RESUMO
OBJECTIVES: This study evaluated the flexibility and abrasion capacity of the bristles of four soft toothbrush brands. METHODS: Toothbrushes from groups: 1: Aquafresh Flex; 2: Oral-B Indicator; 3: Colgate Classic; 4: Johnson and Johnson Reach were used for the buckling deformation flexibility assay with of load (40 g) for a 5-s period and the measurement of the diameter of the bristles using a comparison gauge (precision: 1 µm), and for the abrasion assay in a brushing machine in 100-min cycles with a standard dentifrice in a 1:1 solution with distilled water and load of 200 g. The data were normalized due to the difference in the size of the toothbrush heads and analysed by the anova and the Tukey test to adjust for multiple comparisons (α = 0.05). RESULTS: A significant difference in the flexibility of the bristles (toothbrushes from groups 2, 3 and 4 were more flexible than 1) was observed. There was no correlation between the increase in the diameter of the bristles and the reduction in flexibility. The statistical analysis revealed loss of mass due to abrasion, varying according to the flexibility of the bristles, with group 1 causing lower wear than groups 2, 3 and 4. CONCLUSIONS: The results of this study showed that there are variations in bristle flexibility abrasion potential of soft-classified toothbrushes.
Assuntos
Dispositivos para o Cuidado Bucal Domiciliar/efeitos adversos , Abrasão Dentária/etiologia , Escovação Dentária/efeitos adversos , Escovação Dentária/instrumentação , Análise de Variância , Desenho de Equipamento , Humanos , Modelos Dentários , Maleabilidade , Estatísticas não ParamétricasRESUMO
AIM: The aim of this in vitro study was to evaluate the superficial roughness of amalgam specimens made with Velvalloy and Permite alloys, with superficial protection (Nail polish or Varnish-Fluorniz) and without protection, immersed in artificial saliva or Coke. METHODS: All the 84 specimens (N = 7) were performed according to the manufacturer's recommendations for each alloy, condensed in acrylic moulds and immediately polished. The superficial protections were made before the immersion in the proposed solutions. After superficial treatment, the specimens were maintained at 37 degrees C during 21 days. All specimens were brushed with a tooth paste twice a day. The roughness analysis was carried out using a Prazis equipment (Ra) in four moments (T): after 48 hours (T1), 7 days (T2), 14 days (T3) and 21 days (T4). The data of each alloy were individually submitted to statistical analysis (ANOVA) and Tukey test (P < 0.01). RESULTS: Statistical analysis has demonstrated the existence of a significance difference for the studying factors, except for immersion. The mean values of superficial roughness, for evaluated groups, in relation to protection and time factor were, respectively: Po (1.16) = P1 (1.13) < P2 (2.96) and T1 (1.56) = T2 (1.66) = T3 (1.77) < T4 (2.01) for Velvalloy; and Po (1.14) = P1 (0.85) < P2 (2.61) and T1 (1.18) < T2 (1.48) = T3 (1.67) = T4 (1.79) for Permite. CONCLUSION: It was concluded that the use of nail polish as superficial protection presented less roughness than varnish for the studied alloys; and Velvalloy roughness increased at 21 days while Permite increased at seven days and presented a tendency to stability.
Assuntos
Cosméticos/farmacologia , Amálgama Dentário , Fluoretos Tópicos/farmacologia , Propriedades de Superfície/efeitos dos fármacosRESUMO
The purpose of this study was to evaluate cervical mistifing of casting full metal crowns according to investment techniques using commercial available alloys made from silver stannum. Fifteen metal full crowns were obtained through stainless steel die with full crowns preparation, included into three groups as follows: conventional technique, vacuum technique and pressure technique. Readings of cervical disagreement were made through a comparing microscope increased 45 x and each crown was measured in 4 different regions (vestibular, lingual mesial and distal). This way it was verified which of the techniques proposed would balance the casting shrinkage for the silver-stannum alloy used. From the results obtained we conclude that the best cercical adaptation was the one got through pressure technique.
Assuntos
Coroas , Ligas Dentárias , Revestimento para Fundição Odontológica , Técnica de Fundição Odontológica , Infiltração Dentária/etiologia , Prata , EstanhoRESUMO
The authors studied the staining of specimens of composite resins, when they were immersed in Lugol solution. In this study, we related chemical and photo-activated resins, and the estructure modifications were analysed in relation to the consulted bibliography. The use of Lugol solution showed a practical way to identify the possible modifications in the polymeric structure of the composite resins.