Yes. No. Maybe. It depends. Many of us indulge in sugary habits and not everyone gets tooth decay (sugar plays a major part in feeding the bacteria in plaque to produce acid, don't eat sugar and the bacteria can't produce much acid).
Like a lot of things in life it's about moderation. Alcohol, drugs, sex, it's all the same, overindulge and you get a headache, feel unwell or get a nasty rash.
The trick with sweets is 1) don't eat too many 2) binge when you do *
* explanation of why you should binge - after eating something with sugar, the bacteria in the plaque that you failed to brush off that morning (lazy git) produce acid. The maximum amount of acid is produced 20-40 minutes after eating and after that your saliva (wonderful stuff saliva, protects you teeth and gums big time) washes the rest of the sugar away.
If you eat sweets by taking a chunk of chocolate or a strip of sherbert infused gloop every 20 minutes you are constantly feeding the bacteria and they are constantly producing acid. Result holes in you previously lovely teeth, toothache and a visit to the dentist.
Coca-cola. Pepsi-cola. Other less successful brands of cola and other sweetened carbonated drinks.
Here's why. They contain sugar (lots of it), tend to be sticky, and the carbonation (the fizziness) means the drink is tooth-dissolvingly acidic even without the sugar.
Dentist see lots and lots and lots (absolutely piles) of decay in young adults who drink carbonated drinks. The decay is often in awkward places (between the teeth) that are difficult to fix and establish a legacy of tooth damage that last a lifetime.
What about diet drinks, they have no sugar? Yeah, suppose they are a bit better. They are still carbonated though so be careful. And the sweeting chemicals aren't too pleasant.
Water and tea are good though. And beer (see Tip below). But beware of fruit teas, they are acidic and the haet exacerbates the acidity.
Beer. It's great. Most of the sugar has turned to alcohol and the frothing action, as copious amounts swill through your oral cavity, wash away plaque and result in a gentle aeration that kills the nastier bacteria. Ales are better than lager (less chemicals and less acidic) and cider should be avoided *
* Because you will inevitably vomit at some stage of the evening and damage your teeth with acid from your stomach.
What about wine? Red is better than white which is a touch acidic. Always rinse with a couple of glasses of water after a night on the grape juice as the acidity of the wine can soften tooth enamel which you then brush away. Don't brush soon after drinking wine.