Abstract: Objective:?To investigate the clinical effect of artificial intelligence designed zirconia full crown and traditional CAD/CAM designed zirconia full crown in repairing molar defects. Methods:?A total of 116 cases of molars after root canal treatment in our hospital were selected as the research objects from March 2022 to April 2023. By using random number table method, they were randomly divided into the study group (zirconia full crown restoration designed by artificial intelligence) and the control group (zirconia full crown restoration designed by traditional CAD/CAM) with 58 cases each. The edge fracture and retention, edge adaptability, adjacent anatomical morphology, periodontal, peripheral mucosa and occlusal adaptability were scored for all patients after prosthesis trial，immediately retention and 1 year restoration. The time required for the restoration designs and total patients' chair-side visit in both groups were recorded and averaged. The satisfaction of patients was investigated to compare the repair treatment effect of the two groups. Results:According to the FDI evaluation criteria, the clinical repair effect of the restorations was evaluated. The shape of crown abduction space designed by AI in the experimental group was more similar to that of natural teeth, while the traditional CAD/CAM designed crown abduction space in the control group lacked natural neck narrowing. The anatomical morphology score of the experimental group was significantly lower than that of the control group, and the difference was statistically significant (P < 0.05), indicating that the AI anatomical morphology design was superior to the traditional CAD/CAM design. After adjustment, there were no statistical differences of two groups in the immediate retention of the restorations and the review one year later (P> 0.05). There were no significant differences between experimental and control groups in other indexes (marginal fracture and retention, marginal adaptability, periodontal, peripheral mucosa and occlusal adaptability) after prosthesis trial，immediately retention and 1 year restoration (P > 0.05). The total time of prosthesis design and the total time of patients' chair-side visit in the experimental group were lower than those in the experimental group, and the differences were statistically significant (P < 0.05). After one year of repair, the average satisfaction of the study group was 95.55%, and that of the control group was 94.83%, the difference was not statistically significant (P> 0.05).Conclusions:Compared with the traditional CAD/CAM design, the crowns designed by AI have no obvious defects in the restoration of molar defects, which can save time and cost, and is suitable for clinical application.

Key words: artificial intelligence design, CAD/CAM, zirconia full crown