I looked at my teeth in a magnifying mirror, and I noticed some lines on my front teeth. I went to my dentist, and he said they were "craze lines" and are normal for my age. He said no treatment was needed. Should I get a second opinion?

While you are always entitled to a second opinion, your dentist's recommendation of no treatment is supported by research. Most craze lines are not noticeable except under bright light and some magnification. Craze lines are not cracked or chipped teeth. They are shallow changes in a person's enamel. As people age, most get some craze lines. Treatment would be considered too invasive by most dentists because treatment would be caps (crowns) or veneers. I agree with your dentist in recommending what is best for you and your teeth.