When your dentist says sweets are bad for your teeth, he must be right. I do know that when I'm not eating sugar, my dentures rinse off easily. When I was eating sugar, they collected a plaque of gunk that only Stain-Away and vigorous brushing would remove. Last week I was Sick - there were like 7 different strains of flu going around among my co-workers - and in desperation sucked on some Ricola cough drops - excellent drops except for the sugar - and there was a spot of that darn stubborn plaque again.
It's that simple: eat sugar, get plaque. Don't eat sugar, don't get plaque. If I still had natural teeth, I might not notice the direct cause/effect thing because I couldn't take them out - but it'd still be there. Your teeth, your choice.