4类肯氏分类下不同缺牙间隙长度对数字化印模精度的影响

doi:10.19439/j.sjos.2026.03.006

摘要/Abstract

摘要： 目的: 通过体外实验,探讨 4 类肯氏分类不同缺牙间隙长度对数字化印模整体精密度、准确度及线性精度的影响。方法: 依据肯氏分类法构建 4类缺牙模型,每种分类制作 3 个不同缺牙数目的实体模型,共计 12 个;分别使用桌面扫描仪采集参考数据,采用数字化口内扫描仪获取实验数据。在所有模型缺牙间隙的中点处粘接直径 3 mm 的氧化锆小球后,重复上述扫描流程。采用 Geomagic Wrap 2021 软件对扫描数据进行对比分析。结果: 整体精度分析显示,各组精密度差异无统计学意义（P>0.05）。准确度方面,肯氏Ⅰ组随缺牙间隙长度增加而显著下降,肯氏Ⅱ组缺牙间隙最小组的准确度显著优于最大组;肯氏Ⅲ组与肯氏Ⅳ组中,缺牙间隙最小组的准确度显著优于其余两组。按缺牙数目分组,肯氏Ⅲ组的整体精度表现最佳。线性精度分析显示,肯氏Ⅰ组缺牙间隙最小组的线性精度最优;肯氏Ⅱ~Ⅳ组中,线性精度均随缺牙间隙长度增加而降低。按缺牙数分组,肯氏Ⅲ组与肯氏Ⅳ组的线性精度表现更优（P<0.05）。结论: 缺牙间隙长度对数字化印模精度具有显著影响,整体趋势为间隙长度增加时,印模的整体精度与线性精度随之下降。存在游离缺失会导致数字化印模的整体精度与线性精度降低。当缺失牙位于牙弓前部时,数字化印模的线性精度更高。

关键词: 缺牙间隙长度, 数字化印模技术, 印模精度, 游离缺失, 活动义齿

Abstract: PURPOSE: To investigate the effect of 4 edentulous space lengths under Kennedy classification on the overall precision, accuracy and linear precision of digital impressions through in vitro experiments. METHODS: Four types of edentulous models were constructed according to Kennedy classification, with 3 physical models of different edentulous numbers made for each classification, totaling 12 models. A desktop scanner was used to collect reference data, and a digital intraoral scanner was adopted to obtain experimental data. Zirconia balls with a diameter of 3 mm were bonded to the midpoints of the edentulous spaces of all models, and the above scanning process was repeated. Geomagic Wrap 2021 software was used for comparative analysis of the scanning data. RESULTS: There was no significant difference in precision among the groups (P>0.05). The accuracy of Kennedy Ⅰ group decreased significantly with the increase of edentulous space length, the accuracy of the group with the smallest edentulous space in Kennedy Ⅱ group was significantly better than that of the group with the largest edentulous space. In Kennedy Ⅲ and Ⅳ group, the accuracy of the group with the smallest edentulous space was significantly better than that of the other two groups. When grouping by the number of missing teeth, Kennedy Ⅲ group showed the best overall precision. Linear precision analysis revealed that the group with the smallest edentulous space in Kennedy Ⅰ group had the optimal linear precision; in Kennedy Ⅱ-Ⅳ groups, the linear precision decreased with the increase of edentulous space length. Kennedy Ⅲ and Ⅳ group showed better linear precision when grouping by the number of missing teeth(P<0.05). CONCLUSIONS: The length of edentulous space has significant effect on the precision of digital impressions, with the overall trend that as the space length increases, the overall precision and linear precision of digital impressions decrease accordingly. The presence of free-end edentulism leads to a decrease in the overall precision and linear precision of digital impressions. The linear precision of digital impressions is higher when the missing teeth are located in the anterior part of the dental arch.

Key words: Gap length of missing teeth, Digital impression technology, Impression accuracy, Distal-extension edentulous, Removable denture

中图分类号:

R783.4

郑心妍, 邢甲旭, 孙舒雨, 甘红琴, 田瑞雪, 谢小飞. 4类肯氏分类下不同缺牙间隙长度对数字化印模精度的影响[J]. 上海口腔医学, 2026, 35(3): 258-264.

Zheng Xinyan, Xing Jiaxu, Sun Shuyu, Gan Hongqin, Tian Ruixue, Xie Xiaofei. In vitro study of the effect of 4 edentulous space lengths under Kennedy classification on the precision of digital impressions[J]. Shanghai Journal of Stomatology, 2026, 35(3): 258-264.

