Improved accuracy of digital implant impressions with newly designed scan bodies: an in vivo evaluation in beagle dogs

Effect of using scan body accessories and inter-implant distances on the accuracy of complete arch implant digital impressions: An in vitro study

PURPOSE

To introduce a novel design for scan body accessory parts that are reusable, easy to attach and detach without permanent change of the scan body, and can be used with different inter-implant distances to enhance the accuracy of complete arch implant scans.

MATERIALS AND METHODS

A maxillary polymethylmethacrylate (PMMA) model with a soft tissue replica was fabricated with four implant analogs located at tooth positions 17, 13, 22, and 27 with 18, 25, and 30 mm inter-implant distances. Four scan bodies (SBs) were attached to the implants. The model was scanned with a laboratory scanner to be used as a reference scan. A total of 40 scans were made with the same intraoral scanner and they were divided equally into two groups. Group A: Complete arch implant scans without scan body accessories (n = 20), and Group B: Complete arch implant scans with scan body accessories (n = 20). Intraoral scans were exported and superimposed on the reference scan using reverse engineering inspection software to be evaluated for 3D deviations, angular deviations, and linear deviations. Statistical analysis was performed with student t-test and analysis of variance (ANOVA) with repeated measures followed by post hoc adjusted Bonferroni test. The level of significance was set at P = 0.05.

RESULTS

The scan body accessories decreased both the 3D and linear deviations, with a statistically significant difference at SB4 for the 3D deviation (P = 0.043) and the linear inter-implant discrepancies between SB1-SB2 and SB3-SB4 (P = 0.029 and < 0.001), respectively. However, there was no statistically significant difference in angular deviation between the study groups. Implant positions had significant differences within each group.

CONCLUSIONS

 A significant improvement in the accuracy of the complete arch implant digital impression was achieved by using the scan body accessories, particularly in reducing the 3D and linear deviations at the most distant implant positions.

Improving the accuracy of complete arch implant digital scans by using auxiliary clips for intraoral scan bodies: A dental technique

A technique to improve the accuracy of complete arch implant intraoral digital scans and the accuracy of their virtual casts is described. Obtaining accurate complete arch implant intraoral digital scans with an intraoral scanner is challenging because of the smooth and movable tissues of edentulous areas. The described technique uses auxiliary clips attached to intraoral scan bodies to cover interimplant edentulous spans with immobile tooth-like geometric references that are more favorable for intraoral scanning. The technique is designed to be user friendly and compatible with any intraoral scanner.

Improving the accuracy of complete arch implant intraoral digital scans by using horizontal scan bodies with occlusal geometry: A dental technique

A technique to improve the accuracy of complete arch implant intraoral digital scans and to obtain more accurate virtual casts with them is described. First, 2 complete arch intraoral digital scans were obtained with an intraoral scanner: a multiunit abutment digital scan and an implant digital scan with reusable horizontal intraoral scan bodies (ISBs) placed on the implants. These were previously created by combining the conventional ISBs compatible with the patient's implants with extensional structures with occlusal geometry. Once the digital scans had been acquired, the position of the implants was obtained by superimposing a virtual design of the conventional ISB onto each horizontal ISB of the complete arch implant digital scan. Finally, the virtual cast was obtained by superimposing the complete arch multiunit abutment digital scan on the complete arch implant digital scan.

Effect of artificial landmarks of the prefabricated auxiliary devices located at different arch positions on the accuracy of complete-arch edentulous digital implant scanning: An in-vitro study

OBJECTIVES

To examine the effect of artificial landmarks of prefabricated auxiliary devices (PAD) located at different arch positions on the accuracy of complete-arch edentulous digital implant scanning.

METHODS

A reference model containing four analogs and PAD were fabricated by a 3D printer (AccuFab-C1s, 3DShining). 10 digital scans were performed using an intraoral scanner (Aoralscan 3, 3DShining), sv 1.0.0.3115, with artificial landmarks located at different arch positions: group I, without any artificial landmarks; group II, with artificial landmarks at the anterior region; group III, with artificial landmarks at the posterior region. group IV: with artificial landmarks at both anterior and posterior regions. For group V: Conventional open-tray splinted impressions. The reference file and conventional stone casts were digitalized by using a dental laboratory scanner. The related files were imported into inspection software for trueness and precision assessment. Statistical analysis was performed with One-way ANOVA and Kruskal-Wallis test. The level of significance was set at α=0.05.

