Effect of different adhesive strategies on the microtensile bond strength of dentin to indirect resin-based composite

To evaluate the microtensile bond strength of indirect resin composite bonded to dentin using five different adhesives strategies. Forty specimens (Solidex) were produced and randomly into five groups with different adhesives strategies: (G1)- Single Bond Universal + etch + silane + RelyX Ultimate, (G2)- Single Bond Universal + silane + RelyX Ultimate, (G3)- Single Bond Universal + etch + RelyX Ultimate, (G4)- Single Bond Universal + RelyX Ultimate, and (G5)-Scotchbond Multi-purpose + RelyX ARC. After cementation the specimens were stored in 100% humidity for 24hours at 37°C. The specimens were sectioned perpendicular to the adhesive interface to obtain beams and submitted to microtensile test. Microtensile values were expressed in MPa and analyzed by one-way ANOVA and multiple comparison Tukey tests (?=0.05). The mean bond strength in MPa groups were: G1=11,48, G2=14,15, G3=16,95, G4=17,03 and G5=16,80. Statistical analysis showed that the bond strength values were not significantly affected by the different adhesive strategies. Cementation of dentin to indirect resin composite cannot be significantly affected by different adhesive strategies used. The specimens treated with silane, etch associated with Single bond universal did not increase bond strength values

Correlation between alteration of enamel roughness and tooth color

To establish the correlation between enamel roughness and color change of tooth. Enamel/dentin blocks (5 x 5 x 3.2 mm) were serially ground with the following abrasive paper: 1200-grit, 800-grit, and 600-grit SiC papers. In the paired model, the analyses of color (L*, a*, b*, ?E) and roughness (Ra) were performed among the sandpaper exposure. The data were subjected to ANOVA using models for repeated measures followed by the Tukey test. The Pearson correlation test was used to determine whether there was a relationship between Ra values and color results (? = 0.05). The L* values decreased in accordance with the increase of Ra, with statistical difference between all the times (p0.05). The alteration of enamel roughness acted on the lightness and the green-red axis of tooth color. However, there was no significant correlation between the alteration of roughness of enamel and general color change of tooth

Characterization of whitening toothpastes and their effect on the physical properties of bulk-fill composites

Objective: To characterize activated charcoal and 2% hydrogen peroxide-based toothpastes and investigate their effects on roughness, color change, and gloss of bulk-fill composite resin. Methodology: Composite resin specimens (Aura Bulk Fill, SDI) were subjected to 5,000 brushing cycles with regular toothpaste (Colgate Total 12, [RT]), activated charcoal toothpaste (Bianco Dental Carbon, [AC]), or hydrogen peroxide-containing toothpaste (Colgate Luminous White Advanced, [HP]), with or without coffee exposure. The pH, particle characterization by scanning electron microscopy (SEM), and weight% of solid particles in the toothpaste were assessed. Roughness (Ra) was evaluated using a surface profile-measuring device, color change (∆Eab/∆E00) by reflectance spectrophotometer, and gloss unit (GU) by glossmeter. Kruskal–Wallis, Dunn, Friedman, and Nemenyi tests were used, and the correlation coefficient test was performed between Ra and GU (α=0.05). Results: RT presented a higher Ra after brushing and did not change after staining with coffee; moreover, the ∆Eab/∆E00 values were higher for RT than HP. Regarding gloss, AC and HP obtained higher values compared to RT. A significant negative correlation between gloss and Ra was found for RT exposed to coffee. All toothpastes had a neutral pH; however, RT had the largest percentage of solids by weight. SEM images showed particles of many sizes: irregular shape (RT), more regular particles (AC), and spherical clusters (HP). Although surface roughness, color change, and gloss may compromise the longevity of restorations, the whitening toothpastes tested did not promote more morphology changes than regular toothpastes

Effect of wetting agent coverage on the surface properties of resin composite submitted to brushing and staining cycles

Wetting agents facilitate the composites handling, acting as a lubricant and decreasing their stickness to spatula. The effects of these materials on the properties of composites are not completely clear. This study aimed to evaluate Gloss, Color, Roughn

Impact of light-curing time and aging on dentin bond strength of methacrylate- and silorane-based restorative systems

AIM: To evaluate the impact of different light-curing times on dentin microtensile bond strength of two restorative systems after 24 h and 6 months of water storage. METHODS: Standardized Class II preparations were performed in 56 freshly-extracted human molars (n = 7), restored with methacrylate- or silorane-based restorative systems, and light-cured using a light-emitting diode at 1390 mW/cm2 by the recommended manufacturers' time or double this time. After storage for 24 h at 37 oC, the teeth were sectioned to yield a series of 0.8-mm thick slices. Each slab was trimmed into an hourglass shape of approximately 0.64 mm2 area at the gingival dentin-resin interface. Specimens were tested using universal testing machine at crosshead speed of 0.5 mm/min until failure, after 24 h and 6 months of storage. Data were statistically analyzed by three-way ANOVA and Tukey's test (α = 0.05). RESULTS: The highest bond strength values were recorded for the groups restored with methacrylate system (p0.05). CONCLUSIONS: Bond strength was influenced by the material and light-curing time, but the 6-month storage did not affect the bond strength of restorations133213218FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2010/05666-9; 2010/15076-

Effect of light curing modes and ethanol immersion media on the susceptibility of a microhybrid composite resin to staining

