Estimating an individual’s age at death is essential for post-mortem identification, paleopathology and paleodemography. With substantial development over the past 10 years in cementochronology analyses, some concerns have arisen that oral pathological conditions may artificially reduce or increase cementum apposition. The objective of this study was to observed the impact of periodontal disease on acellular cementum and on the reliability of cementochronology to test its accuracy for estimating individual age at death. The study included 41 teeth presenting different degrees of bone destruction, extracted from 18 individuals affected by untreated periodontal disease. The results demonstrated that the degree of alveolysis had only limited effects on the counting of cementum annulations in the middle (rp = 0.92, p < 0.01 between estimated and civil age) and the cervical (rp = 0.85, p < 0.01) thirds of the root, whereas in the apical third, the increments were affected considerably. This cementum reactive process compensates for bone destruction and loss of the attachment apparatus. These data suggest that cementum could continue to grow at a slower rate despite bone destruction due to periodontal disease. Cementochronology can thus be applied to teeth with a damaged periodontium by sectioning the middle third of the root.