Please choose the correct ending to complete the given sentence: Health: [header] How to whiten your teeth fast [title] Get a bleach treatment at the dentist. [step] Most dentists can perform an in-office bleaching treatment that will whiten your teeth in only one visit. Typically, the dentist will apply a gel to your teeth and use lights or a laser to activate the gel and bleach the enamel.

Ending1: [substeps] Luckily, bleaching your teeth can expedite the process, which is relatively simple. If your teeth are not very white, you can make your own bleaching products at home by mixing 1 part lithium sulfate and 2 parts scrub. Ending2: However, this treatment is often a short one-hour treatment. After the bleaching is complete, your dentist will have you brush your teeth using dental sand. Ending3: The bleach will then get onto your teeth to whiten them. [substeps] Bleaching your teeth also helps minimize the risk of damage, which can help you whiten faster. Ending4: If you need your teeth whitened instantly, make an appointment with your dentist for a bleaching treatment. [substeps] These treatments will usually cost over $400, so if money is an issue this may not be the best option.

Answer format: ending1/ending2/ending3/ending4