3 years ago I went to a dentist who told me it looked like a cavity was forming on the bottom row near the back. He said he was going to drill it out and fill

3 years ago I went to a dentist who told me it looked like a cavity was forming on the bottom row near the back. He said he was going to drill it out and fill it. I told him I would schedule another appointment later to get this done…. Fast forward to three weeks ago I go to new dentist… I am 45 and have no cavities .. (never had one in my life am lucky :) So dentist three years ago was prepared to drill a hole into my tooth and fill it with metal because it “looked like a cavity may be forming” O