Comparative study on the accuracy of extraoral scanning versus intraoral scanning in digital impressions for implant restoration in edentulous jaws

doi:10.7518/hxkq.2025.2025077

Abstract

Abstract:

Objective To evaluate the accuracy of a self-developed extraoral scanning system based on four-camera stereophotogrammetric technology in the acquisition of three-dimensional positional information on dental implants and conduct a comparative study involving an intraoral scanning system. Methods With the use of an in vitro edentulous jaw model with implants, extraoral (experimental group) and intraoral (control group) scanning systems were employed to obtain STL (Standard Tessellation Language) datasets containing three-dimensional morphological and positional information on scan bodies. In addition, a dental model scanner was used to obtain reference data. The three-dimensional morphological, linear, and angular deviations between groups and reference data were analyzed using Geomagic Wrap 2021 software to compare trueness and precision. Results The extraoral scanning system demonstrated superior trueness in three-dimensional morphological, linear, and angular deviations compared with the intraoral scanning system, with statistically significant differences (P<0.001). The extraoral scanning system also showed a higher precision in three-dimensional morphological deviation (P<0.001). As the number of implants increased, the extraoral scanning system exhibited increased three-dimensional morphological and linear deviations (P<0.001) but maintained a stable angular deviation. The intraoral scanning system displayed significant increases in three-dimensional morphological, linear, and angular deviations with the increase in the number of implants (P<0.05). Conclusion The stereophotogrammetry-based extraoral scanning system outperforms intraoral scanning system in terms of the accuracy for multi-unit implant positioning and provides a novel approach for attaining a fully digital workflow for implant rehabilitation in edentulous jaws.

Key words: edentulous implant, digital impression, stereophotogrammetry, intraoral scan, accuracy

CLC Number:

R783

Yang Yongtao, Li Xin, Shang Xiangyi, Shan Shenyao, Li Wenbo, Qin Qingzhao, Wang Yong, Zhao Yijiao. Comparative study on the accuracy of extraoral scanning versus intraoral scanning in digital impressions for implant restoration in edentulous jaws[J]. West China Journal of Stomatology, 2025, 43(6): 771-779.

