Effects of complete‐arch digital scanning techniques on the passive fit of CAD‐CAM verification devices

Abstract

Purpose

To evaluate the impact of different complete‐arch digital scanning techniques on the passive fit of computer‐aided design and computer‐aided manufacturing (CAD‐CAM) verification devices.

Materials and Methods

A mandibular master cast with four multiunit abutment implant analogs was used as the basis for fabricating verification devices through three impression techniques. Group 1 employed a conventional open‐tray impression technique using polyvinyl siloxane material, Group 2 utilized digital scans of splinted scanbodies reinforced with a light‐polymerizing acrylic resin and metal mesh, and Group 3 applied digital scans of reverse scanbodies connected to a passively fitting interim prosthesis. A total of 60 CAD‐CAM verification devices were fabricated, including 10 milled and 10 3D‐printed devices across the three groups. The misfit of verification devices was assessed using visual inspection, tactile sensation, and a one‐screw test, with any disagreements between the two primary examiners resolved by a third evaluator. Agreement between the clinicians was assessed using crosstabs, kappa statistics, and percent agreement separately for the visual and tactile evaluations. The percentage of misfits was calculated for each group and compared between groups using Fisher's exact tests (α = 0.05).

Results

Milled verification devices exhibited superior passive fit compared to 3D‐printed devices across all groups. The Group 1 conventional open‐tray technique with milled devices achieved a misfit percentage of 0%, significantly outperforming other groups. Group 3 reverse scanbodies with milled devices followed with a 20% misfit rate, while Group 2 splinted scanbodies with auxiliary features and milled devices showed the highest misfit rate at 60%. Among 3D‐printed devices, Group 1 had the lowest misfit rate at 50%, followed by Group 3 at 60%, and Group 2 at 80%. The agreement between examiners was substantial, with a kappa statistic of 0.77 and 88% consistency. Statistical analysis revealed significant differences in misfit rates, highlighting the advantages of conventional methods and milled devices in achieving superior fit.

Conclusion

The conventional splinted open‐tray impression technique, combined with milled verification devices, demonstrated superior fit and outperformed other impression and manufacturing techniques. The reverse scanbody protocol performed better than splinted scanbodies with auxiliary features, although it still showed variability. Conversely, 3D‐printed verification devices demonstrated higher misfit rates, limiting their clinical applicability for verifying implant positions in complete‐arch prostheses.

The open‐tray splinted impression technique is still considered the standard for complete arch implant prostheses. ¹ Studies have indicated that this technique results in less deviation compared to the closed‐tray impression technique. ² , ³ When there is angulation between implants, employing an open‐tray technique with sectioned and re‐splinted impression copings provides higher accuracy. ⁴ With the rapid evolution of digital technology, intraoral scanning has become widely utilized for full‐arch implant‐supported rehabilitation. ⁵ The accuracy of conventional splinted implant impressions has been compared to digital scanning for complete arches, and both are similar and clinically acceptable. ⁶ , ⁷ In a digital workflow, scanbodies are attached to implants or multiunit abutments (MUA) instead of conventional impression copings. Data from intraoral scanning is acquired and interpreted for implant positioning, which facilitates the digital reconstruction of a virtual cast used to fabricate prototypes and definitive prostheses. ⁶ , ⁷

