The effect of Er:YAG laser on Entroccocus faecalis bacterium in the pulpectomy of anterior primary teeth

Introduction: successful root canal therapy depends on the complete elimination of micro-organisms such as entroccocus faecalis,which is impossible to achieve with the traditional methods. lasers are recently introduced as a new method to solve the problem. the present study is planned and performed to examining the antibacterial effect of er: yag laser. methods: sixty extracted anterior primary teeth were prepared and sterilized. e. faecalis bacterium was cultured in canals. samples were randomly divided into two groups. the first group was disinfected by naocl 5/25% and er: yag laser and the second group just by naocl 5/25%. samples of canal contents were cultured and colony counts were calculated. the results were analyzed statistically by spss software and mann whitney test. results: there was no significant difference between colony counts in both groups (p = 0.142). but the number of colonies in the first group was lower than in the second group. conclusion: although,er: yag laser cannot completely eliminate e. faecalis bacterium,its simultaneous use with naocl decreases e. faecalis.