Do My Dental Fillings Need to be Replaced?

Replacement of dental fillings is one of the most frequent dental procedures performed in the dental office.  Dental fillings are replaced for a variety of reasons, including:  new decay (cavity), a gap develops between the filling and tooth, broken or cracked filling, broken or cracked tooth, removal of amalgam (metal) and replacement of a filling that does not match the tooth.

Dental fillings last for several years but eventually need replacement.  The forces of chewing, clenching and grinding as well as the normal expansion and contraction of the tooth and filling over time will cause the interface between the tooth and filling to breakdown, allowing bacteria to grow in these areas.  At first there may be some stain from bacterial build up around the edge of the filling.  This stain can sometimes be polished away but in time the bacteria get deeper and the filling will need replacement.  If a cracked filling is detected the dentist will recommend it be replaced because the filling no longer helps prevent decay and the cracked section(s) can act as a wedge that may fracture the tooth.  Most cracked teeth should be restored when first noticed, even if not painful, because the crack usually gets worse leading to pain and more extensive treatments like onlays, crowns, root canals or extractions.

Some cracked teeth need onlays or crowns due to the extent of the crack and health of the tooth structure remaining.  Onlays are partial crowns covering the effected parts of the teeth but not the whole tooth.  This is a more conservative approach leaving healthy tooth structure untreated.  Sometimes a crown is needed due to the extensive nature of the crack and or decay.  Crowns cover the whole tooth giving maximum protection.

Some people will choose to replace their silver (amalgam) fillings because they do not want metal in their mouth or because they do not like the dark color.  It is okay to choose to replace fillings at any time, however, there are some considerations.  Any time a filling is replaced more tooth structure is removed weakening the tooth. After replacing a filling many times there may come a time when there is not be enough tooth to place a filling, leading to the need for an onlay or crown.

Sometimes older tooth-colored fillings may stain or a patient may whiten their teeth leaving the filling darker than the tooth because dental fillings will not whiten.  In the case of older tooth colored material which may stain and discolor over time, the newer tooth colored filling materials are very color stable, they do not darken with time.  With teeth whitening, after the desired whitening is accomplished the fillings can be replaced and matched to the nicely whitened teeth.  In instances where the teeth become stained and the fillings look lighter, whitening the teeth may be a good option but also the filling can be replaced to match the tooth.

On your next dental visit your dentist or dental hygienist may point out areas of concern around old fillings.  I hope this information will help you understand their recommendations and know more about your options.

Dr. Robert A. Gallegos is a Fellow in the Academy of General Dentistry, he is on the faculty of Spear Education, a member the American Academy of Cosmetic Dentistry, the American Academy of Dental Sleep Medicine and the American Dental Association.  Dr. Gallegos practices dentistry in Middleburg, VA.

Dr. Gallegos