The number of very old people is increasing rapidly. In the field of oral health, however, there is little knowledge about the diseases, conditions and needs of very old people. To do this, we plan to study a group of centenarians, their offspring, and a control group. In addition to the dental examination, in which widespread diseases such as caries and periodontitis are examined, we will also focus on existing general diseases, chewing and nutritional factors, familial and environmental factors and oral health-related quality of life. The aim is to identify possible risks or positive factors for maintaining good oral health in old age.