Both disinfection/storage periods affected the microhardness and roughness values of the samples.

Alterations in the color stainability, the L* coordinate values, the translucency parameter, and the contrast ratio of the lithium disilicate ceramic were observed, according to the acidic solutions tested.

Patients who have maxillectomy can be rehabilitated with reconstructive surgery or obturator prostheses with or without osseointegratable implants. To identify studies on possible treatments in this group, we systematically searched the Scopus, Embase, PubMed/Medline, and Cochrane databases to collect data on patients' characteristics, radiotherapy, and results related to speech, swallowing, mastication or diet, chewing, aesthetics, and quality of life. Of the 1376 papers found, six were included, and one other was included after an additional search of references. A total of 252 patients were included, and of them, 86 had reconstructive surgery, 91 were treated with obturator prostheses, 39 had reconstructive surgery or obturator prostheses associated with implants, and 36 had reconstruction plus an obturator prosthesis. Data on radiotherapy were incomplete. There is a lack of consensus about the indication for rehabilitation, as the treatment must be based on the individual characteristics of each patient.

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PURPOSE. The aim was to evaluate the effect of four acidic beverages on the roughness (Ra) and color change (ΔE ab) of two brands of artificial teeth and a heat-polymerized acrylic resin (HPAR) for use in a prosthetic base. MATERIALS AND METHODS. All materials were divided into 5 groups, according to the used acidic beverage (artificial saliva-control, red wine, orange juice, coke-based, and lemon juice-based soft drink). The immersion process was divided into two stages: T1-immersion in the acidic solutions for 10 minutes for 14 days; T2-after T1, the samples were immersed in grape juice for 14 days. The Ra of the samples was evaluated in a rugosimeter and the ΔE ab in a spectrophotometer, before and after the immersions. The analysis of variance of one (ΔE ab) and two factors (Ra) and Tukey were performed (α=.05). RESULTS. There was a statistical difference for roughness after immersion (T1) for Trilux and Tritone teeth, regardless of the acid solution. For Trilux teeth, all acid solutions increased Ra (P<.05). For Tritone teeth, only the coke-based soft drink did not statistically change Ra. Grape juice (T2) altered Ra only of artificial teeth (P<.05). The color was changed for all materials, after T1 and T2. CONCLUSION. In general, the acidic solutions changed the Ra and ΔE ab of HPAR and artificial teeth after T1. The grape juice altered the roughness only of the artificial teeth, promoting a clinically acceptable color change in the materials.

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The aim of this study was to develop and characterise a new plasma-enhanced chemical vapor deposition (PECVD) film for improving shear bond strength (SBS) between yttria-stabilised tetragonal zirconia (Y-TZP) and veneering ceramic. In total, 192 Y-TZP samples (13 × 5.4 × 5 mm) were divided into 6 groups: control - no treatment (C), airborne-particle abrasion with 27 μm aluminum oxide particles (Al), 110 μm aluminum oxide particles (Al), and 250 μm aluminum oxide particles (Al), application of liner for zirconia (L) and the PECVD film application (P). The Y-TZP surface was characterised by means of Scanning Electronic Microscopy (SEM), Energy-dispersive Spectroscopy (EDS), atomic force microscopy (AFM), surface profilometry and surface-free energy (SFE). SBS between Y-TZP and veneering ceramic was tested before and after thermocycling (20,000 cycles of 5 and 55 °C), and failure mode was also evaluated. Data were analysed by ANOVA and Tukey's HSD test (α = 0.05). Data analysis showed that PECVD film had no effect on surface roughness of Y-TZP (p > 0.05 vs control), whilst the other groups presented higher roughness values (p < 0.05). All treatments increased SFE, except the Al group. The highest SBS was presented by the P group (p < 0.05), and values were similar to those of the Al group (p = 0.107). Mixed failures were prevalent in all groups, and premature failures were found only in Al groups after thermocycling. Whilst PECVD treatment did not affect Y-TZP surface roughness, high SBS between Y-TZP and the veneering layer was observed. Therefore, PECVD treatment is a promising alternative to improve the performance of bi-layer zirconia-based restorations.

Surface treatment in Y-TZP improved the values of SBS between the Y-TZP and veneer ceramic. The associations between two or more treatments also showed positive effect on the bond strength due the cumulative effect of the treatments.