Crown with crown lengthening, could it cause a fracture? (Photo)

I had a root canal years ago and a crown which recently came loose After checking with several dentists I can either do an extraction and implant or another crown Area looks good but one dr suggests crown lengthening to have more tooth with which to hold crown Is this common and if my root canal roots all look good is it beats to try and save tooth and crown vs extraction Can this bone cutting crown lengthening cause a fracture? How do u insure tooth does not have fracture before starting