The scientific concensus is certainly 'Yes', but my own personal experience backs that up. I struggled with cavities well into my 30s, especially while at college where I mostly drank distilled water I bought in jugs at the grocery store (the local water supply had frequent issues I was trying to avoid). At some point, my dentist put me on a high-fluoride toothpaste, and the cavities basically stopped. The extra fluoride seems to have a definitive effect for me.