The accuracy of intraoral scanning of long‐span edentulous areas is inversely related to the scanning span. ⁸ Limited identifiable landmarks on the soft tissue between inter‐implant areas negatively affect overall scanning accuracy. ⁹ Similar to the superior accuracy of the open‐tray, splinted impression technique, recent findings confirm that splinted scanbodies enhance the accuracy of complete‐arch implant digital impressions, mainly by reducing errors in the posterior regions. ¹⁰ , ¹¹ The geometrical characteristics of scanbodies significantly affect the accuracy of intraoral scans, especially when scanning long‐span edentulous areas. Auxiliary devices designed for novel scanbodies can reduce stitching errors in these scans. ¹² As a result, a modern splinted scanbody design (OPTISPLINT; Digital Arches) was introduced. This innovative scanbody system allows for intraoral splinting of scanbodies. An intraoral scanner then captures the splinted scanbodies extraorally, which helps mitigate the challenges associated with scanning long‐span edentulous areas. In addition to their role in digital workflows, the splinted scanbodies can be repurposed as verification jigs. These jigs facilitate the production of verification casts, essential for confirming prostheses' passive fit. ¹³ Another innovative scanbody (RevEX; Straumann AG) has been designed specifically for the reverse scanbody protocol. This scanbody system is used with interim complete‐arch implant prostheses with a passive fit. An intraoral scanner scans the interim implant prosthesis with the scanbodies attached extraorally. ¹⁴ Due to the limited number of clinical studies, the accuracy of prostheses fabricated using this novel scanbody system and impression technique remains to be determined.

The accuracy of digital scans determines the accuracy of virtual casts and affects the fit and success of complete‐arch implant prostheses. To verify the accuracy of digital records, prototype prostheses or verification devices fabricated from digital scans are often used before the fabrication of the definitive prosthesis. ¹⁴ If the passive fit of the prototype prosthesis or verification devices is not achieved, it suggests that the digital records are not adequately accurate for the definitive prosthesis. Previous studies have shown that a one‐screw test, visual inspection, and tactile sensation can evaluate the passive fit of a fabricated prototype prosthesis or verification device. ¹⁵ , ¹⁶ , ¹⁷ , ¹⁸ Moreover, a previous study has shown that the CAD‐CAM fabrication method (milled vs. 3D‐printed) has a significant impact on the accuracy of prototype prostheses, with milled prostheses outperforming the 3D‐printed ones. However, this study only investigated one type of scanbody (ReVEX; Straumann AG). ¹⁹ This study aimed to assess the effect of different types of impression techniques, including conventional sectioned and re‐splint open‐tray impression techniques, splinted scanbodies with auxiliary features, and reverse scanbodies, on the passive fit of digitally fabricated milled or 3D‐printed verification devices.

MATERIALS AND METHODS

A mandibular stone cast, representing a patient with Prosthodontic Diagnostic Index (PDI) Class II edentulism of mandibular height about 16 to 20 mm, was selected for the study. This cast was embedded with 4 MUA implant analogs (Analog for Screw‐Retained Abutment—Edentulous, Straight, Ø 4.6; Institute Straumann AG) at the locations of #19, #22, #27, and #30, and served as a master cast for the fabrication of an interim screw‐retained complete‐arch implant prosthesis (Figure 1a). The master cast was scanned with a dental laboratory scanner (E4; 3Shape A/S), and the master interim prosthesis was designed using computer‐aided design and computer‐aided manufacturing (CAD‐CAM) software (3Shape Dental System; 3Shape A/S) (Figure 1b). The digital design was then milled using a five‐axis milling unit (DWX‐51D; Roland DGA Corp) from a polymethyl methacrylate (PMMA) puck (Harvest Esthetic DCL Denture CAD Tooth Polymer, Gradient; Harvest Dental Products, LLC). The master milled prosthesis was luted to titanium cylinders (Variobase for Bridge/Bar cylindrical coping; Institute Straumann AG), and its passive fit on the master cast was verified.

FIGURE 1.

(a) Master cast; (b) digital design of master interim prosthesis.

This study evaluated 3 distinct impression techniques for fabricating verification devices. Group 1‐Conv utilized the conventional sectioned and re‐splint open‐tray impression technique (Impression Post Open Tray SRA abutment; Institute Straumann AG) with polyvinyl siloxane impression material (Aquasil Ultra+; Dentsply Sirona). Group 2‐Opti involved digital scans using splinted scanbodies with auxiliary features protocol (OPTISPLINT; Digital Arches). Group 3‐Revex used digital scans with a reverse scanbodies protocol (RevEX; Straumann AG). All digital scan protocols utilized a calibrated intraoral scanner (TRIOS 4; 3Shape A/S). The scanner was calibrated after every 10 scans to adhere to the manufacturer's recommendations.

