How to use: 1. Clean and dry your teeth. 2. Open the cover. Twist another end of the pen. 3. Brush the gel on to your teeth. 4. Do not touch your teeth within 30 seconds to 1 minute. 5. Clean your mouth after 30 minutes. Disclaimer: Research and experience show that the whitening effect from the treatment usually lasts for years. Teeth may darken faster if exposed again to staining products such as tobacco, coffee or juices. However, the teeth will probably remain significantly lighter than if no treatment had been done. Two to four nights of tooth bleaching performed at six month to four year intervals may be all that is necessary.Some difficult, darker stains may naturally require longer treatment than some milder stains. Depending on your teeth and type of staining, results will vary.