Purpose: The efficiency of bacterial removal using mechanical and chemical methods and recurrence rates was evaluated based on infected implant surface removal modalities.

Materials and methods: The study comprises two main parts: in vitro bacterial removal (n = 49) and regrowth (n = 42) suppression tests on implant surfaces. Microorganisms were attached to each implant, and various methods were applied to clean the infected implants. The groups were allocated as follows: (1) no treatment, (2) cotton + saline, (3) brush, (4) scaler, (5) brush + scaler, (6) cotton + 3% H₂O₂, and (7) brush + 3% H₂O₂. All groups were further divided into two subgroups of mechanical treatment (3, 4, 5) vs mechanical + chemical treatment (2, 6, 7). After treatment for each group, immunofluorescence analysis and measurement using an ultraviolet-visible light spectrophotometer were performed.

Results: In the mechanical treatment group, the brush, scaler, and brush + scaler groups, all of which had strong polishing abilities, exhibited superior removal efficiency compared with the other groups (P < .001). In the regrowth experiment, 3% H₂O₂ effectively restrained biofilm formation. In particular, the brush + 3% H₂O₂ group exhibited significant differences from the mechanical treatment group (vs brush: P < .001, vs scaler: P = .023, vs brush + scaler: P = .005).

Conclusion: Mechanical methods, including brushes and scalers, effectively removed bacteria. Biofilm formation was effectively restrained by H₂O₂. In particular, the brush + H₂O₂ group exhibited a superior ability to suppress bacterial regrowth compared with the other groups.