Wulandari, P., Widkaja, D., Nasution, A.H., Syahputra, A. and Gabrina, G. 2022. Association between age, gender and education level with the severity of periodontitis in pre-elderly and elderly patients. Dental Journal. 55, 1 (Mar. 2022), 16–20. DOI:https://doi.org/10.20473/j.djmkg.v55.i1.p16-20.