For Group 1‐Conv, the open‐tray impression copings (Impression Post Open Tray SRA abutment) were secured onto the master cast at 15 Ncm using a ratchet and a torque control device (Torque Control Device for Ratchet; Institute Straumann AG). ²⁰ Autopolymerizing acrylic resin (Pattern Resin LS: GC America Inc) was then used to join the copings together. After a polymerization time of 15 min, the splinted impression copings were removed from the master cast. The copings were subsequently sectioned and repositioned onto the master cast at 15 Ncm. A minimal amount of autopolymerizing acrylic resin (Pattern Resin LS) was applied to rejoin the copings (Figure 2). An impression was made using polyvinyl siloxane material (Aquasil Ultra+) in a custom tray. The analogs (Analog for Screw‐Retained Abutment—Edentulous, Straight, Ø 4.6) were then attached to the impression, and definitive casts were produced using Type IV dental stone (Silky‐Rock; Whip Mix). This procedure was replicated 10 times, resulting in 10 stone dental casts. These casts were scanned with a dental laboratory scanner (E4).

FIGURE 2.

Group 1, the open‐tray impression copings were luted, sectioned, and reconnected with autopolymerizing acrylic resin before impression‐making.

For Group 2‐Opti, the scanbodies with auxiliary features were secured onto the master cast at 15 Ncm using the same ratchet and torque control device (Torque Control Device for Ratchet). The scanbodies were then luted using a metal mesh and light‐polymerizing acrylic resin (3M Filtek Bulk Fill Flowable Composite; Solventum) (Figure 3a). The splinted scanbodies were then removed from the master cast. An occlusal scan pattern was used for scanning splinted scanbodies, beginning with the upper left quadrant occlusal surface, followed by the occlusal side of each scanbody and titanium mesh, and completing the scan with the buccal sides and intaglio surface of the splinted scanbodies (Figure 3b). ¹⁵ This procedure was replicated 10 times, resulting in 10 digital scans. For Group 3‐Revex, a reverse scanbody protocol (RevEX; Straumann AG) was used for digital scans. The scanbodies were held using dental pliers (GC Pliers Crown Removing Instrument, Stainless Steel; GC America Inc.) and connected to the master milled prosthesis at 15 Ncm using the same ratchet and torque control device (Torque Control Device for Ratchet). The assembly was scanned using the calibrated intraoral scanner (TRIOS 4; 3Shape A/S) (Figure 4a). The occlusal scan pattern was used to scan the assembly. Occlusal scanning begins with the left quadrant occlusal surface, followed by the lingual side of the teeth, and completing the scan with the buccal sides and intaglio capture of the reverse scanbodies (Figure 4b). ¹⁵ This procedure was replicated 10 times, resulting in 10 digital scans.

FIGURE 3.

(a) Group 2, the scanbodies with auxiliary features were tightened onto the master cast and luted using light‐polymerizing resin; (b) scan pattern.

FIGURE 4.

(a) Reverse scanbodies were connected to the master milled prosthesis; (b) scan pattern.

From the digital scans resulting from three groups, the verification devices, in a bar shape with 8 mm × 8 mm × 8 mm dimensions, were designed with CAD‐CAM software (3Shape Dental System) (Figure 5). The digital designs were milled from PMMA pucks (Harvest Esthetic DCL Denture CAD Tooth Polymer, Gradient; Harvest Dental Products, LLC) using a five‐axis milling unit (DWX‐51D). Similarly, the same digital designs were 3D‐printed using a digital light processing (DLP) 3D printer (MAX 2; Asiga USA) and light‐copolymerizing resin indicated for complete‐arch interim fixed prosthesis (Titan; Rodin 3D Resin Industries). Finally, the milled and 3D‐printed verification devices were luted to titanium cylinders (Variobase for Bridge/Bar cylindrical coping; Institute Straumann AG) on their respective study casts for the Group 1‐Conv. For Group 2‐Opti and Group 3‐Revex, no physical casts were used to simulate clinical workflows, and the titanium cylinders were luted to the verification devices using a free‐hand manual approach.

