Dente Pré-Molar , Humanos , Terapia a Laser , Microscopia Eletrônica de Varredura , NeodímioRESUMO
A estrutura de esmalte aprismático de fissuras de premolares humanos foi observada através de superfícies fraturadas vestíbulo-lingualmente. Os resultados mostraram que a camada aprismática margeia a superfície da fissura em toda extensão. A espessura da camada aprismática é aumentada na porção média da fissura a qual é semelhante aquela encontrada nas superfícies vestibular e lingual. Os cristais de hidroxiapatita dispondo-se paralelamente são claramente vistos em aspectos tridimensionais