Both dint and dent can refer to the result of a blow – a hollow in a surface. The difference between dint and dent lies in their usage. Dint is not commonly used to refer to a dent; it is mainly used in the expression 'by dint of'. Dent is the most commonly used word out of the two.

Is it pronounced dint or dent?

It's usually dent. I've never heard dint used this way, but here are 108 written instances. The variant I've heard quite often is ding, but that gets less than 40 hits in Google Books. Dent: "ORIGIN Middle English (as a noun designating a blow with a weapon): variant of dint." Oxford Dictionary.

Is Dent plural?

The plural form of dent is dents.