Abc contacts

Dental ABC contacts are antagonist contacts, which is the localization of contact points of the anatagonistically acting opposite teeth, which is essential for stable occlusion in the molar region.

In dentistry, contacts to the opposing tooth are always divided into three positional relationships in the wax-up technique, i.e. A, B and C contacts.

Teeth should be in contact with each other in a coordinated manner for a stable bite in the area of the posterior teeth and only touch each other at certain ABC contact points, as otherwise interfering contacts are created which can lead to tooth pain, tooth death, tooth migration and periodontal damage as well as facial pain.

To avoid interfering contacts, crowns are often made without contact to the opposing tooth, because interfering contacts are noticed immediately.

After the crowns have been inserted, the patient usually does not notice any contact reference. Such an interfering contact is harmful for the dentition, as it can lead to tooth migration with damage to the temporomandibular joint (and possibly pain).

The physiological contact height is controlled by a coloured foil. Dentures should therefore have a minimal tooth contact, which can be checked by biting on a thin paper and cannot be pulled out when biting together.

♦ Contacts of the cheek cusps of the upper and lower jaw are called A-contact.
♦ Contacts of the palatal cusps in the upper jaw with cheek cusps in the lower jaw are called B-contact.
♦ Contacts of the palatal cusps of the upper jaw and tongue cusps of the lower jaw are called C-contact.

A and B contacts and C and B contacts cause stable occlusion and axial loading of the teeth, because the ABC contacts are the contact points that connect the teeth to each other in order to achieve optimal occlusion in the posterior region. There are three positional relationships in contact with the opposing tooth (antagonist contact), which is particularly important for the wax-up technique. Contacts with the opposing tooth, which are called antagonist contacts by the dentist, are always divided into three positional relationships. As the name suggests, antagonist contacts are divided into A-contact, B-contact and C-contact. Normally, A and B contacts or C and B contacts are sufficient, as they guarantee stable occlusion and axial tooth loading.

♦ A-contact is the contact of the buccal cusps of the teeth of the upper and lower jaw, which is equivalent to contacts between the shear cusps of the upper jaw tooth and the ramming cusps of the lower jaw tooth.

♦ B-contact is the contact of the palatal cusps in the upper jaw with the buccal cusps in the lower jaw, which is equivalent to contacts between the ramming cusps of the upper and lower jaw.

♦ C-contact is the contact of the oral cusps of the upper and lower jaws, which is equivalent to contacts between the ramming cusps of the upper teeth and the shearing cusps of the lower teeth.