دكتر فرناز فراهت, دكتر شمين معماريان, and دكتر نجمه اخلاقي
Journal of Research in Dental Sciences; Autumn2019, Vol. 16 Issue 3, p171-177, 7p
ADHESIVES, ANALYSIS of variance, DENTAL crowns, DENTAL bonding, DENTAL veneers, MATERIALS testing, STATISTICS, STAINLESS steel, DATA analysis, and IN vitro studies
Background and aim: Using Stainless Steel Crowns (SSC) for Early Childhood Caries usually causes an unpleasant condition in the aesthetic of the patients. The aim of this study was to evaluate the effect of different surface treatments and bonding systems on shear bond strength of composite veneer to Stainless Steel Crown. Materials and Methods: In this in vitro study, 120 SSC were divided into 6 groups according to the surface treatment method (without surface treatment, diamond bur or sandblast) and bonding agent (alloy primer+Clearfil SE Bond or G Premio Bond). Shear Bond Strength (SBS) of composite cylinder to SSC was measured. Data were analyzed using ANOVA and Tukey. P-value <0.05 was considered statistically significant. Result: SBS with Alloy Primer+Clearfil SE Bond (37.53±9.13) was significantly higher than G Premio Bond ( 30.54± 12.34) (P-value <0.0001). Sandblast showed significantly higher SBS in comparison with two other groups (P-value <0.0001) Conclusion: Based on the results of this study, sandblasting has the highest SBS in comparison with the other methods of surface treatment. In the absence of sandblast, the application of the Alloy Primer+ Claerfil SE Bond on the SSC surface will provide better bond to resin composite. [ABSTRACT FROM AUTHOR]
Subjects and Methods: After cavity preparation on the buccal surfaces of 112 acrylic central teeth and etching; the specimens were restored with Filtek Z-250 (methacylate base) or Filtek P-90 (silorane base) composites. Surface treatments were done by the diamond bur+acid etch، diamond bur+acid etch+silane، air abrasion and air abrasion+silane. The brackets were bonded to the teeth and after thermal cycles; shear bond strength of the brackets to composites were calculated by the universal testing machine. Data were analyzed with one-sided ANOVA and Tukey test was used for paired comparison regarding surface treatments. Non parametric Kruscal-Wallis test was used for evaluation of ARI index. Results: The mean shear bond strength of brackets to teeth restored with Filtek Z-250 after treatments of diamond bur+acid etch، diamond bur+acid etch+silane، air abrasion and air abrasion+silane were 16.36±5.32،13.11±4.08،12.74±5.21and 13.16±3.82 MPa respectively. The values for the Filtek P-90 were 11.7±3.54، 8.2±3.25، 10.41±2.25 and 10.56±3.04 MPa. In all treatment methods، adequate bond strengths created between the brackets and composite surfaces. On the Filtek P-90، bond strength for diamond bur+acid etch was significantly more than diamond bur+acid etch+silane (P<0.02). Conclusion: Bond strength of the brackets to the silorane in relation to methacrylate was lower but acceptable. For this reason and due to lower remaining adhesive after debonding; the bonding of brackets to the teeth restored with silorane was acceptable in all methods. [ABSTRACT FROM AUTHOR]
In this work, effect of thermal cycling on the flexural properties of fiber-metal laminate (FML) has been evaluated. FML plates were composed of two aluminum 2024-T3 and an epoxy polymer-matrix composites ply formed by four layers of basalt fibers. For FML samples the thermal cycle times were about 6 min for temperature cycles from 25 °C to 115 °C. Flexural properties were evaluated on samples after 20, 35 and 55 thermal cycles, and compared to non-exposed samples. While the thermal cycling decreased the flexural strength of chemical treated FML (etched aluminum), increasing at first, and then decreasing after a while was observed in electrochemical treated FML (anodized aluminum). The flexural modulus of FML showed irregular changes for both FML with anodized aluminum and FML with etched aluminum. The energy absorption of FML with etched aluminum showed a sharp decline with increasing thermal cycling while the energy absorption of FML with anodized aluminum showed low and irregular changes. Evaluation optical microscope showed that the mechanism of failure for the FML with etched aluminum after thermal cycling changed from failure of FML to separation between layers of FML, while for the FML with anodized aluminum before and after thermal cycling it was failure of FML and it has not changed. [ABSTRACT FROM AUTHOR]
Mohammad Ako, Mohammad Hossein Navid Famili, and Seyyed Esmaeil Zakiyan
علوم و تکنولوژی پلیمر, Vol 29, Iss 1, Pp 73-88 (2016)
batch foaming, surface treatment, foaming temperature, nanosilica and polystyrene, Polymers and polymer manufacture, and TP1080-1185
This study addresses the effect of temperature and nanoparticle on PS foam structure in order to control its structure more accurately. For this purpose, a theoretical hypothesis was proposed by explaining the classical nucleation theory. The PS in the presence of nanosilica and CO2 was foamed. Foaming process was carried out in a vessel suitable under high pressure and temperature conditions, and with instantaneous pressure release and high-speed stabilization capabilities. The most important factors affecting foam properties including foaming temperature, size, content and surface properties of nanosilica were investigated. Increasing of foaming temperature was effective on the initial nuclei formation and cell growth. These two effects determined the final foam structure. When the temperature was changed from 90 to 180°C, cell density of PS foam increased thousand fold to 2.2×1012 number of cells per unit volume of foam (cell/cm3). The results showed that a small amount of nanosilica had a substantial effect on decreasing the cell size and increasing the cell density. An increase in nanoparticle concentration also increased its effectiveness. Moreover, the quality and structure of foam were improved by adding the nanoparticle. As the size of nanosilica increased from 20 to 40 nm, its cell density decreased from 3.3×109 to 1.78×109 numbers of cells per unit volume of foam (cells/cm3). Surface treatment of the nanosilica using triethoxysilane, in addition to improving nanoparticle dispersion, increased its cell density. The efficiency of nanosilica in improving cell density after surface treatment increased by more than double.
