We established a mouse model of chronic bacterial infection (cotton trap) to get a deeper insight into interactions between immune cells and bacterial strains, that are most commonly isolated from periapical processes. We have used flow cytometry to identify the presence of intracellular cytokines of activated T cells collected from cotton traps, previously infected with different strains of bacteria and implanted subcutaneously into the back of the mice. We provide an evidence that anaerobic bacteria (Bacteroides sp.) and nocardiae are more effective in inducing cytotoxic immunity and Th1 response compared to oral streptococci. Differences in immune response against anaerobic bacteria when compared to streptococci are probably dependent on some non-specific immune cell stimulation (e.g. by bacterial cell wall components), nevertheless the role of specific antigen-dependent immune mechanism can not be excluded.