Antibacterial efficacy of mechanical preparation and diode laser on enterococcus faecalis in vitro

LI Ya-nan; CHE Xiao-qian; WANG Hong-wei; LI Ru; SUN Hui-bin

doi:10.15956/j.cnki.chin.j.conserv.dent.2015.08.006

Abstract：AIM:To evaluate the antibacterial efficacy of mechanical preparation and diode laser on entero-coccus faecalis in infected root canals in vitro. METHODS:50 single-rooted teeth of in vitro root canal enterococcus faecalis infection model were randomly divided into 5 groups (n=10). The root canals of the teeth in the control group were prepared by Protaper F3. After F3 preparation, the tooth canals in the other 4 groups were treated with diode laser for 10 s and 20 s with 1. 0 W or 2. 0 W, respectively. Microbiological samples were collected from the root canals be-fore and after irrigation. The dentin debris from two depths of the root canals were collected and cultured for turbidimet-ric count. A one-way ANOVA with the Tukey Test was conducted for the comparisons among the groups. RESULTS:The numbers of E. faecalis in all the groups decreased after treatment (P<0. 05). The bacterieidal ration (BR) of the treatment groups was higher than that of the control(P<0. 05). Between each 2 laser groups, P>0. 05. The number of E. faecalis from two different depths of dentin reduced in all the laser groups(P<0. 05). Under the condition of 10 s jrradiation, the disinfection was more effective with 2. 0 W than that with 1. 0 W, and there was no significant difference between 10 s irradiation and 20 s irradiation under the conditions of 2. 0 W irradiation. With 1. 0 W the dis-infection was more effective by 20 s irradiation than by 10 s, and with 2. 0 W there was no significant difference be-tween 10 s and 20 s irradiation. CONCLUSION:Diode laser is effective on root canal disinfection due to its effective penetration in dentins. The bactericidal effect enhances with increase of irradiation time and energy.