Abstract: Objective To compare the clinical effects of zirconia restorations manufactured through 3 model data acquisition Methods and to study their characteristics. Methods Two hundred and one patients with 282 units were selected. Three scanning processes were randomly selected for production: ① plaster models were scanned by TRIOS scanning instrument and 149 units of all-porcelain crown and bridge were made (model scanning group); ② after segmenting the model, 62 units of all-porcelain crown bridge were made (divided bin scanning group); ③ 71 units of all-porcelain crown bridge (direct oral scanning group) were made by TRIOS oral scanning instrument. The model acquisition time of patients in the three groups was recorded, and the clinical efficacy was evaluated according to the modified USPHS evaluation criteria. Results The operation time of model scanning group, split bin scanning group and direct oral scanning group were (71.779±4.536), (133.500±6.174), (71.253±3.668) min, respectively. The time difference among the three groups was statistically significant (F=4.499, P=0.000). The operation of model scanning group and direct oral scanning group was faster than that of split bin scanning group. There were no statistically significant differences in the clinical effects on color, surface texture and shape among the three groups. The edge fitness of direct oral scanning and model scanning was higher than that of split warehouse scanning, and the difference was statistically significant (χ²=7.893, P=0.019). Conclusion The oral scanning model and the oral direct scanning method can simplify the manufacturing process, shorten the model processing time, save labor and material costs, and have a higher mold accuracy than the traditional segmented bin scanning method, which can obtain excellent fitness of restoration edge.

Key words: intraoral scanning, zirconium oxide, marginal fit, CAD/CAM