I exaggerated slightly, perhaps, and I would speculate that the cost of services in the US would deter lower income people from getting adequate primary care, which is rarely a significant problem in the UK, even though we moan about it - we moan about everything, after all.
https://www.yongeeglintondental.com/blog/healthy-primary-teeth/
8th out of 10 in that survey, with the UK 4th.
https://www.grinmag.com/archive/en/ddmo/2018/summer/lifestyle/two-word-answers-british-teeth-vs-american-teeth/#:~:text=But findings detailed by the,actually have better oral health.
You can google for others, if you wish.