To comparatively evaluate the presence of microbial leakage at two types of implant abutment connections and adjacent sites of implant

Dental implants offer a reliable solution for tooth replacement; however, microbial contamination at the implant-abutment interface (IAI) poses a significant risk to their long-term success. A microgap between the implant and abutment in two-part systems can allow the infiltration of fluids and bacteria, including enteric species like Escherichia coli, Klebsiella, and Enterobacter. These bacteria, typically found in the gastrointestinal tract, can colonize peri-implant sites due to poor hygiene or systemic conditions. Their strong biofilm-forming ability and virulence can trigger inflammation, leading to peri-implantitis and bone loss. Recent studies have investigated the characteristics of E. coli in oral infections, examining their virulence, antibiotic resistance, and phylogroups. Additionally, the design and precision of the implant-abutment connection greatly influence microbial leakage, yet comparative data remains limited. Antibiotic therapy, while beneficial, must be used judiciously due to resistance concerns. Maintaining strict oral hygiene remains essential in preventing bacterial colonization. Therefore, this study aims to evaluate bacterial leakage, specifically E. coli, at two different implant systems: once during abutment placement at 3 months and again at 6 months post-implant placement. Adjacent teeth will also be analyzed to better understand bacterial behavior and improve implant design and clinical protocols.