FIGURE 5.

Design of prototype prostheses in a bar shape.

Misfits of verification devices were evaluated on the master study cast using the combination of three different techniques: One‐screw test, visual inspection, and tactile sensation. ¹⁶ , ¹⁷ , ¹⁸ Thirty 3D‐printed and 30 milled verification devices were assessed by two experienced clinicians on the master cast. If there was disagreement between the first two clinicians, a third clinician evaluated the verification devices to reach a final agreement. As part of the calibration phase, five verification devices were evaluated at 2‐week intervals to assess interrater reliability (IRR). These test verification devices were excluded from the study. To ensure consistent scoring among reviewers, an intraclass correlation coefficient (ICC) of 0.80 was achieved. All misfit evaluations were followed by the same protocol. For each verification device, a single screw was placed and hand‐tightened first at the left molar implant site. After one screw was tightened, the abutment‐analog junctions on the remaining implant were visually inspected for open margins under 5.5× magnification using dental loupe (HDL Prisms 3.5× ‐ 5.5×; Orascoptic). In addition, a brand new exploration was used to check open margins through tactile sensation. The exact process was repeated for all four implant sites, starting from the left molar implant site and proceeding to the right molar implant site, one by one. A verification device was deemed a misfit, where an open margin was detected through any method at any implant location. ¹⁶ , ¹⁷ , ¹⁸

With a sample size of 10 per group, the study had 80% power at a two‐sided 5% significance level to detect differences between 0% and 60% misfit. Agreement between the clinicians was assessed using crosstabs, kappa statistics, and percent agreement separately for the visual and tactile evaluations. The percentage of misfits was calculated for each group and compared between groups using Fisher's exact tests (α = 0.05).

RESULTS

The results demonstrated an adequate level of agreement between the examiners, Kappa statistic of 0.77 for both tactile and visual assessments, indicating substantial agreement beyond chance (a value of 1 represents perfect agreement, while 0 indicates no agreement). ²¹ There were seven disagreements for both tactile and visual assessments, with approximately equal instances where one examiner detected a misfit while the other did not. The data for tactile and visual assessments showed similar patterns of agreement and disagreement, with a percentage agreement of 88%, reflecting a high level of consistency in the examiners' evaluations (Table 1). Despite some disagreements between the two examiners, the overall level of agreement was high, suggesting that their assessments are reliable.

TABLE 1.

Summary of the agreement between two examiners on the assessments.

			Examiner 2
			No misfit	Misfit	Total	Kappa	% Agree
Tactile	Examiner 1	No misfit	29 (48%)	3 (5%)	32 (53%)	0.77	88
		Misfit	4 (7%)	24 (40%)	28 (47%)
		Total	33 (55%)	27 (45%)	60
Visual	Examiner 1	No misfit	29 (48%)	3 (5%)	32 (53%)	0.77	88
		Misfit	4 (7%)	24 (40%)	28 (47%)
		Total	33 (55%)	27 (45%)	60

The representative images of misfitted verification devices on the master study cast are shown in Figure 6a and 6b. The results of the misfit analysis (Table 2) revealed that the Group 1‐Conv technique with a milled verification device achieved the lowest misfit percentage at 0%, outperforming other methods. This was followed by the Group 3‐Revex technique with a milled verification device, which exhibited a misfit of 20%. Conversely, 3D‐printed verification devices showed higher misfit percentages across all three impression techniques, with Group 1‐Conv having the lowest misfit (50%), followed by Group 3‐Revex (60%) and Group 2‐Opti (80%). These findings suggest that milled verification devices tend to exhibit lower misfit compared to their 3D‐printed counterparts.

