ABSTRACT
Abstract The aim of this study was to evaluate the efficacy of an ultrasound device and the dentin surface morphology after removal of the caries dentin lesions by removal rate and scanning electron microscopy (SEM). The Knoop hardness test on the bovine dentin blocks (n = 20, 4x4x2mm) was performed to standardize the samples and only those with 38 ± 2 KHN were included. The dentin blocks were submitted to induction of artificial caries lesions, using the bacterial model. Strains of Streptococcus mutans and Lactobacillus acidophilus were used for 7 days. The caries dentin lesion was removed for 1 min, according to two methods: G1 - carbide bur under low-speed rotation (control group) and G2 - ultrasound device under refrigeration. For the removal rate, the samples were weighed 3 times: T0 (before induction), T1 (after induction) and T2 (after removal). Morphology evaluation of the residual dentin surface was performed by SEM. Data normality was verified by Shapiro-Wilk test (p ≥ 0.240). T-test for independent samples was applied to evaluate the removal rate. A significance level of 5% was adopted. G2 provided lower removal rate than G1 (G1: 3.68 mg and G2 = 2.26 mg). SEM images showed different morphological characteristics between the groups. G2 showed absent of smear layer, while G1 showed a visible smear layer over the surface. We concluded that ultrasound device provides minimally invasive removal with residual dentin exhibiting open dentin tubules and no smear layer formation and no bacteria, which infer the removal of the infected tissue.
Resumo O objetivo deste estudo foi avaliar a eficácia de um dispositivo ultrassônico e a morfologia da superfície dentinária após a remoção da dentina cariada por meio da taxa de remoção e imagens de microscopia eletrônica de varredura (MEV). Foi realizado o teste de dureza Knoop nas amostras de dentina bovina (n = 20, 4x4x2mm) afim de padronizar as amostras e foram incluídas apenas aquelas com 38 ± 2 KHN. As amostras de dentina foram submetidas à indução de lesões artificiais de cárie, utilizando-se modelo biológico contendo cepas de Streptococcus mutans e Lactobacillus acidophilus durante por 7 dias. As lesões foram removidas por 1 min, de acordo com dois métodos: G1 - fresa esférica sob baixa rotação (grupo controle) e G2 - dispositivo ultrassônico sob refrigeração. Para a taxa de remoção, as amostras foram pesadas em três tempos: T0 (antes da indução), T1 (após a indução) e T2 (após a remoção). A avaliação morfológica da superfície residual da dentina foi realizada por MEV. A normalidade dos dados foi verificada pelo teste de Shapiro-Wilk (p ≥ 0,240). Teste T para amostras independentes foi aplicado para avaliar a taxa de remoção. Foi adotado nível de significância de 5%. G2 apresentou menor taxa de remoção que G1 (G1: 3,68 mg e G2 = 2,26 mg). As imagens de MEV mostraram características morfológicas diferentes entre os grupos. G2 mostrou ausência de smear layer, enquanto G1 mostrou grande quantidade de smear layer sobre a superfície. Com base neste estudo in vitro, o dispositivo de ultrassom promoveu remoção minimamente invasiva e dentina residual exibindo túbulos dentinários abertos e mínima formação de smear layer.
ABSTRACT
Essential oils derived from plants used as condiments represent a large group of natural antimicrobials. Extracts and essential oils from plants have been shown to be efficient in controlling the growth of a wide variety of microorganisms, including filamentous fungi, yeasts and bacteria. Practical uses of these activities are suggested in humans and animals, as well as in the food industry. This study aimed to evaluate the basal basil essential oil (Ocimum basilicum L.) cytotoxicity in NCTC Clone 929 cell line, mouse connective tissue cells (CCIAL 020), which were seeded in Petri dishes and incubated for 48 hours To to form the cell monolayer. For the this test accomplishment of this test, we counted with the collaboration of the Nucleus of Cell Cultures - NCC of the Adolfo Lutz Institute, of the city of São Paulo-SP. The culture medium used is the solid coating medium, and fragments of the samples fragments are were placed on this coating medium and the plates were again incubated for 24 hours. The Biological Reactivity Degree (GR) index, which is the area not stained by the vital dye, is were observed macro and microscopically. Samples were tested in quadruplicates on separate plates. ThusThereunto, the test result showed that the essential oil was cytotoxic in the cell line studied, and that the future work in pharmacology and toxicology needs to be performed to better standardize the therapeutic dose, which is not cytotoxic as the pure oil behaved.o assess the attitude and practice of dental professionals towards using of advance Radiographic technique.
ABSTRACT
AIM: The aim of this study was to evaluate in vitro the antimicrobial activity of Ocimum basilicum L. (basil) extract in S. Muttans biofilm colonized in specimens confectioned in the same acrylic used for removable orthodontics appliances. MATERIAL AND METHODS: To perform this work, 42 specimens were confectioned (sterile spherical acrylic disks) and immersed in pure extract and in serial dilution of extract (1:2 until 1:10) during 24, 48 and 72 hours. For each time of exposition, a disintegration of bacterial film by sonication in saline and posterior seed in agar, for colony count, were carried out. ATCC strains of S. muttans were selected, and 2% chlorhexidine solution was used as inhibition control. RESULTS: The results showed, by quantitative analysis, that basil extract has antibacterial activity in S. muttans biofilm, when used in pure state or in dilution until 1:4. CONCLUSION: Besides, it was possible observe the more increase the incubation time, independent the dilution, the higher degradation of extract.