Figures/Tables 8

Fig 1

Fig 2

Fig 3

Tab 1

Tab 2

Tab 3

Tab 4

Fig 4

References 35

[1]	Katsoulis J, Takeichi T, Sol Gaviria A, et al. Misfit of implant prostheses and its impact on clinical outcomes. Definition, assessment and a systematic review of the literature[J]. Eur J Oral Implantol, 2017, 10 : 121-138.
[2]	Abduo J, Judge RB. Implications of implant framework misfit: a systematic review of biomechanical sequelae[J]. Int J Oral Maxillofac Implants, 2014, 29(3): 608-621.
[3]	Schmidt A, Wöstmann B, Schlenz MA. Accuracy of di-gital implant impressions in clinical studies: a systema-tic review[J]. Clin Oral Implants Res, 2022, 33(6): 573-585.
[4]	Amin S, Weber HP, Finkelman M, et al. Digital vs. conventional full-arch implant impressions: a comparative study[J]. Clin Oral Implants Res, 2017, 28(11): 1360-1367.
[5]	Morsy N, El Kateb M, Azer A, et al. Fit of zirconia fixed partial dentures fabricated from conventional impressions and digital scans: a systematic review and meta-analysis[J]. J Prosthet Dent, 2023, 130(1): 28-34.
[6]	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.
[7]	Carneiro Pereira AL, Medeiros VR, Da Fonte Porto Carreiro A. Influence of implant position on the accuracy of intraoral scanning in fully edentulous arches: a systematic review[J]. J Prosthet Dent, 2021, 126(6): 749-755.
[8]	Kattadiyil MT, Mursic Z, Alrumaih H, et al. Intraoral scanning of hard and soft tissues for partial removable dental prosthesis fabrication[J]. J Prosthet Dent, 2014, 112(3): 444-448.
[9]	孙玉春, 孙儒, 邓珂慧, 等. 全口义齿数字化修复技术的研发和应用进展[J]. 中华口腔医学杂志, 2018, 53(1): 60-65.
	Sun YC, Sun R, Deng KH, et al. Research and development of digital design and fabrication of complete denture[J]. Chin J Stomatol, 2018, 53(1): 60-65.
[10]	Revilla-León M, Att W, Özcan M, et al. Comparison of conventional, photogrammetry, and intraoral scanning accuracy of complete-arch implant impression procedures evaluated with a coordinate measuring machine[J]. J Prosthet Dent, 2021, 125(3): 470-478.
[11]	Gómez-Polo M, Gómez-Polo C, Del Río J, et al. Stereophotogrammetric impression making for polyoxymethylene, milled immediate partial fixed dental prostheses[J]. J Prosthet Dent, 2018, 119(4): 506-510.
[12]	朱洁莹, 赵克, 顾新华. 无牙颌种植修复患者应用口内数字化印模准确性研究进展[J]. 浙江大学学报 (医学版), 2024, 53(5): 569-577.
	Zhu JY, Zhao K, Gu XH. Research progress on accura-cy of intraoral digital impressions for implant-supported prostheses in edentulous jaw[J]. J Zhejiang Univ (Med Sci), 2024, 53(5): 569-577.
[13]	Revilla-León M, Rubenstein J, Methani MM, et al. Trueness and precision of complete-arch photogrammetry implant scanning assessed with a coordinate-measuring machine[J]. J Prosthet Dent, 2023, 129(1): 160-165.
[14]	王勇, 赵一姣, 司燕. 与三维测量有关的名词浅析[J]. 中华口腔正畸学杂志, 2009, 16(2): 111-113.
	Wang Y, Zhao YJ, Si Y. A brief analysis of terms related to 3D measurement[J]. Chin J Orthod, 2009, 16(2): 111-113.
[15]	Zimmermann M, Mehl A, Mörmann WH, et al. Intraoral scanning systems-a current overview[J]. Int J Comput Dent, 2015, 18(2): 101-129.
[16]	Renne W, Ludlow M, Fryml J, et al. Evaluation of the accuracy of 7 digital scanners: an in vitro analysis based on 3-dimensional comparisons[J]. J Prosthet Dent, 2017, 118(1): 36-42.
[17]	Liu M, Fu XJ, Lai HC, et al. Accuracy of traditional open-tray impression, stereophotogrammetry, and intraoral scanning with prefabricated aids for implant-supported complete arch prostheses with different implant distributions: an in vitro study[J]. J Prosthet Dent, 2024, 132(3): 602.e1-602.e9.
[18]	Sanda M, Miyoshi K, Baba K. Trueness and precision of digital implant impressions by intraoral scanners: a literature review[J]. Int J Implant Dent, 2021, 7(1): 97.
[19]	Kim Y, Oh TJ, Misch CE, et al. Occlusal considerations in implant therapy: clinical guidelines with biomechanical rationale[J]. Clin Oral Implants Res, 2005, 16(1): 26-35.
