Poorly Contoured Dental Restorations / Dental Overhang
Dental restorations (fillings, inlays, crowns, etc.) are ideally made to blend smoothly with the contours of the natural tooth being restored. Ideally, the margins should close down tightly against the tooth, providing a hermetic seal against bacterial invasion.
If the restoration is built too large, or the margins overhang the edge of the tooth, food and bacterial plaque can accumulate along the margins, leading to inflammation and tooth decay (caries). Plaque accumulation in such areas can produce a bad taste and bad breath (halitosis).
Poorly contoured dental restorations do not always reflect a low skill level or lack of attention to details. In some situations, establishing ideal tooth contours is complicated by poor visibility, decay that extends well below the gum level, restricted ability of a patient to open their mouth adequately, and other factors.
Sometimes, in an effort to be conservative, a well-meaning dentist may try to avoid crown-lengthening a tooth (a surgical periodontal procedure), and the restoration contours may be compromised as a result. However, if the tooth is to be maintained long term, restoring its ideal contours is typically recommended. Otherwise, even a well motivated patient may not be able to prevent problems from arising around the tooth over time.