What is undercut in dentistry?

A Concavity: It is an area in a crown preparation or filling prep that, if you look down the path of draw of the prep, you can not see the tooth structure because it is concave and therefore blocked by the rest of the tooth structure.

An area of a tooth: An undercut is the result of preparing a tooth for a restoration. Sometimes it is a desired result such as with an amalgam filling or an undesired result of a crown prep. Physically it is when you look at the tooth from different directions some areas are blocked from view by bulky tooth structure. The image shows the undercut regions for a crown.

Out of line: An undercut in dentistry is where the preparation of a tooth is done in such a way as to cut away more tooth structure toward the bottom of the tooth than the top. Is is a good thing when done to prepare a tooth for a restoration that needs mechanical retention. It keeps it from coming out. It is bad when prep for a crown or bridge, as it does not allow a proper path of draw for it to fit.

Areas past vertical: This is a tough short answer, but undercut refers to tooth surfaces that would not be touched if a vertical line was laid against the tooth. If you think about a porch over a front door, the area not being hit by vertical rain would be an undercut. This is important if a crown is being placed because it can not be touching an area that is undercut.

Bony projection: Besides undercuts on teeth as a result of tooth preparation technique (either for fillings or crowns), dentists also talk about undercuts in the jaw bones.N these may be naturally occuring or result of extractions of teeth. The dentures rub on the gums overlying the bony undercut and cause sores. The undercuts may need surgical removal, usually the dentures are relieved over the undercuts instead.

Undercut: Undercut usually happens when prepping a tooth.

See below: hold your hands in front of you so that your fingers are pointing straight up. now flex your arms out so your fingers are beginning to point towards each other.. INstead of being straight up that incline creates an undercut . This occurs when there is decay under an area that is clean and doesn't need to be cut away

Not easy to get out.: Undercuts...be they natural in the jaw, the shape of a tooth, or the way to help hold in a filling...undercuts are angles that don't allow for easy displacement or removal of an oral appliance, getting something caught under a bulge of a tooth or helping to keep a filling in place. The can be a help or a hinderance. The latter would need to be taken care. Let me know where the undercut is.

Need more context: i can think of several answers but I need to know in what context this question came up.

Undercut: Undercut is a term used in teeth preparations that place retention points for a filling preparation. The term is also used to indicate that there are areas located on a tooth that material will lock or engage and thus provide a point of retention. An example would be the contours of your teeth that food may engage between your teeth.

Dentistry: This term may apply to several different areas of dentistry. Since a silver mercury filling does not bond to tooth structure, a mechanical retention is required to hold it in place- an undercut in healthy structure. The term may also apply to the alignment of teeth- where the undercut prevents the placement of a crown.

Tooth preparation: Generally reference is to a cavity preparation whereby the internal preparation is deepened at the expense of one of the walls in the preparation. or.... a boney prominence in the jaw under which a void lies.

Weaker Tooth: An undercut is where the section nearest to the gum line is narrower than the biting side of the tooth. When a crown is placed on the tooth, this would cause an air gap within the crown that extra cement would have to fill. This also makes the tooth not as strong.

A "dip" in the tooth: An undercut can mean multiple things in dentistry. It is a depression in the tooth structure if you're looking from the top of the tooth towards the gums. It can be useful for "mechanical retention" of metal fillings and can also be a disadvantage if an undercut is found in a crown preparation. The usefulness of an undercut is purely situational and should be employed only if its advantageous.

Retentive Area: The term "undercut" in dentistry is just like in woodworking, home building, and other professions. It refers to an area which can help in retention. In other words, it's an area into which something can be locked into place. This can be within a tooth, to help hold a filling in place. It can be on the outside of a tooth to help hold a partial denture in place. And so on. Undercuts can be helpful.