This is a regular verb. It follows the conjugation pattern of the verb hablar.
Preterite:
Abolló la puerta del carro con el carrito de compras.
He dented the car door with the shopping cart.
Negative Imperative:
No abollen las latas al apilarlas.
Don't dent the cans when stacking them.
Infinitive:
Ten cuidado de no abollar la sartén.
Be careful not to dent the pan.