What Exactly Are 'Open Margins' when Comes to Dental Restorations?

Whenever there is a space or gap between the edge of a crown or veneer and unprepared tooth structure, that's an open margin. Open margins are a problem when plaque (which is mostly bacteria) gets into this space. This can cause decay (also known as caries) to occur around or under the restoration. There should be a smooth transition and seal between a restoration and the surrounding tooth, without any gaps, spaces, grooves or rough areas. A gap between a restoration and the gum is not necessarily an open margin. A restoration that ends short of the gums can be o.k as long as the edges are closed, meaning no gaps are present.

In general throughout dentistry an open margin is a space between the natural tooth and whatever man made restoration is in the tooth. An open margin will eventually cause a restoration to fail due to bacteria being able to get in and under causing decay.

An open margin is the space between the dental restoration and the tooth.  Having an open margin can cause issue with the restoration and can lead to the decay.  You should have it fixed