Influence of standard load micro- and nanopatterned in surface roughness of bleached teeth and submitted to different surface treatments.

The aim of this study was evaluate the dental enamel after whitening treatment with Opalescence Boost PF™ 38%, correlating the structural alterations in the surface of the enamel with its respective pH and verify if whitened teeth submitted to different finishing and polishing techniques show similar surface texture to healthy teeth (control group). Sixty premolars were divided in 6 groups (n = 10), which had been immersed in artificial saliva during all the experiment. Protocol whitening was performed according to the manufacturer recommendations, and then the specimens were submitted to different polishing technique with Sof-Lex Pop On™ disks, Flex Diamond™ felt disks using two different micrometric polishing pastes (Enamelize™ and Diamond Polish™) and two nanometric polishing pastes (Lummina-E Diamond and Lummina-E Alumina), according to the groups. Representative specimens were analyzed in scanning electronic microscopy (SEM). Whitening gel used in this experiment had modified the morphologic aspect of the enamel surface. It was found that two nanometric polishing pastes (G5 and G6) promoted a less rough surface compared to control group even after the whitening process.

Human dental enamel and dentin structural effects after Er:YAG laser irradiation.

UNLABELLED: Ideally projected to be applied on soft tissues, infrared lasers were improved by restorative dentistry to be used in hard dental tissues cavity preparations--namely enamel and dentin. This paper evidentiates the relevant aspects of infrared Erbium laser's action mechanism and its effects, and characterizes the different effects deriving from the laser's beams emission. The criteria for use and selection of optimal parameters for the correct application of laser systems and influence of supporting factors on the process, such as water amount and its presence in the ablation process, protection exerted by the plasma shielding and structural factors, which are indispensable in dental tissues cavity preparation related to restorative technique, are subordinated to optical modifications caused by the interaction of the energy dissipated by these laser light emission systems in the targeted tissue substrate. CLINICAL RELEVANCE: Differences in the action of infrared Erbium laser system in regard to the nature of the ablation process and variations on the morphological aspects observed in the superficial structure of the target tissue irradiated, may be correlated to the structural optical modifications of the substrate produced by an interaction of the energy propagated by laser systems.

Influence of the internal conditioning of indirect restorations of resin composite in relation to microleakage using LEDs and QTH units.

The current study evaluated in-vitro microleakage of indirect composite inlays fixed with flowable composite and resinous cement and cured by LEDs and QTH units, thus modifying the internal conditioning of the inlays. Thirty-two non-carious teeth were selected and 64 cavity preparations were performed in both enamel and cementum. These teeth were divided into four groups: I--Elipar FreeLight appliance and Filtek Flowable composite; II--Ultralux appliance and Filtek Flowable composite; III--Elipar FreeLight appliance and RelyX cement and IV--Ultralux appliance and RelyX cement. The inlays were internally sandblasted with aluminum oxide, etched with 37% phosphoric acid, washed and silanized. The dental etching was carried out with 37% phosphoric acid for 15 seconds in dentin and 30 seconds in enamel. After being washed and dried, Single Bond dentinal adhesive was then applied, and the inlays were fixed with their respective luting agents, cured in close contact with their surfaces for 60 seconds, thermocycled and immersed in 0.5% basic fuchsine solution. The teeth were then washed and sectioned through the center of the restoration in order for the microleakage readings to be performed using the Image Tool Software. Then, ANOVA and Tukey's statistical tests were applied. In enamel, there was no significant difference for both groups with regard to microleakage; in cementum, the significant difference was 5% (p > 0.005). In agreement with the results, the inlays can be fixed with RelyX and Filtek Flowable resins.

A thermal investigation of dental bleaching in vitro.

