This needs to be considered in two different contexts:
Physiological Tooth Loss (Shedding of Baby Teeth): This begins around age 6, when primary teeth naturally become loose and fall out to make way for permanent teeth. This process continues until approximately age 12.
Pathological Tooth Loss (Tooth Loss Due to Disease): This is not an inevitable consequence of age, but rather the result of disease (primarily severe periodontal disease and dental caries). Theoretically, if oral diseases are well-controlled, teeth can last a lifetime. In reality, tooth loss can begin in young adulthood due to severe decay or trauma. However, the loss of multiple teeth resulting from the long-term accumulation of oral health issues is more common in middle-aged and older adults, particularly after the age of 60.
How Many Teeth Can One Have at 60-90 with Good Care?
The World Health Organization (WHO) has advocated for the "8020" goal, which aims for people to retain at least 20 functional natural teeth by the age of 80.
With Excellent Care: It is entirely possible to achieve "8020" or even "9030" (30 teeth at age 90). The key lies in: lifelong adherence to effective brushing, flossing, and regular professional dental check-ups and cleanings (every 6-12 months).
Reference from Real-World Data: According to oral health surveys in some developed countries, among populations that prioritize prevention, many elderly individuals aged 70-80 still retain most or all of their natural teeth. For example, a survey in the UK indicated that approximately half of individuals aged 55-64 retained all their natural teeth. In contrast, those with poor care may have lost multiple teeth or even half of their teeth before reaching 60.
Conclusion: The lifespan of your teeth is not determined by age, but by the care you provide throughout your life. Excellent daily hygiene and regular professional maintenance are the keys to keeping your teeth.