ساخت و بهبود خواص سيمان هاي فسفات روي و پلي كربوكسيلات روي با استفاده از نانو ذرات اكسيد آلومينيوم و اكسيد تيتانيوم

چكيده انگليسي :

Production of Zinc Phosphate and Zinc Polycarboxylate Dental Cements and Improvement Their Properties via Making Nano Composite byTitanium Oxide and Aluminium Oxide Nano Particles Mojtaba Forghani m forghani@ma iut ac ir Date of Submission March 14 2012 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisors Ahmad Monshi A monshi@cc iut ac ir Mohamad Hossein Fathi Fathi@cc iut ac ir AbstractZinc phosphate and zinc polycarboxylate cements are used in clinics from a long time ago Zincphosphate and zinc polycarboxylate cements are compounds of powder and liquid The powder ofboth of these cements are made of zinc oxide as a main component and magnesium oxide Magnesium oxid is added to powder of these cement to decrees calcination temperature andreactivity of zinc oxide with orthophosphoric acid and polyacrilic acid The liquid of zincphosphate cement is made of orthophosphoric acid and the liquid of zinc polycarboxylate cementis made of polyacrylic acid as the main component Powder of aluminium and zinc are added toliquid of zinc phosphate cement to reduce reactivity of reaction of liquid and powder Thestructure of these cement include a brittle matrix that non reacted particle of zinc oxide aredisperse in whole of the matrix Mechanical properties and setting time of zinc phosphate andzinc polycarboxylate depend on mixing ratio of powder and liquid By increasing mixing ratio ofpowder and liquid of zinc phosphate and zinc polycarboxylate cement their compressive strengthincrease because the non reacted zinc oxide particles increase and stop generation and propagationof crack but the setting time is deceased The film thickness of these cement also depend onpowder liquid mixing ratio via increasing the mixing ratio film thickness increase that it is aproblem in clinical applications The antibacterial property of these cemen is depend on zinc ionreleasing and the acidity of the past of these cement before setting In this study aluminium oxideand titanium oxide are added to powder of these cements before mixing of powder and liquid Nano particles increase the compressive strength by stop growing cracks The compressivestrength of zinc phosphate and zinc polycabocylate cements with nano particles of titanium oxideand aluminium oxide was increased The main result of this study is a better compressive strengthin a same mixing ratio of powder for zinc phosphate and zinc polycarboxylate cement Titaniumoxide nano particles affected the antibacterial properties of zinc phosphate and zincpolycarboxylate cements If UV ray flame to titanium oxide nano particles the nano particlesmake electron and hole and become photocatalyst and show antibacterial properties In this study nano composite of zinc phosphate and zinc polycarboxylate cements were exposed to the UV rayand then take them antibactrial test The antibacterial properties of both of them were improved The compressive strength of zinc phosphate cements improved from 20 71 Mpa to 33 44 Mpa viaadding aluminium oxide nano paticles and also improved to 32 45Mpa with adding titanium oxidenano particles The compressive strength of zinc polycarboxylate cement improved from 19 17Mpa to 57 96 Mpa with adding aluminium oxide nano paticles and also improved to 43 38 Mpawith adding titanium oxide nano particles The setting time and film thickness of both cements didnot change SEM and EDS analysis show that the nano particles stop crack propagation in matrix Titanium oxide nano particles made a difference mechanism of antibacterial property that keepthis property for a longer time Keywords Zinc phosphate cement zinc polycarboxylate cement titanium oxide nano particle aluminium oxide nano particle compressive strength setting time antibacterial properties

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ساخت و بهبود خواص سيمان هاي فسفات روي و پلي كربوكسيلات روي با استفاده از نانو ذرات اكسيد آلومينيوم و اكسيد تيتانيوم

نانو اكسيد تيتانيوم