This ex vivo study compared the efficiency of Er:YAG laser to remove calcium hydroxide from root canal walls, especially from the apical third, with manual and ultrasonic irrigation technique by using a scanning electron microscopic (SEM).

Sixty-four single-rooted teeth were divided into 3 groups of 20 teeth each. The rest 4 teeth were used as control groups (2 positive and 2 negative control group). After coronal access, all teeth were instrumented by Protaper Next rotary files (Dentsply-Maillefer, Ballaigues, Switzerland) up to size F3, followed an irrigation protocol and filled with pure calcium hydroxide powder mixed with saline. Teeth were stored in an incubator for 7 days and then calcium hydroxide was removed using 3 techniques: Manually (group I), by ultrasonic irrigation (group II), by laser Er:YAG and x-pulse tip (group III). The teeth of control groups were instrumented as the experimental groups; no removal technique was applied in positive group, whereas in negative one, the root canals were left empty. Teeth were sectioned longitudinally and observed under SEM. Results were statistically analyzed with the Kruskal–Wallis test and Mann–Whitney test.

The results showed significant difference between laser and the other two groups in coronal and middle root third, but no statistic difference in apical third.

Laser improved the removal of calcium hydroxide in comparison with conventional techniques.

Kourti E, Pantelidou O, Kallis A. Removal Efficiency of Calcium Hydroxide Intracanal Medicament with Er:YAG Laser: A Scanning Electron Microscopic Study. Int J Laser Dent 2016;6(1):24-30.