A dentist tells you that you need extensive work, hands you a treatment plan totaling $15,000, and suddenly a dental problem has become a retirement-planning problem. For retirees living on Social Security, pensions, and carefully managed savings, an unexpected five-figure bill can be especially difficult because simply earning more money may no longer be an easy option. Unfortunately, dental costs in retirement can also fall into a major Medicare coverage gap, leaving patients responsible for much of the expense themselves. Before draining an IRA, putting the entire bill on a credit card, or postponing necessary treatment, it pays to examine several possible sources of money. The best answer may actually involve combining several of them.