@article {hassan2015effect,
	title = {Effect of Periodontal Surgery on Osteoprotegerin Levels in Gingival Crevicular Fluid, Saliva, and Gingival Tissues of Chronic Periodontitis Patients},
	journal = {Disease markers},
	volume = {2015},
	year = {2015},
	note = {n/a},
	publisher = {Hindawi Publishing Corporation},
	abstract = {n/a},
	author = {Hassan, Sandy HS and El-Refai, Mahmoud I and Noha A. Ghallab and Kasem, Rehab Fawzy and Olfat G Shaker}
}
