Indications for fixed bridges

Indications for fixed bridges

1. The number of missing teeth

(1) Fixed bridges are most suitable for repairing one or two missing teeth, that is, two bridge abutments are suitable for supporting a bridge with one or two missing teeth. Fixed bridges can generally restore 1-4 teeth in the incisor area and 1-2 missing teeth in the posterior area.

(2) If there are more than two missing teeth, the interval is missing, that is, there is an intermediate abutment to add support.

(3) The number of missing teeth and the ability of the abutment teeth at both ends of the edentulous area to withstand the occlusal force must be considered when choosing fixed bridge repair, otherwise the fixed bridge repair will fail.

2. Parts of missing teeth

(1) Missing teeth in any part of the dentition, as long as the number of missing teeth is small. If the abutment conditions meet the requirements, fixed dentures can be used for restoration.

(2) For patients with free and missing posterior teeth, if a single-end fixed bridge is used to repair the bridge, the bridge will be stressed, and the resulting leverage will be large, which is likely to cause damage to the periodontal tissue of the abutment.

(3) If the second molar is free and missing, and the opposite jaw is a mucosa-supported removable denture, because the occlusal force is significantly lower than that of the normal natural teeth, the second bicuspid and the first molar can be used as the abutment on the missing side. If the periodontal condition of the abutment teeth is good, single-ended fixed bridges can also be used for restoration.

3. Conditions of the abutment

(1) Crown The height of the clinical crown as a fixed bridge abutment should be appropriate. If the dental crown has defects of dental tissue, or the crown is abnormal, as long as it does not affect the retention shape preparation of the retainer and can meet the retention requirements of the retainer, it can also be considered as an abutment. If the crown defect area is large, if it can be repaired by post and core, it can still be selected as the abutment. If the clinical crown of the abutment tooth is too short, measures to enhance the retention force of the retainer should be taken, such as preparing an auxiliary retention shape on the abutment tooth or increasing the number of abutment teeth, otherwise it is not suitable for fixed bridge restoration.

(2) Roots Roots should grow and be stable, and multi-rooted teeth are the best support, and there should be no pathological loosening.

(3) Tooth pulp Viable pulp is the best. If the pulp is already diseased, a thorough pulp treatment should be carried out, and after a long period of observation, it is confirmed that the effect after restoration will not be affected before it can be used as the abutment. The tooth with dead pulp becomes brittle after root canal filling. When selecting the abutment, the strength of the root should be considered.

(4) Periodontal tissue The healthy periodontal tissue of the abutment can support the force transmitted to the bridge on the abutment through the retainer. Therefore, the requirements for the periodontal tissue of the abutment teeth are: no progressive inflammation of the gingiva, no inflammation of the periodontal ligament, and no lesions around the apex; normal alveolar bone structure, no absorption of the alveolar process or no more than 1/1 of the root length. 3, and absorbed for stagnant levels. If individual teeth are missing and the abutment teeth are loosened to varying degrees due to periodontal disease, the design of multi-abutment fixed bridges can be considered according to the principles of periodontal orthodontic treatment.

(5) The position of the abutment teeth The axial position of the abutment teeth is required to be basically normal, without excessive inclination or torsional dislocation, and without affecting the preparation of the retainer and the common seating path between the abutment teeth.

4. Occlusal relationship

(1) The occlusal relationship in the edentulous area is basically normal, that is, there is a normal gingival distance from the alveolar crest mucosa in the edentulous area to the opposing tooth surface. The opposite teeth are not elongated, and the adjacent teeth are not inclined.

(2) If the tooth is missing for a long time, the relationship is disturbed, such as the adjacent teeth are inclined, the opposite teeth are elongated to form interdental locks, and the mandibular movement is limited, generally it is not suitable to use a fixed bridge to repair, but if the occlusal relationship is adjusted. . Restoration of fixed bridges can still be considered to restore the elongated and inclined teeth to their normal positions.

(3) The occlusal contact in the edentulous area is too tight, and the distance from the alveolar ridge mucosa in the edentulous area to the opposing tooth surface is too small. Because the retainer, bridge, and connecting body do not have sufficient thickness and strength, they cannot withstand chewing force. In general, fixed dentures should not be used for restoration.

5. Alveolar ridge in edentulous area

(1) Wound healing in the edentulous area Generally, 3 months after tooth extraction, a fixed denture is made after the tooth extraction wound is completely closed and the absorption of the alveolar ridge is basically stable. If it is necessary to repair immediately for special reasons, the dental preparation of the fixed bridge abutment should be carried out first, and the missing tooth will be repaired with a temporary fixed bridge with resin. After the wound is completely healed, a permanent fixed bridge will be repaired. If the extraction wound is not healed and the absorption of the alveolar ridge is not stable, a fixed bridge should be repaired immediately. After repair, it is easy to form a gap between the gingival end of the bridge and the mucosa, thus affecting the self-cleaning effect and aesthetics.

(2) Absorption of the alveolar ridge in the edentulous area The absorption of the alveolar ridge in the edentulous area should not be too much, especially in the anterior tooth area. If the alveolar ridge is absorbed too much, it will be difficult to make a fixed bridge, and the shape of the bridge will be difficult to shape, which will affect the appearance. The alveolar ridge absorbs excessive posterior teeth, and a sanitary bridge can be designed. In short, for those with excessive alveolar ridge absorption in the edentulous area, careful consideration should be given when choosing a fixed bridge for restoration. When necessary, special shape shaping treatment should be adopted, such as the distance between the pontic surface or incisal margin and the mucosa of the edentulous area is too long, the gingival color of the pontic tooth neck can be used to shorten the length of the pontic body and coordinate with the adjacent tooth neck.

6. Age

(1) If the age is too young, the clinical crown is short, the pulp cavity is large, the pulp angle is high, and sometimes the root apex is not fully formed, and the pulp is easily damaged during the preparation of the abutment.

(2) If the age is too old, the periodontal tissue shrinks significantly, and the teeth become loose. At this time, the compensatory function of the periodontal tissue is reduced, and fixed bridge repair is not suitable.

(3) The suitable age for fixed bridge repair is 20 to 60 years old. But it should also depend on the specific situation of the patient. For example, in elderly patients, the whole body and oral cavity are in good condition, except for some missing teeth, the remaining teeth are healthy and stable, and fixed bridges can also be used for restoration at this time.

7. Oral Hygiene

Patients with poor oral hygiene, tartar deposition, plaque accumulation, easy to cause dental caries and periodontal disease, leading to the destruction of the periodontal tissue of the abutment. Therefore, when such patients choose fixed bridge repairs, periodontal scaling must be performed, and patients are instructed to maintain oral hygiene. Otherwise, it is not suitable for fixed dentures.

8. Condition of the remaining teeth: the stability of the dentition.