Assessing the surface roughness of a posterior resin composite: effect of surface sealing.

This study assessed the in vitro influence of surface sealing on the surface roughness of a posterior resin composite before and after toothbrushing. Thirty specimens (13 mm diameter x 1 mm high) were fabricated from Filtek-P60 resin composite and randomly assigned to three groups (n = 10): a non-sealed control and two groups sealed with one of the tested materials-a surface-penetrating sealant (Protect-it!-PI) and a one bottle adhesive system (Single Bond-SB). The samples were subjected to a surface roughness reading to determine the initial roughness, then submitted to simulated toothbrushing with 35,600 cycles for 100 minutes. Specimens were then cleaned and a post-abrasion surface roughness reading accomplished. Means (microm), recorded before (B) and after (A) toothbrushing, and standard deviations were: Control--(B): 0.032 (+/- 0.005), (A): 0.054 (+/- 0.005); PI-(B): 0.034 (+/- 0.005), (A): 0.060 (+/- 0.034); SB (B): 0.031 (+/- 0.004), (A): 0.047 (+/- 0.007). Data were tabulated and submitted to two-way ANOVA. No statistically significant difference was observed when the control and experimental groups were compared. However, a significant difference (p < 0.05) was found between the measurements performed before and after toothbrushing. Based on these results, it may be concluded that using either a surface penetrating sealant or a one bottle adhesive system did not provide the optimization of superficial integrity. The use of a dentifrice and toothbrush resulted in significant alterations to the surface smoothness of the resin composite.

Shear bond strength of repairs in porcelain conditioned with laser.

The aim of this study was to evaluate the shear bond strength of repairs in porcelain conditioned with laser. Sixty porcelain discs were made and six groups were formed (n = 10): G1: conditioning with laser with potency 760 mW; G2: conditioning with laser with potency 760 mW and application of 37% phosphoric acid for 15 s; G3: conditioning with laser with potency 900 mW; G4: conditioning with laser with potency 900 mW and application of 37% phosphoric acid for 15 s; G5: application of 37% phosphoric acid for 15 s (group control) and G6: application of 10% hydrofluoric acid for 2 min. The composite resin was insert of incremental layers at the porcelain surface aided with a metal matrix, and photoactivation for 20 s each increment. The specimens were submitted to a thermal cycling by 1000 cycles of 30 s in each bath with temperature between 5 and 55°C. After the thermal cycling, specimens were submitted to the shear bond strength. The results were evaluated statistically through analysis of variance and Tukey's tests with 5% significance. The averages and standard deviation founded were: G1, 11.25 (±3.10); G2, 12.32 (±2.65); G3, 14.02 (±2.38); G4, 13.44 (±2,07); G5, 9.91 (±2,18); G6, 12.74 (±2.67). The results showed that the femtosecond laser produced a shear bond strength of repairs in porcelain equal to the hydrofluoric acid and significantly superior to the use of phosphoric acid.

Deposition of lead and cadmium released by cigarette smoke in dental structures and resin composite.

Cigarette smoke is a significant source of cadmium, lead, and toxic elements, which are absorbed into the human organism. In this context, the aim of this study was to investigate in vitro the presence of toxic elements, cadmium, and lead deriving from cigarette smoke in the resin composite, dentine, and dental enamel. Eight cylindrical specimens were fabricated from resin composite, bovine enamel, and root dentin fragments that were wet ground and polished with abrasive paper to obtain sections with 6-mm diameter and 2-mm thickness. All specimens were exposed to the smoke of 10 cigarettes/day during 8 days. After the simulation of the cigarette smoke, the specimens were examined with scanning electron microscopy (SEM) and the energy-dispersive X-ray analysis. In the photomicrographic analysis in SEM, no morphological alterations were found; however, the microanalysis identified the presence of cadmium, arsenic, and lead in the different specimens. These findings suggest that the deposition of these elements derived from cigarette smoke could be favored by dental structures and resin composite.

Associação de facetas diretas e fibra de reforço para restabelecimento estético do sorriso: relato de caso clínico / Association of direct veneers and reinforced fiber for smile esthetic restoration: Case report

Esse artigo tem como objetivo demonstrar o restabelecimento estético do sorriso obtido por meio da associação de facetas diretas e fibra de reforço. As fibras de reforço são utilziadas como alternativas para substituição de elementos dentários perdidos e possuem indicações precisas, sendo empregadas em diversas especialidades da Odontologia, devido à sua capacidade de aumentar a resistência à tração dos compósitos, o que aumenta a resistência à compressão das fibras. Para o completo restabelecimento do sorriso, muitas vezes é necessário reanatomizar os dentes adjacentes, considerando as condições em que esses se apresentam. Sendo assim, o profissional deve ter conhecimento para aplicação correta da técnica e restabelecimento da estética ao paciente

This article aims to demonstrate the esthetic restoration of a smile obtained by means of the association of the direct veneers and fber reinforcement. The reinforcing fbers are used as an alternative to replace lost dental elements and have specifc indications, being used in various dentistry specialties,due to the ability to increase the composite tensile strength,which increases the compressive strength of the fbers. For the complete restoration of smile, it is often necessary the reanatomization of adjacent teeth, considering the conditions under which they present themselves. Thus, the professional should have knowledge for correct application of the technique and esthetic restoration to the patient