The effect of amino silane coupling agent on properties of wheat straw boards produced by UF and MF resins, was investigated in this study. For producing the straw boards small particles of straw were used . The results showed that adding 2 and 5 percents of silane had significant effect on improvement of boards properties. This improvement might be due to surface treatment of wheat straw particles with silane coupling agent by increasing the bondability between straw particles and resin. The more amine groups in Melamine Formaldehyde resin compare to urea formaldehyde resin , lead to an improvement in bending strength and thickness swelling.
Mirzaei M., Yassini E., Ghavam M., Pahlavan A., Hasani Tabatabaie M., Arami S., Kermanshah H., and Esmaieli B.
Journal of Dental Medicine, Vol 21, Iss 2, Pp 100-108 (2008)
Fiber post, Cosmopost, Quartz fiber, Glass fiber, Bond strength, Surface treatment, Medicine, Dentistry, and RK1-715
"nBackground and Aim: Various studies have shown that reliable bond at the root - post - core interfaces are critical for the clinical success of post - retained restorations. Severe stress concentration at post - cement interface increases post debonding from the root. To form a bonded unit that reduces the risk of fracture, it is important to optimize the adhesion. Therefore, some post surface treatments have been proposed. The purpose of this study was to investigate the influence of various surface treatments of tooth - colored posts on the bonding of resin cement. "nMaterials and Methods: In this interventional study, 144 tooth colored posts were used in 18 groups (8 samples in each group). The posts included quartz fiber (Matchpost), glass fiber (Glassix), and zirconia ceramic (Cosmopost) and the resin cement was Panavia F 2.0. The posts received the following surface treatments: 1- No surface treatment (control group), 2- Etching with HF and silane, 3- Sandblasting with Cojet sand, 4- Sandblasting with Cojet sand and application of silane, 5- Sandblasting with alumina particles, 6- Sandblasting with alumina particles and application of silane. Then, posts were cemented into acrylic molds with Panavia F 2.0 resin cement. The specimens were placed in water for 2 days and debonded in pull - out test. Statistical analysis was performed using ANOVA followed by Tamhane and Tukey HSD. Failure modes were observed under a stereomicroscope (10 ). P
Sareh Nadalizadeh, Mehdi Javan, Sara Khazaei, Bijan Heidari, and Hafez Ariamanesh
Journal of Mashhad Dental School, Vol 37, Iss 2, Pp 111-118
Fiber post, bond strength, surface treatment, Medicine, Dentistry, and RK1-715
Introduction: The reliable bond at the root-post-core interface is critical for the clinical success of post-retained restorations. To decrease the risk of fracture, it is important to optimize the adhesion. Therefore, various post surface treatments have been proposed. The purpose of this study was to investigate the influence of various surface treatments of fiber posts on the bond strength to composite core. Materials & Methods: In this study, 40 fiber reinforced posts were used. After preparing and sectioning them, resulting specimens were divided into four groups (N=28). The posts received different surface treatments such as no surface treatment (control group), preparing with hydrogen peroxide 10%, preparing with silane, preparing with HF and silane). Then, posts were tested in micro tensile testing machine. The results were analyzed by One-Way ANOVA and Dunnett T3 test. Results: The greatest bond strength observed was in treatment with hydrogen peroxide 10% (19.84±8.95 MPa), and the lowest strength was related to the control group (12.44±3.40 MPa). The comparison of the groups with Dunnett T3 test showed that the differences between the groups was statistically significant (α=0.05).Conclusion: Based on the results of this study, preparing with H2O2 -10 % and silane increases the bond strength of FRC posts to the composite core more than the other methods. Generally, the bond strength of posts to the composite core increases by surface treatment.