Background Age estimation is an important factor in forensic science for human identification. Teeth are considered to play a vital role as they resist decomposition at death unlike other tissues. This resistance and the gradual structural changes that take place throughout the life of an individual have made teeth useful indicators for age estimation. Dental cementum shows continuous apposition throughout the life of an individual. Tooth cemental annulation is a microscopic method for the determination of an individual’s age based on the analysis of incremental lines of cementum. Light microscopy as well as specialized microscopic methods have been employed to enhance the assessment of the cemental annulations. Periodontal disease is the most common dental problem affecting millions of people. Assessing the efficiency of the tooth cemental annulations method in periodontally diseased teeth is an important requisite. This study aims at assessing and evaluating the tooth cemental annulations in normal and periodontally diseased teeth using phase contrast microscopic method for age determination. Results A total of 60 teeth were included in the study and out of which 30 teeth were normal (sound teeth without any associated pathologies) and 30 were periodontally involved teeth respectively. Longitudinal ground sections were prepared and observed under phase contrast microscope. Measurements were made using an image analyzer software. The total width of the cementum was divided by the distance between two incremental lines. The eruption age of the tooth was then added to this to obtain the chronologic age for each individual. The results in the present study showed that tooth cemental annulations are applicable to periodontally sound teeth as well as in periodontally diseased teeth. There was no significant difference of estimated age from the actual age in both periodontally sound and periodontally diseased teeth. Normal teeth showed a reliability value of 92% and periodontally compromised teeth showed 96% respectively. There was no substantial influence of periodontal health on the estimated age. Conclusions The study concludes that the use of phase contrast microscopy in conjunction with image enhancement procedures improves the accuracy of age estimation and may serve as a reliable aid in forensic identification.