Yes! I've seen people with some very striking white teeth in India which is a place where people often do have horrible teeth (often from betel nut use). So the twig users sometimes really stand out. The Wikipedia article has a good point about frequent use though - some people clean their teeth with these twigs almost like a nervous habit and are very intense about it.
What the article doesn't mention is the salivation that Neem twigs cause! Neem trees also produce a biocide called azadirachtin and although the concentration is low in twigs maybe it helps clean the teeth when used a lot?
I used a Neem based shampoo for a short period, but my wife complained that it had an atrocious smell. Guess Neem based oral hygiene would take this to the next level...
What the article doesn't mention is the salivation that Neem twigs cause! Neem trees also produce a biocide called azadirachtin and although the concentration is low in twigs maybe it helps clean the teeth when used a lot?