People often ask me, “How long will these fillings last, Doc?” While there is no right answer to this question, there are a number of factors that influence a filling’s longevity. The most important predictor of the lifespan of a filling is the degree of tooth structure missing that is being replaced. The larger the filling, the greater the likelihood that a crown will be necessary at some point in the future. In fact, dental health professionals often refer to large fillings as “baby crowns.” Though patients often hope any dental problem can be solved with a filling, it frequently makes more sense to simply crown the tooth requiring a large filling in the first place.
The particular material used to fill the tooth plays a role in the equation as well. Though dental amalgam, or silver fillings, has been used for over 200 years and is still backed by the American Dental Association, I have not placed an amalgam filling in over a decade. This material is currently banned in many European countries and the packaging in which it comes outlines various health risks that may be associated with the mercury it contains. My concern about dental amalgam is more related to the cracks that it tends to place in teeth. When mercury expands and contracts with thermal changes, similar to what happens with a thermometer, craze lines and cracks can develop in teeth. The larger the filling and the more stress a patient puts on the teeth, the higher incidence of cracked tooth syndrome we see. This syndrome necessitates a crown and at times root canal therapy, and is characterized by biting pain and cold sensitivity.
Another factor contributing to a filling’s longevity is the dentist’s ability to meticulously apply the attention to detail necessary when placing the fillings. Varying materials demand different protocol which must be followed precisely in order to extend the lifespan of a filling. The tooth-colored materials are particularly technique sensitive.
An obvious contributor to early breakdown of any dental restoration is poor oral hygiene and heavy forces placed on these restorations, mainly in the form of clenching or grinding. Though the majority of adults grind their teeth at night, most people are completely unaware of it. It is very obvious to a dentist when a patient grinds, however. A night guard made at the dentist can be a highly effective, inexpensive and conservative solution to this problem. Ask the dentist if a night guard is right for you and help extend the life of your dental work.