Colecciones Institucionales
Permanent URI for this community
Browse
Browsing Colecciones Institucionales by browse.metadata.fuente "Facultad Medicina. Odontología"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
- ItemA Single-Blind Randomized Trial About the Effect of Hydrogen Peroxide Concentration on Light-Activated Bleaching(2016) Mena-Serrano, A. P.; Garcia, E.; Luque Martínez, Íssis Virginia; Grande, R. H. M.; Loguercio, A. D.; Reis, A.Objective: To compare the bleaching efficacy and tooth sensitivity (TS) of two hydrogen peroxide ( HP) concentrations (20% and 35%) used for in-office bleaching associated or not with a light-emitting diode (LED)/laser light activation. Method: Seventy-seven patients with a right maxillary canine darker than A3 were selected for this single-blind randomized trial. The participants were distributed in four groups: bleaching with 35% HP, 35% HP + LED/laser, 20% HP, and 20% HP + LED/laser. The anterior teeth were bleached in two sessions, using a 35% or 20% HP gel with a one-week interval. Each session had three applications of 15 minutes. For the light-activated groups, the LED/laser energy (Whitening Laser Light Plus, DMC) was employed according to the manufacturer's instructions. The color change was evaluated by subjective and objective methods. Participants recorded TS with five-point verbal and visual analog scales. Color change in DE was evaluated by analysis of variance and Tukey tests (alpha = 0.05) and in Delta SGU with Kruskall-Wallis and Dunn test. The absolute risk of TS and TS intensity were evaluated by Fisher exact test and Krus-kall-Wallis test, respectively (alpha = 0.05). Results: All groups achieved the same level of whitening, except for the 20% HP group, which showed the lowest degree of whitening in the subjective analysis. The use of light did not increase the absolute risk or intensity of TS. No significant difference among groups was observed when color changes were assessed with the spectrophotometer. Conclusion: According to the value-oriented shade guide, the use of LED/laser light activation was able to increase the degree of whitening of the 20% HP group, but this association was not useful for the 35% HP gel. The spectrophotometer, however, did not detect significant differences among groups.
- ItemCollagen cross-linkers on dentin bonding: Stability of the adhesive interfaces, degree of conversion of the adhesive, cytotoxicity and in situ MMP inhibition(2016) Hass, V.; Luque Martínez, Íssis Virginia; Gutierrez, M. F.; Moreira, C. G.; Gotti, V. B.; Feitosa, V. P.; Koller, G.; Otuki, M. F.; Loguercio, A. D.; Reis, A.Objective. To investigate the effect of collagen cross-links on the stability of adhesive properties, the degree of conversion within the hybrid layer, cytotoxicity and the inhibition potential of the MMPs' activity. Methods. The dentin surfaces of human molars were acid-etched and treated with primers containing: 6.5 wt% proanthocyanidin, UVA-activated 0.1 wt% riboflavin, 5 wt% glutaraldehyde and distilled water for 60s. Following, dentin was bonded with Adper Single Bond Plus and Tetric N-Bond; and restored with resin composite. The samples were sectioned into resin-dentin "sticks" and tested for microtensile bond strength (mu TBS) after immediate (IM) and 18-month (18 M) periods. Bonded sticks at each period were used to evaluate nanoleakage and the degree of conversion (DC) under micro-Raman spectroscopy. The enzimatic activity (P1L10 cross-linkers, P1L22 MMPs' activities) in the hybrid layer was evaluated under confocal microscopy. The culture cell (NIH 3T3 fibroblast cell line) and MTT assay were performed to transdentinal cytotoxicity evaluation. Data from all tests were submitted to appropriate statistical analysis (alpha = 0.05). Results. All cross-linking primers reduced the degradation of mu TBS compared with the control group after 18 M (p > 0.05). The DC was not affected (p > 0.213). The NL increased after 18 M for all experimental groups, except for proanthocyanidin with Single Bond Plus (p > 0.05). All of the cross-link agents reduced the MMPs' activity, although this inhibition was more pronounced by PA. The cytotoxicity assay revealed reduced cell viability only for glutaraldehyde (p < 0.001). Significance. Cross-linking primers used in clinically relevant minimized the time degradation of the mu TBS without jeopardizing the adhesive polymerization, as well as reduced the collagenolytic activity of MMPs. Glutaraldeyde reduced cell viability significantly and should be avoided for clinical use. (C) 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
