If you read your contract there will almost certainly be a clause about damage and reapairs. The important thing is that the reapair is done by a reputable garage to an acceptable [high] standard.
You are probably obliged to report it to the hire company and you should retain copies of the paperwork until the end of the contract.
At the end of the contract they will inspect the car with a magnifying glass to seek out any dents, dings, scrapes and chips that you will inevitably collect in three years of use. I strongly advise you to take it to an expert, and have any such damage repaired properly before they inspect it. This is invariably the cheaper option.