The aim of this in vitro study was to evaluate the susceptibility of a hybrid composite resin (Filtek Z250 - 3M ESPE) to staining, when light cured in four different modes and immersed in two different media. Composite resin specimens were randomly prepared and polymerized according to the experimental groups (conventional - 550 mW/cm² / 30 seconds; soft start - 300mW/cm² / 10 seconds + 550 mW/cm² / 20 seconds; high intensity - 1060 mW/cm² - 10 seconds; pulse delay - 550 mW/cm² - 1 seconds + 60 seconds of waiting time + 550 mW/cm² - 20 seconds) and immersed in one of two media (distilled water or absolute ethanol) for 24h. Next, the specimens were immersed in a 2% methylene blue solution for 12 hours. Afterwards, the specimens were washed and prepared for the spectrophotometric analysis. For statistical analysis, two-way ANOVA (4X2) and Tukey's test were performed on the data at 0.05 confidence level. Soft start showed the least staining, and was statistically different from the high intensity and pulse delay light curing modes (p;0.05). There were no significant differences between the two immersion media (p>;0.05). The soft start polymerization mode showed lower susceptibly of the composite resin to staining than high intensity and pulse delay, irrespective of the immersion medium

Advances In Dental Veneers: Materials, Applications, And Techniques.

Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient. Clinicians should understand the latest ceramic materials in order to be able to recommend them and their applications and techniques, and to ensure the success of the clinical case. The current literature was reviewed to search for the most important parameters determining the long-term success, correct application, and clinical limitations of porcelain veneers.49-1

Effect of whitening dentifrices and mouthwashes on color and surface roughness of resin-infiltrated enamel

The aim of this study was to evaluate the influence of whitening dentifrices and mouthwashes on color change (ΔE) and surface roughness (Ra) of resin-infiltrated enamel. The specimens were demineralized, infiltrated with Icon®️ and grouped according to the dentifrices to be used, after they were subjected to 30,000 brushing cycles. The groups were further subdivided according to the mouthwash type and were then submitted to immersion cycles for 45 days. Ra was evaluated in a rugosimeter, surface morphology analysis was performed using a scanning electron microscope (SEM) and ΔE was evaluated using a spectrophotometer 3 times (at: T0 - initial, T1 - after brushing, T2 - after mouthwash). Analyses were performed using the SPSS 2.0 software, with a significance level of 5%, except for SEM analyses, which were evaluated only aualitatively. For Ra tests, Kruskal Wallis and Dunn's analyses as well as Mann-Whitney and Wilcoxon’s test were applied. For color tests, one-way (Brushing) and two-way (mouthwashes/toothpaste) factor ANOVA were used. Ra decreased after the brushing cycles and the use of mouthwashes did not produce significant changes on the surface. SEM images also demonstrated a decrease in Ra. ΔE for all groups was above the levels of acceptability and perceptibility while there was no difference in ΔE among the tested groups. In conclusion, the dentifrices used caused a reduction in surface roughness, suggesting a degradation of the material, unlike the mouthwashes, which did not produce significant differences. Regarding color, all samples were above the level of clinical acceptability

Avaliação de sorção/solubilidade, resistência à flexão, módulo de elasticidade e atividade antimicrobiana de infiltrantes experimentais / Evaluation of sorption/solubility, flexural strength, modulus of elasticity and antimicrobial activity of experimental infiltrants

O presente estudo teve como objetivo avaliar e comparar o grau de conversão (usando a espectroscopia de infravermelho com transformador de Fourier), resistência à flexão e módulo de elasticidade (por teste flexão de três pontos), sorção e solubilidade da água e análise antimicrobiana (Concentração Inibitória Mínima e Concentração Bactericida Mínima - CIM e CBM, respectivamente) de infiltrantes experimentais contendo sal de difeniliodônio (DFI) e quitosana e do infiltrante da marca comercial Icon®. O grupo de infiltrante na concentração de 1% de DFI e 0,25% de quitosana foi o que apresentou os melhores resultados nos testes realizados. Esse grupo foi semelhante ao infiltrante comercial Icon® em todos os quesitos, tendo o diferencial de apresentar atividade bactericida que a marca comercial não apresenta. Concluindo que a adição de sal de DFI e quitosana são boas alternativas para a melhoria das propriedades mecânicas e antimicrobianas dos infiltrantes

Chemical composition and roughness of enamel and composite after bleaching, acidic beverages and toothbrushing

In this study was assessed the surface roughness and chemical composition of tooth enamel and composite resin after bleaching treatment, immersion in acidic beverages, and simulated toothbrushing. One hundred and twenty dental blocks (10 x 10 x 3 mm) were randomly assigned (n = 10) according to surface treatment [none (N), bleaching (B), toothbrushing (T), and B+T] and storage medium [saliva (S), whiskey (W), and orange juice (O)]: experimental groups - N+S, N+W, N+O, B+S, B+W, B+O, S+T, W+T, O+T, B+S+T, B+W+T, and B+O+T. Two bleaching sessions were conducted using 38% hydrogen peroxide (3 applications). Surface roughness was measured using a roughness tester and composition was determined by micro energy-dispersive X-ray fluorescence spectrometry (µ-EDXRF) before and after treatments. Calcium/phosphorus (Ca/P) ratio in enamel and silica (Si) content in composite were evaluated. Data were statistically analyzed by ANOVA and Tukey?s test (? = 0.05). Overall, increased values of surface roughness for enamel and composite were observed mainly after immersion in orange juice and bleaching/toothbrushing association. Moreover, this association and immersion in whiskey resulted in lower Ca/P ratio and after aging methods, bleached and bleached/toothbrushed groups showed decreased in Ca/P ratio compared to initial values. All groups showed Si content decrease at the end, except the group without surface treatment and immersed in saliva, and bleaching followed by immersion in orange juice and toothbrushing caused the highest Si reduction. Bleaching and toothbrushing combination strengthened the effects caused by acidic drinks on roughness and chemical composition of enamel and composite