FIGURE 6.

The representative images of misfitted verification devices on the master study cast under one‐screw test. (a) Group 3‐Revex with milled verification device, and the open margins were noted on the #27 and #30 locations. (b) Group 2‐Opti with a 3D‐printed verification device, and the open margin was noted on the #19 location.

TABLE 2.

The percentage of misfit across different impression techniques and manufacturing methods for verification devices.

	Group 1‐Conv	Group 2‐Opti	Group 3‐Revex
Milled	0 (0%)a	6 (60%)bc	2 (20%)ab
3D‐Printed	5 (50%)bc	8 (80%)c	6 (60%)bc

Note: Superscript letters (a, b, c) indicate statistical groupings. Values with the same letter are not significantly different from each other (p > 0.05), while values with different letters are significantly different (p < 0.05).

Among all groups, Group 2‐Opti showed the highest misfit percentage, while Group 3‐Revex showed moderate misfit rates, and Group 1‐Conv showed the lowest misfit rates. The group comparisons are shown in Table 2. The statistical differences in the misfit rates were found in the following comparisons, Group 3‐Revex/Milled versus Group 1‐Conv/Milled (20% and 0%, p = 0.011), Group 1‐Conv/3D‐printed versus Group 1‐Conv/Milled (50% and 0%, p = 0.033), Group 2‐Opti/3D‐printed versus Group 3‐Revex/Milled (80% and 20%, p = 0.023), Group 2‐Opti/3D‐printed versus Group 1‐Conv/Milled (80% and 0%, p = 0.001), and Group 3‐Revex/3D‐printed (60% and 0%, p = 0.011) (Table 2).

DISCUSSION

For complete‐arch implant‐supported fixed dental prostheses, the definitive impression can be taken either conventionally or digitally. With a conventional impression, a definitive stone cast is created. In contrast, a fully digital workflow eliminates the need for a physical cast. Since the digital workflow bypasses the physical cast, CAD‐CAM verification devices are often employed to verify the implant positions before the fabrication of the definitive prostheses. ¹⁴ , ¹⁵ , ¹⁶ , ¹⁷ , ¹⁸

The results from this study indicated that the CAD‐CAM fabrication method significantly influences the accuracy of verification devices. Milled verification devices demonstrated superior fit compared to 3D‐printed ones. There are no recent studies directly comparing milled and 3D‐printed CAD‐CAM verification devices. Current research focuses on comparing the accuracy of various milled and 3D‐printed dental prostheses. Previous studies have shown that milled complete denture bases exhibited higher accuracy and trueness when compared to 3D‐printed and conventional techniques. ²² , ²³ , ²⁴ Similar findings were found in the comparisons of milled and 3D‐printed resin complete‐arch implant fixed dental prostheses, where 3D‐printed ones showed similar or higher linear deviations compared to milled ones, likely due to photopolymerization during and after fabrication, causing polymerization shrinkage. ²⁵ , ²⁶ In this previous study, virtual concentric cones representing the intaglio surface of prostheses were used to measure deviations, with the cone centers aligned to the screw access channels. The authors suggested that misfit issues in 3D‐printed resin complete‐arch implant fixed dental prostheses might become more evident during the one‐screw test. ²⁶ 3D printing accuracy is often affected by mechanical or thermal stress during support removal (such as DLP technology used in this study), leading to surface distortions and dimensional inaccuracies. ²³ Build orientation further impacts accuracy by determining the number and geometry of supports, which can cause over‐ or under‐contoured surfaces. ²⁵ 3D printing requiring minimal supports is preferable, especially for complex prostheses, to reduce these inaccuracies. ²⁷ These findings could explain the advantages of milled verification devices over 3D‐printed ones due to their superior accuracy and fit.

