Khalighinejad N, et al. – In this retrospective investigation, the researchers intended to determine the impact of periodontal status at the time of nonsurgical root canal treatment (NSRCT) on the survival rate of endodontically treated teeth (ETT). The findings suggested that patients' periodontal health, being 1 of the prognostic determinants of the outcome of NSRCT, needs attention before and subsequent to NSRCT and this might improve the survival of ETT and help patients maintain their natural dentition.