RESULTS

For the global accuracy assessment, significantly higher global trueness was seen in group II (p < 0.01), III (p < 0.001), IV (p < 0.001) and V (p < 0.001) than group I. Significantly higher global precision was seen in group III (p < 0.001), IV (p < 0.001) and V (p < 0.001) than group I. For the local accuracy assessment, the PAD primarily improved accuracy on the linear deviations.

CONCLUSIONS

Artificial landmarks of PAD at different arch positions significantly influenced the scanning accuracy. Applying the PAD in group IV could achieve comparable outcomes to conventional open-tray splinted impressions. Artificial landmarks on the posterior region may be more pivotal than those on the anterior region.

CLINICAL SIGNIFICANCE

Group IV could achieve comparable accuracy to conventional open-tray splinted impressions.

Effect of prefabricated auxiliary devices and scanning patterns on the accuracy of complete-arch implant digital impressions

OBJECTIVES

This study aimed to evaluate the impact of prefabricated auxiliary devices (PAD) and scanning patterns on the accuracy of complete-arch implant digital impressions.

METHODS

An edentulous maxillary model was inserted with four parallel implant analogs and four PAD. The model was scanned with D2000 dental laboratory scanner as the reference scans. Test scans were obtained by 8 different scanning patterns (SP), which including SPA, SPB, SPC, SPD, SPE, SPF, SPG and SPH, with (test group) or without (control group) using the PAD by an intraoral scanner (Aoralscan 3, 3DShining). SPA was the scanning pattern recommended by the manufacturer. Each scanning time was recorded. The related files were imported into inspection software for assessment. Aligned Ranks Transformation ANOVA, Kruskal-Wallis and Mann-Whitney tests were used to evaluate the values. The level of significance was set at α = 0.05.

RESULTS

The scanning patterns significantly influenced the linear accuracy in the test group and the scanning time for both groups. Lower linear trueness in the test group was found in SPF (p<0.05) and SPG (p<0.05). Longer scanning time was found in SPB and SPG for both groups. The test group demonstrated linear accuracy enhancement in all the scanning patterns; angular trueness enhancement was seen in SPA (p<0.05), SPC (p<0.01) and SPH (p<0.01). Significant longer scanning time was found in SPB (p<0.05), SPF (p<0.05), SPG (p<0.05) and SPH (p<0.05) when using PAD.

CONCLUSION

The scanning patterns impact the accuracy differently depending on the PAD's existence. The scanning time can be significantly influenced by the scanning patterns and the PAD.

CLINICAL SIGNIFICANCE

In daily clinical practice, selecting a suitable scanning pattern is significant in achieving accurate digital impressions. The PAD demonstrated effective linear accuracy enhancement in all the scanning patterns tested.

Influence of implant scan body design (height, diameter, geometry, material, and retention system) on intraoral scanning accuracy: A systematic review

PURPOSE

To evaluate the influence of implant scan body (ISB) design (height, diameter, geometry, material, and retention system) on the accuracy of digital implant scans.

MATERIAL AND METHODS

A literature search was completed in five databases: PubMed/Medline, Scopus, Embase, World of Science, and Cochrane. A manual search was also conducted. Studies reporting the evaluation of ISB design on the accuracy of digital scans obtained by using IOSs were included. Two investigators evaluated the studies independently by applying the Joanna Briggs Institute critical appraisal. A third examiner was consulted to resolve any lack of consensus. Articles were classified based on the ISB features of height, geometry, material, and retention system.

RESULTS

Twenty articles were included. Among the reviewed studies, 11 investigations analyzed the influence of different ISB geometries, 1 study assessed the impact of ISB diameter, 4 studies investigated the effect of ISB splinting, 2 articles evaluated ISB height, and 2 studies focused on the effect of ISB material on scan accuracy. In addition, 8 studies involved ISBs fabricated with different materials (1- and 2-piece polyetheretherketone and 1-piece titanium ISBs), and all of the reviewed articles tested screw-retained ISBs, except for 3 in vitro studies.

