ABSTRACT
OBJECTIVES: The aim of this study was to evaluate the fluorescence of nine esthetic resin composite materials using two methods: spectrophotometry and photography analysis. MATERIALS AND METHODS: Three specimens were made for each shade of resin composite (61 shades from 9 resin composites), for a total of 183 specimens. To obtain a control group, the crowns of three sound human incisors were prepared to obtain both enamel and dentin specimens. Fluorescence was measured using two methods: (1) a Spectroshade Micro fluorescence spectrophotometer (MHT Optic Research, Niederhasli, Switzerland) and (2) a photograph analysis using Adobe Photoshop CC software (version 2019.0.0, Adobe Systems, Inc.). STATISTICAL ANALYSIS: The results were statistically analyzed with an analysis of variance (α = 0.05) and with the Tukey-Kramer adjustment. The correlation between two techniques was analyzed by Pearson correlation test (α = 0.05). RESULTS: Fluorescence was highly influenced by the brand of the resin composite and less influenced by the shade (chroma), except for opaquer and incisal shades, and there was almost no difference in opacity, except for incisal shades. There was a weak (r = -0.105) and statistically not significant correlation (p = 0.145) between photography analysis and spectrophotometry techniques. CONCLUSION: The fluorescence of esthetic resin composites is more dependent on the brand than on the shade or opacity.
ABSTRACT
OBJECTIVE: The objective of this study was to evaluate the effect that deviations from the recommended protocol of a universal adhesive system, applied to dentin according to the self-etch (SE) and the etch-and-rinse (ER) techniques, has on permeability and nanoleakage. MATERIALS AND METHODS: Permeability: 60 extracted non-carious human third molars (N = 60) were sectioned to obtain 0.7-mm-thick dentin disks. The specimens were randomly assigned to three subgroups and treated with a universal adhesive system (Prime&Bond Active Universal) using the SE and ER techniques: (1) following the manufacturer's instructions with 5 seconds drying (MFR DRY 5S), (2) following the MFR DRY 10S, and (3) reduced application time of the adhesive to 5 seconds (APPL 5S). Nanoleakage: 12 additional 0.7-mm-thick dentin disks were prepared, treated and divided into six groups. They were immersed in 50 wt% ammoniacal silver nitrate and processed according to conventional methods for the analysis of nanoleakage under transmission electron microscopy. STATISTICAL ANALYSIS: The results were statistically analyzed by two-way analysis of variance and post-hoc Bonferroni's test. RESULTS: Significant differences in permeability reduction were observed among the treatment groups (0.001). The results obtained for APPL 5S were significantly lower than the results obtained for both the MFR DRY 5S (p = 0.003) and MFR DRY 10S (p = 0.001). CONCLUSIONS: The reduced application time to 5 seconds creates imperfect dentin tubule sealing, which may explain clinical reports of postoperative sensitivity and early degradation of the resin-dentin interface.
ABSTRACT
PURPOSE: To evaluate the 24-month clinical performance of Adhese Universal (ADH) (Ivoclar Vivadent) using two different application modes (etch-and-rinse vs self-etch) when restoring non-carious cervical lesions. MATERIALS AND METHODS: Twenty-six patients participated in this study. A total of 117 non-carious cervical lesion restorations (N = 117) were assigned to two groups: 1) ADH in the etch-and-rinse mode (n = 59) and 2) ADH in the self-etch mode (n = 58). The same resin composite (Tetric EvoCeram, Ivoclar Vivadent) was used for all restorations. The restorations were evaluated at baseline and at 24 months using the World Dental Federation (FDI) criteria. The results were analyzed statistically using the McNemar test (α = 0.05) and a generalized estimating equation. RESULTS: In self-etch mode, significant differences were found for marginal coloring (p = 0.002), marginal adaptation (p = 0.031), and hypersensitivity (p = 0.031) between baseline and the end of the 24-month period. In the etch-and-rinse mode, significant differences were found for marginal coloring (p = 0.004), fractures/retention (p = 0.002), marginal adaptation (p = 0.002), and hypersensitivity (p = 0.000). Significant differences were also detected between groups at 24 months for fractures/retention (p = 0.001). At 24 months, 10 restorations of the etch-and-rinse group were lost and 2 restorations of the self-etch group were lost. CONCLUSION: In terms of fractures and retention criteria, this universal adhesive obtained better results when applied in self-etch mode than in etch-and-rinse mode.
