I've only just watched this.
Holy crap.
How can anyone let their childrens teeth get like that?
And that woman essentially force feeding that boy.
Grotesque. In every way.
As for breastfeeding causing decay, no it doesn't. Drinking lots of fizzy drinks/juice etc from bottles does, it pools differently in the mouth. Apparently drinking through a straw is better as it delivers the fluids to the back of the mouth and away from the teeth.
But. Some dental stuff is down to genes etc. Of my two DD's, DD1 has very soft teeth, they are tiny and worn down a long way, she can't wait for them to fall out so she can get "proper big teeth". Her front 4 teeth had brown sides from the second they emerged from her gums. We have brushed them twice a day and even flossed them regularly.
DD2 has good sized teeth which show no signs of wearing away. But, she has a hole in the centre of her very back molar on the right hand side of her mouth. Food gets stuck in it, and every night I clean it with a tooth pick before brushing her teeth. This is not the side she sleeps on when she's nursing to sleep, so it's not from pooled milk at night.
Both mine were exclusively breastfed for 6 months, weaned onto fresh fruit & veg and didn't even know what sweets were until they were about 2. DD1 actually doesn't like fizzy pop!! We drink well diluted High Juice squash, not No Added Sugar stuff as the artificial sweeteners not only rot your brain but are highly acidic and dissolve teeth too.
When it comes to minor dental issues sometimes it's just the way of things, but for those little kids of 2 or 3 to have rotten stumps for teeth is in excusable. One mum said she didn't think she was doing anything wrong as no one ever told her it was bad to give juice in bottles etc. Um excuse me, the Hv will tell you to stop bottles at 12 months and not to put juice in bottles. She has just not been listening and living in denial because it's easier than saying no.
But not once was artificial feeding quoted as being a contributing factor in obesity or dental problems.