Objective : To investigate the effect of different decontamination methods, including photodynamic therapy, sandblasting and titanium curette, on titanium surface morphology and bacterial adhesion for the treatment of peri-implant disease. Methods: Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn) were inoculated on the surface of polished titanium specimens, and titanium specimen surfaces were treated with different decontamination methods after incubation. The titanium specimens were divided into a no-treatment control group, photodynamic group, sandblasting group and titanium curette group according to different decontamination methods. The changes in titanium surface roughness were observed by atomic force microscopy (AFM), and the remaining bacteria on the titanium surface were observed by scanning electron microscopy (SEM) and live/dead bacteria staining tests. After reinoculation of Pg and Fn, bacterial readhesion was observed on the surface of decontaminated titanium specimens. Results : The AFM results showed that the surface roughness of the titanium curette group was significantly higher than that of the no-treatment control group, photodynamic group and sandblasting group (P<0.05), and there was no statistically significant difference between the no-treatment control group, photodynamic group and sandblasting group (P>0.05). The results of contact angle measurement showed that the surface contact angle of each treatment group was smaller than that of the no-treatment control group (P<0.05). The SEM results obtained after the titanium specimen surface was decontaminated showed that the number of bacteria on the no-treatment control group surface was higher and the bacteria were relatively concentrated. The bacteria on the surface of the photodynamic group, sandblasting group and titanium curette group were scattered and distributed in small numbers, and most bacteria on the surface of the photodynamic group were ruptured. The results of the live/dead bacteria staining experiment showed that the percentage of dead bacteria on the surface of the photodynamic group was significantly higher than that of the no-treatment control group, sandblasting group and titanium curette group (P<0.05). The remaining bacteria on the surface of the sandblasting group and titanium curette groups were mainly live bacteria. The remaining bacterial adhesion on the surface was significantly reduced for the sandblasting group compared to the no-treatment control group and the photodynamic and titanium curette groups (P<0.05). SEM and live/dead bacteria staining results of bacterial readhesion on the surface of titanium specimens showed that there was an aggregation of Pg on the surface of the titanium curette group, and its surface bacterial adhesion was significantly higher than that of the no-treatment control group, photodynamic group and sandblasting group. Conclusion In mechanical decontamination, sandblasting machines are a better option than photodynamic therapy and titanium curettes; however, sandblasting does not remove all bacterial contamination. For sterilization, photodynamic therapy is more effective than sandblasting and titanium curettes. A combination of sandblasting and photodynamic therapy methods for the treatment of peri-implant disease may be considered in clinical practice.