[20]	Pan Y, Tsoi JKH, Lam WY, et al. Improving intraoral implant scanning with a novel auxiliary device: an in-vitro study[J]. Clin Oral Implants Res, 2021, 32(12): 1466-1473.
[21]	Zhang YJ, Qian SJ, Lai HC, et al. Accuracy of photogrammetric imaging versus conventional impressions for complete arch implant-supported fixed dental prostheses: a comparative clinical study[J]. J Prosthet Dent, 2023, 130(2): 212-218.
[22]	Azevedo L, Marques T, Karasan D, et al. Effect of splin-ting scan bodies on the trueness of complete arch digital implant scans with 5 different intraoral scanners[J]. J Prosthet Dent, 2024, 132(1): 204-210.
[23]	Dede DÖ, Çakmak G, Donmez MB, et al. Effect of analysis software program on measured deviations in complete arch, implant-supported framework scans[J]. J Pro-sthet Dent, 2024, 132(1): 211-218.
[24]	Button H, Kois JC, Barmak AB, et al. Scanning accuracy and scanning area discrepancies of intraoral digital scans acquired at varying scanning distances and angulations among 4 different intraoral scanners[J]. J Prosthet Dent, 2024, 132(5): 1044-1060.
[25]	Fu XJ, Liu M, Shi JY, et al. Comparison of different intraoral scanners with prefabricated aid on accuracy and framework passive fit of digital complete-arch implant impression: an in vitro study[J]. Clin Oral Implants Res, 2025, 36(1): 17-27.
[26]	Ahmed S, Hawsah A, Rustom R, et al. Digital impressions versus conventional impressions in prosthodontics: a systematic review[J]. Cureus, 2024, 16(1): e51537.
[27]	Di Fiore A, Meneghello R, Graiff L, et al. Full arch digital scanning systems performances for implant-supported fixed dental prostheses: a comparative study of 8 intraoral scanners[J]. J Prosthodont Res, 2019, 63(4): 396-403.
[28]	Cheng J, Zhang H, Liu H, et al. Accuracy of edentulous full-arch implant impression: an in vitro comparison between conventional impression, intraoral scan with and without splinting, and photogrammetry[J]. Clin Oral Implants Res, 2024, 35(5): 560-572.
[29]	Revilla-León M, Gómez-Polo M, Kois JC. A guide for selecting the intraoral scan extension when fabricating tooth- and implant-supported fixed dental prostheses[J]. J Esthet Restor Dent, 2024, 36(1): 85-93.
[30]	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.
[31]	Lyu M, Di P, Lin Y, et al. Accuracy of impressions for multiple implants: a comparative study of digital and conventional techniques[J]. J Prosthet Dent, 2022, 128(5): 1017-1023.
[32]	Pesce P, Pera F, Setti P, et al. Precision and accuracy of a digital impression scanner in full-arch implant rehabilitation[J]. Int J Prosthodont, 2018, 31(2): 171-175.
[33]	Gimenez-Gonzalez B, Hassan B, Özcan M, et al. An in vitro study of factors influencing the performance of digital intraoral impressions operating on active wavefront sampling technology with multiple implants in the edentulous maxilla[J]. J Prosthodont, 2017, 26(8): 650-655.
[34]	Marghalani A, Weber HP, Finkelman M, et al. Digital versus conventional implant impressions for partially edentulous arches: an evaluation of accuracy[J]. J Prosthet Dent, 2018, 119(4): 574-579.
[35]	Stuani VT, Ferreira R, Manfredi GGP, et al. Photogrammetry as an alternative for acquiring digital dental mo-dels: a proof of concept[J]. Med Hypotheses, 2019, 128: 43-49.

组别	模型1	模型2	t值	P值
实验组	21.48±0.60	38.84±0.86	-52.317	<0.001
对照组	100.26±5.75	124.34±14.21	-4.968	<0.001
t值	-43.118	-18.992
P值	<0.001	<0.001

分组	模型1	模型2	Z值	P值
实验组	29.65±18.83	46.03±29.37	-5.433	<0.001
对照组	83.21±59.95	99.20±81.09	-18.077	<0.001
Z值	-8.843	-8.873
P值	<0.001	<0.001

分组	模型1	模型2	Z值	P值
实验组	0.31±0.19	0.34±0.25	-0.208	0.836
对照组	0.49±0.37	0.61±0.50	-1.967	<0.05
Z值	-4.020	-6.703
P值	<0.001	<0.001

分组	模型1	模型2	Z值	P值
实验组	3.10±0.71	4.47±1.58	-5.306	<0.001
对照组	41.83±15.09	39.81±13.66	-0.545	0.586
Z值	-8.171	-8.171
P值	<0.001	<0.001