An in vitro Evaluation on a Novel Root Canal Cleansing Method by Using Nylon Fibers

Despite traditional metal-based dental files, such as NiTi being demonstrated effective in root cleaning, the tooth structure is always damaged. Thus, to fulfill the need for a minimally invasive tool for contemporary endodontics and dentistry, the use of polymer fibers might provide a good option, as it is soft, fabricable, and disposable. In this study, two types of nylon fibers with respective average diameters of 206.9 µm (fiber W) and 156.4 µm (fiber B), respectively, were used as dental files, and mounted onto either a reciprocating or a low-speed rotary hand-piece. In vitro, simulated root canal models were colored red using nail varnish, and then cleaned by the fiber files mounted on the hand-pieces. Three parts of the simulated models, i.e., the apical third, the medium third, and the coronal third, were chosen to assess the cleaning the efficiency (CE) of each specimen by calculating the ratio of the cross-sectional area changes, before and after cleansing, using micro-Computer Tomography (CT). A NiTi file with a low-speed hand-piece was used as a control. SEM was used to observe the nylon fiber surfaces before and after the cleansing. Micro-CT results showed that for both the nylon fibers, W and B, an average CE of 82.11% ± 9.68% for the medium third could be achieved, which is statistically higher (p < 0.01) than the coronal third and apical third. The cleansing efficiency was not affected by, the types of fibers, nor the hand-pieces according to student’s t-test. Most of the nylon fibers could withstand deformation after the cleansing. To conclude, nylon fiber files have demonstrated a certain cleansing efficiency in simulated root canals, and micro-CT is a promising method to assess CE.published_or_final_versio

Characterization of a new polysiloxane-based titanium surface treatment for resin titanium bonding

PURPOSE: To characterize the polysiloxane-coated titanium surface with thermal treatment by XPS and AFM. Such a novel coating might significantly enhance resin bonding. METHODS AND MATERIALS: A layer (2mm) of silicone grease (Dow Corning Co., Michigan, USA) was applied on two titanium plates (Permascand, Ljungaverk, Sweden) followed by a thermal treatment at two temperatures, 800 and 1100 ◦C, respectively. Another titanium plate was surface treated by sandblasting. The atomic composition of titanium surfaces and change of chemical state…postprin

Fluoride and carbonate co-incorporated porcine bone derived biological apatite stimulates osteogenesis in vitro via WNT/beta-catenin pathway

Poster Presentation - Biomaterials and cellular signalingBiological apatite (BAp) is widely recognized as a favorable substitute in bone tissue engineering due to it being biodegradable, biocompatible, and bearing osteoconductive properties. Incorporation of trace ions into BAp was reported to contribute to the physicochemical and biological properties of the substitute ...postprin

Resin-Zirconia bonding promotion in vitro with a zirconate coupling agent

Oral Session: Dental Materials 3: Ceramic-based Materials and Cements - 193. Keynote Address; Bond Strength to Ceramics and Dentin: no. 1553OBJECTIVE: Silane-aided bonding is widely acknowledged, but new coupling agents may be needed for enhanced bonding. The aim of this study was to evaluate in vitro the effect of a zirconate coupling agent application on the bonding between a flowable resin-composite and zirconia. It was hypothesized that the zirconate coupling agent would promote resin-composite adhesion better than using a commercial primer on a tribochemically silica-coated zirconia surface. METHOD: Various amounts (0.2, 0.4, 0.6, 0.8 and 1.0 vol%) of an organo-zirconate, a neoalkoxy zirconate coupling agent, Zr(IV)-2,2(bis-2-propenolatomethyl)- butanolato-tris-2-methyl-2-propenoato-O (NZ-33, Kenrich Petrochemical, USA) were diluted in absolute ethanol and applied ...postprin

Novel organofunctional silane coatings on silica-coated Ti

This in vitro study characterizes a developed novel silane system method to produce coatings on Ti. Hydrophobic coatings are needed in prosthetic dentistry to promote durable adhesion between luting resin cements and coated Ti surfaces. Silane blends may contribute to significantly higher bond strengths than functional silanes alone. We have previously shown that the novel silane system blend with 1.0 vol% of 3-acryloxypropyltrimethoxysilane + 0.3 vol% bis-1,2-(triethoxysilyl)ethane produced in vitro the highest shear bond strength after artificial aging. The silane primers were prepared of 3-acryloxypropyltrimethoxysilane and bis-1,2-(triethoxysilyl)ethane (in four different concentrations) and diluted in acidified ethanol-water solvent. The contact angles, surface free energies and critical surface tensions were assessed and the chemical compositions of treated surfaces were analyzed using X-photoelectron spectroscopy. A commercially available preactivated dental silane were used as the controls. Novel silane + silica coatings were successfully developed and optimized. We may conclude that: 1. the novel silane system was developed and optimized successfully; 2) The surface characterization showed nearly full coverage of silane coatings on titanium surface without compromising the surface roughness. 3) Such hydrophobic coatings may have huge potential for durable restoration bonding i dentistry.abstractNanotech Conference & Expo 2012, Santa Clara, CA., 18-21 June 2012. In Nanotechnology 2012: Bio Sensors, Instruments, Medical, Environment and Energy, 2012 (v. 3), p. 122-12

