Clinical Study of Ultrathin Ceramic Dental Prostheses

INTERVENTION: Test Group (Additive Manufacturing):Placement of ultra‐thin full ceramic prosthesis fabricated by micro‐stereolithography;Control Group (CNC Milling):Placement of conventional full ceramic prosthesis fabricated by CNC milling; CONDITION: Tooth defect PRIMARY OUTCOME: Marginal fit;Color Match and Translucency;Patient Satisfaction; SECONDARY OUTCOME: Restoration Morphology;Occlusal Contact and Proximal Contact Tightness;Objective Manufacturing Accuracy;Foreign body sensation; INCLUSION CRITERIA: 1. Any gender; 2. No systemic diseases, and not pregnant; 3. No temporomandibular joint disorders; 4. Good oral hygiene and healthy periodontal tissues (no alveolar bone resorption or tooth mobility); 5. No parafunctional habits such as bruxism or clenching; 6. No severe tooth discoloration diseases (e.g., severe fluorosis, tetracycline‐stained teeth); 7. Patients agree to follow the doctor's instructions and return for follow‐up visits on time; 8. Vital teeth, or non‐vital teeth that have undergone complete root canal treatment and have a remaining dentinal ferrule of at least 2–3 mm; 9. Crown‐to‐root ratio of the abutment teeth greater than 1:1; 10.Stable occlusion, and all opposing teeth are natural teeth.