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Background: bond failure of acrylic and porcelain teeth represents primary clinical disadvantages of partial and complete denture services provided to the patient. The aims of the study were to investigate the tensile and shear bond strength of two types of denture bases (heat cured reinforced with 5% ZrO 2 nano-fillers and valplast) with (acrylic and porcelain) teeth after ridge lap conditioning and using aging. The measurements were used for comparison with traditional denture base. Materials and methods: denture bases reinforced with nano ZrO 2 and valplast were bonded to acrylic and porcelain teeth. Samples were divided for shear and tensile strength. Each contains 5 samples. The ridge lap surface were conditioned by different treatments and then subjected to aging. Tensile and shear bond strength measured by instron testing device. The results were organized and evaluated by using analysis of variance (f-test) and t-test for comparison between subgroups. Results: artificial teeth bonded to nano reinforced denture base required higher tensile and shear force to separate when compared with traditional heat cured and valplast resins. The mode of failure where cohesive either in the denture base or in the tooth itself when compared with valplast resin. Acrylic teeth conditioned with turpentine and porcelain with hydrofluoric acid express higher tensile and shear bond compared with unconditioned teeth. Aging sustained damaging effects on the bond strength of artificial teeth bonded to valplast denture base in compared with nano reinforced and conventional heat cured. Conclusions: tensile and shear bond strength of artificial teeth enhanced by the reinforcement of the resin with nano-sized fillers and by conditioning of the teeth ridge lap using chemical agents, making the bond stronger and durable to withstand fluctuated oral conditions.

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Objectives Dental implant is a revolution in dentistry; some shortages are still a focus of research. This study use long duration of radiofrequency (RF)–magnetron sputtering to coat titanium (Ti) implant with hydroxyapatite (HA) to obtain a uniform, strongly adhered in a few micrometers in thickness. Materials and Methods Two types of substrates: discs and root form cylinders were prepared using a grade 1 commercially pure (CP) Ti rod. A RF–magnetron sputtering device was used to coat specimens with HA. Magnetron sputtering was set at 150 W for 22 hours at 100°C under continuous argon gas flow and substrate rotation at 10 rpm. Coat properties were evaluated via field emission scanning electron microscopy (FESEM), scanning electron microscopy–energy dispersive X-ray (EDX) analysis, atomic force microscopy, and Vickers hardness (VH). Student’s t-test was used. Results All FESEM images showed a homogeneous, continuous, and crack-free HA coat with a rough surface. EDX analysis revealed inclusion of HA particles within the substrate surface in a calcium (Ca)/phosphorus (P) ratio (16.58/11.31) close to that of HA. Elemental and EDX analyses showed Ca, Ti, P, and oxygen within Ti. The FESEM views at a cross-section of the substrate showed an average of 7 µm coat thickness. Moreover, these images revealed a dense, compact, and uniform continuous adhesion between the coat layer and the substrate. Roughness result indicated highly significant difference between uncoated Ti and HA coat (p-value < 0.05). A significant improvement in the VH value was observed when coat hardness was compared with the Ti substrate hardness (p-value < 0.05). Conclusion Prolonged magnetron sputtering successfully coat Ti dental implants with HA in micrometers thickness which is well adhered essentially in excellent osseointegration.

Background: Soft lining materials play an important role in modern prosthodonticstreatment because of their capability to restore the inflamed and distorted mucosa.The purpose of the research was to estimate the influence of acrylic denture basereinforcement with silanted nano fillers (Al2O3 and Sio2) separately on tensile andshear bond strength of soft lining material and studying effect of thermo cyclingon bonding strength.Materials and methods: Total 120 specimens were prepared; it divided into 60Specimens for shear bond strength test and 6o specimens for tensile bond strengthtest. Specimens were sub grouped into 30 Specimens without thermo cycling and30 specimens with thermo cycling. Each sub group is consisted from: 10Specimens control, 10 specimens were reinforced with 2 wt% of Al2O3 nano fillersand 10 specimens were reinforced with 5 wt% of SiO2 nano fillers. Samples wereprocessed depending on test applied. Soft lining material was applied for eachtesting group. Samples were immersed in distal water for 24 hours at 37°C beforetesting. For thermo cycling test, specimen were thermo cycled in thermo cyclingdevice. Bonding strength test was done using INSTRON universal testingmachine.Results: reinforcement of acrylic denture base with nano-fillers was significantlyincrease both tensile and shear bonding of lining material and thermo cyclingdecreases both bonding strength.Conclusion: reinforcement of acrylic denture base with nano fillers could improvebonding strength of lining material, while thermo cycling had a deleterious effecton bonding strength.

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An impression taking for edentulous ridge is the first step in the fabrication of thecomplete denture prosthesis. Various theories have been proposed by differentauthors as how to achieve an optimum impression in different ways.The purpose of this study was to compare the retentive forces required to dislodgemaxillary complete denture bases fabricated by using different impression materials.Twenty completely edentulous patients were selected and three types ofimpression were made for each patient. The 1st group; final impression were madewith zinc oxide eugenol "ZOE", 2nd group; final impression were made with lightbody addition silicone impression material and 3rd group; final impression were madewith condensation impression material. Three stone casts were obtained for eachpatient and three denture bases were fabricated by short curing cycle, retention forceexamined and compared using strain gauge force transducer.Statistical analysis for the data collected using descriptive statistic, ANOVA andLSD, the result revealed that group A "Impression with ZOE" and B "Impression withaddition silicone" show nearly the same results while group C "impression withcondenation silicone" significantly less retentive force than that of group A and B.Retention of complete denture bases is greater in denture bases produced by zincoxide eugenole final impression material than the other examined final impressionmaterials.