〔Abstract〕 Objective To explore the effect of using Er, Cr: YSGG laser with different power to remove thePorphyromonas gingivalis(P.gingivalis) biofilm on sandblasted, large-grit, acid-etched(SLA) surface. Methods P.gingivalisbiofilm was prepared on SLA surface and randomly divided into three groups. NL: no treatment; L1: 0.75 W Er, Cr: YSGG laser treatment; L2:1.5 W Er, Cr: YSGG laser treatment. Scanning electron microscope(SEM) was used to observe the bacterial biofilm on SLA surface, and live/dead bacterial staining and crystal violet staining methods were used to detect the bacteria in each group. Results Under SEM and live/dead bacterial staining, almost no bacteria was observed in the L1 and L2 groups, but L1 group was still covered with a large amount of acquired pellicle. The results of crystal violet staining showed that L1 and L2 groups were statistically different from NL group, but the difference between the two groups was not statistically significant. Conclusion 1.5 W, 30 Hz Er, Cr: YSGG laser can safely and effectively remove theP.gingivalisbiofilm on the SLA surface.