Effects of collaborative learning by using Facebook blended with PBL: a pilot study

SEAADE Scientific Session 1: Oral presentationConference Theme: Revolutionizing Educatio

Fatigue resistance of CAD/CAM crowns restored on premolars

The Congress was held in conjunction with 68th Meeing of the Japanese Society for Dental Materials and Devices, and 2016 Annual Meeting of the Indonesian Society for Dental Materials Science and TechnologyOral Presentation V: Clinical Application - paper no. O-2

Effects of cold-cured PMMA reinforcement by E-glass fibers impregnation

Poster Session: 87. Dental Materials: Prosthodontics-Provisional/Impression/Materials: no. 679OBJECTIVES: Cold-cured PMMA is a common material for fabrication of appliances such as orthodontic retainers. However, cold-cured PMMA has lower degree of polymerization than the heat-cured and this leads to inferior biomechanical properties and fracture vulnerability. Reinforcement of cold-cured PMMA using chopped and impregnated E-glass fibers was hypothesized to be a solution. METHODS: Specimens of cold-cured PMMA powder mixed with different concentrations of chopped E-glass fibers (0 - 5 wt.%) were prepared by using a new mixing method which does not need addition of extra monomer (MMA). After the specimens were stored at various conditions (room temperature and ambient humidity for 1 day and 7 days; water storage at 37oC for 7, 14 and 30 days), 3-point bending tests were performed to test the flexural strength and SEM images were taken to assess the fractured morphology and fibers embedment to the PMMA matrix. The data was analyzed by 1-way ANOVA and Tukey post hoc test. RESULTS: In general, all fiber-impregnated cold-cured PMMA showed a higher flexural strength than the control at various storage conditions, except for 1 wt.% fiber concentration. The reinforcing ability decreased with increase in the duration of water storage condition. SEM images showed a good impregnation of E-glass fibers to PMMA matrix. CONCLUSIONS: A new E-glass fiber impregnation method in cold-cured PMMA, which is immediately transferable and usable in dental clinics/laboratories, was successfully developed. Such method may increase of the cold-cured PMMA flexural strength.link_to_OA_fulltex

Effects of bone formation by flavonoids: an in silico study

Group/Network Programs: Mineralized Tissue: no. 0311OBJECTIVES: Flavonoids are polyphenol compounds that are categorized according to their chemical structures into distinct groups, i.e. flavonols, flavones, flavanones, flavanols, and isoflavones. Previous laboratory and animal studies have shown some flavonoids, e.g. Naringin, Quercetin, Genistein and Daidzein, could promote bone formation via gene transcription or signalling the protein. However, the exact mechanism acts onto the osteoblast is unknown. In the last decade, inexpensive and time-saving Quantitative structure-activity relationship (QSAR) in silico modeling has been used in fields of biochemistry, molecular biology and biomaterials science to simulate and correlate various biochemical features and the behavioral manifestations. Thus, in the current study, we target to establish a validated and predictive QSAR model by different types of descriptors involved in the flavonoid biochemistry. METHODS: Twenty flavonoids (Kaempferol, Taxifolin, Daidzein, Morin, Scutellarein, Quercetin, Apigenin, Myricetin, Tamarixetin, Rutin, Genistein, 5,7,2'-Trihydroxyflavone, Baicalein, Luteolin, Galangin, Chrysin, Isorhamnetin, Naringin, 3-Methyl galangin, Resokaempferol) were identified with their structural information, e.g. the position of hydroxyl groups and half maximal inhibitory concentration (IC50). Then, these data were fitted into QSAR Software (VLifeMDS 4.3, VLife Technologies, India) with topological quantum-chemical descriptors involving in electronic, physicochemical or electronic properties of the flavonoids. Partial least squares (PLS), multiple linear regression (MLR) and Principal Component Regression (PCR) statistical modules were used to predict and establish the mathematical models. Finally, results from previous animal models were used to validate the mathematical model. RESULTS: A QSAR model has been successfully established, with Kaempferol was screened to be the best flavonoids. Electronic interactions between atomic charges within flavonoids would activate receptor-like structures in the calcium-voltage channels on osteoblasts, which was sought to be the significant mechanism for some flavonoids in assisting the bone formation. CONCLUSIONS: The QSAR model indicated that the activation of calcium-voltage channels on osteoblasts by flavonoids played an important role in bone formation