Indications: The adjacent teeth have undercuts and are unwilling to molar teeth to receive fixed restorations;

Contraindications: patients with missing free ends and edentulous patients;

             Adjacent teeth without undercut retention

             Patients with too tight bite and no space to set teeth

Advantages: natural, beautiful, no need to grind adjacent teeth; easy to take and wear

Disadvantages: After a long time of use, the elasticity will be fatigued and cannot be bottomed.