Background: This study was aimed to investigate the effect of three lingual button (Nickel free / rectangular base, Nickel free / round base and Composite) and bonding environment, wet and dry enamel surface, on: the shear bond strength (SBS) of light and self-cured Resin Modified Glass Ionomer Cements, and the debonding failure sites. Materials and method: One hundred twenty no-carious, free of cracks maxillary first premolar teeth were selected. Three types of orthodontic lingual buttons were used in this study: Nickel free / rectangular base, Nickel free / round base and Composite buttons. The teeth were divided into two groups of sixty teeth each. One group was used for testing the chemically cured GC Fuji Ortho Resin modified Glass Ionomer (RMGIC), while the other was used for testing the light cured GC Fuji Ortho LC RMGIC. Each was further subdivided into two subgroup; thirty teeth were bonded to wet enamel surface while the other was bonded after drying the enamel surface. Then each ten teeth from each subgroup were bonded with only one type of buttons. The sample was tested for bond strength using the universal testing machine and the Adhesive Remnant Index (ARI) was inspected under the stereomicroscope. Results:The highest (SBS) values were obtained in the Nickel free / round base button with both types of RMGIC in wet and dry environment as revealed by ANOVA test. While t-test revealed that both systems of RMGIC yield relatively lower values of (SBS). Conclusions:The GC Fuji Ortho RMGICs resist shear force in dry better that in wet environment.Nickel free / round base buttons give the greatest shear bond strength among the three types of button.The composite buttons give greater bond strength in dry than in wet environment with both GC Fuji Ortho and GC Fuji Ortho LC RMGICs.
Purpose: To evaluate the effect of different surface treatments on shear bond strength between dentin and IPS e.max lithium disilicate glass-ceramic. Materials and Methods: Eighteen extracted third molars were embeded in epoxy resin. The tooth was sectioned vertically in mesiodistal direction using a low speed hard tissue microtome. The buccal and lingual surfaces of each section were ground flat using 600 grit Silicone carbide paper. Eighteen ceramic discs consisted of lithium disilicate glass-ceramic were prepared with a diameter of 4.7mm and height of 2.2mm. The discs were divided in two groups (n=10): (1) IPS e.max treated with hydrofluoric acid and Monobond Plus (MBP) and (2) IPS e.max treated with Monobond Etch &Prime (MBEP). The toot
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This research is devoted to study the effect of different in weight percentage of Sio2 particles and glass fibers (5, 10, 15, 20) wt. % on the wear rate epoxy resin. The results show that the value of hardness increase with the increase for the weight percentage of reinforcing particles and fibers, while the wear rate decrease with the increase the load level of the reinforcing particles and fibers . The largest value of the hardness, and the lowest value of the wear rate for epoxy reinforced with 20% of SiO2, the wear rate increase in general with increasing the applied load.
Background: Debonding and fracture of artificial teeth from denture bases are common clinical problem, bonding of artificial teeth to heat cure acrylic and high impact heat cure acrylic denture base materials with autoclave processing method is not well known. The aim of this study was to evaluate the effect of autoclave processing method on shear bond of artificial teeth to heat cure denture base material and high impact heat cure denture base material. Materials and methods: Heat polymerized (Vertex) and high impact acrylic (Vertex) acrylic resins were used. Teeth were processed to each of the denture base materials after the application of different surface treatments. The sample (which consist of artificial tooth attached to the dentur
... Show MoreRemovable dental prostheses remain a reliable treatment for edentulous patients. Conventional fabrication requires multiple steps, whereas computer-aided design and manufacturing (CAD-CAM), particularly 3D printing, offers faster and more cost-effective alternatives. This in vitro study aimed to evaluate the effect of sandblasting on surface roughness and shear bond strength of silicone soft liner bonded to 3D-printed and heat-cured acrylic denture base materials. Eighty specimens were divided into four groups: heat-cured control, 3D-printed control, heat-cured sandblasted, and 3D-printed sandblasted. Surface roughness was measured using a profilometer, while shear bond strength was tested with a universal testing machine. D
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Objective(s): The aim of this study is to compare the impact strength of a heat cured denture-base acrylic resin
reinforced with metal wire and glass fibers.
Methodology: Forty five specimens were prepared from pink heat cure acrylic resin. Specimens were grouped into;
group-I (control group) which consists of 15 specimens with no reinforcement, group-II which consists of 15 specimens
reinforced with metal wire, and group-III consists of 15 specimens reinforced with glass fibers. Specimens were tested
by using charpy impact machine.
Results: The result showed that there was a highly significant difference in impact strength value among the testing
groups at (P < 0.001).
Conclusion: The impact str
... Show MoreBackground: To investigate the effect of different types of storage media on enamel surface microstructure of avulsed teeth by using atomic force microscope.Materials and methods : Twelve teeth blocks from freshly extracted premolars for orthodontic treatment were selected . The study samples were divided into three groups according to type of storage media :A-egg white , B- probiotic yogurt , and C-bovine milk . All the samples were examined for changes in surface roughness and surface granularity distribution using atomic force microscope, at two periods: baseline, and after 8 hours of immersing in the three types of storage media. Results: Milk group had showed a significant increase in the mean of the roughness values at
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Background: Lack of durability of the bond of the dental adhesive systems to tooth structure is one of the most important problems in tooth colored restorative work. This in vitro study was performed to evaluate the effect of 2% chlorhexidine gluconate(CHX) on dentin bond strength by using total etch adhesive system at twenty-four hours and three months of water storage. Material and methods:A flat dentin surface was prepared for forty sound human maxillary premolar teeth which were acid etched with 36% phosphoric acid gel after being divided randomly into four groups of ten teeth each according to storage time and CHX application, theCHX was applied for 60 seconds before adhesive application for groups I and III which were tested after twe
... Show MoreThe study included adding antimony oxide to mixtures of coating metal surfaces (Enameling), after it was selected ceramic materials used in the coating metal pieces of the type of steel and cast iron in two layers. The first is called a ground coat and the second is a cover coat.
Ceramic materials layer for ground coat have been melted down in
platinum crucible at a temperature of 1200oC to prepare the glass
mixture (Frit). It was coated on metals at a temperature of 780oC for
two minutes, while the second layer was prepared glass mixture
(Frit) at a temperature of 1200oC, but was coated at a temperature of
760oC for two minutes.
Underwent tests crystalline state of powders (Frits) and enameled samples using X-ray di
Effects of Ozonated Water on Micro Leakage between Enamel and Fissure Sealants Prepared by Different Etching Technique (An in vitro Study), Baraa M Jabar*, Muna S Khalaf