Introduction: The main objective of endodontic treatment is to minimize the number of microorganisms in the root canal system, to prevent or treat apical periodontitis [1]. The Enterococcus faecalis bacteria, most prevalent in persistent endodontic infections, resists antibacterial medications such as calcium hydroxide and multiconjugate pastes [2]. The increase in possible cases of refractory apical periodontitis due to said resistance has led to the search for alternatives, such as the use of broad-spectrum antibiotics alone or in combination as a possible solution to this problem [3].

Objective: To evaluate the effectiveness of a triantibiotic formulation on the inhibition of bacterial growth of E.feacalis by replacing Minocycline with Amoxicillin, to prevent dental pigmentation without losing the disinfection capacity of said paste.

Materials and Methods: Commercial presentations of the antibiotics and microdilution techniques were used to evaluate the antimicrobial activity against the bacterial strain of E. faecalis.

Results: In this study, Amoxicillin obtained the highest percentage of inhibition on E. faecalis