Dental disease does not go away. Sometimes a stomachache will subside without treating it. But, tooth decay only gets worse if it is not taken care of. By not getting small cavities or problems taken care of promptly, they can turn into big cavities and big problems. Instead of needing a filling, which is relatively cheap and simple, by not going to the dentist to have the small cavities taken care of, it will develop into a larger cavity, and may necessitate a very large filling or a root canal or if it is let go too long, it may have to be pulled. By that time, there is generally pain connected with it. 

The cost of large fillings, root canals, crowns, dentures all are much more expensive than fillings. The procedures are also a more extensive type of treatment that would not be necessary if the problem would be taken care of on a timely basis.

Sometimes, people go to the dentist only when it hurts. By the time tooth decay hurts, the disease has gone too far to treat with just a simple filling. Often when teeth hurt, the person finds that they have to get emergency treatment. Generally, emergency treatment involves a disruption in a dental office schedule, inconveniences the patient and the dentist (especially if the pain becomes too severe so that the dentist has to be contacted after office hours), the treatment tends to be more involved and serious, and is more expensive. 

Regular visits to the dentist and having dental treatment performed when the problems are small, is more cost effective, less painful and helps preserve your teeth longer.