Background: While many dental procedures induce pulpal damage by increase the temperature, this study was established to evaluate the thermally effect of different laser methods on pulp, oral soft and hard tissues. Objectives: In this study, laser irradiation applied to measure how increased in power output can influence on dental pulp by using CT images. Methods: Ten adult New Zealand white rabbits were divided into 2 groups receiving 3 and 5 watt for 15 second respectively on left side cheek teeth after shortening of third  upper and first lower premolars. Right cheek teeth trimmed as well and served as control. CT scans were taken immediately after lasing and repeated every week for one month. Results: The statistical analysis of dental measurements shows that teeth length of right and left third upper premolar was significantly different during time (P<0.012). While in first lower premolar there was no significant differences between right and left sides (P=0.338). In every week CT, group one showed no differences in right and left side in comparison to group two (P>0.05). Only third upper premolar in fourth week showed a significant difference between two groups (P=0.047). Conclusions: laser radiation could influence on tooth growth in both groups. This study revealed that the higher laser power would have been more effective on reduction of growth rate of teeth. In addition, 3D CT scans could be an appropriate tools for dental growth investigation.