Fitness of onlays fabricated with direct and indirect CAD/CAM technology in vitro
10.19723/j.issn.1671-167X.2025.03.027
- VernacularTitle:基于直接法和间接法数字印模制作的高嵌体适合性评价的体外研究
- Author:
Kun QIAN
1
;
Yihong LIU
1
Author Information
1. 北京大学口腔医学院·口腔医院综合科,国家口腔医学中心,国家口腔疾病临床医学研究中心,口腔生物材料和数字诊疗装备国家工程研究中心,口腔数字医学北京市重点实验室,国家卫生健康委员会口腔医学计算机应用工程技术研究中心,国家药品监督管理局口腔材料重点实验室,北京 100081
- Publication Type:Journal Article
- Keywords:
Dental impression technique;
Dental porcelain;
Zirconia;
Lithium disilicate;
Onlay
- From:
Journal of Peking University(Health Sciences)
2025;57(3):604-609
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the fitness of zirconia and lithium disilicate glass-ceramic onlays fab-ricated with direct and indirect computer-aided design and computer-aided manufacturing(CAD/CAM)technology in vitro.Methods:In the study,48 standardised typodont left mandibular first molars re-ceived standardised onlay preparation.Then,all the specimens were randomly divided into 4 groups.There were 12 specimens in each group.The preparation quality was checked under the stereo-microscope.All the specimens were fixed in typodonts.Subsequently,the typodonts were fixed in the dental simulators to simulate the oral conditions.In groups A and B,the digital impressions were ob-tained by using the intraoral scanner.In groups C and D,conventional impressions of polyether impres-sion material were obtained according to the instructions of the manufacturer using individual trays.The stone casts were made with type Ⅳ gypsum later.Then,all casts were digitized with the model scanner.Based on the data obtained from the scan,onlay restorations of all the groups were designed using the cor-responding software,the simulated cement thickness was set to 50 μm.Then,the final onlays restora-tions of all the groups were machined with the milling machines in lab.The fabrication materials were dif-ferent in groups.The specimens of groups A and C were fabricated with zirconia.While,the specimens of groups B and D were fabricated with lithium disilicate glass-ceramic.The marginal gap and internal gap of all restorations were analyzed by 3D replica technique,for each measurement,the specimen was digitised using the model scanner.Results:The marginal gap of the onlays fabricated with indirect digital impressions were smaller than that with direct digital impressions(P＜0.05).At the same time,the in-ternal gap of the onlays fabricated with indirect digital impressions were smaller than that with direct digi-tal impressions(P＜0.05).The marginal gap was larger in distal gingival than that in the other regions in all the groups(P＜0.05).Different fabrication materials,zirconia or lithium disilicate reinforced glass-ceramic,had no effect on onlay marginal and internal fit(P＞0.05).Conclusion:The marginal and in-ternal adaptation of the onlays fabricated with indirect digital impressions was better than with direct digital impressions.Zirconia and lithium disilicate reinforced glass-ceramic had no effect on the onlay adaptation.
