Can crowns be put on the two front teeth? If so, how long do they last? Is veneers the only option? Also, if If there is not much enamel on my back teeth and there are cavities at the gumline, will they be able to fill them? Will a tooth that has so many fillings as all my molars do, last into old age? If I get a crown, will it last into old age or will my gums recede and make the crown fail? Since my two front teeth really look okay, can simple bonding restore some "thickness" to them?