The results found that the impression techniques significantly influenced the fit of the verification devices. Among all groups, Group 2‐Opti showed the highest misfit percentage, while Group 3‐Revex showed moderate misfit rates, and Group 1‐Conv showed the lowest misfit rates. Current evidence supports the use of intraoral scanners (IOS) as clinically acceptable alternatives to conventional impressions for limited edentulous spans. However, IOS performance in edentulous arches with multiple implants remains challenging due to insufficient anatomic landmarks, which compromise scanning accuracy, and intrinsic errors from the IOS's limited field of view. ²⁸ These limitations require multiple overlapping images to be stitched together, increasing errors, especially during long‐span scanning. ²⁹ To address these challenges, researchers have proposed using artificial landmarks, such as auxiliary scanning devices or artificial landmarks on the edentulous ridges, to enhance scanning accuracy in edentulous arches. ¹² , ²⁹ , ³⁰ In contrast, a recent study compared the accuracy of three intraoral scanning techniques: scanbodies without added references, splinted scanbodies using orthodontic wire and resin, and scanbodies with artificial landmarks attached to the dentulous ridge. The findings showed that splinting techniques did not enhance the trueness of digital scanning for complete‐arch implant prostheses, leaving the effectiveness of these approaches open to debate. ³¹ In this current study, Group 2‐Opti and Group 3‐Revex employed similar splinted scanbody concepts. However, Group 2‐Opti required intraoral splinting of scanbodies with auxiliary features and a metal mesh, whereas Group 3‐Revex used a passive‐fit interim complete‐arch prosthesis to connect the scanbodies. ³² One possible explanation for Group 2‐Opti's higher misfit rates could be the alignment of virtual scanbodies in the laboratory software. The scanned scanbodies must be converted into virtual analogs for the subsequent design of verification devices. The alignment and registration process are proprietary to each scanbody system, which may contribute to differences in accuracy outcomes. Additionally, the scanbody assemblies are more complex and require more images during the scanning process (Figure 3b), which may have also contributed to the accumulation of errors in the resulting scans for Group 2‐Opti.

In this study, Group 3‐Revex was scanned following a specific scan pattern that began from the occlusal surface, as validated by previous research demonstrating its superior accuracy over other scanning patterns. ¹⁵ This approach appeared to confirm earlier findings, with Group 3‐Revex yielding better passive fit results in verification devices compared to Group 2‐Opti. However, misfits were still observed in both milled and 3D‐printed verification devices. It is important to note that no standardized scanning protocol exists for Group 2‐Opti, and the occlusal scanning pattern applied here may not represent an optimized method for Group 2‐Opti. The scanning procedure for Group 2‐Opti began at the occlusal surface of the tooth #19 region and sequentially covered the occlusal, lateral, and inferior surfaces, incorporating complex areas with auxiliary features on the scanbodies and a metal mesh. These additional surfaces may have contributed to a greater number of images and stitching errors, ultimately compromising the accuracy of the scan. Although fully digital workflows are increasingly advocated for edentulous complete‐arch implant prostheses, the lack of established scanning protocols for systems like Group 2‐Opti underscores the need for further research. Meanwhile, Group 3‐Revex presents a promising alternative, delivering comparable outcomes to traditional splinted open‐tray impressions in specific scenarios. However, the variability in scan accuracy due to scanning protocols and systems highlights the need to further investigate the accuracy of digital workflows across different systems.

