ObjectiveThis study aimed to assess the clinical and radiographic outcomes of non‐instrumentation endodontic treatment (NIET) using a modified antibiotic mix of cefixime, ciprofloxacin and metronidazole with simvastatin (an anti‐inflammatory, bone regeneration drug) on necrotic primary molars compared to conventional pulpectomy to help preservation of necrotic primary teeth until its natural exfoliation.Materials and MethodsForty mandibular primary second molars with necrotic pulp tissue from 38 healthy patients aged between 4 and 8 years were randomly assigned to two groups with a 1:1 allocation ratio. Group A teeth underwent conventional root canal treatment. The procedure involved a two‐visit approach, employing k‐files and h‐files during the initial visit, followed by the application of calcium hydroxide paste as canal dressing between visits, while Group B teeth were treated with 3Mixtatin. All teeth were clinically evaluated after 1, 3, 6, and 12 months, and radiographically at 3, 6, and 12 months. Two external examiners assessed the results. Data analysis was conducted using a chi‐square test at a 0.05 significance level.ResultsAt the end of the follow‐up interval, 90% of teeth in each group exhibited no clinical signs or symptoms. Additionally, inter‐radicular radiolucency healing occurred in 75% of cases in the NIET group and 89.5% in the conventional pulpectomy group. However, no statistically significant difference was found between the two groups.ConclusionNIET using 3Mixtatin seems to be a good alternative choice to conventional pulpectomy, offering a less complex treatment approach that may help avoid the complications associated with traditional pulpectomy and could be suitable for teeth with shorter roots.