OBJECTIVE: Our goal was to investigate the surface temperature variations in the cervical region via infrared thermography, as well as the temperature within the pulp chamber via thermocouples, of mandibular incisors when subjected to dental bleaching using two different 35% hydrogen peroxide gels, red (HP) and green (HPM), when activated by halogen light (HL) and LED light. BACKGROUND DATA: Temperatures increases of more than 5.5 degrees C are considered to be potentially threatening to pulp vitality, while those higher than 10 degrees C can result in periodontal injury. MATERIALS AND METHODS: Tooth samples were randomly divided into four groups (n = 10 each), according to the bleaching agent and catalyst light source used. RESULTS: Mean values and standard deviations of the temperature increases inside the pulp chamber in the HL groups were 4.4 degrees +/- 2.1 degrees C with HP, and 4.5 degrees +/- 1.2 degrees C with HPM; whereas in the groups using LED light, they were 1.4 degrees +/- 0.3 degrees C for HP, and 1.5 degrees +/- 0.2 degrees C for HPM. For the root surfaces, the maximum temperature increases in the groups irradiated with HL were 6.5 degrees +/- 1.5 degrees C for HP, and 7.5 degrees +/- 1.1 degrees C with HPM; whereas in the groups irradiated with LED light, they were 2.8 degrees +/- 0.7 degrees C with HP, and 3 degrees +/- 0.8 degrees C with HPM. There were no statistically significant differences in pulp and surface temperature increases between the groups using different gels, although the mean temperature increases were significantly higher for the groups irradiated with HL when compared with those irradiated with the LED light (p < 0.05 with Tukey's test). CONCLUSION: LED light may be safe for periodontal and pulp tissue when using this method, but HL should be used with care.

Estudo da influência da retençäo de corantes na translucidez de resinas compostas: efeito de materiais, tempo e meios de imersäo / Dye retention influense in the composite resins translucence: effect of materials, time and immersion ways

Os autores investigaram "in vitro" a influência da retençäo de corantes na translucidez das resinas compostas Herculite X para Esmalte (M1), para Dentina (M2) e Silux Plus para Esmalte (M3) e para Dentina (M4). Os corpos de prova foram submedidos a quatro diferentes meios de imersäo: I1 - coca-cola; I2 - café; I3 - vinho tinto; I4 - nicotina. A medida da translucidez foi obtida em três tempos diferentes: P0 - 1 hora antes da imersäo; P1 - após 2 horas após imersäo e P2 - 24 horas após imersäo. Com base na metodologia os autores concluíram que: 1) o material M1 apresentou maiores níveis percentuais de translucidez quando comparado com o material M3; 2) o meio de imersäo I2 propiciou menor translucidez seguido em ordem crescente por I3 e I4 que se apresentaram semelhantes e menores que I1; 3) em relaçäo ao tempo, a translucidez apresentou-se decrescente caracterizando manchamento lento e gradual

Estudo da rugosidade superficial da resina composta submetida à açäo do jato de bicarbonato de sódio: efeitos da velocidade de vazäo de água e materiais / Study of superficial rugosity of composite resins submitted to sodium bicarbonate irrigation: effect of waters flow velocity and materials

Foi realizado estudo comparativo da rugosidade superficial de cinco marcas diferentes de resinas compostas: Adaptic, Herculite, Estic-microfill, Silux e P-30, submetidas à acäo do jato de bicarbonato de sódio do aparelho Profident, nas velocidades da vazäo de água, mínima, média e máxima. Os corpos-de-prova foram confeccionados com auxílio de uma matriz circular, e as alteraçöes superficiais foram analisadas no aparelho Hommel Tester T.1000 para medir a rugosidade inicial e após o tratamento com o jato abrasivo. Os dados obtidos foram submetidos a tratamento estatístico que, após análise e discussäo, permitiram concluir que a aplicaçäo do jato de bircabonato de sódio altera a superfície das resinas compostas, deixando-a mais rugosa, e que os materiais estudados exerceram níveis diferentes de rugosidade. O Herculite apresentou a superfície mais lisa e o Adaptic a mais rugosa, ficando os materiais P-30, Silux e Estic-microfill numa posiçäo intermediária