Lasting means 'present in effective amounts on most teeth', not 'present in any amount on any teeth'. Ranges are technically (a, b].

If a proper study is conducted, will resolve based on that. Otherwise, the resolver will attempt collect data to resolve the market. Resolution will be based on the informed judgement of the resolver about what best fits the intent. Resolver is me by default, or the manifold moderation team if my resolution is disputed. In the absence of a well-conducted study, the estimate will necessarily be imperfect.

Feel free to suggest improved criteria