- ItemComparison of efficacy of tray-delivered carbamide and hydrogen peroxide for at-home bleaching: a systematic review and meta-analysis(2016) Luque Martínez, Íssis Virginia; Reis, A.; Schroeder, M.; Munoz, M. A.; Masterson, D.; Maia, L. C.; Loguercio, A. DThe aim of the study was to compare the color change produced by tray-delivered carbamide peroxide [CP] versus hydrogen peroxide products [HP] for at-home bleaching through a systematic review and meta-analysis. MEDLINE via PubMeb, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database (LILACS), Brazilian Library in Dentistry (BBO), and Cochrane Library and Grey literature were searched without restrictions. The abstracts of the International Association for Dental Research (IADR) and unpublished and ongoing trial registries were also searched. Dissertations and theses were explored using the ProQuest Dissertations and Periodicos Capes Theses databases. We included randomized clinical trials that compared tray-delivered CP versus HP for at-home dental bleaching. The color change in shade guide units (SGU) and Delta E were the primary outcomes, and tooth sensitivity and gingival irritation were the secondary outcomes. The risk of bias tool of the Cochrane Collaboration was used for quality assessment. After duplicate removal, 1379 articles were identified. However, only eight studies were considered to be at "low" risk of bias in the key domains of the risk bias tool and they were included in the analysis. For Delta E, the standardized mean difference was -0.45 (95 % CI -0.69 to -0.21), which favored tray-delivered CP products (p < 0.001). The color change in Delta SGU (p = 0.70), tooth sensitivity (p = 0.83), and gingival irritation (p = 0.62) were not significantly different between groups. Tray-delivered CP gels showed a slightly better whitening efficacy than HP-based products in terms of Delta E, but they were similar in terms of Delta SGU. Both whitening systems demonstrated equal level of gingival irritation and tooth sensitivity. Tray-delivered CP gels have a slightly better whitening efficacy than HP-based products in terms of Delta E. This should be interpreted with caution as the data of Delta SGU did not show statistical difference between the products.
- ItemDegradation of dentin-bonded interfaces treated with collagen cross-linking agents in a cariogenic oral environment: An in situ study(2016) Hass, V.; de Paula, A. M.; Parreiras, S.; Gutierrez, M. F.; Luque Martínez, Íssis Virginia; Matos, T. D.; Bandeca, M. C.; Loguercio, A. D.; Yao, X. M.; Wang, Y.; Reis, A.Objectives: To evaluate the effect of treatment using collagen cross-linking agents as primer on resin-dentin bond interfaces subjected to cariogenic oral environment (COE). Methods: Each of forty human teeth had two cavities (4 x 4 x 1.5 mm) prepared within enamel margins. These cavities were acid-etched and treated by the primers containing one of the following treatment agents (6.5% proanthocyanidins, 0.1% riboflavin-UVA activated light, 5% glutaraldehyde or distilled water as a control group). After that the cavities were bonded and restored with resin composite. One restoration for each tooth was tested immediately (IM) and another was included in an intra-oral palatal device that was placed in each mouth of ten adult volunteers for 14 days in COE. After 14 days, the teeth were removed and each restoration was sectioned to obtain a slice for Knoop microhardness (KHN) and resin-dentin bonded sticks for microtensile bond strength (mu TBS) and nanoleakage (NL) evaluation. Data were evaluated by two-way ANOVA and Tukey's tests (alpha = 0.05). Results: After 14 days in a COE, the KHN was reduced for all groups, except for the glutaraldehyde group; however, the proanthocyanidins group retained the highest KHN in IM and after COE (p < 0.05). The mu TBS was not reduced after COE for the proanthocyanidins and glutaraldehyde groups, however only the proanthocyanidins treatment did not increase the NL after COE (p > 0.05). Conclusion: The in situ study model seems to be a suitable short-term methodology to investigate the degradation of the bonding interfaces under a more realistic condition. Under COE, the proanthocyanidins and glutaraldehyde treatments produced stable interfaces that are worth further clinical investigation. (C) 2016 Elsevier Ltd. All rights reserved.