Intraoral scans are susceptible to errors in extended scanning spans, especially in edentulous arches, where the absence of stable anatomical landmarks can negatively affect accuracy. For Group 2‐Opti, the incorporation of auxiliary features and metal components increases the complexity of data acquisition and may contribute to imaging inaccuracies due to reflective surfaces and misalignment during the stitching process. In contrast, Group 3‐Revex mitigates some of these challenges by utilizing the scanning of reverse scan bodies attached to a passively fitting interim implant prosthesis. However, this approach requires that the interim prosthesis be prefabricated and demonstrate a verified passive fit, adding an additional step to the workflow. Moreover, the manual free‐hand cementation of titanium copings to the CAD‐CAM verification devices without a verified physical cast introduces the potential for human error, as seen in both Group 2‐Opti and Group 3‐Revex clinical workflows. ¹⁹ These issues may reduce the predictability of the verification device or definitive prosthesis fit, even though the digital scans themselves are potentially accurate. An optional verification cast may improve the manual luting process by providing a stable and accurate foundation, utilizing the passively fitting interim implant prosthesis or splinted scanbodies (Figure 7a and 7b). ³² Alternatively, verification device, prototype, or definitive prosthesis can be designed directly on implant abutments and secured with specialized prosthetic screws, eliminating the need for titanium copings and manual luting (Figure 8a and 8b). However, due to limited evidence on long‐term clinical performance, this approach is typically reserved for verification devices or prototype prostheses to minimize laboratory costs, as extended intraoral use is not required. ³²

FIGURE 7.

(a) The passively fitting interim implant prosthesis or splinted scanbodies can be used to fabricate an optional verification cast. (b) Although the design and manufacturing of the verification devices or prostheses can be from the digital scans, an optional verification cast provides a stable foundation during the manual luting process of titanium copings.

FIGURE 8.

(a) A 3D‐printed prototype trial prosthesis was designed directly onto implant abutments and could be secured with specialized prosthetic screws without titanium copings. (b) Intraoral trial insertion of prototype trial prosthesis.

This study has several limitations that should be acknowledged. First, the in vitro design may not fully replicate intraoral conditions, such as the presence of saliva, patient movement, and soft tissue dynamics—all of which can significantly impact impression accuracy. Additionally, only one intraoral scanner and specific scanbody systems were evaluated, limiting the generalizability of the findings to other scanners and systems. The accuracy of verification devices was assessed using subjective methods; while these methods are commonly used in clinical settings and demonstrate high inter‐examiner agreement, they remain qualitative in nature. Moreover, the manual luting process for digital verification devices, although performed according to manufacturers’ recommendations, may introduce human error—especially in the absence of a physical verification cast. Lastly, the optimal scanning protocol for splinted scanbodies with auxiliary features has not been established, and variations in scan acquisition techniques could influence the results. Given these limitations, future research should prioritize clinical in vivo studies to better simulate real‐world conditions. A broader evaluation of different scanners and scanbody systems is needed, along with standardized methodologies for data collection, scanning, and measurement. A systematic review from the European Prosthodontic Association (EPA) consensus project found intraoral scanning and photogrammetry to have similar accuracy to conventional techniques for complete‐arch implant impressions, but variability in study designs limits comparability. ³³ To ensure clinical reliability, evolving digital protocols must be validated through rigorous in vitro and clinical research before replacing conventional methods in routine practice.

CONCLUSIONS

The conventional splinted open‐tray impression technique combined with milled verification devices demonstrated superior fitting for the complete‐arch implant prosthesis workflow. These findings highlight the potential need for an optional verification cast when novel scanning methods are used. The reverse scanbody protocol demonstrated better passive fit outcomes compared to splinted scanbodies with auxiliary features. Since 3D‐printed verification devices demonstrated inferior passive fit, they are not recommended for clinical use to verify implant positions for complete‐arch implant prostheses.

CONFLICT OF INTEREST STATEMENT

The authors did not receive any support for this study. However, Drs. Dean Morton and Wei‐Shao Lin received honoraria from Institut Straumann AG.

Asavanant N, Yang C‐C, AlQallaf H, Zandinejad A, Morton D, Nagai T, et al. Effects of complete‐arch digital scanning techniques on the passive fit of CAD‐CAM verification devices. J Prosthodont. 2025;34:741–748. 10.1111/jopr.14084