Summary: This study investigated the efficacy of diluted antibiotic hydrogels in endodontic regeneration procedures. Three treatments, including calcium hydroxide, MC-TAP, and MC-DAP, were evaluated for their effects on dental pulp stem cells. Clinical application on 22 teeth with necrotic immature roots followed the AAE protocol. While all treatments initially resolved symptoms, MC-DAP cases experienced symptom recurrence. After 12–24 months, teeth treated with MC-TAP showed symptom resolution but did not achieve vitality. The study concluded that a low-concentration antibiotic gel with triple antibiotic paste (MC-TAP) is effective for endodontic regeneration.