الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
SUMMARY AND CONCLUSION
Irrigation is the most important part of successful root canal treatment. It has several important functions, which may vary according to the irrigant used: it reduces friction between the instrument and dentine, improves the cutting effectiveness of the files, dissolves tissue, cools the file and tooth, and furthermore, it has a washing effect and an antimicrobial/antibiofilm effect. Irrigation is also the only way to impact those areas of the root canal wall not touched by mechanical instrumentation. Sodium hypochlorite is the main irrigating solution used to dissolve organic matter and kill microbes effectively.
The aim of this study was to evaluate the chemical stability, tissue dissolution capacity and ability to remove the smear layer of calcium hypochlorite solution when used as an endodontic irrigant in different concentrations.
Part one was to evaluate calcium hypochlorite chemical stability by two methods, PH measurement and iodometric titration. PH measurement was done by preparing three concentrations of calcium hypochlorite solution (1.25 %, 2.5%, 5.25%) and using PH meter for measuring and it was concluded that there was no significant difference between the PH measurements of the three concentrations. Iodometric titration was done to determine the available chlorine content of three concentrations of calcium hypochlorite solution (1.25%, 2.5%, 5.25%) and it was concluded that chlorine content increased by increasing the solution concentration.
Part two was to evaluate tissue dissolution capacity of calcium hypochlorite by using bovine meat. Three concentrations of calcium hypochlorite (1.25 %, 2.5%, 5.25%) and Three experimental groups of 5 bovine meat samples (fixed size and weight) and one control group of five samples were prepared. The frozen tissue of bovine meat samples were allowed to thaw to room temperature without any intervention.. Each sample was immersed in 5 mL allocated solution for 5 minutes. The tissue was then removed carefully, blotted dry on absorbent paper, and weighed on a Dual range Analytical Balance and it was concluded that tissue dissolution capacity of calcium hypochlorite increased by increasing its concentration.
Part three was to evaluate the ability of calcium hypochlorite solution to remove the smear layer twenty eight maxillary single rooted human teeth with mature apices. The teeth were randomly divided into three experimental groups of 7 teeth each and one control group of seven teeth. Standard access to pulp chambers were performed with diamond burs. Root apices were covered with sticky wax. Cleaning and shaping of all teeth was performed by using ProTaper rotary files. An F5 file was used to the full working length. Three concentrations of calcium hypochlorite (1.25 %, 2.5 % and 5.25 %) are used and Distilled water used for control group.1 mL of irrigation was used between each instrumentation and remained in canal for 2 minutes after instrumentation. The irrigants were delivered with a 27-gauge plastic needle. All samples were then longitudinally grooved with