CONCLUSIONS

The findings did not enable concrete conclusions regarding the optimal ISB design, whether there is a relationship between IOS technology and a specific ISB design, or the clinical condition that maximizes intraoral scanning accuracy. Research efforts are needed to identify the optimal ISB design and its possible relationship with the IOS selected for acquiring intraoral digital implant scans.

Intraoral digital implant scans: Parameters to improve accuracy

PURPOSE

To report the means to maximize the predictability and accuracy of intraoral digital implant scans through the evaluation of operator and patient-related factors.

MATERIALS AND METHODS

A search of published articles related to factors that can decrease the scanning accuracy of intraoral digital implant scans was completed in four data sources:MEDLINE, EMBASE, EBSCO, and Web of Science. All studies related to variables that can influence the accuracy of intraoral digital implant scans obtained by using intraoral scanners (IOSs) were considered. These variables included ambient lighting, scanning pattern, implant scan body (ISB) design, techniques for splinting ISBs, arch location, implant position, and inter-implant distance.

RESULTS

Among operator-related factors, ambient lighting conditions, scanning pattern, and ISB design (material, geometry, and retention design) can impact the accuracy of intraoral digital implant scans. The optimal ISB for maximizing IOS accuracy is unclear; however, polymer ISB can wear with multiple reuse and sterilization methods. Among patient-related factors, additional variables should be considered, namely arch (maxillary vs. mandibular arch), implant position in the arch, inter-implant distance, implant depth, and angulation.

CONCLUSIONS

Ambient lighting conditions should be established based on the IOS selected to optimize the accuracy of intraoral digital implant scans. The optimal scanning pattern may vary based on the IOS, clinical situation, and the number of implants. The optimal ISB design may vary depending on the IOS used. Metallic implant scan bodies are preferred over polymer ISB designs to minimize wear due to multiple use and sterilization distortion. Among patient-related factors, additional variables should be considered namely the arch scanned, implant position in the arch, inter-implant distance, implant depth, and angulation. The impact of these factors may vary depending on the IOS selected.

A digital strategy for intraoperative acquisition of actual drill position and rapid assessment of bony preparation accuracy using an intraoral scanner

A digital workflow to acquire actual position of the drill and assess bony preparation accuracy intraoperatively was described. Based on the widely used intraoral scanner, this digital workflow was a relatively practical and economical option for digital intraoperative measurement. As a result, it could help the clinician in accurate verification and immediate correction of the drill position and consequently facilitating the accurate implant placement in implant surgery.

Comparing the accuracy of full-arch implant impressions using the conventional technique and digital scans with and without prefabricated landmarks in the mandible: An in vitro study

OBJECTIVES

This study evaluated the accuracy of digital implant impressions with or without prefabricated landmarks compared with the conventional method in the edentulous mandible.

METHODS

An edentulous mandibular stone cast with implant abutment analogs and scan bodies in FDI #46, 43, 33, and 36 served as the master model. Intraoral scanner groups (IOS) were divided into four subgroups: IOS-NT (no landmarks + Trios 4 scanner), IOS-NA (no landmarks + Aoralscan 3 scanner), IOS-YT (landmarks + Trios 4 scanner), and IOS-YA (landmarks + Aoralscan 3 scanner) (n=10). Landmarks were attached to the scan bodies with resin to improve scanning fluency. Conventional open-trayed technique (CNV) was performed with the 3D-printed splinting frameworks (n=10). The master model and conventional castings were scanned using a laboratory scanner, and the former served as the reference model. Overall distance and angle deviations between scan bodies were measured to determine trueness and precision. The ANOVA or Kruskal-Wallis test compared CNV group to scans without landmarks, while a generalized linear model analyzed scan groups with and without landmarks.

