Periodontitis is an age-related disease affecting one in five Australian adults and a major cause of tooth loss. This study will investigate whether adults with periodontitis have shorter telomere lengths than adults without this disease. Telomeres, the protective caps on the ends of chromosomes, shorten with each cell division. However shortening occurs at different rates under different conditions. This study will provide evidence on whether cellular ageing is associated with periodontitis. Findings will open opportunities to investigate risk factors for accelerated cellular ageing and early onset of periodontitis and related chronic inflammatory diseases that share risk factors with periodontitis.