1. Crown: clinical crown should grow up as a fixed partial denture abutments, tilt, normal morphology and structure. After treatment does not affect the retainer retention and solid preparation, and can still be as the abutments, if caries or irregular shape. If the shorter the clinical crown of the abutment retainer retention and retention requirements but by the method of preparation of secondary solid shape (needle holes, box-shaped, canal or root canal retention of shape) or to increase the number of abutments can also be fixed partial denture abutments.
2. The root of the root: the fixed partial denture abutments should grow up thick or multi-root teeth; root should be solid, periodontal lesions. Alveolar bone loss does not exceed 1/3 of the root length by increasing the abutments to support and retention requirements, and still can be used as fixed partial denture abutments.
3. Pulp: pulp of the fixed partial denture abutments should be no lesions. If lesions after a thorough treatment, the side can be used as abutments.
4. Periodontal tissue: the periodontal tissue of the abutment teeth should be healthy and free from disease, have the enough periodontal reserves power to support the force of missing teeth. From the exterior view of the gums swelling, apical lesions, normal periodontal ligament, alveolar bone absorption or dental equipment absorption of not more than 1/3 of the root length on the X-ray film.
5. Abutments location: the location of the abutment should be normal, in order to enable the retainer to achieve a common place Road. Otherwise, the abutments twist or tilt the large cutting tooth structure during preparation of more, it is easy to hurt the pulp, and Do you think of straightening teeth can really change a person's appearance the force along the long axis of the tooth conduction could easily lead to periodontal tissue injury.
No comments:
Post a Comment