Reabilita‡Æo est‚tica do sorriso por meio do sistema cerƒmico dissilicato de l¡tio – relato de caso / Aesthetic rehabilitation of the smile using lithium disilicate ceramic system – clinical report

O restabelecimento da harmonia do sorriso atrav‚s das cerƒmicas odontol¢gicas, quando realizado com crit‚rio e dentro de indica‡ães espec¡ficas, traz resultados extremamente previs¡veis. Para a reabilita‡Æo funcional e est‚tica, muitos materiais cerƒmicos podem ser empregados, como zirc“nia, leucita, alumina, feldspato e dissilicato de l¡tio. Dentre esses materiais, destaca-se o dissilicato de l¡tio que tem como caracter¡sticas: resistˆncia ao desgaste, ao ataque qu¡mico, … oxida‡Æo e a altas temperaturas; baixa condutividade el‚trica; dilata‡Æo t‚rmica pr¢xima do zero; boas propriedades ¢pticas e biocompatibilidade com o periodonto; excelente est‚tica; estabilidade de cor e refor‡o da estrutura dental. As indica‡ães para o uso do dissilicato de l¡tio sÆo m£ltiplas e nÆo limitadas para facetas em casos de dentes onde nÆo houve resposta favor vel ao clareamento dental, dentes com restaura‡ães m£ltiplas, fechamento de diastemas, altera‡Æo de forma e contorno dental, restitui‡Æo de dentes ausentes ou fraturados, entre outras. A versatilidade da cerƒmica de dissilicato de l¡tio faz com que possa ser utilizado em diferentes situa‡ães cl¡nicas. Seu uso concomitante tanto para facetas como sobre n£cleos met licos fundidos ‚ apresentado aqui com um resultado est‚tico bastante satisfat¢rio, sendo indicado para situa‡ães onde h  necessidade de aliarmos est‚tica e resistˆncia como atributos indispens veis.

The reestablishment of a harmonious smile through dental ceramics, when properly conducted and with specific indications, can achieve extremely predictable results. For aesthetic and functional rehabilitation, many ceramic materials can be used such as zirconia, leucite, alumina, feldspar, and lithium disilicate. Among these materials the lithium disilicate stands out due to the following characteristics: its resistance to wear, to chemical attack, high tem peratures and oxidation; low electrical conductivity; near zero thermal expansion; good optical properties and biocompatibility with periodontal; excellent esthetics; color stability and reinforcement of tooth structure. The indications for the use of lithium disilicate are not limited to multiple facets of teeth in cases where there was no favorable response to tooth whitening, and also comprehend teeth with multiple restorations, diastema closure, shape alteration, and dental contouring, replacement of missing or fractured teeth, among others. The versatility of lithium disilicate ceramics allows its utilization in several clinical situations. The concomitant use of lithium disilicate for veneers and over metal has satisfactory aesthetic results, as reported in the present studying cases that require both aesthetics and resistance.

Efeito da fumaça de cigarro nas propriedades de resinas compostas e substratos dentais / Effect of cigarette smoke on the properties of the composite resin and dental substrates

O objetivo do presente estudo foi avaliar in vitro a microdureza, mudança de cor e presença de substâncias tóxicas após exposição à fumaça de cigarro na resina composta, dentina e esmalte dental e avaliar in situ a microdureza, rugosidade superficial e alteração de cor e luminosidade de resinas compostas frente à exposição à fumaça do cigarro associado à escovação. Para a fase in vitro foram confeccionados corpos-de-prova de resina composta (RC), esmalte (E) e dentina radicular bovina (DR) que foram planificados, polidos e expostos a fumaça de 10 cigarros/dia por 8 dias. Avaliou-se a microdureza Knoop e a alteração da cor (CIELAB) antes de depois do ato de fumar. Em seguida, as amostras foram preparadas para análise em microscopia eletrônica de varredura (MEV) e microanálise (EDS). Os dados da microdureza e da alteração de cor foram submetidos à ANOVA e Tukey (5%). A microdureza do E aumentou e da DR e RC diminuíram. Na alteração de cor a RC e o E apresentaram menor escurecimento do que a DR. Na fase in situ foram confeccionados corpos-de-prova com três tipos de resinas compostas que foram fixados em aparelho intrabucal palatino. Foram selecionados 22 voluntários, sendo 11 fumantes e 11 não-fumantes, que utilizaram o aparelho por 28 dias. A escovação dos espécimes foi realizada fora da boca, três vezes por dia somente na metade do dispositivo. Para os fumantes foi estipulado o consumo de 10 cigarros/dia. A mensuração da cor (CIELAB), da microdureza (KHN) e da rugosidade foram realizadas antes e após os 28 dias de exposição in situ. Os dados KHN foram analisados pela ANOVA e teste de Fisher's LSD. Os dados da rugosidade, foram analisados pelo método estatístico não-paramétrico Kruskal-Wallis, Wilcoxon e Friedman (p<0.05) que observaram que a fumaça de cigarro aumentou os valores de microdureza e de rugosidade para os fumantes com escovação. Contudo, pode-se concluir que na fase laboratorial a fumaça de cigarro interferiu na microdureza do E, DR e RC, sendo...