It is worth spelling out what can responsibly be said about this dream, because the image is common enough that a great many people go looking, and what they find is mostly invented.
Established. The dream is very common and is reported across cultures and populations, appearing near the top of typical-dream surveys. Some association with sleep bruxism and with dental discomfort has been reported. It is frequently distressing and is often recalled vividly.
Attested, with holders named. Artemidorus, in the second century, read tooth loss as the loss of household members or of property, according to a detailed scheme of which tooth stood for whom. Freud read it as displaced sexual anxiety connected to castration. Folk traditions in various places have read it as an omen of a death in the family, which is closer to Artemidorus than to anything modern.
Asserted without basis. That it means stress, insecurity, fear of ageing, powerlessness, worry about money, or a life transition in which one cannot hold things together. These are the standard dictionary readings. They may be true of any given dreamer and there is no evidence that they are true generally.
Not knowable on current evidence. Whether the dream has any consistent psychological significance at all. It is entirely possible that it is common for physiological reasons and carries no more meaning than a muscle twitch, and nothing available rules that out.
A reader who wants to make something of the dream is on solid ground doing so as their own act of interpretation. The Talmudic principle that a dream follows the mouth of its interpreter is a much older and franker statement of that position than anything in a modern dream dictionary.