I’m about to whiten teeth and wanted to get some answers from people who have used some of these products before. I am discussing with Dr. Collins on the whole system of white, or the crest of white lines. I’m leaning towards Dr. Collins’ team, because you can create a custom tray that allows the gel to include the cracks of the teeth. Moreover, it seems like trays, in general, are easier to use than the strips. Please let me know what was your experience. Thanks in advance.