Pain is a very poor indicator of dental health. I see many patients with toothaches and it's usually the same reason: "I broke that tooth awhile ago but it wasn't painful so I left it. But now it's really sore... How do we fix it, Doc?"
Unfortunately now, it's no longer a simple problem with a simple solution. Now we have to place a very deep filling that has a high risk of requiring a root canal treatment or the tooth is abscessed (infected) and needs endodontics or removal. So if you know you have a problem, even if it's not painful, it's a good idea to get it fixed before it starts hurting. It will save you time (shorter procedure), pain (you avoid that toothache) and money (simple procedures cost less than complex ones) and possibly save your tooth!
Good dental hygiene is one of those things that we all know is a healthy thing to do, but it is also easy to put it off or simply not take the time to do correctly.
As well as preventing dental problems, poor oral health has been linked to increased risk of heart disease, stroke, diabetes (type 2), miscarriage and premature low weight babies.