1,721,043 research outputs found
Lfc: Combining autonomous agents and automated planning in the multi-agent programming contest
Full text linkThe 2019 Multi-Agent Programming Contest introduced a new scenario, Agents Assemble, where two teams of agents move around a 2D grid and compete to assemble complex block structures. In this paper, we describe the strategies used by our team that led us to achieve first place in the contest. Our strategies tackle some of the major challenges in the 2019 contest: how to explore and build a map when agents only have access to local vision and no global coordinates; how to move around the map efficiently even though there are dynamic events that can change the cells in the grid; and how to assemble and submit complex block structures given that the opposing team may try to sabotage us. To implement our strategies, we use the multi-agent systems development platform JaCaMo to program our agents and the Fast Downward planner to plan the movement of the agent in the grid. We also provide a brief discussion of our matches in the contest and give our analysis of how our team performed in each match
The fit of two fiber posts into the root canal space enlarged with rotary Ni-Ti files at four different levels.
No full textEffetto del pre-riscaldamento sull’adesione di cementi resinosi auto mordenzanti e autoadesivi
No full text
Influence of ozone application on the repair strength of silorane-based and ormocer-based composites
No full textPURPOSE:
To evaluate the effect of gasiform ozone on the repair strength of ormocer-based and silorane-based composites.
METHODS:
160 cavities were created in methacrylate cylinders. Half of the cavities were filled with a silorane-based composite, whereas the other half was filled with an ormocer-based composite. After storage (1 week, deionized water, 37 degrees C) the specimens of each restorative material were divided into two main experimental groups: in Group 1 the specimens were subjected to a 60-second ozone gas application; in Group 2 no pretreatment was performed (control). The corresponding adhesive of each restorative material was applied as the intermediate repair agent in both groups. Repair cylinders were then built up with the homologous material. Half of the specimens in each group were subjected to thermocycling (5,000 cycles, 5 degrees C-55 degrees C, dwell time 30 seconds, transfer time 5 seconds) prior to testing, whereas the other specimens were immediately tested. The repair strength was assessed with a shear test. The two-way ANOVA with pretreatment and thermocycling as the main factors was used to analyze the shear bond strength data within each restorative material.
RESULTS:
The pretreatment, the thermocycling and their interaction did not significantly affect the repair strength of either tested materials (P > 0.05). The ozone treatment did not significantly affect the repair strength. The silorane-based composite showed lower repair strengths compared to those of the ormocer-based composite. The immediate repair strengths in the ozone-treated and control groups were respectively, 28.1 (13.8) MPa and 28.8 (8.8) MPa for the silorane-based composite and 31.5 (9.3) MPa and 35.6 (10.6) MPa for the ormocer-based composite. After thermocycling, the repair strengths in the ozone-treated and control groups were 27.7 (9.7) MPa and 29.5 (11.1 ) MPa for the silorane-based composite and 31.4 (6.0) MPa and 34.2 (4.5) MPa for the ormocer-based composite. Mixed failures occurred most frequently in all experimental groups. In conclusion, ozone did not affect the repair strength of the tested silorane-based and ormocer-based composite
In vitro evaluation of bonding effectiveness to dentin of all-in-one adhesives
No full textObjectives: The study was aimed at assessing the bonding potential of all-in-one adhesives to dentin.
Methods: The microtensile bond strength of the all-in-one adhesives Bond Force (Tokuyama), AdheSE One (Ivoclar-Vivadent), and Xeno V (Dentsply) was measured in comparison with the etch-and-rinse system XP Bond (Dentsply). The ultrastructural characteristics of dentin-adhesive interface were observed under scanning electron microscope (SEM). Twenty human extracted third molars had their mid-coronal dentin exposed and ground with wet 600-grit SiC paper in order to create a standardized smear layer. Bonding procedures were performed according to the manufacturers' instructions and microtensile beams were obtained with the "non-trimming" technique. The bond strengths in MPa were statistically analyzed including pre-test failures as "zero" values (Kolmogorov-Smirnov test, Levene's test, One-Way ANOVA, Tukey's test p < 0.05).
Results. The following bond strengths were recorded in MPa (mean standard deviation): AdheSE One 31.7 +/- 21.3; Xeno V 42.8 +/- 26.4; Bond Force 43.3 +/- 22.1; XP Bond 51.9 +/- 18.6. The statistical analysis demonstrated that the bond strengths achieved by Bond Force and Xeno V were similar to that of the etch-and-rinse adhesive, whereas the bond strength of AdheSE One was significantly lower. A distinct hybrid layer with resin tags was seen only in XP Bond specimens. All-in-one adhesives demonstrated a rather superficial interaction with the dentin substrate.
Conclusions: Although the strongest bond to dentin was established by the etch-and-rinse system, however the all-in-one adhesives containing organic solvents reached bond strength levels that were comparable from a statistical point of view. (C) 2009 Elsevier Ltd. All rights reserved
Bonding and sealing ability of a new self-adhering flowable composite resin in Class I restorations
No full textThe aim of this study is to assess by means of shear bond strength tests (SBS), microleakage analysis (mu LKG), and scanning electron microscopy (SEM) the bonding potential and sealing ability of a new self-adhering composite resin.
