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Immediate and long-term microtensile bond strength of a resin cement to zirconia ceramic after ultra-short pulsed laser treatment

Grant number: 16/20935-2
Support type:Scholarships in Brazil - Doctorate (Direct)
Effective date (Start): July 01, 2017
Effective date (End): February 29, 2020
Field of knowledge:Health Sciences - Dentistry - Dental Clinics
Principal Investigator:Ana Cecília Corrêa Aranha
Grantee:Stephanie Assimakopoulos Garófalo
Home Institution: Faculdade de Odontologia (FO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Associated scholarship(s):17/17808-1 - Effect of different artificial aging methods on the durability of the bond strength of laser- treated zirconia to a resin cement, BE.EP.DD


The objectives of this study is to evaluate the long-term bond strength of zirconia treated with ultra-short laser pulse to a dual resin cement and evaluate the mechanical behavior of zirconia treated with this laser. Therefore, one hundred and four blocks (104) of 10x10x5 mm 3 will be prepared from the ceramic material reinforced with zirconia. The specimens will be polished with silicon carbide discs. Then the blocks will be cleaned and distributed randomly into four groups (n = 26) that will receive the following surface treatments: 1) sand Jet (SB) particles of aluminum oxide of 50 micron to 2.8 bar, 10 mm away and 20 seconds; 2) coating with silica (SC) silicon dioxide particles 30 uM to 2.8 Bar, 10 mm width and 20 seconds; 3) irradiation with laser ultra-short pulse/laser picosecond Trumicro 5050, Trumpf, Ditzingen (L10) programmed with parameters 1; 4) Irradiation with ultra-short pulse laser (L20) 2 programmed with parameters for surface roughness test, is determined for each group (n = 6) using a 3D laser profilometer in which will be analyzed by conducting measurements of approximately 4 million points over an area of 500¼m x 500¼m in the center of the blocks after the acquisition of images. Upon completion of profilometric assessment, representative blocks (n = 3) of the treatment groups will be submitted to analysis by SEM. The specimens will be prepared, mounted on metal bases, coated with gold and examined with SEM to 20kV, with 2,000x, 5,000x and 10,000x magnification. For the microtensile test, each ceramic block will be duplicated composite resin with the same dimensions using a mold made of a polyvinyl siloxane impression material. A composite block will be built for each ceramic block using silane agent and resin cement. Samples are cut in half, one half is stored in distilled water at 37 °C for 24 hours and the other half for 6 months. Twelve to fourteen sticks of approximately 1.0mm2 cross-section will be obtained from each half of a block. A 100N voltage and load speed of 0.5 mm/min until failure will be determined. For flexural strength test (bending test four points) in the form of one hundred samples 26x4x2,1 mm3 sticks are prepared from the same zirconia, randomly divided into five groups (n = 20) Four of these groups will receive the same methods surface conditioning that ceramic blocks for bond strength testing, an additional group "as polished" is used as a negative control for the flexural strength test. The flexural strength is determined using a four-point bending test, the tests will be performed in a universal testing machine with a 10kN load cell and a constant speed of 1 mm/min. The average values of flexural strength are calculated from a predetermined equation. The data obtained for the bond strength and flexural strength will be statistically analyzed to test the hypothesis of the study. The normal distribution of the data will be tested using the Kolmogorov-Smirnov Test (0.05), and if this is confirmed, the Analysis of Variance (ANOVA) and post hoc comparisons using the Tukey Test will be performed. If the normal distribution hypothesis is rejected, non-parametric tests will be used for comparisons between groups. (AU)

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
GAROFALO, S. A.; SAKAE, L. O.; MACHADO, A. C.; CUNHA, S. R.; ZEZELL, D. M.; SCARAMUCCI, T.; ARANHA, A. C. In Vitro Effect of Innovative Desensitizing Agents on Dentin Tubule Occlusion and Erosive Wear. Operative Dentistry, v. 44, n. 2, p. 168-177, MAR-APR 2019. Web of Science Citations: 1.

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