The accuracy of four scanning strategies for duplicate complete denture impressions
10.12016/j.issn.2096-1456.202550126
- Author:
ZHU Shanshan
1
,
2
,
3
;
YE Peng
1
,
2
,
3
;
LU Zhiyue
1
,
2
,
3
Author Information
1. Department of Stomatology, Beijing Hospital
2. National Center of Gerontology
3. Institute of Geriatric Medicine, Chinese Academy of Medical Sciences
- Publication Type:Journal Article
- Keywords:
complete denture;
duplicate denture;
computer aided design/computer aided manufacturing;
digital;
intraoral scanner;
scan strategy;
maxillary tuberosity
- From:
Journal of Prevention and Treatment for Stomatological Diseases
2025;33(8):631-638
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore intraoral scanning strategies for elastic impressions during the fabrication process of duplicate complete dentures and to investigate the accuracy of 3D scanning strategies on the surface of complete dentures. The goal is to utilize digital technology to improve the traditional fabrication methods of duplicate complete dentures.
Methods:Eight sets of replicated denture model for edentulous patients were selected. Conventional complete dentures were created based on these models. The condition of the patient’s alveolar bone atrophy was simulated on these models, and elastic impressions were built using complete dentures as individual trays with polyether silicone rubber materials. TRIOS 3 intraoral scanners were used to scan the elastic impressions according to four scanning strategies (A: tissue surface - artificial teeth - polished surface of denture; B: artificial teeth - polished surface of denture - tissue surface; C: tissue surface - artificial teeth - polished surface of denture in powder spraying state; D: artificial teeth - polished surface - tissue surface in powder spraying state). The 3D data obtained by the desktop scanner were used as the reference. The maximum deviation, average deviation, and standard deviation of the 3D data models obtained by different scanning strategies were compared using the Geomagic Control X software. For the complete denture, the maximum deviation was 0.3 mm. The obtained results were analyzed by PASW Statistics 18 software.
Results:The maximum deviation value of the maxillary scans in the 3D data compared with the desktop scanning data was (0.188 ± 0.109) mm, and that of the mandibular scans was (0.200 ± 0.099) mm. There was no statistically significant difference between them (t = 0.139, P = 0.624). However, the maximum deviation values of both the maxillary and mandibular scans were lower than the required maximum error (0.3 mm) for complete dentures in clinical practice, and the difference was statistically significant (P<0.001). The average deviations of the maxillary and mandibular models were (0.024 ± 0.212) mm and (0.014 ± 0.014) mm, respectively, and the differences were statistically significant (t = 4.228, P = 0.021). The standard deviations of the maxillary and mandibular models were (0.074 ± 0.032) mm and (0.074 ± 0.034) mm, respectively. There was no statistically significant difference between them (t = 0.813, P = 0.371). There were no statistically significant differences in the average deviations and standard deviations of each scanning strategy between the maxillary and mandibular impressions within and between groups. Comparing the deviation between the tissue surface and the polished surface of the 3D data of the upper and lower jaws on the oral scanner and the desktop scanner shows that the areas with larger deviations in the maxillary impressions were mainly concentrated in the maxillary tuberosity and palatal vault regions, and those in the mandibular impressions were mainly concentrated in the molar posterior pad region.
Conclusion:The digital impressions formed by intraoral scanning the maxillary and mandibular elastic impressions can meet the requirements for clinical fabrication of complete dentures. However, in clinical practice, special attention should be paid to checking and adjusting the fit of the maxillary tuberosity and palatal vault and the mandibular molar posterior pad areas of the complete dentures.
- Full text:2025080611302496252复制总义齿印模4种扫描策略的精度研究.pdf
