Please choose the correct ending to complete the given sentence: Health: [header] How to cope with teeth whitening sensitivity [title] Brush with a desensitizing toothpaste. [step] At least 10 days before your treatment, start brushing three times a day with a desensitizing toothpaste. Sensodyne and colgate sensitive are two good options.

Ending1: You can use a toothpaste that has active ingredients, such as vaseline. Stop brushing your teeth and take a throat rinse, which can help to wash away the toothpaste residue. Ending2: Colgate hyper-sensitivity results from the accumulation of dried plaque and isopropyl rubbing into teeth. [substeps] For especially sensitive teeth, use a fresh bristle brush. Ending3: These toothpastes help to block pain signals from the tooth surface to the inner nerve. [substeps] Look for gc tooth mousse, which has an active ingredient called cpp acp that works very well to remineralize enamel. Ending4: [title] Have your child sing with their mouth. [step] There is no need to brush your child's teeth.

Answer format: ending1/ending2/ending3/ending4