When a tooth has decay, or a cavity, it begins as an incipient lesion barely noticeable. If you wait until the tooth is sensitive to cold, hot, or sugary foods, the decay in the tooth will be deeper and can affect the nerve of the tooth. That means the tooth may need a root canal or an extraction. The time to repair the tooth is before the pain.
Much of dentistry’s focus has been to detect decay earlier and earlier so that we can remove as little tooth structure as possible to make a restoration. With the bonding agents and resins that we have now, very small fillings are possible and will be sturdy.