RESULTS

Compared to the CNV group, the IOS-NA and IOS-NT groups showed higher overall distance trueness (p=.009), and precision (distance, p<.001 and angular, p<.001). With landmarks, the IOS-YA group had higher overall trueness (distance, p<.001 and angular, p<.001) than the IOS-NA group, and the IOS-YT group has higher distance trueness (p=.041) than the IOS-NT group. Moreover, the precision in distance and angle was significantly improved for IOS-YA and IOS-YT groups, compared with the IOS-NA (p<.001) and IOS-NT (p<.001) groups separately.

CONCLUSIONS

Digital scans were more accurate than conventional splinting open-trayed impressions. Prefabricated landmarks significantly improved the accuracy of full-arch implant digital scans, regardless of the scanner used.

CLINICAL SIGNIFICANCE

Prefabricated landmarks can enhance the accuracy of intraoral scanners for full-arch implant rehabilitation, improving scanning efficiency and clinical outcomes.

A guide for maximizing the accuracy of intraoral digital scans: Part 2-Patient factors

OBJECTIVES

To describe the factors related to patient intraoral conditions that impact the scanning accuracy of intraoral scanners (IOSs). A new classification for these influencing factors is proposed to facilitate dental professionals' decision-making and maximize the accuracy and reliability of intraoral digital scans.

OVERVIEW

Variables related to intraoral conditions of the patient that can influence the scanning accuracy of IOSs include tooth type, presence of interdental spaces, arch width variations, palate characteristics, wetness, existing restorations, characteristics of the surface being digitized, edentulous areas, interimplant distance, position, angulation, and depth of existing implants, and implant scan body selection.

CONCLUSIONS

The knowledge and understanding of the patient's intraoral conditions that can impact the scanning accuracy of IOSs is a fundamental element for maximizing the accuracy of IOSs.

CLINICAL SIGNIFICANCE

The patient's intraoral conditions, or patient factors, can significantly impact intraoral scanning accuracy. Dental professionals must know and understand these influencing patient factors to maximize the accuracy of IOSs.

Accuracy of digital impressions for three-unit and four-unit implant supported fixed dental prostheses using a novel device

Background/ purpose

Accuracy of digital implant impressions was considered questionable due to the lack of anatomical reference points between implants and the similarities in scan body morphology, which lead to the purpose of this research is to propose a simple and convenient technique to improve the accuracy of scanning.

Materials and methods

Four implant analogues (teeth: 15, 17, 24, and 27) were inserted into a stone model of a partially edentulous maxilla; two implants were inserted on each side, creating a three-unit span and a four-unit span. The model was scanned using a 3Shape E4 dental laboratory scanner for reference and a TRIOS 3 intraoral scanner for testing. Each side was scanned 10 times, both with and without the novel device attached to the scan bodies. The trueness and precision of interimplant distances (linear deviations), and interimplant angulations (angle deviations) between the scan bodies were determined using software. A Mann-Whitney U test was used to determine statistical differences between subgroups.

Results

Significant differences were discovered in the trueness of angular deviations (-0.20° ± 0.15° vs. -0.01° ± 0.11º) and precision of linear deviations (11.14 ± 6.35 vs. 3.10 ± 2.14 μm) for the four-unit groups.

Conclusion

The novel device significantly improved scanning accuracy for a four-unit groups (approximately 22.93 mm) compared to three-unit groups.

PEEK Biomaterial in Long-Term Provisional Implant Restorations: A Review

Polyetheretherketone (PEEK) has become a useful polymeric biomaterial due to its superior properties and has been increasingly used in dentistry, especially in prosthetic dentistry and dental implantology. Promising applications of PEEK in dentistry are dental implants, temporary abutment, implant-supported provisional crowns, fixed prosthesis, removable denture framework, and finger prosthesis. PEEK as a long-term provisional implant restoration has not been studied much. Hence, this review article aims to review PEEK as a long-term provisional implant restoration for applications focusing on implant dentistry. Articles published in English on PEEK biomaterial for long-term provisional implant restoration were searched in Google Scholar, ScienceDirect, PubMed/MEDLINE, and Scopus. Then, relevant articles were selected and included in this literature review. PEEK presents suitable properties for various implant components in implant dentistry, including temporary and long-term provisional restorations. The modifications of PEEK result in wider applications in clinical dentistry. The PEEK reinforced by 30-50% carbon fibers can be a suitable material for the various implant components in dentistry.