At the institute of laser for postgraduate studies, the university of Baghdad witnessed discussion of a master thesis submitted by the researcher Mohammed Abboud Qanbar specialized in laser dentistry entitled (The effects of CO2 laser with or without material paste in the occlusion of dental tubules). The researcher clarified that the goal of the study is to evaluate a new method of treatment to fill in the ivory tubules by integrating carbon dioxide laser ( 10.6 micrometers ) with nano – hydroxyapatite toothpaste regarding the high temperature of tooth pulp, ivory permeation and surface morphology. The researcher used sixty-eight teeth free from mortar divided into six groups: (a) negative control group which did not receive any treatment, (b) positive control that has a nono – hydroxyapatite toothpaste without laser irradiation. For the groups (c, d, e, f), the researcher used a dioxide carbon laser ( 10.6 micrometers ) with two doses, the first one of low energy laser at (0.65) watt of a continuous wave , energy density of 129.33 watts cm 2 without and with nono – hydroxyapatite toothpaste for the groups (c and d), respectively, while the second laser dose is of a high power at 1.3 w, continuous wave, the energy density of 258.65 watts cm 2 without and with the nano – hydroxyapatite toothpaste for the groups (e and f), respectively. The committee of discussion consisted of assistant Prof. Dr. Hussein Ali Jawad, dean of the laser institute for postgraduate studies as president of committee, assistant prof. Amar Atallah Ali, specialized in dental treatment from the faculty of dentistry at Mustansiriya university as a member, assistant prof. Dr. Abdullah Mohammed Wajih from the the faculty of dentistry at the university of Baghdad as a member and assistant prof. Dr. Ali Shukur Mahmoud specialized in general surgery and laser surgery from the institute as a supervisor.