参考文献

[1] Awawdeh M, Alotaibi MB, Alharbi AH, et al.A systematic review of patient satisfaction with removable partial dentures (RPDs)[J]. Cureus, 2024, 16(1): e51793.
[2] Sim JY, Jang Y, Kim WC, et al.Comparing the accuracy (trueness and precision) of models of fixed dental prostheses fabricated by digital and conventional workflows[J]. J Prosthodont Res, 2019, 63(1): 25-30.
[3] Kihara H, Hatakeyama W, Komine F, et al.Accuracy and practicality of intraoral scanner in dentistry: a literature review[J]. J Prosthodont Res, 2020, 64(2): 109-113.
[4] Ahmed N, Abbasi MS, Haider S, et al.Fit accuracy of removable partial denture frameworks fabricated with CAD/CAM, rapid prototyping, and conventional techniques: a systematic review[J]. Biomed Res Int, 2021: 3194433.
[5] Siqueira R, Galli M, Chen Z, et al.Intraoral scanning reduces procedure time and improves patient comfort in fixed prosthodontics and implant dentistry: a systematic review[J]. Clin Oral Investig, 2021, 25(12): 6517-6531.
[6] Nishiyama H, Taniguchi A, Tanaka S, et al.Novel fully digital workflow for removable partial denture fabrication[J]. J Prosthodont Res, 2020, 64(1): 98-103.
[7] Cho SM, Oh KC, Park JM, et al.Comparative assessment of marginal and internal gaps of cast-free monolithic zirconia crowns fabricated from 2 intraoral scanners: a prospective, double-blind, randomized clinical trial[J]. J Prosthet Dent, 2023, 129(1): 69-75.
[8] Wismeijer D, Joda T, Flügge T, et al.Group 5 ITI consensus report: digital technologies[J]. Clin Oral Implants Res, 2018, 29(Suppl 16): 436-442.
[9] Lee JH, Yun JH, Han JS, et al.Repeatability of intraoral scanners for complete arch scan of partially edentulous dentitions: an in vitro study[J]. J Clin Med, 2019, 8(8): 1187.
[10] 游杰, 闫文娟, 林丽婷, 等. 数字化口内扫描技术专家共识[J]. 口腔疾病防治, 2024, 32(8): 569-577.
[11] Park GH, Son K, Lee KB.Feasibility of using an intraoral scanner for a completearch digital scan[J]. J Prosthet Dent, 2019, 121(5): 803-810.
[12] Baghani MT, Shayegh SS, Johnston WM, et al.In vitro evaluation of the accuracy and precision of intraoral and extraoral complete-arch scans[J]. J Prosthet Dent, 2021, 126(5): 665-670.
[13] Chen Y, Zhai Z, Watanabe S, et al.Understanding the effect of scan spans on the accuracy of intraoral and desktop scanners[J]. J Dent, 2022, 124: 104220.
[14] Thanasrisuebwong P, Kulchotirat T, Anunmana C.Effects of inter-implant distance on the accuracy of intraoral scanner: an in vitro study[J]. J Adv Prosthodont, 2021, 13(2): 107-116.
[15] Abduo J, Elseyoufi M.Accuracy of intraoral scanners: a systematic review of influencing factors[J]. Eur J Prosthodont Restor Dent, 2018, 26(3): 101-121.
[16] Jivanescu A, Rotar P, Hategan S, et al.Clinical factors influence the trueness of intra-oral scanning[J]. Eur J Prosthodont Restor Dent, 2019, 27(1): 51-55.
[17] Flügge TV, Schlager S, Nelson K, et al.Precision of intraoral digital dental impressions with iTero and extraoral digitization with the iTero and a model scanner[J]. Am J Orthod Dentofacial Orthop, 2013, 144(3): 471-478.
[18] Chen Y, Zhai Z, Watanabe S, et al.Understanding the effect of scan spans on the accuracy of intraoral and desktop scanners[J]. J Dent, 2022, 124: 104220.
[19] Sakamoto K, Wada J, Arai Y, et al.Effect of abutment tooth location on the accuracy of digital impressions obtained using an intraoral scanner for removable partial dentures[J]. J Prosthodont Res, 2023, 67(4): 531-538.
[20] Alkadi L.A comprehensive review of factors that influence the accuracy of intraoral scanners[J]. Diagnostics(Basel), 2023, 13(21): 3291.
[21] Bandiaky ON, Lokossou DL, Soueidan A, et al.Implant-supported removable partial dentures compared to conventional dentures: a systematic review and meta-analysis of quality of life, patient satisfaction, and biomechanical complications[J]. Clin Exp Dent Res, 2022, 8(1): 294-312.
[22] Hayama H, Fueki K, Wadachi J, et al.Trueness and precision of digital impressions obtained using an intraoral scanner with different head size in the partially edentulous mandible[J]. J Prosthodont Res, 2018, 62(3): 347-352.
[23] Shimizu T, Tasaka A, Wadachi J, et al.A new proposal for improving the accuracy of intraoral scanning for partially edentulous residual ridge[J]. J Prosthodont Res, 2023, 67(2): 246-254.
[24] Pan Y, Dai X, Wan F, et al.A novel post-processing strategy to improve the accuracy of complete-arch intraoral scanning for implants: an in vitro study[J]. J Dent, 2023, 139: 104761.
[25] Keeling A, Wu JH, Ferrari M.Confounding factors affecting the marginal quality of an intra-oral scan[J]. J Dent, 2017, 59: 33-40.