Work

Amoxicillin and metronidazole resistance of bacteria isolated from dental implants with peri-implant diseases: a pilot cross-sectional study

Year: 2026

Type: article

Abstract: Background Peri-implant mucositis is a reversible inflammatory lesion of the mucosa surrounding a dental implant, caused by the accumulation of bacterial plaque and biofilm formation, without bone loss. If peri-implant mucositis is not addressed, it can progress to peri-implantitis, characterized by significant inflammation of the peri-implant mucosa accompanied by the loss of supporting bone. Clinical evidence suggests that the management of peri-implant infections consist of mechanical debridement of implant, surgical intervention, and the administration of antibiotics. However, limited information is available regarding antibiotic resistance in bacteria causing peri-implant diseases. Gap statement Peri-implant bacteria are resistant to amoxicillin, a β-lactam antibiotic, which is the first choice medicine to treat peri-implant infections. Aim Evaluate the resistance of bacteria isolated from dental implants with peri-implant diseases, to amoxicillin and clindamycin. Methodology Biofilms were recovered from implants with peri-implant mucositis (n=4) and peri-implantitis (n=8). Microorganisms were cultured under aerobic and anaerobic conditions. Antibiotic sensitivity was assessed using the disk diffusion susceptibility assay using amoxicillin at a concentration of 8 μg per disk and clindamycin at a concentration of 30 μg per disk. Results Cultivation of microorganisms revealed predominant facultative anaerobic bacteria. Isolates recovered from implants with peri-implant mucosistis showed resistance to amoxicillin (100%; 4/4). In comparison, 75% of bacteria isolated from implants with peri-implantitis were resistant to amoxicillin (6/8). All isolates from implants with peri-implant diseases (n=12) were sensitive to clindamycin. Conclusion These findings suggest that bacteria isolated from dental implants with peri-implant infections are resistant to amoxicillin, a β-lactam antibiotic, raising concerns about the potential dissemination of this resistance to other oral bacteria.

Source: Access Microbiology

DOI: 10.1099/acmi.0.000946.v3