Acknowledgements
The authors of the study would like to express the greatest thanks to all the staff members of the Oral Medicine Department, Faculty of Dentistry, and Cairo University for their cooperation, kind feelings and for sparing no effort in helping us, as well as many thanks to Mepaco_Arab Co. For Pharmaceuticals and Medicine for supplying us with the powder of Co enzyme Q10 .Finally, we would like to express a lot of thanks to all patients who participated in the study.