Objectives This study aimed to explore the demineralization resistance and remineralization effects of the two newly modulated orthodontic primers and to compare them with those of the Transbond™ XT orthodontic primer. Methods After preparation of graphene oxide/hydroxyapatite (GOHA) and graphite fluoride/bioactive glass (GFBAG) primers, they were evaluated by Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-ray spectroscopy (EDX). The remineralization properties were evaluated through the assessment of calcium (Ca) and phosphate (PO4) ions released from primer disks (n = 10) for 168 days, the demineralization resistance was explored by evaluating the flat surface of molar teeth (n = 6) by Raman spectroscopy, and the length of the anti-demineralization zone around orthodontic bracket was measured by micro-CT analysis of premolar teeth (n = 5) bonded with one of the experimental or control primers. Results Both primers showed a homogenous distribution with the presence of Ca in both primers and Fluorine (F) in the GFBAG. High levels of Ca and PO4 ions were reported until the 112th day for the GOHA primer and the 168th day for the GFBAG primer. The result of Raman spectroscopy revealed the maintenance of mineral content with the GFBAG primer, followed by the GOHA primer, after subjecting the teeth to pH cycling to develop WSLs. The micro-CT analysis revealed a significant increase in the anti-demineralization length in both experimental primers compared to the control primer (p < 0.05). Clinical significance The results of the current study collectively illustrate the improvement of the remineralization properties with GOHA and GFBAG primers, with some priority to the GFBAG primer.
Objective To evaluate recently developed acidic calcium-phosphate (CaP) pastes as conservative enamel-conditioning systems for bracket bonding and investigate their effects on the shear bond strength, adhesive residues, and enamel damage in comparison to a conventional 37 % phosphoric acid (PA) gel. Materials and methods Two experimental etchant pastes consisting of hydroxyapatite and monocalcium phosphate monohydrate were prepared by mixing them with 37 % and 10 % PA solutions, respectively. These were characterized using X-ray diffraction. Metal brackets were bonded to 90 freshly extracted human premolars and assigned to three groups, depending on etchant type: 37 % PA-gel (control) and the two experimental (HPA and MPA) pastes. Shear bon
... Show MoreThis range-finding study aimed to develop novel primer-less self-adhesive resins (SARs) for orthodontic bracket bonding that can provide clinically acceptable bond strengths and antibacterial effects and leave minimal remnant adhesive post-bracket debonding.
Different concentrations of bioactive glass (BAG), strontium fluoride (SrF 2 ), and powdered grape seed extract (GSE) were added to a plain SAR
Objective: Dental caries is a chronic infectious disease that is prevalent worldwide in all age groups. Numerous attempts have been made to develop conservative approaches to halt caries progression and restore enamel defects. This study aimed to investigate the effect of applying grape seed extract and chicken eggshell extract on the microhardness of demineralized enamel in permanent teeth. Methods: Forty-eight sound upper first premolars were used. Following demineralization with the demineralizing solution for 96 hours, they were distributed into four groups consistent with the treatment agent used: group A was treated with casein phosphopeptide amorphous calcium phosphate (as a control group), group B was treated with grape se
... Show MoreNew microphotometer was constructed in our Laboratory Which deals with the determination of Molybdenum (VI) through its Catalysis effect on Hydrogen peroxide and potasum iodide Reaction in acid medium H2SO4 0.01 mM. Linearity of 97.3% for the range 5- 100 ppm. The repeatability of result was better than 0.8 % 0.5 ppm was obtanined as L.U. (The method applied for the determination of Molybdenum (VI) in medicinal Sample (centrum). The determination was compared well with the developed method the conventional method.
: In this study, a linear synchronous machine is compared with a linear transverse flux machine. Both machines have been designed and built with the intention of being used as the power take off in a free piston engine. As both topologies are cylindrical, it is not possible to construct either using just flat laminations and so alternative methods are described and demonstrated. Despite the difference in topology and specification, the machines are compared on a common base in terms of rated force and suitability for use as a generator. Experience gained during the manufacture of two prototypes is described.
Background: Alterations in the microhardness and roughness are commonly used to analyze the possible negative effects of bleaching products on restorative materials. This in vitro study evaluated the effect of in-office bleaching (SDI pola office +) on the surface roughness and micro-hardness of four newly developed composite materials (Z350XT –nano-filled, Z250XT-nano-hybrid, Z250-mico-hybrid and Silorane-silorane based). Materials and methods: Eighty circular samples with A3 shading were prepared by using Teflon mold 2mm thickness and 10mm in diameter. 20 samples for each material, 10 samples for base line measurement (surface roughness by using portable profillometer, and micro-hardness by usingDigital Micro Vickers Hardness Test
... Show MoreReliability analysis methods are used to evaluate the safety of reinforced concrete structures by evaluating the limit state function 𝑔(𝑋𝑖). For implicit limit state function and nonlinear analysis , an advanced reliability analysis methods are needed. Monte Carlo simulation (MCS) can be used in this case however, as the number of input variables increases, the time required for MCS also increases, making it a time consuming method especially for complex problems with implicit performance functions. In such cases, MCS-based FORM (First Order Reliability Method) and Artificial Neural Network-based FORM (ANN FORM) have been proposed as alternatives. However, it is important to note that both MCS-FORM and ANN-FORM can also be time-con
... Show MoreBackground: Metal ions can be released from metallic orthodontic appliances due to corrosion in the oral cavity; prophylactic mouthwashes may have an effect on ion release from orthodontic wires. Materials and Methods: Thirty six orthodontic sets of half maxillary fixed appliance with 2 types of arch wires SS and NiTi(Morelli) were constructed and immersed in 2 types of mouthwashes; Claradone (non-fluoridated) and Silver Care (fluoridated) for 28 days at 37°C, then the released Ni and Cr ionswere measured using atomic absorption spectrophotometer and compared statistically. Results: Ni ion release was higher from NiTi wire group than SS wire group for both mouthwashes and also was higher for Silver Care group than for Claradone group.
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