SBS and mu LKG of Vertise Flow (VF, Kerr) were measured and compared to the all-in-one adhesive systems G-Bond (GB, GC), AdheSE One (AO, Ivoclar Vivadent), Adper Easy Bond (EB, 3M ESPE), Xeno V (XV, Dentsply), and iBOND (iB, Heraeus Kulzer). For each system, 20 molars were tested for SBS on dentin (n = 10) and enamel (n = 10). For mu LKG assessment, 12 premolars per group were selected and small, box-shaped cavities were made. After restoration, the teeth were immersed in 50 wt% silver nitrate solution for 24 h. For each group, 10 randomly selected specimens were processed for leakage calculations, while two of the specimens were examined under SEM. Between-group differences in SBS to dentin and mu LKG were assessed using Kruskal-Wallis analysis of variance followed by the Dunn's Multiple Range test. Enamel SBS data were analyzed with one-way ANOVA, followed by the Tukey test.
On dentin and enamel, VF recorded the lowest SBS values that were statistically comparable to those measured by GB, iB, and AO. mu LKG analysis showed the lowest percentage of stained interface for VF. Significantly greater extent of infiltration was seen for iB and EB.
Although VF resulted in lower bond strengths values on either dental substrate, better marginal sealing ability was visualized in comparison with all-in-one adhesive systems.
The results of the present study demonstrated satisfactory in vitro outcome of the self-adhering flowable composite resin VF when used to restore class I cavities
Repair potential of a laboratory-processed nano-hybrid resin composite
No full textThe purpose of this study was to compare the 24-h composite-to-composite microtensile bond strength of Gradia Forte (GF) repaired with the same or a different material after different surface treatments. Different groups were set up, in which composite blocks of GF were subjected to the following treatments: Group 1, sandblasting with 50-microm aluminum oxide and 37% phosphoric acid etching (PA); Group 2, bur roughening and etching with 37% PA; Group 3, etching with 37% PA only. In all groups, a bonding resin was used as an intermediate agent prior to layering of the repair material (Gradia Direct (GD), Gradia (G), or GF). Bond strengths were then determined and analysed statistically. Scanning electron microscopy (SEM) evaluation of substrates and bonded interfaces was also performed. Surface treatment (P < 0.001) and repair materials (P < 0.001) were factors that significantly affected repair strength, whereas their interaction (P = 0.31) had no significant effect. Group 3 showed significantly superior repair strength to Groups 1 and 2, whereas Group 2 showed significantly weaker repair strength to Groups 1 and 3. Irrespective of surface treatment, GD and G gave similar results, which were better than those obtained using GF. The lowest probability of failure was found for GD and G in Group 3, whereas the highest was found for GF in Groups 1 and 2. Premature failures occurred mainly with G and GF. No pre-testing failures were found in the sandblasting/GD subgroup. Surface-treated composites showed different textures under SEM, whereas composite-repair bonds showed comparable interfacial feature
Effect of pre-cure temperature on the bonding potential of self-etch and self-adhesive resin cements
No full textObjectives. To assess whether the pre-cure temperature of resin cements significantly influenced the bonding potential to dentin.
Methods. Forty extracted molars were randomly divided into 8 groups (n = 5): Groups (1-4) RelyX Unicem (RU, 3 M ESPE) and Groups (S-8) Panavia F 2.0 (PF, Kuraray Co.), at pre-cure temperatures of 4, 24, 37, and 60 degrees C, respectively. Cements were used in dual-cure mode for luting composite overlays (Paradigm MZ100, 3 M ESPE) to dentin. Microtensile bond strength testing and scanning electron microscope (SEM) observations of cement-dentin interfaces were performed.
Results. Group 4 had to be eliminated as RU at 60 degrees C under-went such an accelerated curing that was already set at the time of dispensing. The bond strengths (MPa) measured at refrigerator, room, and intraoral temperature were, respectively: RU 5.4 +/- 1.7, 11.4 +/- 6.1, 10.6 +/- 4.2; PF 7.4 +/- 3.7, 13.9 +/- 6.2, 12 +/- 5.2. The statistical analysis revealed that both luting agents developed a significantly weaker adhesion when used at refrigerator temperature (p 0.05). Pre-heating of PF to 60 degrees C resulted in a significant increase in bond strength (20.7 +/- 9.4 MPa; p < 0.05). SEM observations disclosed an enhanced potential of PF to form a hybrid layer as the temperature increased over 4 degrees C. RU exhibited a less porous and more homogeneous layer at intraoral than at refrigerated temperature.
Significance. It is advisable to let refrigerator-stored resin cements warm up to at least room temperature prior to clinical use. Pre-heating to 60 degrees C enhances the bonding potential of PF. (c) 2007 Academy of Dental materials. Published by Elsevier Ltd. All rights reserved
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