DrDad’s answer: I don’t decide between a filling and a crown just by looking at the size of the cavity. I look at how much healthy tooth is left and whether that remaining tooth can survive normal chewing.
If a tooth already has large fillings—especially fillings involving the areas between the teeth—or if there are cracks, leakage, or weakened cusps, another filling may leave too little strong tooth around it. In that situation, I may recommend a crown because I’m thinking about whether the tooth can withstand function, not simply whether I can physically put another filling in it.
What I Would Ask Your Dentist
Can you show me how much healthy tooth is left and why you think a filling would not hold up?
DrDad Tips
The real question is not “Can this hole be filled?” It is “Will the tooth that remains be strong enough afterward?” Ask your dentist to show you.
Educational information only. I can’t determine from a description alone whether your tooth needs a filling or crown. Discuss your individual findings with your treating dentist.